technetium-tc-99m-tetrofosmin and Coronary-Disease

Thymoma is an uncommon tumour, which is often asymptomatic and may be detected coincidentally on cross-sectional imaging performed for other reasons. We report a case of thymoma detected on myocardial scintigraphy performed for suspected coronary artery disease. Extracardiac pathology may be suggested by abnormal non-cardiac tracer uptake on myocardial scintigraphy. An awareness of the potential causes of this is essential to allow potentially life threatening non-cardiac disorders to be recognized and treated promptly.

Topics: Aged; Coronary Disease; Diagnosis, Differential; Humans; Incidental Findings; Male; Organophosphorus Compounds; Organotechnetium Compounds; Radionuclide Imaging; Radiopharmaceuticals; Thymoma; Thymus Neoplasms; Tomography, X-Ray Computed

The assessment of myocardial viability has become an important aspect of the diagnostic and prognostic work-up of patients with ischemic cardiomyopathy. Although revascularization may be considered in patients with sufficient viable myocardium, patients with predominantly scar tissue should be treated medically. Patients with left ventricular dysfunction who have viable myocardium are the patients at highest risk because of the potential for ischemia but at the same time benefit most from revascularization. It is important to identify viable myocardium in these patients, and radionuclide myocardial scintigraphy is an excellent tool for this. Single-photon emission computed tomography perfusion scintigraphy (SPECT), whether using (201)thallium, (99m)Tc-sestamibi, or (99m)Tc-tetrofosmin, in stress and/or rest protocols, has consistently been shown to be an effective modality for identifying myocardial viability and guiding appropriate management. Metabolic and perfusion imaging with positron emission tomography (PET) radiotracers frequently adds additional information and is a powerful tool for predicting which patients will have an improved outcome from revascularization. New techniques in the nuclear cardiology field, like attenuation corrected SPECT, dual isotope simultaneous acquisition (DISA) SPECT and gated FDG PET are promising and will further improve the detection of myocardial viability. Also the combination of multislice computed tomography scanners with PET opens possibilities of adding coronary calcium scoring and non-invasive coronary angiography to myocardial perfusion imaging and quantification. Evaluation of the clinical role of these creative new possibilities warrants investigation.

Topics: Coronary Disease; Fluorodeoxyglucose F18; Humans; Myocardium; Organophosphorus Compounds; Organotechnetium Compounds; Positron-Emission Tomography; Radiopharmaceuticals; Rubidium Radioisotopes; Technetium Tc 99m Sestamibi; Thallium Radioisotopes; Tomography, Emission-Computed, Single-Photon; Ventricular Dysfunction, Left

Event rates associated with a normal or low-risk myocardial perfusion SPECT imaging study have been shown by numerous investigators to be associated with <1%/y of follow-up. Thus, the aim of this study was to evaluate the prognostic value of a normal (99m)Tc-tetrofosmin study in a geographically diverse registry of patients undergoing stress myocardial perfusion SPECT. A total of 4,728 consecutively tested patients who underwent stress (99m)Tc-tetrofosmin SPECT at 5 U.S. hospitals were included in this series.. Patients were monitored for the occurrence of major cardiac events and hospitalizations. Uniform methods of data collection and standardized epidemiologic methods for follow-up were used at all centers. We used a risk-adjusted, Cox proportional hazards model to assess time to cardiac death.. Of the 4,728 patients, one third underwent adenosine stress SPECT and two thirds underwent treadmill exercise. The observed annualized survival rate for those patients with a normal (99m)Tc-tetrofosmin study was 0.6%. Similarly, excellent survival rates were noted for the male and female subsets of this population as well as for patients who could exercise and for those undergoing pharmacologic stress testing. Compared with prior published outcomes studies on stress (201)Tl or (99m)Tc-sestamibi SPECT, the overall survival rates were similar and ranged from 99.3% to 99.7%.. Results from this large multicenter registry provide further supportive evidence that the excellent prognosis associated with a normal SPECT scan is independent of the radiopharmaceutical used.

Topics: Adenosine; Cause of Death; Cohort Studies; Coronary Disease; Exercise Test; Female; Humans; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Predictive Value of Tests; Prognosis; Radiopharmaceuticals; Registries; Risk Factors; Stress, Physiological; Survival Rate; Tomography, Emission-Computed, Single-Photon; United States

The accurate noninvasive diagnosis and functional evaluation of coronary artery disease is an important step in selecting the appropriate management strategy. Dobutamine stress myocardial perfusion imaging is an alternative to exercise in patients with limited exercise capacity. In many centers, the test is performed on patients who have a contraindication for vasodilator stress testing. Recent studies have shown hyperemia induced by the standard dobutamine-atropine stress test is not less than hyperemia induced by dipyridamole. The feasibility of the test is 90% and is often higher in patients without beta-blocker therapy. The safety of the test has been well studied and was also demonstrated in specific patients groups, such as patients with left ventricular dysfunction, the elderly, and heart transplant recipients. The diagnostic accuracy has been demonstrated in patients with and without myocardial infarction and in specific groups such as those with hypertension, left ventricular hypertrophy, and heart transplant recipients and after revascularization. The technique has a high sensitivity for prediction of functional recovery in patients with myocardial dysfunction referred for revascularization. The presence and severity of myocardial perfusion abnormalities assessed by this method are powerful predictors of cardiac events, incremental to clinical data. This article describes the methodology, safety, feasibility, diagnostic accuracy, and prognostic value of dobutamine stress myocardial perfusion imaging in patients with known or suspected coronary artery disease, with additional considerations for the application of the test in specific patient groups.

Topics: Angioplasty, Balloon, Coronary; Coronary Circulation; Coronary Disease; Dobutamine; Echocardiography; Electrocardiography; Heart; Heart Rate; Heart Transplantation; Humans; Organophosphorus Compounds; Organotechnetium Compounds; Tomography, Emission-Computed, Single-Photon

Simultaneous assessment of left ventricular myocardial perfusion and systolic function was accomplished by utilizing ECG-gated myocardial perfusion SPECT. This development in nuclear cardiology will be attributed to the recent advances in new 99mTc-labeled perfusion agents, multi-detector SPECT system and software for automatic edge-detection of the left ventricle. In this article, we described about the clinical utilities of this method in detecting "hibernating myocardium," severe coronary artery disease patients with exercise-induced LV dysfunction, in predicting functional recovery after reperfusion therapy for acute myocardial infarction patients and in diagnosing patients with right heart diseases.

Topics: Coronary Circulation; Coronary Disease; Electrocardiography; Gated Blood-Pool Imaging; Humans; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Severity of Illness Index; Software; Systole; Technetium Tc 99m Sestamibi; Tomography, Emission-Computed, Single-Photon; Ventricular Function, Left

Whether tachycardia-dependent paroxysmal AV block, an uncommon complication of exercise stress testing in patients with infranodal conduction disturbances, can result from acute ischemia of the conduction system is still speculative, and is based on post-hoc evidence of right coronary artery disease and abolition of block after coronary angioplasty.. In two patients, from a database of 3000 undergoing nuclear exercise stress testing, transient paroxysmal AV block developed 1-4 minutes after the injection of the radionuclide agent. Nuclear perfusion imaging demonstrated stress-induced ischemia of the posteroseptal segments, which corresponds to the anatomical region of the His bundle, and perfusion recovery in the images obtained at rest. Angiography disclosed critical narrowing of the right coronary artery in both cases.. Nuclear myocardial perfusion imaging provides noninvasive evidence that transient ischemia of the posteroseptal segment, anatomically corresponding to the His bundle, can result in paroxysmal AV block in patients with severe right coronary artery and chronic infranodal conduction disturbances. The demonstration of the underlying pathophysiological mechanism is useful for selecting the most effective treatment strategy.

Topics: Acute Disease; Aged; Angioplasty, Balloon, Coronary; Coronary Angiography; Coronary Disease; Exercise; Exercise Test; Heart Block; Heart Conduction System; Humans; Male; Middle Aged; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Syncope; Tomography, Emission-Computed, Single-Photon

The noninvasive assessment of myocardial viability in patients with coronary artery disease and depressed left ventricular function has proven clinically useful for identifying those patients with ischemic cardiomyopathy who benefit most from coronary revascularization. Thallium-201 (201Tl) imaging at rest has been the radionuclide imaging technique most often utilized for distinguishing viable myocardium from scar. However, new technetium-99m (99mTc) perfusion agents such as 99mTc-sestamibi and 99mTc-tetrofosmin have emerged as alternatives to 201Tl for imaging of regional myocardial perfusion. Whether these new agents, which have better physical properties for imaging with a gamma camera than 201Tl, are valid for use in assessing myocardial viability is still uncertain. Recent clinical studies have demonstrated that these agents, when imaged using quantitative SPECT, can identify patients with myocardial hibernation who exhibit improved regional systolic function following revascularization. Experimental laboratory studies have shown that the uptake of 99mTc-sestamibi and 99mTc-tetrofosmin in ischemic myocardium is only slightly lower than the uptake of 201Tl. These 99mTc-labeled agents remain bound intracellularly in mitochondria of viable myocytes under conditions of myocardial stunning and short-term hibernation, producing severe myocardial asynergy. With respect to determination of viability, the inferior wall region is at times problematic since attenuation of 99mTc-sestamibi and 99mTc-tetrofosmin is greatest in this area. Demonstration of preserved systolic thickening on ECG-gated SPECT images is indicative of viability in the instance of decreased regional 99mTc counts due to attenuation and not scar. Administration of nitrates prior to tracer injection improves the sensitivity for identifying viable myocardial segments using rest imaging with 99mTc-sestamibi or 99mTc-tetrofosmin. Thus, it appears that the new 99mTc perfusion imaging agents can be successfully employed for the determination of myocardial viability in the setting of severe regional dysfunction and chronic coronary artery disease. The greater the myocardial uptake of these agents in the resting state, the greater the probability of improved systolic function after coronary revascularization.

Topics: Animals; Coronary Disease; Electrocardiography; Humans; Myocardial Reperfusion; Myocardium; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Technetium Tc 99m Sestamibi; Tomography, Emission-Computed, Single-Photon; Ventricular Dysfunction, Left

Over the last 20 years, nuclear cardiology has become a mainstay in the evaluation of ischemic heart disease. In the setting of acute coronary syndromes (myocardial infarction or unstable angina), myocardial perfusion imaging has emerged as an important tool in assessing the functional significance of angiographic coronary stenoses, evaluating the efficacy of therapeutic interventions, and risk-stratifying patients in the postinfarction period. Recent literature has demonstrated the diagnostic and prognostic value, as well as the cost-effectiveness, of perfusion imaging in acute chest pain syndromes and the diagnostic superiority of perfusion imaging compared with two-dimensional echocardiography. Acute perfusion imaging is now being included in the algorithm for the triage and management of acute chest pain syndromes. Emergency physicians are increasingly using nuclear cardiac imaging modalities for aid in the evaluation of patients who present with chest pain of uncertain origin.

Topics: Acute Disease; Algorithms; Coronary Disease; Cost-Benefit Analysis; Diagnosis, Differential; Echocardiography; Electrocardiography; Gated Blood-Pool Imaging; Humans; Organophosphorus Compounds; Organotechnetium Compounds; Predictive Value of Tests; Radiopharmaceuticals; Sensitivity and Specificity; Syndrome; Technetium Tc 99m Sestamibi; Thallium Radioisotopes; Tomography, Emission-Computed, Single-Photon; Triage

Little is known about the effect of chronic beta-blockade on adenosine actions. We sought to investigate the effect of oral beta-blockers on the presence, extent, and severity of myocardial perfusion abnormality induced by adenosine in patients with coronary artery disease.. In this crossover study, 45 male patients with coronary artery disease on beta-blocker therapy with atenolol, bisoprolol, or metoprolol underwent adenosine myocardial perfusion imaging both on and off beta-blockade in a random order on separate days. Myocardial perfusion was assessed both qualitatively and quantitatively. Hemodynamic response, image analysis, and sensitivity for the detection of coronary stenosis (>or=50% luminal diameter reduction on x-ray coronary angiography) were compared between the on and off beta-blocker studies.. Rate pressure product both at baseline and at peak adenosine infusion decreased by 23% +/- 15% and 21% +/- 18%, respectively, after beta-blockade (P < 0.001 for all). The median (interquartile range) summed difference score, a measure of defect reversibility, and quantitative defect size were both significantly lower after beta-blockade (median, 7.0 [interquartile range, 2.0-9.5] vs. median, 5.0 [interquartile range, 0-8.0], P = 0.002; and quantitative defect size, 18% [interquartile range, 9%-34%] vs. quantitative defect size, 6% [interquartile range, 0%-19%], P < 0.001, respectively). The overall sensitivity for the detection of coronary stenosis decreased from 0.76 (95% confidence interval, 0.65-0.88) to 0.58 (95% confidence interval, 0.45-0.71) after beta-blockade (P = 0.03).. beta-blockade causes a small but significant reduction in the extent and severity of perfusion abnormality by adenosine. This may reduce the diagnostic sensitivity of adenosine myocardial perfusion imaging for the detection of flow-limiting coronary stenosis.

Topics: Adenosine; Adrenergic beta-Antagonists; Aged; Atenolol; Blood Pressure; Coronary Angiography; Coronary Circulation; Coronary Disease; Coronary Stenosis; Cross-Over Studies; Electrocardiography; Female; Heart; Heart Rate; Humans; Male; Middle Aged; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Tomography, Emission-Computed, Single-Photon; Vasodilator Agents

Pomegranate juice contains antioxidants such as soluble polyphenols, tannins, and anthocyanins and may have antiatherosclerotic properties. However, no study has investigated the effects of pomegranate juice on patients who have ischemic coronary heart disease (CHD). We investigated whether daily consumption of pomegranate juice for 3 months would affect myocardial perfusion in 45 patients who had CHD and myocardial ischemia in a randomized, placebo-controlled, double-blind study. Patients were randomly assigned into 1 of 2 groups: a pomegranate juice group (240 ml/day) or a placebo group that drank a beverage of similar caloric content, amount, flavor, and color. Participants underwent electrocardiographic-gated myocardial perfusion single-photon emission computed tomographic technetium-99m tetrofosmin scintigraphy at rest and during stress at baseline and 3 months. Visual scoring of images using standardized segmentation and nomenclature (17 segments, scale 0 to 4) was performed by a blinded independent nuclear cardiologist. To assess the amount of inducible ischemia, the summed difference score (SDS) was calculated by subtracting the summed score at rest from the summed stress score. The experimental and control groups showed similar levels of stress-induced ischemia (SDS) at baseline (p >0.05). After 3 months, the extent of stress-induced ischemia decreased in the pomegranate group (SDS -0.8 +/- 2.7) but increased in the control group (SDS 1.2 +/- 3.1, p <0.05). This benefit was observed without changes in cardiac medications, blood sugar, hemoglobin A1c, weight, or blood pressure in either group. In conclusion, daily consumption of pomegranate juice may improve stress-induced myocardial ischemia in patients who have CHD.

Topics: Aged; Aged, 80 and over; Beverages; Coronary Disease; Double-Blind Method; Exercise Test; Female; Humans; Lythraceae; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Phytotherapy; Plant Preparations; Radiopharmaceuticals; Time Factors; Tomography, Emission-Computed, Single-Photon; Treatment Outcome

Regular exercise in patients with stable coronary artery disease has been shown to improve myocardial perfusion and to retard disease progression. We therefore conducted a randomized study to compare the effects of exercise training versus standard percutaneous coronary intervention (PCI) with stenting on clinical symptoms, angina-free exercise capacity, myocardial perfusion, cost-effectiveness, and frequency of a combined clinical end point (death of cardiac cause, stroke, CABG, angioplasty, acute myocardial infarction, and worsening angina with objective evidence resulting in hospitalization).. A total of 101 male patients aged < or =70 years were recruited after routine coronary angiography and randomized to 12 months of exercise training (20 minutes of bicycle ergometry per day) or to PCI. Cost efficiency was calculated as the average expense (in US dollars) needed to improve the Canadian Cardiovascular Society class by 1 class. Exercise training was associated with a higher event-free survival (88% versus 70% in the PCI group, P=0.023) and increased maximal oxygen uptake (+16%, from 22.7+/-0.7 to 26.2+/-0.8 mL O2/kg, P<0.001 versus baseline, P<0.001 versus PCI group after 12 months). To gain 1 Canadian Cardiovascular Society class, 6956 dollars was spent in the PCI group versus 3429 dollars in the training group (P<0.001).. Compared with PCI, a 12-month program of regular physical exercise in selected patients with stable coronary artery disease resulted in superior event-free survival and exercise capacity at lower costs, notably owing to reduced rehospitalizations and repeat revascularizations.

Topics: Aged; Angioplasty, Balloon, Coronary; Cardiac Catheterization; Coronary Disease; Disease-Free Survival; Exercise Test; Exercise Therapy; Hospitalization; Humans; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Oxygen Consumption; Radionuclide Imaging; Radiopharmaceuticals

We assessed Takotsubo (ampulla) cardiomyopathy compared with acute coronary syndrome (ACS) using two-dimensional echocardiography and 99mTc-tetrofosmin myocardial SPECT.. We examined 10 patients with Takotsubo cardiomyopathy and 16 with ACS at the time of emergency admission (acute phase), at three to nine days after the attack (subacute phase) and at one month after the attack (chronic phase). The left ventricle was divided into nine regions on echocardiograms and SPECT images, and the degree of abnormalities in each region was scored in five grades from normal (0) to severely abnormal (4).. Coronary angiography revealed total or subtotal occlusion in patients with ACS but no stenotic legions in those with Takotsubo cardiomyopathy. The amount of ST segment elevation (mm) was 7.9 +/- 3.4 in patients with Takotsubo cardiomyopathy and 7.3 +/- 3.7 in those with ACS (N.S.). Abnormal wall motion scores on echocardiograms were 13.8 +/- 4.4, 4.4 +/- 3.8 and 1.8 +/- 2.3 during the acute, subacute and chronic phases in patients with Takotsubo cardiomyopathy, and 13.9 +/- 4.0, 11.7 +/- 3.7, 7.6 +/- 4.2, respectively in patients with ACS. The value of MB fraction of creatine phosphokinase (IU/l) was 34 +/- 23 in patients with Takotsubo cardiomyopathy and 326 +/- 98 in those with ACS (p < 0.001). Abnormal myocardial perfusion scores on 99mTc-tetrofosmin myocardial SPECT were 11.4 +/- 3.2, 3.2 +/- 3.3 and 0.7 +/- 1.1 during the acute, subacute and chronic phases respectively, in patients with Takotsubo cardiomyopathy, and 15.8 +/- 4.1, 13.5 +/- 4.4, 8.2 +/- 4.4, respectively, in those with ACS. The numbers of myocardial segments that did not uptake 99mTc-tetrofosmin during the acute phase were 0.5 +/- 0.8 and 3.6 +/- 2.8 in patients with Takotsubo cardiomyopathy and ACS, respectively.. Impaired coronary microcirculation might be a causative mechanism of Takotsubo cardiomyopathy.

Topics: Acute Disease; Aged; Aged, 80 and over; Cardiomyopathies; Coronary Disease; Diagnosis, Differential; Female; Heart Ventricles; Humans; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Reproducibility of Results; Sensitivity and Specificity; Syndrome; Tomography, Emission-Computed, Single-Photon; Ventricular Dysfunction, Left

Recent studies performed with positron emission tomography have suggested that coronary flow reserve (CFR) is moderately to severely reduced after the arterial switch operation (ASO). These findings are of great concern but have not been confirmed by other methods.. Eleven symptom-free children were studied between 4 and 11 (median 6.0) years after the ASO. Flow velocity in the left anterior descending (LAD) and right coronary arteries (RCA) was measured with a 0.014-inch Doppler FloWire (Cardiometrics) before and after intracoronary injection of adenosine (0.5 microg/kg) and nitroglycerin (5 microg/kg). CFR was defined as the ratio of hyperemic to basal average peak velocity (APV). The median (range) CFR in the LAD was 3.7 (3.0 to 4.8) and 3.4 (2.9 to 4.8) in the RCA. The increase in APV after intracoronary injection of nitroglycerin was 300% (240% to 420%) in the LAD and 260% (190% to 460%) in the RCA. APV at rest was 15.0 (14.0 to 21.0) cm/s in the LAD and 16.0 (9.6 to 30.0) cm/s in the RCA. A linear relation was found between right ventricular systolic pressure and resting APV in the RCA (r=0.77, P=0.0056), and between resting APV and CFR (r=-0.61, P<0.05) in the RCA.. The CFR and coronary vasoreactivity to nitroglycerin in children treated for transposition of the great arteries with the ASO was within normal limits. Increased right ventricular pressure and myocardial hypertrophy can cause increased resting coronary flow velocity in the RCA and affect CFR negatively.

Topics: Adenosine; Blood Flow Velocity; Cardiac Catheterization; Child; Child, Preschool; Coronary Angiography; Coronary Circulation; Coronary Disease; Coronary Vessels; Echocardiography; Electrocardiography; Humans; Laser-Doppler Flowmetry; Linear Models; Nitroglycerin; Organophosphorus Compounds; Organotechnetium Compounds; Pulmonary Valve Stenosis; Tomography, Emission-Computed, Single-Photon; Transposition of Great Vessels; Vasodilator Agents; Vasomotor System; Ventricular Function, Left

There are no large studies available to guide the selection of thallium (Tl), methoxyisobutylisonitrile (MIBI) or tetrofosmin (Tf) for myocardial perfusion imaging. Our objective was to compare the technical and clinical performance of the three in routine clinical practice. We randomised 2,560 patients to receive Tl, MIBI or Tf. A 1-day stress/rest protocol was used for MIBI and Tf. Tracer uptake was scored using a 17-segment model, quality and artefact scores were assigned, and ratios of heart (H), liver (L), subdiaphragmatic (S) and lung activity were measured. Mean quality scores (stress/rest) were Tl 2.13/2.16, MIBI 2.18/2.39, Tf 2.18/2.42 ( P=ns stress and <0.00001 rest). For attenuation artefact, Tl>MIBI=Tf ( P<0.05) and for low-count artefact Tl>MIBI>Tf ( P<0.001). For H/S, Tl>MIBI=Tf, for H/L Tl>MIBI=Tf, and for H/lung Tl

Topics: Adenosine; Artifacts; Coronary Disease; Cross-Sectional Studies; Dobutamine; Exercise Test; Heart; Heart Diseases; Humans; Myocardium; Organophosphorus Compounds; Organotechnetium Compounds; Quality Control; Radiography; Radionuclide Imaging; Radiopharmaceuticals; Reproducibility of Results; Sensitivity and Specificity; Technetium Tc 99m Sestamibi; Thallium; United Kingdom

In myocardial perfusion scintigraphy, the clinical significance of fixed defects presents some difficulty. In this study, we evaluated whether additional information on left ventricular function assessed by quantitative gated single-photon emission computed tomography (gated SPET) would increase the diagnostic yield of the study in such patients. We studied 55 patients with a previous myocardial infarction and 20 patients without a previous myocardial infarction using gated SPET 99Tc(m)-tetrofosmin myocardial perfusion imaging. Each patient had to have a persistent perfusion defect consisting of at least three contiguous segments in the same vascular territory. The left ventricle was divided into 20 segments which were analysed for perfusion and wall thickening on a 4-point severity scale. Of the 55 patients with myocardial infarction, 19 (35%) patients showed preserved wall thickening in the region of the previous infarction with fixed perfusion abnormalities, which suggested residual myocardial viability. In the 20 patients without myocardial infarction, preserved wall thickening was seen in 10 (50%) patients with fixed perfusion defects, suggesting an attenuation artefact. Conversely, in 16 (29%) patients in the myocardial infarction group and two (10%) patients in the non-myocardial infarction group normal perfusion was associated with severely diminished wall thickening possibly due to stunning. We found an excellent correlation between wall thickening and left ventricular ejection fraction both for the patients with myocardial infarction and the patients without myocardial infarction (r = 0.86 and r = 0.82, respectively, both P<0.0001). A reasonable correlation between perfusion and left ventricular ejection fraction was found for the patients with myocardial infarction (r = 0.41, P = 0.002), and a non-significant correlation for the patients without myocardial infarction (r = 0.37, P = 0.1). Quantitative gated SPET myocardial imaging allows the detection of residual wall thickening in patients with a previous myocardial infarction who show severe fixed perfusion defects. In patients without myocardial infarction, gated SPET imaging allows differentiation between an attenuation artefact and a fixed perfusion defect due to coronary artery disease. In addition, gated SPET may show diminished ventricular function in normally perfused segments possibly due to myocardial stunning. The addition of gated SPET myocardial perfusion imaging increases diagnost

Topics: Aged; Coronary Circulation; Coronary Disease; Female; Heart; Humans; Image Processing, Computer-Assisted; Male; Middle Aged; Myocardial Infarction; Myocardial Stunning; Organophosphorus Compounds; Organotechnetium Compounds; Perfusion; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon; Ventricular Function, Left

Several studies have shown the accuracy of gated single photon emission computed tomography (SPECT) using thallium-201 and technetium tracers in the assessment of myocardial perfusion and function. Gated SPECT has been successfully utilized to detect post-stress left ventricular ejection fraction (LVEF) reduction resulting from post-ischemic stunning in patients with coronary obstruction. The aim of this study was to evaluate whether the post-stress LVEF impairment could be related to the post-stress end-systolic ventricular dilation resulting from post-ischemic endocardial stunning. Two hundred and eighty-two consecutive patients were studied by conventional diagnostic 2 day stress/rest gated SPECT following injection of 925 MBq of 99mTc-tetrofosmin using a dual-headed SPECT camera. One hundred and forty-seven of these patients (52%) showed reversible perfusion defects, 69 (24%) permanent defects and the remaining 66 (24%) had normal perfusion. One hundred and thirty-eight of these patients had a history of myocardial infarction (MI) and 19% underwent coronary angiography without an intervening cardiac event. Perfusion was analysed on ungated images using 20 segments scored on a five-point scale (0, normal; 4, no uptake), while wall thickening (WT) was assessed visually on stress/rest end-systolic images using a four-point score (0, normal; 3, absence of WT). LVEF and volumes were calculated using an automatic algorithm. The post-stress and rest ratios were determined for both end-diastolic (EDV) and end-systolic (ESV) volume. Normal values for all these parameters were obtained using data from 149 patients with a low likelihood (<5%) of coronary artery disease (CAD). In 50 of the 147 (34%) of patients with reversible perfusion defects, post-stress LVEF was >5% lower than rest values (stunned group), while the remaining 97 patients did not show a significant LVEF change (group 2A). The percentage of patients who developed exercise-induced angina, the percentage of patients who underwent coronary angiography and the segmental summed perfusion and WT scores were significantly higher in the stunned group compared with group 2A. Only ESV increased significantly post-stress, and this increase occurred only in stunned patients. Both EDV and ESV ratios were significantly higher in the stunned group compared with normal controls (P=0.008 and P<0.000001, respectively) and with the subgroup 2A (P=0.011 and P<10(-12), respectively). The ESV stress/rest ratio correl

Topics: Aged; Chest Pain; Coronary Angiography; Coronary Circulation; Coronary Disease; Exercise Test; Female; Gated Blood-Pool Imaging; Humans; Male; Middle Aged; Myocardial Stunning; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Stroke Volume; Thallium; Tomography, Emission-Computed, Single-Photon; Vasodilation; Ventricular Function, Left

We evaluated the use of adenosine, dobutamine and arbutamine with (99m)Tc-tetrofosmin myocardial perfusion imaging. Forty patients under investigation for suspected coronary artery disease were recruited. Each had a resting scan and two separate stress scans on different days, in a randomized cross-over study. Resultant images were blindly reported in 13 segments per scan as normal, reversible or fixed defects. A score was given (0-3) for segmental defect severity. Haemodynamic responses were as expected for each agent. Subjective side effect scores did not differ overall between agents. Adenosine caused a significantly higher incidence of abnormal taste (54%) than dobutamine and arbutamine (both 23%) and a lower incidence of palpitations (25% vs 69% and 54%, respectively), all P<0.05. Arbutamine caused significantly more chest pain than adenosine (77% vs 46%) though less flushing (35% vs 68%), both P<0.05. Comparison of the results obtained showed highly significant levels of segmental agreement for visual and semi-quantitative analysis between adenosine and arbutamine, kappa value and correlation coefficient of 0.78 and 0.86, respectively, dobutamine and adenosine 0.69 and 0.78, and arbutamine and dobutamine 0.75 and 0.78, all P<0.0001. Adenosine, arbutamine and dobutamine differ in their haemodynamic response and side effect profile but provide highly comparable results during (99m)Tc SPECT imaging.

Topics: Adenosine; Adrenergic beta-Agonists; Blood Pressure; Catecholamines; Coronary Disease; Cross-Over Studies; Dobutamine; Electrocardiography; Exercise Test; Female; Heart; Heart Rate; Hemodynamics; Humans; Image Processing, Computer-Assisted; Male; Middle Aged; Observer Variation; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon

We developed new method to calculate myocardial blood flow increase rate at exercise (MBF-IR) with 99mTc-tetrofosmin (TF) radionuclide (RN) angiography and myocardial perfusion SPECT and assessed its feasibility using clinical data.. Fifteen patients who were suspected to have coronary artery disease underwent TF RN angiography and SPECT at exercise and at rest. Seven patients had coronary stenosis and eight patients had no significant coronary stenosis in coronary angiography. MBF-IRs were calculated by the following equation: [formula: see text] where Cr = regional myocardial count at rest, Ce = regional myocardial count at exercise [formula: see text] = the area under ventricular time activity curve at rest and [formula: see text] = the area under ventricular time activity curve at exercise.. Rate pressure product (RPP) was similar in patients with and without coronary stenosis (24,509 +/- 6701.9 vs. 27,196 +/- 4862.4, p = 0.39). MBF-IR was 1.88 +/- 0.73 in the area covered by stenosed coronary artery, 2.53 +/- 0.75 in unstenosed coronary artery in patients who have significant coronary stenosis and 2.97 +/- 0.77 in normal coronary patients. MBF-IRs in the area covered by stenosed coronary arteries were significantly smaller than that of normal coronary artery patient (p = 0.037). Interobserver and intraobserber reproducibility were good (r = 0.96, 0.95 respectively). There was strong positive correlation between MBF-IR and RPP in normal patients (r = 0.69, p = 0.0018), suggesting MBF increase depends on the cardiac workload.. MBF-IR can be estimated by the combination of TF RN angiography and SPECT at exercise and at rest.

Topics: Aged; Coronary Angiography; Coronary Circulation; Coronary Disease; Exercise; Feasibility Studies; Female; Heart; Heart Function Tests; Humans; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Radionuclide Angiography; Radiopharmaceuticals; Reproducibility of Results; Tomography, Emission-Computed, Single-Photon

Myocardial uptake of 99Tcm-tetrofosmin in vivo is determined by a combination of flow and metabolic status of myocytes. The accumulation of tetrofosmin in the mitochondria is related to their ability to transduce metabolic energy into electronegative membrane potential. Trimetazidine (TMZ), an anti-ischaemic drug, appears to have a metabolic cytoprotective effect related to mitochondrial function, since it does not induce systemic or coronary haemodynamic changes. In this study, we evaluated the effects of TMZ on tetrofosmin uptake in hypoperfused myocardial regions in patients with coronary artery disease (CAD). Twenty-two patients, 14 with previous myocardial infarction (group A) and eight with a history of angina (group B), with angiographically documented CAD were studied. All patients underwent two tetrofosmin SPET studies at rest, before (baseline) and 1 week after TMZ administration (post-TMZ). On quantitative analysis, 131 segments showed less tetrofosmin uptake at baseline. In these segments, tetrofosmin uptake was 51 +/- 13% at baseline and 55 +/- 15% post-TMZ (P < 0.001 vs control). In the 86 hypoperfused segments of group A, tetrofosmin uptake was 48 +/- 14% at baseline and 52 +/- 17% post-TMZ (P < 0.001 vs control). In the 45 hypoperfused segments of group B, tetrofosmin uptake was 56 +/- 9% at baseline and 60 +/- 10% post-TMZ (P < 0.001 vs control). In the remaining 309 segments, no significant difference in tetrofosmin uptake before and after TMZ was observed. In conclusion, our results suggest that TMZ administration may increase myocardial uptake of tetrofosmin in hypoperfused regions at rest in patients with CAD, based on its metabolic effect.

Topics: Aged; Coronary Disease; Hemodynamics; Humans; Male; Middle Aged; Myocardium; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon; Trimetazidine; Ultrasonography; Vasodilator Agents

Exercise stress myocardial perfusion scintigraphy has been used for the diagnosis of transplant coronary artery stenosis (TCAS) in cardiac allograft recipients. However, the role of pharmacologic stress myocardial perfusion imaging has not been evaluated. Aim of the study is to assess the accuracy of dobutamine stress 99m technetium tetrofosmin myocardial perfusion imaging for the diagnosis of TCAS in heart transplant recipients.. We studied 50 patients (age 56 +/- 8 year, 45 men) at a mean of 6.4 +/- 2.8 years after cardiac transplant with dobutamine (up to 40 ìg/kg/min) stress 99m technetium tetrofosmin SPECT. Resting images were acquired 24 hours after the stress study. Significant TCAS was defined as > or =50% luminal diameter stenosis by coronary angiography.. Significant TCAS was detected in 30 patients (60%). Myocardial perfusion abnormalities (reversible and/or fixed defects) were detected in 27 of the 30 patients with and in 9 of the 20 patients without significant TCAS (sensitivity = 90%, CI 82-98, specificity = 55% CI 41-69, positive predictive value = 75%, CI 63-87, negative predictive value = 79%, CI 67-90 and accuracy = 76%, CI 64-88). Patients with multivessel TCAS had a larger stress perfusion defect score (5.6 +/- 3.1 vs 3.2 +/- 2.4, p < 0.05) compared to patients with single vessel TCAS. Among patients with abnormal perfusion who had no significant TCAS, 2 had lesions <50%, 2 had luminal irregularities and 5 had no abnormalities at angiography. Therefore specificity was 62% (8/13) in patients without any detectable angiographic abnormalities.. Dobutamine stress tetrofosmin myocardial perfusion imaging is a highly sensitive method for the detection of TCAS in recipients of cardiac allografts. The high negative predictive value of the test indicates that patients who demonstrate normal perfusion by this method may be excluded from further invasive studies.

Topics: Aged; Confidence Intervals; Coronary Angiography; Coronary Disease; Dobutamine; Electrocardiography; Exercise Test; Female; Heart Transplantation; Humans; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Predictive Value of Tests; Probability; Sensitivity and Specificity; Tomography, Emission-Computed, Single-Photon; Transplantation, Homologous

New forms of ventricular pacing are increasingly studied as an option in the management of patients with heart failure. Coronary artery disease (CAD) is the most frequent cause of heart failure, and patients with complete left or right bundle branch block (LBBB and RBBB) and a reduced left ventricular ejection fraction (LVEF) are the best candidates for this new therapy. However, the prevalence of this clinical presentation is uncertain. During a 1-year period, 433 patients with documented CAD (mean age 64 +/- 10 years, 79% men) who were referred for myocardial perfusion imaging were prospectively studied. All patients underwent a 2-day stress-rest gated 99mTc-Tetrofosmin SPECT study with evaluation of resting LV enddiastolic (LVEDV) and endsystolic (LVESV) volumes and LVEF. The resting ECG was examined in all patients for the presence of complete LBBB or RBBB. Of the 433 patients with CAD 36 patients (8.3%) had LBBB (n = 14) or RBBB (n = 22) and a QRS width > 120 ms. These 36 patients were in general older and more frequently had diabetes and atrial fibrillation. Patients with LBBB or RBBB had a significantly lower LVEF (41 +/- 16% vs 48 +/- 14%, P < 0.01) and significantly higher LV volumes compared to patients without LBBB or RBBB (177 +/- 79 mL vs 131 +/- 53 mL, P < 0.001 for LVEDV and 116 +/- 76 mL vs 73 +/- 49 mL, P < 0.001 for LVESV). In total, 112/433 (26%) had an LVEF < or = 40%; 16 had also a LBBB or RBBB (3.7% of the whole population, 14% of the patients with a LVEF < or = 40%). Within the group of patients with a LVEF > or = 40%, patients with BBB had comparable LVEF (26 +/- 9% vs 30 +/- 8%, P = NS) but significantly higher LVEDV and LVESV (230 +/- 70 mL vs 190 +/- 64 mL, P < 0.05 for LVEDV and 170 +/- 65 mL vs 135 +/- 56 mL, P < 0.05 for LVESV). In this prospective registry 3.7% of all patients with known CAD had LBBB or RBBB in combination with a LVEF < or = 40%. This represented 14% of all patients with a LVEF > or = 40%. These limited numbers should be kept in mind when considering biventricular pacing as a new therapeutic options in patients with heart failure.

Topics: Aged; Bundle-Branch Block; Cardiac Pacing, Artificial; Cardiac Volume; Coronary Disease; Diabetes Complications; Diabetes Mellitus; Female; Humans; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Patient Selection; Prevalence; Prospective Studies; Registries; Tomography, Emission-Computed, Single-Photon; Ventricular Dysfunction, Left; Ventricular Dysfunction, Right

To elucidate the after-effect of exercise on left ventricular (LV) function, end-diastolic volume (EDV), end-systolic volume (ESV) and ejection fraction (LVEF) were evaluated at 1 h after exercise and at rest by technetium-99m tetrofosmin gated myocardial single-photon emission tomography (SPET) using an automated program in 53 subjects. The subjects were grouped as follows: normal scan (n = 16), ischaemia (n = 19) and infarction (n = 18), based on the interpretation of perfusion images. Postexercise LVEF did not differ from resting LVEF in the groups with normal scan and infarction. In patients with ischaemia, postexercise EDV (90+/-17 ml, mean +/-SD) and ESV (44+/-15 ml) were significantly higher than EDV (84+/-15 ml, P = 0.001) and ESV (36+/-14 ml, P<0.0005) at rest. LVEF was significantly depressed 1 h after exercise (53%+/-9% vs 58%+/-9%, P<0.0001). In ischaemic patients with depressed postexercise LVEF, LVEF difference between rest and postexercise showed a significant correlation with the sum of defect scores, which were reversible from exercise to rest perfusion images (r = 0.92, P<0.0001). These results indicate that exercise-induced LV dysfunction (myocardial stunning) continues for at least 1 h in ischaemic patients and that the extent of LVEF depression is determined by the severity of ischaemia.

Topics: Blood Volume; Coronary Disease; Exercise; Female; Gated Blood-Pool Imaging; Heart; Humans; Image Processing, Computer-Assisted; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Rest; Stroke Volume; Tomography, Emission-Computed, Single-Photon; Ventricular Function, Left

A one-hour protocol for stress myocardial scintigraphy using technetium-99m-tetrofosmin (Tc-tetrofosmin) was compared with coronary arteriography for the detection of coronary artery stenosis in 90 consecutive patients without prior myocardial infarction, revascularization procedure or vasospastic angina. Tc-tetrofosmin stress myocardial scintigraphy acquired a rest image 20 min after intravenous administration of Tc-tetrofosmin (185 MBq, 1/5 vial) using a three-head gamma camera collecting 20-sec views over 360 degrees. The stress test using bicycle ergometer was performed and administration of Tc-tetrofosmin (740 MBq, 4/5 vial) was repeated at the peak stress point. The stress image was acquired 15 min after the second injection with 5-sec views over 360 degrees. Coronary arteriography revealed the presence of significant coronary artery stenosis (> 75%) in 56 vessels of 45 patients, including 35 patients with single-vessel disease, 5 with two-vessel disease, 2 with three-vessel disease, and 3 with left main trunk disease. The overall sensitivity and specificity for the detection of coronary artery disease by visual analysis were 91.1% and 77.8%, respectively, and by quantitative analyses (using bull's-eye method) were 95.6% and 91.1%, respectively. The individual stenotic vessel sensitivities in the right coronary artery, left anterior descending artery, and left circumflex artery were 84.6%, 90.9%, and 78.6%, respectively. The specificities were 97.3%, 95.9%, and 100.0%, respectively. These results suggest that stress myocardial scintigraphy using the present new protocol is a promising approach for the detection of coronary artery stenosis.

Topics: Angina Pectoris; Coronary Angiography; Coronary Disease; Exercise Test; Female; Heart; Humans; Male; Middle Aged; Myocardial Infarction; Organophosphorus Compounds; Organotechnetium Compounds; Prospective Studies; Radionuclide Imaging; Radiopharmaceuticals; Sensitivity and Specificity

We compared the left ventricular (LV) end-diastolic volume (EDV), end-systolic volume (ESV) and ejection fraction (LVEF) as calculated by Cedars automated quantitative gated SPECT (QGS) to those determined by first-pass radionuclide angiography (FPRNA) and contrast left ventriculography (LVG) in a group of 21 patients (mean age 61.4 +/- 9.2 y).. A total of 740 MBq 99mTc-tetrofosmin was administered rapidly into the right cubital vein at rest, and FPRNA was performed using a multicrystal gamma camera. One hour after injection, QGS was performed with a temporal resolution of 10 frames per R-R interval. LVG was performed within 2 wk.. The EDV, ESV and LVEF calculated by QGS were highly reproducible (intraobserver, r = 0.99, r = 0.99 and r = 0.99, respectively; interobserver, r = 0.99, r = 0.99 and r = 0.99, respectively; P < 0.01) and were more consistent than those determined by FPRNA (intraobserver, r = 0.97, r = 0.95 and r = 0.93, respectively; interobserver, r = 0.86, r = 0.96 and r = 0.91, respectively; P < 0.01). There was a good correlation between EDV, ESV and LVEF by FPRNA and those by LVG (r = 0.61, r = 0.72 and r = 0.91, respectively; P < 0.01), and there was an excellent correlation between QGS and LVG (r = 0.73, r = 0.83 and r = 0.87, respectively; P < 0.01). The mean EDV by QGS (100 +/- 11.3 mL) was significantly lower than by FPRNA (132 +/- 16.8 mL) or LVG (130 +/- 8.1 mL), and the mean ESV by QGS (53.8 +/- 9.3 mL) was lower than by FPRNA (73.0 +/- 13.3 mL). Ejection fraction values were highest by LVG (57.1% +/- 3.2%), then QGS (51.8% +/- 3.0%) and FPRNA (48.9% +/- 2.4%).. QGS gave more reproducible results than FPRNA. LV volumes and LVEF calculated by QGS correlated well to those by LVG.

Topics: Adult; Aged; Coronary Disease; Electrocardiography; Female; Gated Blood-Pool Imaging; Heart; Heart Ventricles; Humans; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Perfusion; Radiopharmaceuticals; Reproducibility of Results; Stroke Volume; Tomography, Emission-Computed, Single-Photon; Ventriculography, First-Pass

It has been demonstrated that nitrate administration enhances the detection of myocardial viability in thallium-201 and technetium-99m sestamibi myocardial perfusion studies. The aim of this study was to assess the influence of nitrate administration on technetium-99m tetrofosmin myocardial uptake in patients with coronary artery disease and left ventricular dysfunction.. Twenty eight patients with coronary artery disease, previous myocardial infarction and left ventricular ejection fraction < 40% underwent, within 48 hours, rest/postnitroglycerin (0.4 mg sublingually) technetium-99m tetrofosmin single photon emission tomography (SPET), comparing these results with that of thallium-201 rest/redistribution SPET in 13 patients (first group) and with that of thallium-201 rest/reinjection SPET in the other 15 patients (second group). Tomograms based on the 3 spatial planes were divided into 15 segments and regional tracer uptake was quantitatively analysed. Viability was defined as presence of tracer uptake > or = 50% of peak activity.. The percentage of peak activity at rest or after nitrate administration of technetium-99m tetrofosmin correlated, with that of thallium-201, at rest and after redistribution or reinjection (r = 0.8; p < 0.001). On resting technetium-99m tetrofosmin studies 167 of the 420 segments that were analysed had < 50% of peak activity. 14.5% of these segments showed reversibility after nitrate administration, with an increase in 99mTc-tetrofosmin uptake from 45 +/- 5% to 55 +/- 4% of peak activity (p = 0.001), in the first group, and from 40 +/- 9% to 57 +/- 9% of peak activity (p = 0.003), in the second group. Overall agreement between rest/postnitroglycerin technetium-99m tetrofosmin SPET studies and rest/redistribution or rest/reinjection thallium-201 SPET studies, regarding the presence of myocardial viability, was 87% and 90%, respectively. All except one reversible segments on tetrofosmin studies after nitrates had viability criteria on thallium studies.. Nitrate administration at rest enhances the detection of myocardial viability using technetium-99m tetrofosmin SPET, correlating with viability criteria observed on thallium studies. It represents a simple and useful technique in the assessment of myocardial viability.

Topics: Aged; Clinical Protocols; Coronary Circulation; Coronary Disease; Female; Humans; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Thallium Radioisotopes; Tomography, Emission-Computed, Single-Photon; Ventricular Function, Left

A one-hour protocol for stress myocardial scintigraphy using technetium-99m (99mTc) tetrofosmin was compared with scintigraphy using thallium-201 (201Tl) for the detection of coronary artery disease in 43 consecutive patients who underwent stress 201Tl and 99mTc-tetrofosmin myocardial scintigraphy, and coronary arteriography within 1 week. For the stress 99mTc-tetrofosmin test, rest imaging data were acquired 20 min after intravenous injection of 5-7 mCi 99mTc-tetrofosmin, using a 3-head gamma camera collecting 20-sec views over 360 degrees. After dobutamine infusion or bicycle ergometer exercise, 20-25 mCi of 99mTc-tetrofosmin was additionally injected at peak stress. The stress images were acquired 15 min after the second injection with 5-sec views over 360 degrees. All patients also underwent 201Tl exercise and redistribution (4-hour) imaging following a standard protocol. The overall sensitivity for detecting coronary artery disease was 96.0%, with an overall specificity of 93.3% for both types of scintigraphy. Qualitative analyses of 21 conventionally divided left ventricular segments showed that the overall segmental concordance between the 99mTc-tetrofosmin and 201Tl imagings was 85.2% on the rest images and 82.1% on the stress images. The segmental concordance of the rest images was 87.0% in patients with neither significant stenosis nor myocardial infarction, 86.2% in patients with significant stenosis without myocardial infarction, and 82.9% in patients with significant stenosis and myocardial infarction, and the concordance values of the stress images were 85.4%, 87.5% and 75.6%, respectively. These preliminary results suggest that stress myocardial scintigraphy using the present new protocol is a promising approach for the detection of coronary artery disease, with diagnostic sensitivity and specificity comparable to those of stress 201Tl scintigraphy.

Topics: Coronary Angiography; Coronary Disease; Exercise Test; Female; Humans; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Radionuclide Imaging; Radiopharmaceuticals; Sensitivity and Specificity; Thallium Radioisotopes

Exercise 99mTc-tetrofosmin myocardial scintigraphy is as accurate as exercise 201TI imaging. Thus far, no data are available on tetrofosmin imaging during pharmacologic stress. We evaluated the feasibility of using. 99mTc-tetrofosmin myocardial SPECT during vasodilation with dipyridamole for detecting coronary artery disease.. Sixty-four patients, enrolled in three centers in the U.S., underwent one-day dipyridamole/rest tetrofosmin SPECT. Coronary angiography, performed in 59 patients within 2 mo of the SPECT study, revealed normal coronary arteries or insignificant coronary stenosis in 11 patients and significant (> or = 50% luminal diameter stenosis) coronary stenoses in 48 patients.. Sensitivity and specificity of tetrofosmin SPECT for detecting coronary artery disease were 85% and 55%, respectively, in the overall population and 81% and 55% in patients without prior coronary artery bypass surgery. The overall sensitivity and specificity of tetrofosmin tomographic imaging for detection of individual coronary stenoses were 53% and 72%, respectively, in the overall population and 54% and 80% in the patients without prior coronary artery bypass surgery.. One-day dipyridamole/rest 99mTc-tetrofosmin myocardial perfusion imaging is feasible and has a high sensitivity for detection of coronary artery disease.

Topics: Adult; Aged; Aged, 80 and over; Coronary Disease; Dipyridamole; Female; Heart; Humans; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Sensitivity and Specificity; Tomography, Emission-Computed, Single-Photon; Vasodilator Agents

This study was designed to compare the tracer kinetics between 99mTc-sestamibi and 99mTc-tetrofosmin in a heterogeneous group of 24 patients admitted for routine perfusion imaging.. Twelve patients were studied with 99mTc-tetrofosmin and 12 with 99mTc-sestamibi. In each group, six patients had a low likelihood for coronary artery disease, and six patients had angiographically proven coronary artery stenoses of > 75% or previous myocardial infarction. Analysis of myocardial and liver uptake and clearance as well as target-to-organ contrasts were performed with planar stress images.. Myocardial uptake of 99mTc-tetrofosmin was higher from 5 min (0.37 +/- 0.12 counts/pixel x MBq-1, p = 0.008) to 60 min (0.32 +/- 0.10 counts/pixel x MBq-1, p = 0.04) compared to 99mTc-sestamibi. Biological half-life for 99mTc-tetrofosmin (278 +/- 32 min) in normal myocardium was significantly shorter (p = 0.008) than for 99mTc-sestamibi (680 +/- 45 min). Biological liver half-life for 99mTc-tetrofosmin (67 +/- 16 min) was also significantly shorter (p = 0.02) than for 99mTc-sestamibi (136 +/- 18 min). Heart-to-lung ratios for 99mTc-tetrofosmin (2.49 +/- 0.43 at 5 min to 2.66 +/- 0.55 at 60 min) and 99mTc-sestamibi (2.52 +/- 0.37 at 5 min to 2.95 +/- 0.50 at 60 min) were similar. Whereas heart-to-liver ratios for 99mTc-tetrofosmin (1.04 +/- 0.24 at 5 min, increasing to 1.51 +/- 0.44 at 60 min) were significantly higher from 30-60 min postinjection (p = 0.05 at 30 min to p = 0.02 at 60 min) compared to the 99mTc-sestamibi (0.83 + 0.16 at 5 min to 1.08 +/- 0.27 at 60 min).. Technetium-99m-tetrofosmin displays a shorter myocardial half-life compared to 99mTc-sestamibi. The rapid liver clearance of 99mTc-tetrofosmin, combined with comparable myocardial retention, resulted in higher heart-to-liver ratios but similar heart-to-lung contrasts compared to 99mTc-sestamibi from 30-60 min.

Topics: Coronary Disease; Exercise Test; Female; Half-Life; Heart; Humans; Liver; Male; Middle Aged; Myocardium; Organophosphorus Compounds; Organotechnetium Compounds; Radionuclide Imaging; Radiopharmaceuticals; Technetium Tc 99m Sestamibi

Dipyridamole-loading 99mTc-tetrofosmin myocardial scintigraphy was performed for patients with coronary artery disease who underwent percutaneous transluminal coronary angioplasty (PTCA) in order to examine whether SPECT imaging prior to treatment is useful for the determination of prognosis after coronary intervention. Thirty-six patients including 9 with angina pectoris (AP), 22 with old myocardial infarction (OMI) and 5 OMI with AP were underwent dipyridamole-loading 99mTc-tetrofosmin myocardial SPECT before and after coronary intervention. The length of follow-up was 185 +/- 107 days after PTCA. Improvement of myocardial uptake was observed on myocardial SPECT in all cases with AP. Improvement of the myocardial uptake was observed 50% (4/8) of patients with OMI who had no myocardial viability. It was suggested that the improvement of myocardial uptake after PTCA was due to incomplete fill-in in cases with AP and that the presence of fill-in was important for level of fill-in in patients with AP. The improvement of myocardial uptake in the scar tissue in patients with OMI contributed to the hibernating myocardium. We concluded that correct detection of hibernating myocardium was difficult despite the superior imaging capability of 99mTc-tetrofosmin myocardial SPECT.

Topics: Aged; Angioplasty, Balloon, Coronary; Coronary Disease; Dipyridamole; Female; Follow-Up Studies; Heart; Humans; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon; Treatment Outcome

Technetium-99m tetrofosmin (Myoview) has unique properties for myocardial perfusion imaging very early after injection of the tracer. We used a very short same-day rest/stress protocol, to be performed within 2 h and evaluated its diagnostic accuracy. The study included 144 patients from seven Spanish and four Portuguese centres with a diagnosis of uncomplicated coronary artery disease (CAD); 78 patients (54%) had no history of prior myocardial infarction. Patients were injected with /=50%) was achieved with a sensitivity of 64% for the left anterior descending artery, 49% for the left circumflex artery and 86% for the right coronary artery, and an accuracy of 71%, 72% and 73% respectively. Concordance of SPET and CA was 62% for single-vessel disease and 68% for multivessel disease. In conclusion, this Spanish-Portuguese multicentre clinical trial confirmed, in a considerable number of patients who underwent coronary angiography, the feasibility of 99mTc tetrofosmin (Myoview) rest/stress myocardial SPET using a very short protocol (2 h).

Topics: Coronary Angiography; Coronary Disease; Exercise Test; Female; Heart; Humans; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Sensitivity and Specificity; Time Factors; Tomography, Emission-Computed, Single-Photon

Technetium-99m tetrofosmin is a new myocardial imaging agent with improved handling and kinetic characteristics. The purpose of this study was to compare the ability of planar and SPECT Tc-99m tetrofosmin imaging with Thallium-201 planar data to detect coronary artery disease and individual vessel lesions ( > 50% diameter stenosis). Seventy-two patients with definite or suspected coronary artery disease were included. Sixty-three had angiographic evidence of coronary artery disease, among whom 42 had had a previous myocardial infarction, while 21 had not. The total number of diseased arteries was 111. Patients underwent symptom-limited treadmill or bicycle exercise to similar endpoints. Thallium and tetrofosmin images were analysed separately by consensus reading. Interpretation was made for five standard anatomical regions (anterior, septal, inferior, lateral and apex), classified into four categories (normal, reversible, fixed and mixed defects). Sensitivity and specificity to detect coronary artery disease were 71% and 78% for Thallium-201 vs 68% and 78% for tetrofosmin by planar imaging, and 87% and 89% for tetrofosmin by SPECT. The improved sensitivity of SPECT was confirmed both in patients with and without previous myocardial infarction. The sensitivity to detect individual vessel lesions was improved by SPECT (59% tetrofosmin SPECT vs 50% thallium planar and 51% tetrofosmin planar). Individual vessel lesion detection by SPECT was 50% for the left anterior descending coronary artery, 42% for the left circumflex and 86% for the right coronary artery. This study confirms the value of technetium-99m tetrofosmin as a myocardial imaging agent. Improvements in diagnosis and in evaluating extent of disease can be expected from using SPECT.

Topics: Adult; Aged; Coronary Angiography; Coronary Disease; Echo-Planar Imaging; Exercise Test; Female; Heart; Hemodynamics; Humans; Image Interpretation, Computer-Assisted; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Sensitivity and Specificity; Thallium Radioisotopes; Tomography, Emission-Computed, Single-Photon

Tetrofosmin is a new 99mTc-labeled myocardial perfusion imaging agent. Biodistribution studies suggest more favorable heart-to-adjacent organ biokinetics than for 99mTc-sestamibi after injection during exercise. The aim of this work was to determine intraindividually whether tetrofosmin is more suitable than sestamibi for pharmacological stress testing in a 1-day protocol.. Thirty subjects underwent two similar 1-day, rest and dipyridamole stress imaging protocols: one using tetrofosmin, the other using sestamibi. SPECT was performed 60 min after tracer administration. Myocardial images were analyzed both visually and quantitatively.. Heart-to-liver activity ratios measured on the anterior SPECT projections were significantly higher for tetrofosmin than for sestamibi in the rest and stress studies. Heart-to-lung ratios were similar for both tracers. Significant linear correlations between tetrofosmin and sestamibi perfusion indices were found in normals and in patients with proven or suspected coronary artery disease. In segments showing abnormal uptake during stress, the perfusion indices were similar for tetrofosmin and sestamibi at rest and during stress. The degree of reversibility in these segments was also similar for both tracers. Finally, the extent, intensity and severity of perfusion defects were similar for both tracer studies.. Tetrofosmin has a more optimal biodistribution than sestamibi when used in a 1-day, rest and dipyridamole stress myocardial SPECT imaging protocol. No significant difference in either the quality or diagnostic interpretation of the images could be demonstrated.

Topics: Aged; Coronary Disease; Dipyridamole; Female; Heart; Humans; Image Processing, Computer-Assisted; Male; Organophosphorus Compounds; Organotechnetium Compounds; Technetium Tc 99m Sestamibi; Tissue Distribution; Tomography, Emission-Computed, Single-Photon; Vasodilator Agents

Recent trials with selected patients have indicated that 99Tcm-tetrofosmin is a suitable agent for myocardial perfusion imaging. We performed 99Tcm-tetrofosmin perfusion imaging in an unselected group of 297 patients routinely referred to our department. Single photon emission tomographic (SPET) imaging was performed 45-60 min post-injection using a 2-day stress and rest protocol. Altogether, 192 patients were stressed on a treadmill and 105 using intravenous dobutamine. Comparison with angiography was possible in 86 patients, 65 of whom had atheromatous coronary artery disease and 21 of whom had normal coronary arteries (6 of whom fulfilled the criteria for syndrome X). The sensitivity for the detection of coronary artery disease was 94% (93% for exercise stress and 95% for dobutamine). The overall specificity was 85% (87% for exercise stress and 80% for dobutamine in the 15 normal patients and the segments supplied by disease-free coronary vessels in patients with disease elsewhere). We conclude that 99Tcm-tetrofosmin is a highly sensitive and specific agent for the detection of coronary artery disease, using both exercise and dobutamine stress, with few limitations.

Topics: Adult; Aged; Angina Pectoris; Chest Pain; Coronary Angiography; Coronary Disease; Exercise Test; Female; Heart; Humans; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Rest; Sensitivity and Specificity; Tomography, Emission-Computed, Single-Photon

The purpose of this study was to clarify the diagnostic value of identifying viable myocardium using 99mTc-Tetrofosmin scintigraphy. Twenty-one patients with chronic coronary artery disease were studied using 201Tl exercise myocardial scintigraphy with reinjection and 99mTc-Tetrofosmin exercise myocardial scintigraphy. All patients had a history of old myocardial infarction. For 99mTc-Tetrofosmin scintigraphy, 222 MBq of 99mTc-Tetrofosmin was injected during exercise, and exercise images were obtained 20 min thereafter. There hours later, 666 MBq of 99mTc-Tetrofosmin was injected at rest, and images were obtained 40 min and 220 min later. Myocardial viability in the 99mTc-Tetrofosmin scintigraphy was estimated as fill-in findings (FF) or over 50% of %RI uptake (%TF) in the rest image. Myocardial viability in the 201Tl scintigraphy was estimated as redistribution (RD), fill-in findings in the reinjection image (FR) or over 50% of %RI uptake in the reinjection image (% TL). Sixteen of the 21 patients (76%) who underwent 201Tl scintigraphy (RD 10, FR 3, %TL 3 cases) and 15 of the 21 patients (71%) who underwent 99mTc-Tetrofosmin scintigraphy (FF 11, %TF 4 cases) had viable myocardium in the infarcted area. A comparison between the 99mTc-Tetrofosmin rest images obtained 40 min after the injection and that of 220 min revealed no redistribution findings. The %RI uptake of the infarcted area in the resting 99mTc-Tetrofosmin image (47 +/- 16%) was slightly lower than that in the 201Tl reinjection image (52 +/- 16%). In conclusion, viable myocardium was as clearly identified by 99mTc-Tetrofosmin, as by 201Tl scintigraphy.

Topics: Aged; Chronic Disease; Coronary Disease; Exercise Test; Female; Heart; Humans; Image Enhancement; Injections, Intravenous; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Radionuclide Imaging; Thallium Radioisotopes; Tissue Survival

We performed a multicenter trial of 99mTc-tetrofosmin myocardial SPECT for the assessment of acute thrombolysis, pre and post elective PTCA and myocardial viability in comparison with 201Tl myocardial SPECT. The participants consisted of 212 patients at 44 institutions and the study lasted for 10 months. In assessing acute thrombolysis, the perfusion defect from the acute to subacute phase was reduced by 25% and that from the subacute to chronic phase by 10%. The mean perfusion defect score at subacute and chronic phase was correlated well with regional wall motion. The mean defect score during the subacute phase could predict future wall motion abnormalities. In assessing pre and post PTCA, 99mTc-tetrofosmin stress/rest myocardial SPECT could identify the changes of perfusion as in the case with successful PTCA and/or restenosis. In assessing the myocardial viability, 99mTc-tetrofosmin rest myocardial SPECT was superior to 201Tl redistribution, and equal to 201Tl reinjection method. In summary, we concluded that 99mTc-tetrofosmin is a powerful tool, with which to diagnose and manage patients with coronary artery diseases.

Topics: Adult; Aged; Angioplasty, Balloon, Coronary; Coronary Disease; Female; Heart; Humans; Japan; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Predictive Value of Tests; Thallium Radioisotopes; Thrombolytic Therapy; Tomography, Emission-Computed, Single-Photon

This study performed to establish the most suitable method in one-day protocol and to evaluate clinical usefulness of 99mTc-tetrofosmin myocardial scintigraphy after dipyridamole infusion. Image quality and liver overlapping of the myocardial SPECT were evaluated in 107 patients with old myocardial infarction (42 cases), angina pectoris (53 cases) and others (12 cases). Left ventricular wall motion and coronary artery stenosis were compared to myocardial uptake score in 55 patients who received cardiac catheterization. The suitable image quality was acquired in early SPECT images using 259 MBq of 99mTc-tetrofosmin. The overlapping between inferior wall and liver uptake was able to minimize over 45 minutes interval from injection of 99mTc-tetrofosmin to data acquisition. The segments of normal wall motion had no perfusion defect of the myocardial SPECT in all cases (100% (148/148)). The segments of abnormal wall motion had decreased myocardial uptake of the myocardial SPECT (77% (24/31)). The agreement between coronary artery stenosis and decreased myocardial uptake was 96% (24/25) in right coronary artery, 87% (26/30) in left anterior descending coronary artery and 83% (19/23) in left circumflex coronary artery. These data suggests that image quality of dipyridamole loading 99mTc-tetrofosmin myocardial scintigraphy. Myocardial perfusion in the 99mTc-tetrofosmin myocardial scintigraphy is good correlation to both left ventricular wall motion and coronary artery stenosis.

Topics: Adult; Aged; Coronary Disease; Dipyridamole; Female; Heart; Humans; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Predictive Value of Tests; Tomography, Emission-Computed, Single-Photon; Vasodilator Agents

The aim of this study was to determine whether the diagnosis for coronary artery disease (CAD) with 99mTc-tetrofosmin (Tf) myocardial scintigraphy was improved by the combination of function image and perfusion image as compared with perfusion alone. Tf myocardial scintigraphy was performed with one-day protocol (stress/rest) in 51 patients (CAD: 32, Non-CAD: 19) without previous myocardial infarction. Function image was obtained by first pass method, and perfusion image by SPECT. Number of diseased vessels was 14 in right coronary artery (RCA), 18 in left anterior descending (LAD), and 12 in left circumflex (LCX). Ischemia was diagnosed by 2 different parameters 1) perfusion image alone, 2) combination of perfusion image and regional ejection fraction (rEF). On perfusion image, accuracy was 53%, 94% and 86% in RCA, LAD, and LCX respectively. On perfusion + rEF, accuracy was 76%, 90% and 84% in RCA, LAD, and LCX respectively. Specificity in RCA was 45% on perfusion, 84% on perfusion + rEF. Sensitivity in RCA was 77% on perfusion, 54% on perfusion + rEF. LAD and LCX did not change by the addition of function image. By addition of function image, accuracy and specificity of diagnosis in area of RCA improved significantly (p < 0.01). Thus the addition of function image in Tf myocardial scintigraphy would be useful to improve the diagnosis, especially in region of RCA.

Topics: Aged; Coronary Disease; Female; Heart; Humans; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Predictive Value of Tests; Sensitivity and Specificity; Tomography, Emission-Computed, Single-Photon; Ventriculography, First-Pass

There is no evidence of myocardial redistribution after tetrofosmin injection, therefore, two separate injections are needed to differentiate scar from ischemia with this tracer. The injections can be given on the same day (one-day protocol) or on separate days (two-day protocol). As part of a Phase II clinical study, a one-day protocol was compared with a two-day protocol.. Fifty-five patients with suspected coronary artery disease were studied according to the following protocol: on the first day at rest, anterior, left lateral, left anterior oblique 40 degrees and 70 degrees images were acquired 30 min after injection of 8 mCi of tetrofosmin for 5 min each. Two days later, exercise and rest images were acquired on the same day. At peak exercise, 8 mCi of tetrofosmin were injected and 30 min later the same four standard planar images were recorded as on Day one. Four hours after the exercise injection, 24 mCi of tetrofosmin were injected at rest and imaging was repeated 30 min later. Qualitative comparisons between the one- and two-day protocols were performed in 50 patients in whom all data were available following blinded evaluation of images by three readers.. All three readers reported identical results for the 26 patients. A difference in extent or location between the observers was found in seven patients, differences between normal and abnormal in eight patients, while discrepancies between ischemia and necrosis were noted in four patients. In five patients, an ischemic area was found according to the one-day protocol, but according to the data of the two-day protocol, this area was judged to be necrotic. One observer reported the opposite in one patient. These discrepancies between the reversibility of defects were restricted to the inferior wall. Comparison with 201Tl data showed no systematic pattern of variation.. Tetrofosmin can be used in a one-day protocol. However, in planar imaging, the inferior wall should be reported with caution.

Topics: Coronary Disease; Electrocardiography; Exercise Test; Female; Heart; Humans; Male; Middle Aged; Observer Variation; Organophosphorus Compounds; Organotechnetium Compounds; Radionuclide Imaging; Thallium Radioisotopes; Time Factors

Tetrofosmin is a 99mTc-labeled myocardial perfusion imaging agent that has shown encouraging results in Phase I and II clinical trials. The purpose of this study was to determine the biokinetics of this agent following administration during exercise and at rest in order to determine an optimal imaging protocol. Twenty patients with suspected coronary artery disease underwent symptom-limited treadmill exercise. Six to 8 mCi of 99mTc-tetrofosmin was injected at peak exercise and 22-24 mCi was injected 4 hr later at rest. Serial 5-min planar images were obtained in the left anterior oblique view at 5, 10, 15, 30, 60, 120 and 180 min after the radiotracer injection. Regions of interest were drawn on the serial images around the entire heart and portions of liver, lung, spleen, gallbladder and gastrointestinal tract. Average decay-corrected counts per pixel in each organ were plotted against time. In addition, heart-to-adjacent organ ratios were also determined. On stress images, the heart had the highest activity at all times, with the exception of gallbladder in the first 15 min. On rest images, the gallbladder, liver and gastrointestinal tract initially had higher activity than the heart; but the activity in these organs cleared rapidly over the subsequent 30-60 min. Heart-to-adjacent organ ratios were > 1.0 at all times in the stress images. Heart-to-organ ratios were < 1.0 in the first 15 min on the rest images for the liver and gastrointestinal tract. However, 30 min later, all ratios on the rest images were > or = 1.0. Technetium-99m-tetrofosmin images were considered to be of good to excellent quality with good myocardial delineation and adequate contrast between the heart and background. These These observations indicate that a convenient one-day tetrofosmin imaging protocol similar in duration to conventional 201Tl imaging is feasible.

Topics: Adult; Aged; Coronary Disease; Exercise Test; Female; Humans; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Radionuclide Imaging; Time Factors

A new myocardial perfusion imaging agent, 99mTc-1,2-bis[bis(2-ethoxyethyl phosphino]ethane (99mTc-PPN1011) was administered to 52 patients with various heart diseases each at rest and peak exercise on different days (Method A) and on the same day (Method B). The safety, optimal dosage, imaging procedures and the clinical usefulness were evaluated. No drug related adverse reactions were found. Image quality was considered adequate for diagnosis with as little as 185 MBq per injection, though the optimal dose range was 370-740 MBq. SPECT images were obtainable as early as 10 min, also until 3 hours after injection. There were no significant differences in clinical efficacy between method A and B, as well as sequential tests at rest and exercise. 99mTc-PPN1011 and 201T1 images in the same patient were compared segment by segment. Image quality of 99mTc-PPN1011 was significantly superior to that of 201T1. Analysis of images indicated that both agent were similar in diagnostic efficacy. It was concluded that 99mTc-PPN1011 is useful for myocardial perfusion imaging.

Topics: Adult; Aged; Coronary Circulation; Coronary Disease; Heart; Humans; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Tomography, Emission-Computed, Single-Photon

In myocardial perfusion scintigraphy (MPS), typically a stress and a rest study is performed. If the stress study is considered normal, there is no need for a subsequent rest study. The aim of the study was to determine whether nuclear medicine technologists are able to assess the necessity of a rest study.. Gated MPS using a 2-day 99mTc protocol for 121 consecutive patients were studied. Visual interpretation by 3 physicians was used as gold standard for determining the need for a rest study based on the stress images. All nuclear medicine technologists performing MPS had to review 82 training cases of stress MPS images with comments regarding the need for rest studies, and thereafter a test consisting of 20 stress MPS images. After passing this test, the nuclear medicine technologists in charge of a stress MPS study assessed whether a rest study was needed or not or if he/she was uncertain and wanted to consult a physician. After that, the physician in charge interpreted the images and decided whether a rest study was required or not.. The nuclear medicine technologists and the physicians in clinical routine agreed in 103 of the 107 cases (96%) for which the technologists felt certain regarding the need for a rest study. In the remaining 14 cases the technologists were uncertain, i.e. wanted to consult a physician. The agreement between the technologists and the physicians in clinical routine was very good, resulting in a kappa value of 0.92. There was no statistically significant difference in the evaluations made by technicians and physicians (P = 0.617).. The nuclear medicine technologists were able to accurately determine whether a rest study was necessary. There was very good agreement between nuclear medicine technologists and physicians in the assessment of the need for a rest study. If the technologists can make this decision, the effectiveness of the nuclear medicine department will improve.

Topics: Benchmarking; Clinical Competence; Coronary Disease; Decision Support Systems, Clinical; Exercise Test; Female; Follow-Up Studies; Humans; Male; Middle Aged; Myocardial Perfusion Imaging; Nuclear Medicine; Observer Variation; Organophosphorus Compounds; Organotechnetium Compounds; Practice Patterns, Physicians'; Predictive Value of Tests; Process Assessment, Health Care; Radiopharmaceuticals; Sensitivity and Specificity; Sweden

To assess associations between clinically significant depression (major depressive disorder [MDD] and minor depressive disorder [MiDD]) and endothelial function (EF), via forearm hyperemic reactivity (FHR), in patients referred for myocardial perfusion imaging. Studies have linked MDD to impaired EF, an early marker of coronary heart disease (CHD) and risk factor for cardiac events, in healthy, noncardiac patients, although no studies have assessed the MDD-EF association in patients with or at risk for CHD.. Depression was assessed, using the Primary Care Evaluation of Mental Disorders structured interview in 323 patients (n = 242 men; mean age = 59 years) with or at risk for CHD. FHR was assessed, using a dynamic nuclear imaging technique that measures the dilatory capability of the brachial artery during hyperemic challenge. The relative uptake ratio (RUR) of blood flow between hyperemic and nonhyperemic arms was used to measure FHR.. Patients with MDD and MiDD had lower RURs (mean values = 3.31 and 3.34, respectively), indicating poorer EF than patients without depression (mean = 4.27) (F = 5.19, p < .01), irrespective of CHD status. All results were adjusted for covariates including sociodemographic, medical, biochemical, and physiological variables.. Patients with clinical levels of depression had worse FHR than patients without depression, irrespective of CHD status and after adjusting for covariates. Data extend previous findings, suggesting that the link between clinical depression and worse CHD outcomes may be mediated by EF.

Topics: Adult; Aged; Aged, 80 and over; Brachial Artery; Coronary Disease; Depression; Depressive Disorder, Major; Endothelium, Vascular; Female; Forearm; Humans; Hyperemia; Male; Middle Aged; Nitric Oxide; Organophosphorus Compounds; Organotechnetium Compounds; Psychiatric Status Rating Scales; Regional Blood Flow; Risk Factors; Severity of Illness Index; Tomography, Emission-Computed, Single-Photon; Vasodilation

Shortening scan time and/or reducing radiation dose at maintained image quality are the main issues of the current research in radionuclide myocardial perfusion imaging (MPI). We aimed to validate a new iterative reconstruction (IR) algorithm for SPECT MPI allowing shortened acquisition time (HALF time) while maintaining image quality vs. standard full time acquisition (FULL time).. In this study, 50 patients, referred for evaluation of known or suspected coronary artery disease by SPECT MPI using 99mTc-Tetrofosmin, underwent 1-day adenosine stress 300 MBq/rest 900 MBq protocol with standard (stress 15 min/rest 15 min FULL time) immediately followed by short emission scan (stress 9 min/rest 7 min HALF time) on a Ventri SPECT camera (GE Healthcare). FULL time scans were processed with IR, short scans were additionally processed with a recently developed software algorithm for HALF time emission scans. All reconstructions were subsequently analyzed using commercially available software (QPS/QGS, Cedars Medical Sinai) with/without X-ray based attenuation correction (AC). Uptake values (percent of maximum) were compared by regression and Bland-Altman (BA) analysis in a 20-segment model.. HALF scans yielded a 96% readout and 100% clinical diagnosis concordance compared to FULL. Correlation for uptake in each segment (n = 1,000) was r = 0.87at stress (p < 0.001) and r = 0.89 at rest (p < 0.001) with respective BA limits of agreement of -11% to 10% and -12% to 11%. After AC similar correlation (r = 0.82, rest; r = 0.80, stress, both p < 0.001) and BA limits were found (-12% to 10%; -13% to 12%).. With the new IR algorithm, SPECT MPI can be acquired at half of the scan time without compromising image quality, resulting in an excellent agreement with FULL time scans regarding to uptake and clinical conclusion.

Topics: Adenosine; Aged; Aged, 80 and over; Algorithms; Coronary Disease; Exercise Test; Female; Humans; Image Processing, Computer-Assisted; Male; Middle Aged; Myocardial Perfusion Imaging; Organophosphorus Compounds; Organotechnetium Compounds; Prospective Studies; Radiopharmaceuticals; Time Factors; Tomography, Emission-Computed, Single-Photon; Ventricular Function, Left

The aim of this study was to determine the long-term prognostic value of early poststress lung/heart ratio (LHR) of (99m)Tc-tetrofosmin radioactivity.. We studied 276 patients (aged 62.2 + or - 8.9 years, 168 men) with stress/rest (99m)Tc-tetrofosmin myocardial gated-SPECT and coronary angiography. To evaluate myocardial ischaemia, we calculated the summed stress score, summed rest score and summed difference score indices. For the eLHR calculation, an anterior image was acquired, 4-6 min after radiotracer injection at stress (eLHR was defined as mean counts per pixel in the lung region of interest divided by the mean counts per pixel in the myocardial region of interest). Cardiovascular death and nonfatal myocardial infarction were considered as hard cardiac events, and late revascularization procedures as soft cardiac events. The Cox proportional hazards model in a stepwise method was used to determine the independent predictors for hard and soft cardiac events.. During the follow-up period hard cardiac events occurred in 28 patients (10.1%) and soft cardiac events in 32 patients (11.6%). Implying multiple Cox regression analysis, eLHR was found to be a significant independent predictor for both soft and hard cardiac events. The hazard ratio (for a 0.1 unit increase) was 4.41 (95% CI 1.52-12.73, p=0.006) for soft cardiac events and 4.22 (95% CI 2.07-8.62, p<0.001) for hard cardiac events. The other significant prognostic factors were use of beta-blockers, the summed stress score and the use of nitrates for soft events, and exercise duration and the summed stress score for hard cardiac events.. Early poststress (99m)Tc-tetrofosmin LHR has an independent and powerful value in predicting hard and soft cardiac events.

Topics: Aged; Cardiac Catheterization; Cardiac-Gated Single-Photon Emission Computer-Assisted Tomography; Cardiovascular Diseases; Comorbidity; Coronary Angiography; Coronary Disease; Exercise; Exercise Test; Female; Humans; Kaplan-Meier Estimate; Lung; Male; Middle Aged; Myocardial Infarction; Myocardial Perfusion Imaging; Myocardial Revascularization; Organophosphorus Compounds; Organotechnetium Compounds; Prognosis; Proportional Hazards Models; Radiopharmaceuticals; Single-Blind Method; Smoking

We assessed the usefulness of gated stress/rest 99mTc-tetrofosmin myocardial perfusion single photon emission computed tomography (SPECT) to predict ischemic cardiac events in Japanese patients with various estimated pretest probabilities of coronary artery disease (CAD).. Of the 4031 consecutively registered patients for a J-ACCESS (Japanese Assessment of Cardiac Events and Survival Study by Quantitative Gated SPECT) study, 1904 patients without prior cardiac events were selected. Gated stress/rest myocardial perfusion SPECT was performed and segmental perfusion scores and quantitative gated SPECT results were derived. The pretest probability for having CAD was estimated using the American College of Cardiology/American Heart Association/American College of Physicians-American Society of Internal Medicine guideline data for the management of patients with chronic stable angina, which includes age, gender, and type of chest discomfort. The patients were followed up for three years. During the three-year follow-up period, 96 developed ischemic cardiac events: 17 cardiac deaths, 8 nonfatal myocardial infarction, and 71 clinically driven revascularization. The summed stress score (SSS) was the most powerful independent predictor of all ischemic cardiac events (hazard ratio 1.077, CI 1.045-1.110). Abnormal SSS (> 3) was associated with a significantly higher cardiac event rate in patients with an intermediate to high pretest probability of CAD. Normal SSS (< or = 3) was associated with a low event rate in patients with any pretest probability of CAD.. Myocardial perfusion SPECT is useful for further risk-stratification of patients with suspected CAD. The abnormal scan result (SSS > 3) is discriminative for subsequent cardiac events only in the groups with an intermediate to high pretest probability of CAD. The salient result is that normal scan results portend a benign prognosis independent from the pretest probability of CAD.

Topics: Aged; Coronary Disease; Electrocardiography; Exercise Test; Female; Follow-Up Studies; Humans; Male; Organophosphorus Compounds; Organotechnetium Compounds; Prognosis; Radiopharmaceuticals; Stress, Physiological; Tomography, Emission-Computed, Single-Photon

To prospectively determine the accuracy of 64-section computed tomographic (CT) angiography for the depiction of coronary artery disease (CAD) that induces perfusion defects at myocardial perfusion imaging with single photon emission computed tomography (SPECT), by using myocardial perfusion imaging as the reference standard.. All patients gave written informed consent after the study details, including radiation exposure, were explained. The study protocol was approved by the local institutional review board. In patients referred for elective conventional coronary angiography, an additional 64-section CT angiography study and a myocardial perfusion imaging study (1-day adenosine stress-rest protocol) with technetium 99m-tetrofosmin SPECT were performed before conventional angiography. Coronary artery diameter narrowing of 50% or greater at CT angiography was defined as stenosis and was compared with the myocardial perfusion imaging findings. Quantitative coronary angiography served as a reference standard for CT angiography.. A total of 1093 coronary segments in 310 coronary arteries in 78 patients (mean age, 65 years +/- 9 [standard deviation]; 35 women) were analyzed. CT angiography revealed stenoses in 137 segments (13%) corresponding to 91 arteries (29%) in 46 patients (59%). SPECT revealed 14 reversible, 13 fixed, and six partially reversible defects in 31 patients (40%). Sensitivity, specificity, and negative and positive predictive values, respectively, of CT angiography in the detection of reversible myocardial perfusion imaging defects were 95%, 53%, 94%, and 58% on a per-patient basis and 95%, 75%, 96%, and 72% on a per-artery basis. Agreement between CT and conventional angiography was very good (96% and kappa = 0.92 for patient-based analysis, 93% and kappa = 0.84 for vessel-based analysis).. Sixty-four-section CT angiography can help rule out hemodynamically relevant CAD in patients with intermediate to high pretest likelihood, although an abnormal CT angiography study is a poor predictor of ischemia.

Topics: Aged; Chi-Square Distribution; Coronary Angiography; Coronary Disease; Female; Humans; Logistic Models; Male; Organophosphorus Compounds; Organotechnetium Compounds; Predictive Value of Tests; Prospective Studies; Radiopharmaceuticals; ROC Curve; Sensitivity and Specificity; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed

The coronary angiography provides information on the anatomical state of the coronary tree, while myocardial perfusion scintigraphy (MPI) facilitates the evaluation of the grade of ischaemia that a particular stenosis produces. The purpose of MPI is to detect the coronary stenosis that provokes the ischaemia and is termed the "culprit lesion". The aim of this study was to evaluate the accuracy of 1-day DypEX 99mTc-tetrofosmin tomography in the identification and localization of culprit lesion in the patients with known coronary artery disease (CAD).. Ninety-one (91) patients with known CAD were studied. In all of them significant coronary narowing (> 75% luminal stenosis) was angiographically detected. All the patients were submitted to 2 i.v. injections of 99mTc-tetrofosmin, one in a peak of pharmacologic dipyridamole stress protocol with concomitant low level bicycle exercise 50W (DypEX) and the other 3 h after exercise. Quantification of regional tetrofosmin uptake was performed using short-axis myocardial tomogram that was divided on 17 segments for each study. Reversibility score (RS) > or =3 determinated culprit lesion. Two of segments with scor 5 (index of reversibility scor--IRS) in the territory of coronary artery stenoses determinated culprit lesion.. A total of 273 vascular territories (4641 segments) were analyzed before percutaneous coronary intervention (PCI). Overall sensivity, specificit, and accuracy using RS > or =3 and IRS were 90.1%, 87.1%, 89.4%, with positive predictive value 95.8%, and 94.1%, 93.3%, 94%, with positive predictive value 98%, respectively.. RS and IRS significantly improve sensitivity, specificity, and accuracy for determination of culprit lesion in patients undergoing PCI.

Topics: Angioplasty, Balloon, Coronary; Coronary Circulation; Coronary Disease; Coronary Stenosis; Dipyridamole; Elective Surgical Procedures; Exercise Test; Female; Humans; Male; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Sensitivity and Specificity; Tomography, Emission-Computed, Single-Photon

The aim of this prospective study was to evaluate the prognostic value of exercise myocardial scintigraphy in patients who undergo incomplete revascularization with percutaneous coronary stenting. In 322 consecutive patients (mean age 61 +/- 10 years), exercise technetium-99m-tetrofosmin single-photon emission computed tomography scintigraphy was prospectively performed 4 to 6 months after an incomplete revascularization procedure. Follow-up lasted < or = 84 months (median 33). Patients with normal findings were at low risk of cardiac events compared with patients with mildly abnormal and severely abnormal findings (yearly event rate 1.5% vs 5.1% and 8.5%, respectively, p < 0.01). A significant difference was observed in hard, soft, and composite event-free survival among patients with normal, mildly abnormal, and severely abnormal findings (p < 0.01, p < 0.03, and p < 0.01, respectively). Nuclear data provided significant incremental prognostic value for cardiac events compared with the clinical, angiographic, and exercise test findings. In conclusion, in patients with incomplete revascularization procedures, exercise myocardial scintigraphy provides significant independent information concerning the subsequent risk of cardiac events, with an annualized event rate of < 2% for patients with normal scan findings. Myocardial scintigraphy is able to provide incremental prognostic information after adjusting for clinical, angiographic, and exercise variables.

Topics: Aged; Angioplasty, Balloon, Coronary; Coronary Angiography; Coronary Disease; Exercise Test; Female; Humans; Male; Middle Aged; Myocardial Infarction; Organophosphorus Compounds; Organotechnetium Compounds; Prognosis; Prospective Studies; Radiopharmaceuticals; Stents; Tomography, Emission-Computed, Single-Photon

Topics: Coronary Disease; Female; Humans; Myocardium; Organophosphorus Compounds; Organotechnetium Compounds; Perfusion; Radionuclide Imaging; Radiopharmaceuticals; Sensitivity and Specificity

Erdheim-Chester's disease is a form of histiocytic granulomatosis afflicting the skeletal system and various inner organs. Apart from incidental findings of involvement of various structures and tissues, a complete diagnostic workup to evaluate afflicted bodily parts is not known. The authors we present several specific isotope-diagnostic techniques of a case to support the identification of this rare multisystem infiltrative disease.

Topics: Bone and Bones; Coronary Disease; Erdheim-Chester Disease; Heart; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Orbital Diseases; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Technetium Tc 99m Medronate; Tomography, Emission-Computed, Single-Photon; Whole Body Imaging

The authors analyzed the efficiency of ECG-gated single-photon emission computed tomography (SPECT) with 99mTc-tetraphosmin in diagnostics of short-term myocardium stunning in CAD patients with transient ischemia. The technique was applied to 16 CAD patients. Combined evaluation of perfusion was based on the analysis of radiotracer uptake level in left ventricle (LV) myocardium. In order to evaluate myocardium function the authors measured LV systolic thickening index, using 20-segment pattern. 8 out of 16 patients (50%) displayed the phenomenon of stress-induced stunning. The volume of stunned myocardium in individual patients was 2 to 7 LV segments. In general, up to 37% (29/78) of reversible perfusion defects are subjected to short-term stunning under the condition of transient ischemia. After surgical treatment, 84% of segments with signs of stunning normalized their functioning both under stress and at rest.

Topics: Coronary Disease; Electrocardiography; Exercise Test; Female; Humans; Male; Middle Aged; Myocardial Contraction; Myocardial Stunning; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon

Ventricular arrhythmias have been shown to originate in the myocardial peri-infarct region due to irregular heterotopic conduction. Hypoperfused but viable myocardium is often localised in those areas and may be involved in the pathogenesis of arrhythmias. We tested the hypothesis that these myocardial perfusion/metabolism mismatches (MM) are significantly associated with ventricular arrhythmias in the chronic post infarction state.. 47 post infarction patients were included in the study. 33 suffered from ventricular arrhythmia whereas 14 did not. All patients underwent (99m)Tc tetrofosmin SPECT and (18)F-FDG PET. A region-of-interest(ROI)-analysis was used to assess viable myocardium based on predefined MM-criteria. Univariate analyses as well as a logistic regression model for the multivariate analysis were carried out.. 94% of the arrhythmic patients displayed at least one MM-segment as compared to 64% of the non-arrhythmic patients. MM-segments and arrhythmia showed a statistically significant relation (p = 0.018). The logistic regression model predicted the occurrence or absence of arrhythmia in 85% of all cases. Multivariate analysis gave consistent results, after adjusting for symptomatic chronic heart failure (CHF), aneurysms and age.. Our results support the hypothesis that hypoperfused but viable myocardium represents an arrhythmogenic substrate and is a relevant risk factor for developing ventricular arrhythmias following myocardial infarction. Therefore, the detection of MM-segments allows the identification of patients with a higher risk for future cardiac events.

Topics: Coronary Disease; Female; Fluorodeoxyglucose F18; Humans; Male; Middle Aged; Myocardial Infarction; Myocardial Reperfusion; Myocardium; Organophosphorus Compounds; Organotechnetium Compounds; Positron-Emission Tomography; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon; Ventricular Dysfunction, Left; Ventricular Fibrillation

We studied the incremental value of stress technetium-99m tetrofosmin imaging for predicting all-cause mortality in 503 women (aged 58 +/- 12 years) with known or suspected coronary artery disease. The annual mortality rate was 1.4% with normal perfusion and 4% with abnormal perfusion (p <0.01) during a follow-up of 3.5 +/- 1.2 years. In an incremental multivariate analysis model, clinical predictors of mortality were age, diabetes mellitus, smoking, and a lower systolic blood pressure during stress. An abnormal scan was incremental to clinical data in predicting mortality.

Topics: Aged; Chi-Square Distribution; Coronary Disease; Dobutamine; Exercise Test; Female; Humans; Middle Aged; Mortality; Organophosphorus Compounds; Organotechnetium Compounds; Predictive Value of Tests; Proportional Hazards Models; Radionuclide Imaging; Radiopharmaceuticals; Risk Factors

To assess whether quantification of myocardial systolic velocities by pulsed wave tissue Doppler imaging can differentiate between stunned, hibernating, and scarred myocardium.. Observational study.. Tertiary referral centre.. 70 patients with reduced left ventricular function caused by chronic coronary artery disease.. Pulsed wave tissue Doppler imaging was done close to the mitral annulus at rest and during low dose dobutamine; systolic ejection velocity (Vs) and the difference in Vs between low dose dobutamine and the resting value (DeltaVs) were assessed using a six segment model. Assessment of perfusion (with Tc-99m-tetrofosmin SPECT) and glucose utilisation (by 18F-fluorodeoxyglucose SPECT) was used to classify dysfunctional regions (by resting cross sectional echocardiography) as stunned, hibernating, or scarred.. 253 of 420 regions (60%) were dysfunctional. Of these, 132 (52%) were classified as stunned, 25 (10%) as hibernating, and 96 (38%) as scarred. At rest, Vs in stunned, hibernating, and scar tissue was, respectively, 6.3 (1.8), 6.6 (2.2), and 5.5 (1.5) cm/s (p = 0.001 by ANOVA). There was a gradual decline in Vs during low dose dobutamine infusion between stunned, hibernating, and scar tissue (8.3 (2.6) v 7.8 (1.5) v 6.8 (1.9) cm/s, p < 0.001 by ANOVA). DeltaVs was higher in stunned (2.1 (1.9) cm/s) than in hibernating (1.2 (1.4) cm/s, p < 0.05) or scarred regions (1.3 (1.2) cm/s, p = 0.001).. Quantitative tissue Doppler imaging showed a gradual reduction in regional velocities between stunned, hibernating, and scarred myocardium. Dobutamine induced contractile reserve was higher in stunned regions than in hibernating and scarred myocardium, reflecting different severities of myocardial damage.

Topics: Cicatrix; Coronary Disease; Diagnosis, Differential; Echocardiography; Female; Fluorodeoxyglucose F18; Humans; Male; Middle Aged; Myocardial Contraction; Myocardial Infarction; Myocardial Stunning; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Stroke Volume; Tomography, Emission-Computed, Single-Photon; Ventricular Dysfunction, Left

Clinical decisions regarding diagnosis and effective treatment of coronary artery disease frequently require integration of information from various imaging modalities, which are acquired, processed, and read at different physical locations and times. We have developed methods to integrate the information in 2 cardiac imaging studies, perfusion SPECT and coronary angiography. Three-dimensional (3D) models of the coronary artery tree created from biplane angiograms were automatically aligned with 3D models of the left ventricular epicardial surface created from perfusion SPECT. Myocardial mass at risk was used as a unique measure to validate the accuracy of the unification.. Thirty patients were injected with the perfusion agent (99m)Tc-tetrosfosmin during balloon occlusion while undergoing percutaneous transluminal coronary angioplasty for single-vessel coronary artery disease. Thus, a single, severe perfusion defect was induced by a single coronary artery occlusion of known severity and placement. The accuracy of the unification was measured by computing the overlap between physiologic area at risk, determined using SPECT perfusion quantification techniques only, and anatomic area at risk, determined using coronary artery anatomy aligned with the epicardial surface of the left ventricle.. The unification resulted in an 80% overlap of areas at risk, and an overlap of 84% of normal areas, for all coronary artery distributions. The mass at risk measured based on the unified anatomic information correlated with the physiologically based mass at risk as y = 0.92x + 10.3 g; r = 0.76, SEE = 10.4 g.. A unification algorithm for automatically registering 3D models of the epicardial surface from perfusion SPECT and 3D coronary artery trees from coronary angiography has been presented and validated in 30 patient studies.

Topics: Algorithms; Angioplasty, Balloon, Coronary; Coronary Angiography; Coronary Disease; Female; Heart; Humans; Image Processing, Computer-Assisted; Imaging, Three-Dimensional; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon

To determine if there was any difference in the ability of physicians to predict prognosis with technetium 99m ((99m)Tc) sestamibi or (99m)Tc tetrofosmin in a large consecutive series of patients at high risk for coronary artery disease who underwent coronary angiography.. This study included 1,818 consecutive patients who underwent a rest and stress single photon emission computed tomographic (SPECT) examination with either (99m)Tc sestamibi (n = 915) or (99m)Tc tetrofosmin (n = 903) and cardiac catheterization. A clinical index was generated and consisted of clinical and demographic variables. Information concerning death, cardiovascular death, and nonfatal myocardial infarction was 93% complete during the 1.5-year study period. Cox proportional hazards models were generated to help determine the incremental contribution of SPECT sum stress score (SSS) and the imaging agent variable to the clinical index.. Exercise was used for stress testing in 473 (52%) patients who received (99m)Tc tetrofosmin and 519 (57%) patients who received (99m)Tc sestamibi (P =.06). Cardiovascular death or myocardial infarction occurred in 130 patients. Resulting P values for chi(2) differences between models for the end points of (a) death from any cause, (b) cardiovascular death, and (c) cardiovascular death or myocardial infarction showed that SSS combined with clinical index was a significantly better model than adjusting for only baseline characteristics (P =.001, P <.001, P =.004, respectively). Incremental addition of either (99m)Tc tetrofosmin or (99m)Tc sestamibi to those models containing SSS and the clinical index did not show further significant improvement (P =.87, P =.88, and P =.26 for death from any cause, cardiovascular death, and cardiovascular death or myocardial infarction, respectively).. This study shows that the type of clinically available (99m)Tc-labeled myocardial perfusion agents should not affect interpretation of results for risk stratification and prognostic assessment.

Topics: Adenosine; Aged; Cardiovascular Diseases; Coronary Circulation; Coronary Disease; Dipyridamole; Dobutamine; Exercise Test; Female; Humans; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Prognosis; Proportional Hazards Models; Risk Assessment; Technetium Tc 99m Sestamibi; Tomography, Emission-Computed, Single-Photon

The aim of the study was to determine optimal thresholds for semiquantitative perfusion parameters and to evaluate the influence of different segmentation models in detecting malperfused regions.. In 6 healthy subjects and 13 patients with coronary artery disease, contrast-enhanced first-pass perfusion imaging was performed using a SR-TrueFISP-sequence. Thresholds for semiquantitative parameters were established, and different segmentation models of the left ventricular myocardium were tested. The standard of reference for patient studies was single photon emission computed tomography.. Optimal thresholds were determined in healthy subjects for the perfusion parameters upslope, AUC, and peak SI of mv-0.5*std, mv-1.5*std, and mv-1.0*std, respectively. Using the optimal threshold for each parameter/segmentation combination sensitivities and specificities of stress studies were between 66% and 93% and 77% and 92%, respectively. Subdivision of radial segments into subendo/subepicardial segments increased sensitivities for perfusion deficits.. Subdivision of radial myocardial segments is essential in analysis of magnetic resonance first-pass perfusion series. Semiquantitative perfusion parameters possess different sensitivities for the detection of perfusion deficits.

Topics: Adult; Aged; Contrast Media; Coronary Circulation; Coronary Disease; Female; Gadolinium DTPA; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Sensitivity and Specificity; Tomography, Emission-Computed, Single-Photon

It has been shown that exercise may lead to the myocardial stunning with reduction of LVEF, persisting for some time despite recovery of perfusion. The aim of this study was to check whether the post-stress decrease of LVEF lasts as long as 3 h after exercise.. The study was performed in 46 patients with CAD and in 10 normals (NMS). All patients underwent myocardial gSPECT after (99m)Tc-tetrofosmin injection at rest and during stress with 2-day protocol. SPECT was started 1h after tracer injection at rest (R) and twice: 1h (S1) and 3hs (S3) after injection at stress. LVEF was calculated by the method of Germano et al.. All LVEF values were significantly lower in CAD patients than in the control group. In NMS mean LVEF was at rest similar to those obtained 1 h and 3 h after stress injection (59.0 +/- 4.1, 60.0 +/- 5.9, 58.0 +/- 4.6, respectively; p >0.05). A post-exercise decrease of LVEF was observed in 2 normal patients both at S1 and at S3. In CAD group LVEF values were lower at S1 than at R (50.8 +/- 13.6 versus 49.3 +/- 12.8; p <0.05) and at S3 were lower than at S1 (49.3 +/- 12.8 versus 46.0 +/- 12.2;p <0.001). A significant decrease of LVEF was found in 18/46 patients 1 h post stress and in 36/46 3 h post stress. In patients with reversible perfusion decrease, a significant correlation was found between post-exercise deterioration of perfusion and post-exercise LVEF reduction both at S1 (r = 0.744; p <0.02) and at S3 (r = 0.734; p <0.02). Stress induced decrease in LVEF correlated also with severity of perfusion abnormalities.. In the majority of patients with CAD physical stress applied for diagnostic purposes results in an impairment of the LV function. A decrease of the LVEF is observed 1 h after exercise, but it increases in frequency and grows stronger during the next 2 h. The post-stress LVEF reduction is related to the severity of perfusion abnormalities. Patients with CAD who underwent diagnostic stress test should remain under observation during several hours after termination of exercise.

Topics: Adult; Aged; Coronary Disease; Exercise Test; Female; Heart; Humans; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Radioisotopes; Time Factors; Tomography, Emission-Computed, Single-Photon; Ventricular Dysfunction, Left; Ventricular Function, Left

Myocardial perfusion single photon emission computed tomography (SPECT) artefacts introduced as a result of patient motion are known to produce artefacts that mimic the appearances of coronary artery disease. The advent of 99mTc based radiopharmaceuticals permits greater flexibility in patient scheduling, but variable physical demands of protocols may be associated with variations in the likelihood of patient motion.. A prospective cross-sectional study of 177 myocardial perfusion SPECT patients using 99mTc tetrofosmin was used to compare the incidence of visually detectable motion for three protocol variations. The rotating cinematic display and sinograms of the datasets were visually assessed by two experienced technologist observers blinded to the second observer's responses and the clinical outcome.. Among the 354 individual studies analysed, 43.8% contained visually detectable motion. 36.2% of rest studies demonstrated visually detectable motion compared to 51.4% for stress (P<0.05). Fifty per cent of 1 day rest/stress studies demonstrated motion, 39.3% of 2 day rest/stress studies demonstrated motion, and 46.8% of 2 day stress/rest studies demonstrated motion.. One day 99mTc based myocardial perfusion SPECT studies are 1.3 times more likely to contain motion than the 2 day rest/stress protocol. The 2 day stress/rest protocol is 1.2 times more likely to contain motion than the 2 day rest/stress. The stress study is 1.4 times more likely to contain motion than the rest study while the stress study performed first in the sequence is 1.4 times more likely to contain motion than the stress study performed second. The 2 day rest/stress protocol is the preferred protocol to minimize patient motion.

Topics: Adult; Aged; Aged, 80 and over; Artifacts; Coronary Circulation; Coronary Disease; Cross-Sectional Studies; Exercise Test; Female; Humans; Middle Aged; Motion; Myocardium; Organophosphorus Compounds; Organotechnetium Compounds; Perfusion; Prospective Studies; Rest; Risk; Time Factors; Tomography, Emission-Computed, Single-Photon; Treatment Outcome

Technetium-99m (Tc-99m) tetrofosmin single-photon emission computed tomography (SPECT) is a useful alternative to thallium-201 scintigraphy for the assessment of myocardial perfusion. This study assessed the incremental value of exercise Tc-99m tetrofosmin SPECT for the prediction of cardiac events in patients with known or suspected coronary artery disease. Exercise Tc-99m tetrofosmin SPECT imaging was performed in 655 consecutive patients. Follow-up was successful in 648 patients (98.9%). Ten patients underwent early coronary revascularization and were excluded. End points were cardiac death, nonfatal infarction, and late (>60 days) coronary revascularization. An abnormal study was defined as the presence of fixed and/or reversible perfusion defects. A summed stress score (SSS) was derived to estimate the extent and severity of perfusion defects. An abnormal scan was detected in 344 patients (54%). During a mean follow-up period of 4 +/- 1.3 years, 56 patients (9%) died (22 cardiac deaths). Nonfatal myocardial infarction occurred in 19 patients (3%), and 89 patients (14%) underwent late coronary revascularization. An abnormal scan was an independent predictor of cardiac death (hazard ratio 3.5, confidence intervals [CI] 1.1 to 12.2) and provided incremental information over clinical and exercise test data (log-likelihood -133 to -125, p <0.05). The SSS provided incremental prognostic information over clinical data as well (log-likelihood -133 to -127, p <0.05) (hazard ratio 1.23, CI 1.10 to 1.38). An abnormal scan (hazard ratio 3.3, CI 1.1 to 12.2)) and the SSS (hazard ratio 1.25, CI 1.07 to 1.45)) were powerful independent predictors of the combined end point of any cardiac event. Thus, exercise Tc-99m tetrofosmin myocardial perfusion SPECT provides information incremental to clinical data for the prediction of cardiac events in patients with known or suspected coronary artery disease.

Topics: Aged; Analysis of Variance; Coronary Disease; Exercise Test; Female; Follow-Up Studies; Humans; Male; Middle Aged; Myocardial Revascularization; Organophosphorus Compounds; Organotechnetium Compounds; Predictive Value of Tests; Prognosis; Proportional Hazards Models; Radiopharmaceuticals; Risk Factors; Severity of Illness Index; Survival Analysis; Tomography, Emission-Computed, Single-Photon

Topics: Adult; Aged; Bias; Blood Flow Velocity; Cardiac Volume; Coronary Circulation; Coronary Disease; Factor Analysis, Statistical; Female; Fluorodeoxyglucose F18; Humans; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Oxygen Radioisotopes; Radiopharmaceuticals; Severity of Illness Index; Stroke Volume; Tomography, Emission-Computed; Ventricular Function, Left

Evaluation of possible cardiac complications is essential for safe and effective respiratory rehabilitation of patients with chronic respiratory diseases (CRDs). The aim of this study is to clarify the pathophysiology of electrocardiographic (ECG) changes during exercise and the prevalence of coronary artery disease (CAD) in CRD patients without a history of myocardial ischemia.. We studied 42 CRD patients with exercise-induced ST depression by cardiopulmonary exercise testing (CPET). They were selected from 249 consecutive CRD patients without any history of CAD who underwent CPET between January 1999 and December 2001. Thirty-three patients without respiratory diseases who had positive ST depression during exercise were selected as disease control subjects. Exercise myocardial SPECT was performed to evaluate myocardial ischemia and right ventricular (RV) overload as measured by increased RV uptake.. Among the 249 consecutive CRD patients without any history of CAD, positive ST depression during exercise was found in 42 (16.9%). Only 2 of the 42 patients (4.8%) had an ST depression other than in II, III, or aVF leads. The incidence of myocardial ischemia by perfusion SPECT was significantly lower in CRD patients (26.2%) than in disease control subjects (78.8%). The most common finding in the CRD patients during exercise was RV overload but without ischemia (26 cases; 61.9%). Ischemia was found in 11 patients (26.2%), with 10 of these patients also having RV overload. Neither ischemia nor RV overload was found in 5 patients (11.9%); these patients were eventually diagnosed as normal.. The incidence of myocardial ischemia as determined by perfusion SPECT was low in CRD patients with positive exercise-induced ECG changes. On the other hand, RV overload was observed in most such cases. Cardiac perfusion SPECT is a useful technique to evaluate cardiac ischemia and RV overload simultaneously. CPET with 12-lead ECG monitoring is necessary in CRD patients before respiratory rehabilitation. Further examination for ischemia should be done if positive ST depression is found.

Topics: Aged; Coronary Circulation; Coronary Disease; Electrocardiography; Exercise Test; Female; Humans; Male; Organophosphorus Compounds; Organotechnetium Compounds; Pulmonary Disease, Chronic Obstructive; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon; Ventricular Dysfunction, Right

The value of stress harmonic power Doppler imaging (HPDI) for the evaluation of myocardial perfusion has never been assessed in patients after acute coronary syndrome (ACS).. To evaluate the agreement between stress HPDI and single photon emission computed tomography (SPECT) imaging for the assessment of myocardial perfusion after unstable angina or myocardial infarction.. Thirty patients with a recent ACS underwent HPDI and SPECT. Images were obtained at rest and during dipyridamole infusion (0.56 mg/kg over 4 min). Apical two- and four-chamber views were used for HPDI. Ten myocardial segments were scored for myocardial perfusion. Semiquantitative and quantitative video intensity analysis with background subtraction were performed.. Concordance by patients between quantitative HPDI and SPECT was 76% (kappa=0.40, Phi=0.46) for normal versus abnormal perfusion. When semiquantitative analysis was used, concordance was 72% (kappa=0.42, Phi=0.46). Agreement between methods was best in the left anterior descending artery territory for quantitative (80%) (kappa=0.60, Phi=0.60) and semiquantitative analysis (78%) (kappa=0.51, Phi=0.60) for normal versus abnormal perfusion. Discrepancies between HPDI and SPECT were most important in the circumflex territory, with a concordance of 59% (kappa=0.22) for identification of normal perfusion versus irreversible and reversible defects.. These results suggest that HPDI can detect myocardial perfusion at rest and during pharmacological stress in patients after a recent ACS. Given the suboptimal agreement with SPECT, further advances are required before the routine use of contrast echocardiography is possible for the assessment of myocardial perfusion.

Topics: Acute Disease; Aged; Aged, 80 and over; Contrast Media; Coronary Circulation; Coronary Disease; Echocardiography; Female; Humans; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Polysaccharides; Radiopharmaceuticals; Research Design; Syndrome; Tomography, Emission-Computed, Single-Photon

A 69-year-old woman presented with dyspnea on exertion. Echocardiography showed dilatation and diffuse hypokinesis of the left ventricle. 99mTc-tetrofosmin myocardial SPECT showed moderately reduced uptake in the anteroseptal wall and the inferior wall on the rest images, but was improved on the ATP loading images. 123I-BMIPP myocardial SPECT showed severely reduced uptake in the anterior wall and the inferior wall. These SPECT findings suggested ischemic heart disease rather than dilated cardiomyopathy. Coronary angiography showed no organic stenosis, but diffuse coronary ectasia was noted in three vessels. Intravascular ultrasound revealed remarkable coronary ectasia, with a maximal diameter of 8.2 mm. Coronary flow velocity as measured by Doppler blood flow guide wire was remarkably reduced. Coronary spasms were not provocated by ergonovine loading test. These findings suggested that microvascular thrombi and disturbance of dilatation caused myocardial ischemia in this patient. We treated the patient with ticlopidine and nicorandil. Following treatment left ventricle wall motion, 99mTc-tetrofosmin and 123I-BMIPP myocardial SPECT findings were improved.

Topics: Aged; Coronary Disease; Coronary Vessels; Dilatation, Pathologic; Fatty Acids; Female; Heart; Humans; Iodine Radioisotopes; Iodobenzenes; Microcirculation; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon

In nuclear perfusion imaging of the myocardium, a false-negative test result in patients with balanced three-vessel disease is a well-known pitfall. This paper describes a patient with typical chest pain and a negative myocardial perfusion scintigram. At coronary angiography, intermediate stenoses in the left anterior descending (LAD), left circumflex (LCX), and right coronary (RCA) arteries were present. Fractional flow reserve, measured by coronary pressure measurement, was 0.54, 0.56, and 0.66 respectively for the LAD, LCX, and RCA, unequivocally demonstrating the presence of balanced three-vessel disease. The patient underwent successful bypass surgery and remained event-free thereafter.

Topics: Adult; Chest Pain; Coronary Artery Bypass; Coronary Circulation; Coronary Disease; Diagnosis, Differential; False Negative Reactions; Humans; Male; Organophosphorus Compounds; Organotechnetium Compounds; Predictive Value of Tests; Radionuclide Imaging

Topics: Breast Neoplasms; Coronary Disease; Echocardiography; Electrocardiography; Female; Humans; Image Interpretation, Computer-Assisted; Middle Aged; Neoplasm Staging; Organophosphorus Compounds; Organotechnetium Compounds; Radionuclide Imaging; Radiopharmaceuticals; Radiotherapy

To evaluate whether the post-stress and rest functional parameters, measured by Gated-SPECT, have incremental prognostic value compared with perfusion parameters in predicting cardiac events (CE), in a population of CAD patients with dilated LV.. A total of 670 consecutive patients (mean age: 62; range 29-86 yrs.) underwent conventional diagnostic 2-day gated-SPECT with 99mTc-tetrofosmin (55% exercise stress test, 45% dip stress): 605 patients (mean age: 62 yrs., range: 34-86 yrs.) had known or suspected CAD, whereas 65 (mean age: 60 yrs, range: 29-80 yrs) had low pre-test likelihood of CAD (<10%), a normal post-stress perfusion scan and no hypertension. Fifty-three percent of CAD patients had a history of MI. Perfusion was analyzed on ungated images using 20 segments scored on a 5-point scale (0=normal, 4=no uptake), while wall thickening was assessed visually on stress/rest end-systolic images using a 4-point score (0=normal, 3=absence of WT). LVEF and volumes were calculated using an automatic algorithm. Post-stress and rest ratio were determined for both end-diastolic and end-systolic volume, while the post-stress LVEF change (d-LVEF) was calculated according to the following formula: (Stress LVEF-rest LVEF)/rest LVEF*100.. By using a cutoff value of 126 ml for rest-EDV, and of 68 ml for rest-ESV we found a LV dilation in 129/605 patients (21%). These thresholds were the mean values plus two standard deviations obtained in the control group. 111/129 (86%) were followed up for a mean period of 147.0 months. 83 of 111 (75%) patients had a history of MI and forty three (39%) had undergone surgical revascularizations. During the follow-up, 21 events (5 cardiac deaths, 3 nonfatal MI, 13 late revascularizations) occurred. All post-stress perfusion and functional parameters were more compromised in patients with CE compared with patients without events, but only rest EDV, rest ESV, post-stress ESV and WT-SSS reached statistical significance (201 ml vs 176 ml; p=0.035; 137 ml vs 113 ml; p=0.047; 143 ml vs 117 ml; p=0.034, 19 vs 15; p=0.048, respectively). Multivariate Cox proportional analysis demonstrated that stress ESV added significantly prognostic information over WT-SSS in predicting CE (p=0.046).. Stress ESV has incremental prognostic value compared with wall thickening in predicting CE, in CAD patients with dilated cardiomyopathy. Perfusion parameters failed to show prognostic information in these patients.

Topics: Adult; Aged; Aged, 80 and over; Analysis of Variance; Coronary Angiography; Coronary Disease; Exercise Test; Female; Humans; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Prognosis; Proportional Hazards Models; Radiopharmaceuticals; Rest; Tomography, Emission-Computed, Single-Photon; Ventricular Dysfunction, Left

Uncertainty remains as to the most appropriate preoperative screening investigation to evaluate patient cardiac risk in prospective renal transplant recipients. We prospectively compared tachycardic-stress (exercise/pacing) scintigraphy with coronary angiography for the detection of significant coronary artery disease in this group. With a negative predictive value of 92%, tachycardic-stress scintigraphy may reduce the need for unnecessary coronary angiography in these patients.

Topics: Coronary Angiography; Coronary Disease; Exercise Test; Female; Humans; Kidney Failure, Chronic; Kidney Transplantation; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Predictive Value of Tests; Prospective Studies; Radionuclide Imaging; Risk Assessment; Sensitivity and Specificity

The aim of this study was to assess the value of the cavity-to-myocardium count ratio (C/M ratio) calculated in exercise and resting technetium-99m (Tc-99m) tetrofosmin single photon emission computed tomography (SPECT) images to identify patients with depressed exercise and resting left ventricular ejection fraction (LVEF). We studied 60 patients with recent coronary artery diseases (CAD) undergoing first-pass ventriculography to calculate LVEF and myocardial perfusion SPECT imaging to calculate left ventricular C/M ratios. The group A of 30 CAD patients with higher LVEF (> or = 40%) had significant higher C/M ratios than the group B of 30 CAD patients with abnormal LVEF (< 40%) during exercise and rest. However, C/M ratios between exercise and rest did not differ significantly in the both groups A and B. There is significant correlation between exercise/rest LVEF and exercise/rest C/M ratios. Tc-99m tetrofosmin C/M ratios calculated SPECT perfusion images are useful parameters in identifying patients with depressed LVEF in CAD patients.

Topics: Adult; Aged; Coronary Disease; Exercise Test; Female; Humans; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon; Ventricular Function, Left; Ventriculography, First-Pass

Kawasaki disease (KD) is an acute vasculitis syndrome of unknown etiology that mainly affects the coronary arteries. The purpose of this study was to assess the agreement between dipyridamole stress technetium-99m tetrofosmin (Tc-TF) myocardial perfusion single photon emission computed tomography (SPECT) and coronary angiography in these patients. Twenty-nine children with KD were included in this study. All of the 29 children also received dipyridamole stress Tc-TF myocardial perfusion SPECT within 1 month of their coronary angiographic studies. The results showed that (1) 89.7% of children had negative coronary angiographic findings without significant coronary stenoses, and 10.3% of children had positive coronary angiographic findings with significant coronary stenosis; (2) 44.8% of children had negative Tc-TF myocardial perfusion SPECT findings without abnormal myocardial perfusion, and 55.2% of children had positive Tc-TF myocardial perfusion SPECT findings with abnormal myocardial perfusion; (3) 44.8% of children had both normal coronary angiographic and Tc-TF myocardial perfusion SPECT findings, and 10.3% of children had both abnormal coronary angiographic and Tc-TF myocardial perfusion SPECT findings; and (4) There was no significant agreement between coronary angiographic and Tc-TF myocardial perfusion SPECT findings. We concluded that poor agreement exists between coronary angiographic and Tc-TF myocardial perfusion SPECT findings with coronary stenoses and abnormal myocardial perfusion in children with KD.

Topics: Adolescent; Child; Child, Preschool; Coronary Angiography; Coronary Disease; Dipyridamole; Female; Humans; Infant; Male; Mucocutaneous Lymph Node Syndrome; Observer Variation; Organophosphorus Compounds; Organotechnetium Compounds; Prospective Studies; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon

The aim of this study was to assess the value of the left ventricular cavity-to-myocardium count ratio (C/M ratio) of technetium-99m (Tc-99m) tetrofosmin single photon emission computed tomography (SPECT) to identify abnormal left ventricular ejection fraction (LVEF) responses after exercise in patients with coronary artery diseases (CAD). We studied 50 patients with recent CAD undergoing rest and exercise first-pass ventriculography to calculate LVEF and rest and exercise Tc-99m tetrofosmin myocardial perfusion SPECT to calculate left ventricular C/M ratios. Group A, consisting of 25 CAD patients with normal responses (increased LVEF> or =5% after exercise), had significantly higher rest and exercise C/M ratios than those of the group B, consisting of 25 CAD patients with abnormal responses (increased LVEF <5% after exercise) after exercise. However, the C/M ratios between exercise and rest did not differ significantly between groups A and B. In addition, there was significant correlation between LVEF and C/M ratios in all of the patients. C/M ratios of Tc-99m tetrofosmin myocardial perfusion SPECT are useful parameters for identifying patients with abnormal LVEF responses among patients with CAD.

Topics: Adult; Aged; Coronary Disease; Exercise Test; Female; Heart; Heart Ventricles; Humans; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Prognosis; Radiopharmaceuticals; Stroke Volume; Tomography, Emission-Computed, Single-Photon; Ventricular Function, Left

Increased lung uptake of thallium-201 (Tl-201) and technetium-99m (Tc-99m) MIBI in myocardial perfusion imaging is a reliable marker of left ventricular dysfunction. The goal of our study was to establish whether the lung-to-heart (L/H) uptake ratio with a newer cardiac imaging agent, Tc-99m tetrofosmin, can also provide valuable information about left ventricular function. We studied 60 patients with recent coronary artery diseases (CAD) undergoing first-pass radionuclide ventriculography to calculate left ventricular ejection fraction (LVEF) and myocardial perfusion imaging to calculate the L/H ratio. Group A consisting of 30 CAD patients with higher LVEF (> or =40%) had a significantly lower L/H ratio than group B consisting of 30 CAD patients with abnormal LVEF (<40%) during exercise and rest. In groups A and B, the exercise and rest L/H ratios did not differ significantly. However, a statistically significant inverse correlation was found between the L/H ratio and LVEF during exercise and rest among the 60 patients. L/H ratios, measured by 99mTc-tetrofosmin imaging, provide clinically useful information with which to predict left ventricular dysfunction in CAD patients.

Topics: Adult; Aged; Coronary Disease; Exercise; Exercise Test; Female; Humans; Lung; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Rest; Stroke Volume; Technetium Tc 99m Sestamibi; Tomography, Emission-Computed, Single-Photon; Ventricular Dysfunction, Left; Ventricular Function, Left; Ventriculography, First-Pass

The incremental prognostic value of dual-isotope myocardial perfusion scintigraphy using technetium-99m tetrofosmin for the stress images was evaluated in 597 consecutive patients with known or suspected coronary artery disease. We used semi-quantitative visual analysis with a five-point scoring system and calculated the summed stress score, the summed rest score and the summed difference score. During the 2-year follow-up period, 46 "hard" cardiac events occurred: 16 cardiac deaths and 30 non-fatal myocardial infarctions. Kaplan-Meier analysis demonstrated a favourable prognosis for patients with normal scans as compared with patients with mildly to moderately or severely abnormal scans ( P<0.001). Multivariate analysis demonstrated incremental prognostic information for nuclear variables. A very low rate of hard cardiac events was observed in patients with a low summed stress score. Thus, nuclear variables provide incremental prognostic information and could be used to guide the management process with respect to whether or not to proceed with further invasive procedures.

Topics: Adult; Aged; Aged, 80 and over; Coronary Disease; Electrocardiography; Exercise Test; Female; Heart; Humans; Male; Middle Aged; Multivariate Analysis; Organophosphorus Compounds; Organotechnetium Compounds; Prognosis; Proportional Hazards Models; Radiopharmaceuticals; Survival Analysis; Thallium Radioisotopes; Tomography, Emission-Computed, Single-Photon

A 49-year-old man was hospitalized for precordial pain. The result of a resting electrocardiograph was normal. Tc-99m tetrofosmin stress myocardial imaging was performed and uptake in the area of the left scapula was seen. The abnormality was caused by a subcutaneous tumor. Histologic examination revealed a hibernoma.

Topics: Coronary Disease; Heart; Humans; Lipoma; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Radionuclide Imaging; Radiopharmaceuticals; Shoulder; Soft Tissue Neoplasms

Administration of dipyridamole produces angina and ST depression in 20%-30% and 6%-34% of patients, respectively. This study aimed to evaluate the clinical implications of the presentation of angina and/or ST depression during the administration of dipyridamole in the study of coronary heart disease by myocardial perfusion SPECT (MPS).. The study population is constituted by 593 consecutive patients without left branch block or ventricular pacemaker rhythm who were referred to our service to undergo MPS with dipyridamole. A SPECT was performed after the administration of 99mTc-tetrosfosmine and drug stimulation with dipyridamole (0.142 mg/kg/min for 4 minutes). A coronariography was performed in 338 patients (57%). The frequency of clinical and electrical positivity and their relationship with the MPS and the coronariography were studied.. The rate of angina and ST depression was 32% (n = 190) and 10% (n = 58), respectively. Myocardial perfusion defects were observed in 465 patients (78%), and signs of scintigraphic ischemia in 311 (52%). The patients with ST depression presented a higher frequency of perfusion defects (93% vs 76%, p = 0.0012) and scintigraphic ischemia (89% vs 49%, p < 0.0001). In addition, perfusion defects in more than one territory were observed in these patients in a higher percentage (53% vs 34%, p = 0.0036). Among the patients who underwent cardiac catheterization, those who had a ST depression had a greater extension of coronary heart disease (1.8 +/- 1.2 vs 1.3 +/- 1.0 diseased vessels, respectively. p = 0.0100) and a higher frequency of multivessel disease (61% vs 43%, p = 0.0380). Those patients who had clinical positivity showed a scintigraphic ischemia more frequently (66% vs 47%, p < 0.0001), however no statistically significant differences were observed between the presence of patients with perfusion defects or in the extension of these defects as well as in the number of diseased vessels in the coronariographic study.. During the administration of dipyridamole, the ST depression is associated with more frequent scintigraphic ischemia, larger extension of perfusion defects and more diseased vessels. The appearance of angina is associated with scintigraphic ischemia, but it is not necessarily associated with the extension of perfusion defects or greater number of diseased vessels.

Topics: Angina Pectoris; Convalescence; Coronary Angiography; Coronary Circulation; Coronary Disease; Dipyridamole; Electrocardiography; False Negative Reactions; False Positive Reactions; Heart; Humans; Myocardial Infarction; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Predictive Value of Tests; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon; Vasodilator Agents

We prospectively compared dipyridamole single-photon emission computed tomography (SPECT) imaging with Tc-99m sestamibi and Tc-99m tetrofosmin for the detection of reversible perfusion defects in patients with mild-to-moderate coronary artery disease.. Tc-99m tetrofosmin has a lower first-pass myocardial extraction fraction compared to Tc-99m sestamibi and thus could underestimate mild perfusion defects.. Eighty-one patients with 50% to 90% stenosis in one or two major epicardial vessels without previous myocardial infarction, and seven with <5% probability of coronary artery disease underwent dipyridamole SPECT imaging with both agents. The SPECT data were analyzed quantitatively.. Tc-99m sestamibi detected reversible perfusion defects in a greater number of segments (total 363 and 285, p < 0.001, and mean +/- SD, 2.2 +/- 3.0 and 1.8 +/- 2.5 per patient, p = 0.008, for Tc-99m sestamibi and Tc-99m tetrofosmin, respectively), demonstrated a larger extent of perfusion defect (mean +/- SD, 15.8% +/- 12.3% and 12.0% +/- 11.4%, p < 0.03, for Tc-99m sestamibi and Tc-99m tetrofosmin, respectively) and more often correctly identified patients with disease in more than one coronary artery (p = 0.02). There was better defect contrast with Tc-99m sestamibi (defect/normal wall count ratios were 0.60 +/- 0.15 vs. 0.73 +/- 0.14 for Tc-99m sestamibi and Tc99m tetrofosmin, respectively, p = 0.01, for reversible defects seen in identical segments with both agents; and 0.73 +/- 0.16 vs 0.79 +/- 0.17, respectively, p <0.01, for reversible defects detected with either agent alone). There was no significant difference in diagnostic sensitivity or image quality.. These differences between two commonly used tracers may have significant diagnostic and prognostic implications.

Topics: Adult; Aged; Coronary Circulation; Coronary Disease; Dipyridamole; Exercise Test; Female; Humans; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Sensitivity and Specificity; Technetium Tc 99m Sestamibi; Tomography, Emission-Computed, Single-Photon; Vasodilator Agents

To compare the accuracy and feasibility of harmonic power Doppler and digitally subtracted colour coded grey scale imaging for the assessment of perfusion defect severity by single photon emission computed tomography (SPECT) in an unselected group of patients.. Cohort study.. Regional cardiothoracic unit.. 49 patients (mean (SD) age 61 (11) years; 27 women, 22 men) with known or suspected coronary artery disease were studied with simultaneous myocardial contrast echo (MCE) and SPECT after standard dipyridamole stress.. Regional myocardial perfusion by SPECT, performed with (99m)Tc tetrafosmin, scored qualitatively and also quantitated as per cent maximum activity.. Normal perfusion was identified by SPECT in 225 of 270 segments (83%). Contrast echo images were interpretable in 92% of patients. The proportion of normal MCE by grey scale, subtracted, and power Doppler techniques were respectively 76%, 74%, and 88% (p < 0.05) at > 80% of maximum counts, compared with 65%, 69%, and 61% at < 60% of maximum counts. For each technique, specificity was lowest in the lateral wall, although power Doppler was the least affected. Grey scale and subtraction techniques were least accurate in the septal wall, but power Doppler showed particular problems in the apex. On a per patient analysis, the sensitivity was 67%, 75%, and 83% for detection of coronary artery disease using grey scale, colour coded, and power Doppler, respectively, with a significant difference between power Doppler and grey scale only (p < 0.05). Specificity was also the highest for power Doppler, at 55%, but not significantly different from subtracted colour coded images.. Myocardial contrast echo using harmonic power Doppler has greater accuracy than with grey scale imaging and digital subtraction. However, power Doppler appears to be less sensitive for mild perfusion defects.

Topics: Aged; Cohort Studies; Contrast Media; Coronary Disease; Dipyridamole; Echocardiography, Doppler; Echocardiography, Doppler, Color; False Positive Reactions; Feasibility Studies; Female; Humans; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Polysaccharides; Radiopharmaceuticals; Sensitivity and Specificity; Tomography, Emission-Computed, Single-Photon

Despite the diagnostic efficacy of stress myocardial perfusion imaging, the correlation between the actual perfusion tracer activity and diseased state of a coronary artery has not been studied in detail. We estimated exercise-related perfusion augmentation in relation to disease states of a coronary artery in diabetic and non-diabetic patients by a newly developed quantitative technetium (Tc)-99m-tetrofosmin myocardial imaging technique. Tc-99m-tetrofosmin tomographic imaging with an exercise-rest protocol was performed in 26 stable coronary patients and in 8 age-matched controls. Percent increase (%IR) in myocardial count during symptom-limited submaximal exercise-stress was calculated in 16 non-infarcted polar map segments and in each coronary territory by a subtraction technique with corrections for physical decay and injected tracer doses, and the results were compared with those of angiographically quantified coronary diameter stenosis (%DS). Percent IR and peak heart rate during exercise showed a positive linear correlation both in coronary territories with significant stenosis (%DS > or = 75%) and in control or nonstenotic (%DS < 75%) territories. The regression line in stenotic regions was, however. significantly (p < 0.01) shifted downward compared to that in non-stenotic regions. Percent IR in stenotic regions showed a significant inverse correlation with %DS. Coronary stenosis of 75% or more was identified by a %IR cutoff value of 40% with 77% sensitivity, 70% specificity, and an accuracy of 72%. In coronary territories with a %DS of less than 75%, %IR in diabetic patients was significantly lower (46+/-15%) than that in nondiabetic patients (61+/-25%). Thus, blunted exercise-related augmentation of myocardial uptake of Tc-99m-tetrofosmin correlates with the severity of coronary narrowing and diabetic state.

Topics: Adult; Aged; Coronary Angiography; Coronary Circulation; Coronary Disease; Diabetes Complications; Exercise; Female; Heart; Humans; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon

The purpose of this study was to compare the clinical utility of two image reconstruction algorithms in myocardial perfusion SPECT (single-photon emission computed tomography): filtered back-projection (FBP) and ordered subset expectation maximization (OSEM). A rest/stress one-day protocol with 99mTc-MIBI or tetrofosmin was performed on 102 consecutive patients who underwent coronary angiography. After SPECT data acquisition, images were reconstructed with FBP and OSEM algorithms. We assessed diagnostic performance (sensitivity, specificity and accuracy) in detecting coronary artery stenosis and evaluated regional tracer uptake with a 4-point scoring system. Although there were no significant differences in diagnostic performance between FBP and OSEM reconstruction, the OSEM method yielded higher uptake in the RCA area than the FBP method by reducing the count-loss artifact due to hepatic uptake of the tracers. In addition, regional uptake in the LCX area was significantly lower in the OSEM image than in the FBP image; this phenomenon was observed mainly in patients with coronary stenosis and/or infarction in the LCX territory. In conclusion, OSEM and FBP offered comparable diagnostic performance in stress myocardial perfusion SPECT. The OSEM method contributed to reduction of the count-loss artifact in inferior and posterior walls and to easy recognition of hypoperfusion in the LCX area.

Topics: Algorithms; Chi-Square Distribution; Coronary Angiography; Coronary Disease; Dipyridamole; Exercise Test; Female; Heart; Humans; Image Processing, Computer-Assisted; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Reproducibility of Results; Rest; Sensitivity and Specificity; Technetium Tc 99m Sestamibi; Tomography, Emission-Computed, Single-Photon

Technetium-99m (Tc-99m)-tetrofosmin is a radio isotope that has been shown to be an accurate alternative to thallium-201 for detecting coronary artery disease. However, its prognostic value is less well determined. To this end, 459 consecutive patients (mean age 58 +/- 10 years) with suspected or known coronary artery disease underwent exercise single-photon emission tomography Tc-99m-tetrofosmin scintigraphy. Follow-up, defined as the time from scanning until a soft event (revascularization procedures), a hard event (myocardial infarction and cardiac death), or patient response, lasted up to 78 months (median 38). An ischemic scintigraphic perfusion score, which takes into account both the extent and severity of reversible perfusion defects, was calculated to estimate the severity of perfusion abnormalities. Patients with normal scans were at low risk of events (yearly hard event rate 0.5% and soft event rate 0.9%). The rate of outcomes increased significantly with abnormal scans (yearly hard event rate 4.9% and soft event rate 10.3%). Statistical analysis using the Kaplan-Meyer survival curves showed a significant difference in event-free survival between patients with normal and abnormal scans. With use of Cox proportional-hazards analysis, after adjusting for prescan information, nuclear data provided incremental prognostic value for hard events (clinical and exercise data vs nuclear data; chi-square = 15.5 vs 33.4, p <0.001). Exercise single-photon emission tomographic scintigraphy using Tc-99m-tetrofosmin provides significant independent information on the subsequent risk of hard and soft events. The annual event rate for hard and soft events is <1% for patients with a normal scan. Furthermore, this tracer yields incremental prognostic information in addition to that provided by clinical and exercise data for hard events.

Topics: Coronary Disease; Disease-Free Survival; Exercise Test; Female; Follow-Up Studies; Humans; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Predictive Value of Tests; Prognosis; Proportional Hazards Models; Radiopharmaceuticals; Risk Assessment; Time Factors; Tomography, Emission-Computed, Single-Photon

We evaluated the diagnostic accuracy of a new method for quantitative analysis of myocardial perfusion at exercise using (99m)Tc-tetrofosmin tomographic imaging. (99m)Tc-tetrofosmin imaging of an exercise-rest sequence was performed in 30 patients with coronary artery disease (CAD) and eight age-matched control subjects. The exercise-induced myocardial count increase was calculated as the relative value (per cent increase ratio, %IR) to that at rest by correcting for physical decay for (99m)Tc and injected doses and by a subtraction technique. Exercise and rest (99m)Tc-tetrofosmin images were assessed visually and quantitatively using the per cent peak count and %IR of the myocardial count at exercise. Segments with significant coronary stenosis (diameter stenosis=75% or more) showed a significantly lower %IR than did those without significant coronary stenosis in the CAD patients (37+/-19% vs 63+/-21%, P<0.05). The diagnostic efficacy of visual analysis for detecting coronary stenosis was as follows: sensitivity, 58.1% and specificity, 81.4%. When %IR=37% was used for detecting significant coronary stenosis, sensitivity and specificity increased to 74.2% and 93.2%, respectively. Furthermore, the quantitative analysis significantly (P=0.04) improved the overall diagnostic accuracy from 73.3% to 86.7% compared to that of visual assessment. Thus, augmentation of myocardial (99m)Tc-tetrofosmin uptake at exercise is blunted in the myocardium with significant coronary stenosis. The calculation of myocardial count increase at exercise relative to that at rest can improve the diagnostic value of (99m)Tc-tetrofosmin SPECT imaging and may contribute to more accurate quantification of myocardial ischaemia and impaired tracer uptake in coronary artery disease.

Topics: Adult; Aged; Coronary Circulation; Coronary Disease; Exercise; Female; Heart; Humans; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Tomography, Emission-Computed, Single-Photon

Myocardial perfusion imaging has lower sensitivity for the diagnosis of coronary artery disease in patients with three-vessel disease. The presence of post-stress dysfunction of the left ventricle, evaluated by electrocardiography(ECG) gated single photon emission computed tomography(SPECT) with a quantitative gated SPECT program, was investigated in patients with coronary artery disease, and also whether combining post-stress dysfunction and myocardial perfusion imaging improved the diagnosis of coronary artery disease.. ECG gated technetium-99m-tetrofosmin SPECT was performed using a one day, stress and rest, protocol in 139 patients. SPECT and coronary angiography were performed within 1 month. The coronary artery disease group consisted of 89 patients: 43 with one-vessel disease(1VD), 28 with two-vessel disease(2VD), and 18 with three-vessel disease(3VD). The group with zero-vessel disease(0VD) consisted of 50 patients. According to post-stress and rest ejection fraction(EF) and end-systolic volume (ESV), post-stress dysfunction is defined as follows: rest EF--post-stress EF > or = 5% and post-stress ESV--rest ESV > or = 5 ml.. In the coronary artery disease group, post-stress ESV was larger than rest ESV(37.8 +/- 26.4, 34.0 +/- 24.2 ml, p < 0.001), and post-stress EF was lower than rest EF (61.5 +/- 11.1%, 64.2 +/- 10.8%, p < 0.001). In the 0VD group, ESV and EF were the same for post-stress and rest (25.7 +/- 20.8, 26.2 +/- 21.6 ml, NS; 70.4 +/- 9.5%, 70.0 +/- 9.6%, NS). Post-stress dysfunction was 6.0% in the 0VD group and 30.3% in the coronary artery disease group(p < 0.001). Furthermore, post-stress dysfunction in the 2VD (35.7%) and 3VD(38.9%) groups was higher than that in the 0VD group(p < 0.01, p < 0.01). Sensitivity of coronary artery disease diagnosis by myocardial perfusion imaging was 75%. The combination of post-stress dysfunction and myocardial perfusion imaging improved sensitivity from 75% to 82%(p < 0.05), but reduced the specificity from 92% to 86%(p = 0.08).. Post-stress dysfunction is a useful parameter for clinical diagnosis of coronary artery disease.

Topics: Aged; Coronary Angiography; Coronary Disease; Electrocardiography; Exercise Test; Female; Humans; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Sensitivity and Specificity; Stroke Volume; Tomography, Emission-Computed, Single-Photon

We investigated the prognostic value of 99mTc-Tetrofosmin myocardial SPECT (99mTc-TF) in dysfunctional multivessel coronary disease patients who underwent revascularization (RV) or only medical treatment (MT).. In 78 coronary patients with 2-3 diseased vessels and left ventricular ejection fraction (EF) <= 40% (24 10%), we have assessed the extension of the stress perfusion defect, and percent of reversibility (R) by quantification of stress-rest myocardial SPECT 99mTc-TF bull's eyes (2 days-protocol), lung/heart ratio (LH) calculated in the original stress SPECT images, and EF by equilibrium radionuclide ventriculography obtained at 24 h. A R value >= 8% was used to identify viable (V) patients. A total of 28 patients underwent RV and 50 only received MT. After a mean follow-up of 22.9 20 months (3-60), they were considered as coronary events (CE): cardiac death, non-fatal infarction and heart transplant. CE rate was 20.5% (16/78).. No significant differences were found in the pre-revascularization study characteristics, except a significantly higher mean R value in RV (10.6 9.5%) than in MT patients (6.4 7.8%) p: 0.03, and the main difference was that RV patients showed less CE 2/28 (7%) than the MT group 14/50 (28%) p: 0.02. The CE rate was lower in V patients who underwent RV (6%) than in V patients with MT (45%) p: 0.03, but no significant difference was obtained in non-V patients between RV (7%) and MT (16%) groups. In viable patients, the corresponding survival curves (Kaplan-Meier) showed a CE-free survival at 5 years of 79% in patients RV and of 42% in MT patients, p: 0.03, without significant difference in non-V patients.. Patients with viable myocardium by myocardial SPECT have a good prognosis after revascularization, and show higher risk of CE if they are only medically treated. Myocardial viability is an indispensable assessment in prognosis evaluation and, above all, in therapeutic decision making in dysfunctional multivessel coronary disease patients.

Topics: Adult; Aged; Cell Survival; Coronary Circulation; Coronary Disease; Death, Sudden, Cardiac; Exercise Test; Female; Follow-Up Studies; Gated Blood-Pool Imaging; Heart; Heart Transplantation; Humans; Male; Middle Aged; Myocardial Infarction; Myocardial Revascularization; Myocardium; Organophosphorus Compounds; Organotechnetium Compounds; Prognosis; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon; Ventricular Dysfunction, Left

Resting (99m)Tc-tetrofosmin (TF) uptake was compared with thallium ((201)Tl) rest-redistribution (R-RD) uptake in patients with previous myocardial infarction (MI) and significant coronary artery disease (CAD) to assess the ability of TF to detect viable myocardium. We studied 30 patients (21 males and nine females, mean age 53.9+/-12.5 years) with prior MI and left ventricular dysfunction who had been referred for coronary revascularization procedures. Myocardial single photon emission computed tomography (SPECT) images were obtained 1 h after injection of 750 MBq of TF. Within 1 week of the TF study, R-RD (201)Tl SPECT imaging was performed after injection of 111 MBq of (201)Tl . Quantitative analysis was performed in 21 segments. Viability was defined as the presence of tracer uptake greater than 50% of the peak activity on baseline studies or after reversibility. There was significant correlation between the quantitative regional R-RD (201)Tl activity and the resting TF activity (r=0.88, P<0.001). Quantitative analysis showed that the uptake of the two tracers was comparable in normal segments as well as in segments with fixed (201)Tl defects. In contrast, in segments with reversible (201)Tl defects, TF uptake was significantly greater than resting (201)Tl uptake, but lower than R-RD (201)Tl uptake. There were 52 segments (47% of the severely reduced segments on TF images) that showed no viability with TF, but were viable on the redistribution (201)Tl studies. We conclude that quantitative resting TF SPECT underestimates the presence of viable myocardium compared with R-RD (201)Tl imaging on the basis of using 50% of the peak activity as the viability threshold.

Topics: Adult; Aged; Biological Transport; Coronary Disease; Female; Humans; Image Processing, Computer-Assisted; Male; Middle Aged; Myocardial Infarction; Myocardial Revascularization; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Thallium Radioisotopes; Tissue Distribution; Tomography, Emission-Computed, Single-Photon; Ventricular Dysfunction, Left; Wound Healing

Exercise rehabilitation improves the clinical status in ischaemic heart disease. The purpose of this study was to assess the influence of exercise rehabilitation on myocardial perfusion and sympathetic heart innervation. Sixteen patients with ischaemic heart disease and previous myocardial infarction were investigated by means of exercise/rest tetrofosmin and metaiodobenzylguanidine (MIBG) exercise/rest single-photon emission tomography (SPET) studies, before and 6 months after starting an exercise rehabilitation programme. Tomograms were divided into 15 segments, and these were grouped into five myocardial anatomical regions. Regional uptake of both tracers was quantified and expressed as a percentage of maximum peak activity. The percentage < or =55% was chosen to evaluate defect size, and the results were expressed as a percentage of left ventricular mass. Areas with perfused and denervated myocardium and areas with ischaemic myocardium were calculated. In addition, regions with <75% of peak activity in the exercise perfusion study at baseline were divided into two groups according to whether there was an increase in peak activity of >10% (representing reversible regional defects) or an increase of <10% (representing fixed regional defects) in the rest study. These percentages were compared with the percentages obtained in the innervation study, and with the percentages obtained in exercise/rest perfusion and innervation studies performed 6 months after starting rehabilitation. Myocardial perfusion defects were significantly smaller than myocardial innervation defects before and 6 months after starting exercise rehabilitation. The area of ischaemia 6 months after starting exercise rehabilitation was significantly smaller than that before rehabilitation (0.31%+/-1.4% vs 1.4%+/-1.6%, P<0.01). The size of innervation defects and the area of perfused and denervated myocardium did not show significant differences between the two studies performed before and 6 months after starting exercise rehabilitation. In reversible regional defects the percentage of peak activity was significantly increased 6 months after starting exercise rehabilitation in exercise and rest studies (P<0.001), while in fixed regional defects it was significantly increased only in exercise studies (P<0.001). There was no significant change in the regional MIBG percentages. We conclude that in ischaemic heart disease, exercise rehabilitation over a period of 6 months improves myocardial p

Topics: 3-Iodobenzylguanidine; Blood Pressure; Coronary Circulation; Coronary Disease; Exercise Test; Exercise Therapy; Heart; Heart Rate; Humans; Iodine Radioisotopes; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Sympathetic Nervous System; Tomography, Emission-Computed, Single-Photon

The purpose of this study was to compare left ventricular (LV) volume and ejection fraction (LVEF) measurements obtained with electrocardiographic gated single-photon emission computed tomographic (SPECT) myocardial perfusion imaging (GS-MPI) with those obtained with gated SPECT cardiac blood-pool imaging (GS-pool). Fifteen patients underwent GS-MPI with technetium-99m-tetrofosmin and GS-pool with technetium-99m-erythrocyte, within a mean interval of 8 +/- 3 days. Eight patients had suspected dilated cardiomyopathy and seven patients had angiographically significant coronary artery disease. End-diastolic volume (EDV), end-systolic volume (ESV) and LVEF measurements were estimated from GS-MPI images by means of Cedars-Sinai automatic quantitative program and from GS-pool images by the threshold technique. Mean differences between GS-MPI and GS-pool in EDV, ESV and LVEF measurements were -2.8 +/- 10.5 ml [95% confidence interval (CI): -8.6 +/- 3.0 ml], 2.6 +/- 7.3 ml (CI: -1.4 +/- 6.6 ml) and -2.3 +/- 5.1% (CI: -5.1 +/- 0.6%), respectively. No significant difference in the mean differences from 0 was found for EDV, ESV or LVEF measurements. Bland-Altman plots revealed no trend over the measured LV volumes and LVEF. For all parameters, regression lines approximated lines of identity. The excellent agreement between GS-MPI and GS-pool measurements suggests that, for estimation of LV volumes and LVEF, these two techniques may be used interchangeably and measurements by one method can serve as a reference for the other.

Topics: Adult; Aged; Cardiomyopathy, Dilated; Coronary Disease; Databases, Factual; Female; Gated Blood-Pool Imaging; Humans; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Phantoms, Imaging; Radiopharmaceuticals; Reference Values; Technetium; Tomography, Emission-Computed, Single-Photon; Ventricular Function, Left

Global and regional myocardial uptake was determined with technetium-99m tetrofosmin and a 4 hour exercise (370 MBq i.v.) and rest (740 MBq i.v.) protocol, in 24 patients with non-insulin dependent diabetes mellitus and in 22 control subjects. The purpose of this study was to evaluate impaired coronary microvascular function in diabetics by measurement of % uptake increase in myocardial counts. The parameter of % uptake increase (deltaMTU) was calculated as the ratio of exercise counts to rest myocardial counts with correction of myocardial uptake for dose administered and physical decay between the exercise study and the rest study. Global deltaMTU was significantly lower in the diabetics than in control subjects (14.4 +/- 5.4% vs. 21.7 +/- 8.5%, p < 0.01). Regional deltaMTU in each of 4 left ventricular regions (anterior, septal, inferior, posterolateral) was significantly lower in the diabetic group than in the control group (p < 0.01) respectively, but there were no significant differences between deltaMTU in the 4 left ventricular regions in the same group. deltaMTU was useful as a non-invasive means of evaluating impaired coronary microvascular function in diabetics.

Topics: Blood Pressure; Coronary Circulation; Coronary Disease; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Exercise Test; Female; Heart; Heart Rate; Hemodynamics; Humans; Male; Microcirculation; Middle Aged; Myocardium; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Reference Values; Regression Analysis; Tissue Distribution; Tomography, Emission-Computed, Single-Photon

Thallium (Tl) 201 and technetium (Tc) 99m tetrofosmin single-photon emission CT are routinely used in the evaluation of coronary artery disease. Mediastinal tumors demonstrate Tl 201 and Tc 99m tetrofosmin uptake. We report a 56-year-old man who developed chest pain after a previously successful angioplasty and stent of the left anterior descending coronary artery. He underwent a Tl 201, Tc 99m tetrofosmin exercise study. Abnormal mediastinal activity was visualized in both the Tl 201 and Tc 99m tetrofosmin images. Subsequently, the patient underwent resection of a stage II thymoma. Unanticipated focal extracardiac accumulation during myocardial scintiscanning should lead to further investigation to exclude mediastinal tumor.

Topics: Coronary Disease; Exercise Test; Humans; Male; Middle Aged; Neoplasms, Unknown Primary; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Thallium Radioisotopes; Thymectomy; Thymoma; Thymus Neoplasms; Tomography, Emission-Computed, Single-Photon

When using 99mTc-tetrofosmin for myocardial perfusion SPECT, increased liver, intestinal, or gastric activity may create a major problem in the visual and quantitative interpretation Of the inferoposteroseptal walls, particularly at rest. The aim of this study was to determine what measures were required to minimize this extracardial activity.. Ninety-seven patients had a SPECT scan at rest without attenuation correction. They were divided into 3 groups. Preparation consisted of no action taken (group 1), 150 mL whole milk 10 min after administration of tetrofosmin (group 2), or 450 mL water 10 min before acquisition (group 3). A further 55 patients had a SPECT scan at rest with attenuation correction. They were also divided into 3 groups, and preparation consisted of 150 mL whole milk 10 min after administration of tetrofosmin (group 4), 450 mL water 10 min before acquisition (group 5), or both whole milk and water (group 6). The presence of activity in liver, bowel, and stomach was determined visually on reconstructed images. Activity was defined as interfering when it might result in either an underestimation or an overestimation of the uptake in the myocardial wall.. Interfering activity was seen in 83% of the patients in group 1, in 74% in group 2, in 33% in group 3, in 61% in group 4, in 67% in group 5, and in 20% of group 6.. The interpretation of inferoposteroseptal wall activity on myocardial rest SPECT images is facilitated by having the patient drink both whole milk and water at specified times before data acquisition.

Topics: Adult; Aged; Animals; Coronary Disease; Digestive System; Exercise Test; Female; Heart; Humans; Liver; Male; Middle Aged; Milk; Myocardium; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Rest; Tissue Distribution; Tomography, Emission-Computed, Single-Photon

This study was designed to elucidate the usefulness of crosstalk correction for dual-isotope simultaneous acquisition (DISA) with 99mTc-tetrofosmin and FDG in estimating myocardial perfusion and viability.. Eighteen patients with coronary artery disease were studied. First, SPECT was performed with a low-energy high-resolution collimator after a single injection of 99mTc-tetrofosmin (single 99mTc-tetrofosmin). Second, PET and DISA with an ultra-high-energy collimator were performed after glucose loading and an injection of FDG. DISA was designed to operate with simultaneous 3-channel acquisition, and weighted scatter correction of crosstalk from the 18F photopeak to the 99mTc photopeak was performed by modification of an existing dual-window technique. The FDG SPECT images were compared with the images obtained by PET. Both crosstalk-corrected and uncorrected 99mTc-tetrofosmin images were generated and compared with the single 99mTc-tetrofosmin images.. Regional percentage uptake of FDG agreed well between DISA and PET. However, regional percentage uptake of 99mTc-tetrofosmin was generally higher on the uncorrected 99mTc-tetrofosmin images than on the single 99mTc-tetrofosmin images, especially in areas of low flow (percentage count of 99mTc-tetrofosmin > or = 50%). The crosstalk correction contributed to improving the agreement between regional percentage uptakes and significantly improved the detectability of myocardial perfusion-metabolism mismatching.. With 3-channel acquisition and weighted-scatter correction of crosstalk from the 18F photopeak to the 99mTc photopeak, DISA with 99mTc-tetrofosmin and FDG is feasible for assessing regional myocardial perfusion and viability.

Topics: Aged; Coronary Disease; Female; Fluorodeoxyglucose F18; Gamma Cameras; Heart; Humans; Male; Middle Aged; Myocardial Infarction; Myocardium; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Regression Analysis; Tomography, Emission-Computed, Single-Photon

Several studies have explored the feasibility of using myocardial perfusion imaging to detect allograft vasculopathy after heart transplantation. We undertook the present prospective consecutive study to comparatively evaluate the role of serial myocardial perfusion single-photon emission computed tomography (SPECT) scanning and coronary arteriography (CAG) in detecting coronary artery stenosis suitable for coronary angioplasty in heart transplant recipients.. Within a 2-week interval during a follow-up period of 5.6 (95% confidence limits 2.1 to 12) years, 255 serial CAGs and myocardial perfusion scintigraphies were performed in 67 patients. Arteriography and scintigraphy were performed once yearly after heart transplantation. We retrospectively analyzed the data.. Myocardial scintigraphy showed pathologic reversible defects in 9 out of 67 patients. Four of these patients had significant (>50% and also >70%) focal segmental stenosis in the middle and proximal parts of the coronary arteries (Type A lesions), 1 had diffuse and circumferential narrowing in the distal parts (Type B lesions), whereas CAG showed no lesions in the remaining 4 patients. The patients with significant Type A lesions were revascularized with percutaneous coronary angioplasty. Coronary arteriography showed that 1 patient had extensive Type A and Type B lesions, whereas myocardial perfusion scans detected no. The predictive value of a negative (normal) SPECT was 98% (95% confidence limits 94% to 100%) for the detection of lesions suited for revascularization.. Annual myocardial SPECT seems well suited to screen for significant coronary artery stenosis. A SPECT study without reversible defects virtually excludes lesions suitable for coronary artery revascularization.

Topics: Adolescent; Adult; Child; Coronary Angiography; Coronary Disease; Female; Heart; Heart Transplantation; Humans; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Prospective Studies; Radiopharmaceuticals; Sensitivity and Specificity; Technetium Tc 99m Sestamibi; Tomography, Emission-Computed, Single-Photon

The purpose of this study was to compare six methods of measuring the left ventricular (LV) transient ischaemic dilation (TID) ratio during stress-rest myocardial perfusion single-photon emission tomography (SPET). The TID ratio was defined as the mean LV short-axis area at stress divided by the mean LV area of similar slices at rest. The centre of the LV wall was defined as either the maximum, mean or median of the radial short-axis count profiles. The area within the endocardial wall was also calculated for each definition of the LV wall centre. We identified 50 consecutive patients undergoing dipyridamole technetium-99m-tetrofosmin SPET imaging and angiography. Continuous receiver operating characteristic (CROC) analysis showed no significant difference between the six methods in terms of identifying severe coronary artery disease (P >0.47). Algorithms using the mean or the median value in the profile were significantly more robust than those using the maximum (P <0.0005). TID measured by all the algorithms is an indicator of severe coronary disease (P < 0.05). The algorithms compared provide a repeatable, quantitative and specific measure of the TID ratio.

Topics: Algorithms; Case-Control Studies; Coronary Disease; Exercise Test; Heart; Heart Ventricles; Humans; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; ROC Curve; Tomography, Emission-Computed, Single-Photon

The authors compared retrospectively the diagnostic accuracy of three protocols--201Tl stress-redistribution, 2-day 99mTc-tetrofosmin and the dual-isotope protocol (rest 201Tl/stress99m Tc-tetrofosmin)--for the detection of ischaemic heart disease (IHD) in a total of 115 patients without previous myocardial infarction (IM). 201Tl protocol (group A) was used to examine 43 patients, incl. 15 women, mean age 51 years (38-69 years). The 2-day 99m Tc-tetrofosmin protocol was used to examine 39 patients incl. 12 women, mean age 49 years (30-71 years). The dual-isotope protocol was used in 33 patients, incl. 8 women, mean age 52 years (31-69 years). In all patients coronarography was performed, stenosis of the artery >50% was considered significant for IHD. The sensitivity of the dual-isotope protocol was 95% and 96% resp. and 92% in the 2-day tetrofosmin and 201Tl protocol, (p>0.05). The specificity of the dual-isotope protocol was 82% and 89% resp. and 88% in the 201Tl and 2-day tetrofosmin protocol, (p >0.05). The diagnostic accuracy was 91% in the dualisotope and 201Tl protocol and 92% in the 2-day protocol (p>0.05). No significant difference was revealed in the sensitivity, specificity and diagnostic accuracy for the detection of IHD between different protocols in patients without previous IM.

Topics: Adult; Aged; Coronary Circulation; Coronary Disease; Exercise Test; Female; Humans; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Sensitivity and Specificity; Thallium Radioisotopes; Tomography, Emission-Computed, Single-Photon

Topics: Coronary Disease; Electrocardiography; Exercise; Humans; Hyperemia; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Rest; Tomography, Emission-Computed, Single-Photon

A 68-year-old man suffering from chronic heart failure due to coronary artery disease (CAD) underwent rest technetium-99m (99mTc)-tetrofosmin and thallium-201 (201Tl) with reinjection studies, but died thereafter. The heart was removed and sectioned into short-axis slices and examined by gross and microscopic pathologic methods. A close correlation between the amount of residual cardiomyocytes and the level of regional tracer activity in the left ventricular wall was obtained for redistribution 201Tl, reinjection 201Tl and rest 99mTc tetrofosmin images. The correlation coefficients were r=0.901 for the 201Tl redistribution images, r=0.913 for the 201Tl reinjection images and r=0.917 for the rest 99mTc-tetrofosmin images. This case report provides further evidence of the validity of SPECT tetrofosmin imaging for the determination of myocardial viability in CAD.

Topics: Aged; Cell Survival; Coronary Disease; Heart; Humans; Male; Myocardium; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Thallium Radioisotopes; Tomography, Emission-Computed

Gated SPECT using Tc-99m-labeled flow tracers provides simultaneous assessment of global and regional myocardial perfusion and function. The aim of this study was to evaluate whether regional wall thickening (WT) obtained after stress and at rest makes it possible to identify and analyze a subgroup of post-ischemic stunned patients.. We studied 20 patients (18 males) who underwent conventional diagnostic dual-day stress/rest Gated SPECT following injection of 925 MBq of 99mTc-tetrofosmin using a dual-head SPECT camera (Vertex ADAC). The mean age of these patients was 59 years (38-71) and 10 of them had a history of previous acute myocardial infarction (AMI). Perfusion was analyzed on ungated images using 20 segments scored on a 5-point scale (0 = normal, 4 = no uptake), while WT and motion were assessed visually on stress/rest end-systolic images using a 4-point score (0 = normal, 3 = absence of WT/motion). Left ventricular ejection fraction (LVEF) and volumes were calculated. All patients underwent coronary angiography.. All patients showed at least one reversible defect with post-stress WT reduction and normal rest WT. The stunned group showed a significant post-stress reduction of LVEF and a statistically non-significant increase of end systolic volume (ESV). A good correlation was observed between global perfusion and WT score both at stress and rest conditions; LVEF showed a significant inverse correlation with global post-stress and rest perfusion and WT score. ESV and the global perfusion stress/rest score showed a good correlation, while end-diastolic volume did not correlate. In 44% of the segments with fixed defects, there was a normal WT and normal coronary-related vessel (false positives); 28% of reversible segments showed a post-stress pathological WT and five of them a rest pathological WT.. The gated SPECT myocardial perfusion evaluation allowed us to analyze a subgroup of post-stress stunned coronary artery disease patients. The post-stress LVEF reduction in this population seems to be due to the increase of end-systolic volume caused by endocardial ischemia. The stunned segments showed severe perfusion defects.

Topics: Adult; Aged; Coronary Angiography; Coronary Disease; Electrocardiography; Exercise Test; Female; Heart; Humans; Male; Middle Aged; Myocardial Stunning; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon

This study sought to determine the anatomic and physiologic correlates of increased right ventricular (RV) activity on exercise single-photon emission computed tomography (SPECT) perfusion imaging in patients with coronary artery disease (CAD).. Because SPECT perfusion imaging delineates relative myocardial blood flow, patients with global left ventricular (LV) hypoperfusion but normal RV perfusion may have increased relative RV tracer uptake as an indicator of multivessel CAD.. Rest thallium-201 and exercise 99mTc-sestamibi or 99mTc-tetrofosmin SPECT perfusion images were analyzed for peak RV and LV activity (RV:LV index) in 315 patients, including 240 patients with documented CAD, 39 patients with no significant CAD on arteriography, and a "normalcy" group of 36 patients with a low pre- and posttest probability of CAD.. Resting RV:LV perfusion index ranged from 0.32 to 0.34 in each group, increasing to 0.36 with exercise in control and normalcy groups. CAD patients with the highest exercise RV:LV were those with severe left main CAD (or "left main equivalent"), with a lesser degree of proximal right CAD (0.51, n = 14, p < 0.001 vs. other groups). An exercise RV:LV >0.42 with a exercise:rest ratio >1.2 was present in 93% patients with this pattern of CAD, but was absent in 97% of the normalcy group, 92% of patients without significant angiographic CAD, and 100% of patients with proximal right CAD tighter than stenoses in the left system.. Increased RV:LV activity exercise may occur in patients with acute RV strain, but is otherwise an indicator of exercise-induced RV:LV perfusion imbalance associated with severe CAD, particularly high-grade left main with less severe proximal right CAD.

Topics: Coronary Circulation; Coronary Disease; Exercise Test; Humans; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Technetium Tc 99m Sestamibi; Thallium Radioisotopes; Tomography, Emission-Computed, Single-Photon; Ventricular Function, Left; Ventricular Function, Right

A woman with coronary artery disease underwent a new imaging technique: dobutamine-stress electrocardiography (ECG)-gated tetrofosmin-single photon emission computed tomography (SPECT). Dobutamine-stress ECG-gated tetrofosmin-SPECT with automatic left ventricular function analysis software programs detected improvement and a biphasic response of dysfunctional myocardium during dobutamine infusion, which suggested viable but hibernating myocardium. Dobutamine-stress ECG-gated tetrofosmin-SPECT with automatic left ventricular function analysis software programs has the potential to detect viable but dysfunctional myocardium with contractile reserve.

Topics: Aged; Coronary Disease; Dobutamine; Electrocardiography; Female; Humans; Myocardial Stunning; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon

Of the study was to show that changing patient position from supine to prone results in improved specificity of myocardial SPECT (MS).. We examined the influence of patient position in MS on the diagnosis of coronary heart disease (CHD) in 151 patients. By using a Tc-99m-labeled compound (Tetrofosmin, Myoview, Nycomed, Amersham) examinations could be performed in supine and prone position within 35 minutes. Examinations were performed as a two-day stress-rest protocol with one gamma camera head and 180 degrees rotation without absorption correction.. Semi-quantitative patient and heart phantom data show similar values for anterior and inferior wall in prone position in contrast to a lower count ratio of inferior to anterior wall in supine position. This demonstrates the importance of patient position with respect to artifacts specificity. Changing patient position from supine to prone mainly improves diagnostic specificity for CHD in the inferior wall in men (from 58% to 90%) and in the anterior wall in women (from 80% to 93%). Sensitivity is the same for both techniques.. Changing patient position from supine to prone significantly improves diagnostic specificity while sensitivity remains unchanged.

Topics: Adipose Tissue; Adult; Aged; Artifacts; Coronary Angiography; Coronary Disease; Female; Heart; Humans; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Phantoms, Imaging; Prone Position; Radiopharmaceuticals; Sensitivity and Specificity; Tomography, Emission-Computed, Single-Photon

To evaluate segmentary reverse defects (RD) (uptake higher in exercise than in rest) in 99mTc-tetrofosmin SPECT.. 1,124 consecutive SPECT studies were reviewed and 80 (7%) segmentary RD were identified. Thirty-eight patients with RD attributed to artifact (extra cardiac uptake) were excluded. Thus, 42 patients (3.6%), 21 with and 21 without previous infarct, were studied. Thirteen out of 21 RD in patients without previous infarct corresponded to inferior region and 8 to the anterior region. In three out of 8 patients in whom the coronary angiography was performed, the coronary arteries were angiographically normal and 5 had stenosis of between 50% to 70% of coronary arteries corresponding to RD. Of the 21 RD in patients with previous infarct, the RD site corresponded to the same region of the necrosis (15 inferior and 6 anterior). All had viability criteria (uptake higher than 40% in more than 50% of the region) in rest uptake SPECT quantification. In nine out of 11 patients in whom a coronary angiography was carried out, patency of the artery responsible for the infarct was verified.. 3.6% of segmentary RD, which were not attributed to the artifact, were observed in myocardial perfusion 99mTc-tetrofosmin SPECT studies. Half of these cases corresponded to regions without previous infarct and with normal coronary arteries or non-severe coronary stenosis. The remaining corresponded to regions with previous infarct and with viability criteria.

Topics: Convalescence; Coronary Angiography; Coronary Disease; Evaluation Studies as Topic; Female; Heart; Humans; Male; Middle Aged; Myocardial Infarction; Myocardium; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon

Dobutamine stress echocardiography and 99mTc-tetrofosmin single-photon emission computed tomography (T-SPECT) were performed simultaneously in subjects in whom coronary artery disease (CAD) had been proven or excluded at coronary angiography, in order to establish their accuracy and agreement in the diagnosis of CAD, and in localisation and evaluation of the extension of ischaemia. No simultaneous comparison of the two techniques has been performed previously.. Seventy patients (50 men, mean age 63 +/- 10 years, 21 with previous myocardial infarction) underwent simultaneous dobutamine stress echocardiography and T-SPECT. The response to stress was blindly and independently analysed, adopting a 16-region segmentation and referring to the three major coronary arteries.. Sixty-two patients (agreement 89%, kappa = 0.776) and 91% of left ventricular regions (kappa = 0.665) were classified concordantly, independently of the presence or absence of previous myocardial infarction (90%, kappa = 0.740 versus 91%, kappa = 0.589, respectively). At coronary angiography, 47 patients had CAD (disease prevalence 67%). The sensitivity and specificity of stress echocardiography for the diagnosis of anterior descending, circumflex and right coronary artery disease were 62, 78 and 73%, and 79, 79 and 83%, respectively. The corresponding values for T-SPECT were 70, 75 and 78%, and 94, 79 and 90%, respectively.. These data indicate a high concordance between wall motion abnormalities observed using stress echocardiography and perfusion defects observed using T-SPECT; their sensitivity in identifying critical stenoses was similar. Inadequate stressor amounts, and less frequently hyperdynamic regional response may reduce the accuracy of stress echocardiography, while dobutamine effects on coronary flow may prevent T-SPECT from showing subtle flow maldistributions in the presence of worsened wall motion.

Topics: Adult; Aged; Aged, 80 and over; Coronary Angiography; Coronary Disease; Dobutamine; Echocardiography; Exercise Test; Female; Humans; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon

This study was designed to evaluate gated 99mTc-tetrofosmin SPECT for prediction of functional recovery proven by sequential MRI. 99mTc-labeled tetrofosmin is a recently introduced tracer for myocardial perfusion. However, its role for viability assessment is still under investigation.. 99mTc-tetrofosmin uptake in 19 patients with coronary artery disease and severe left ventricular dysfunction was correlated to regional wall thickening before and 4.5 +/- 0.8 mo after successful coronary artery bypass grafting, as derived from corresponding gated short-axis MRI. Preoperative wall thickening determined by gated SPECT was used as an additional parameter for prediction of functional outcome. Optimal threshold cutoffs to separate reversible from irreversible dysfunction were determined by receiver operator characteristic (ROC) analysis.. The sensitivity and specificity of regional 99mTc-tetrofosmin for prediction of functional recovery was 87% and 42%, respectively (cutoff: 50% of maximum tracer retention). The area under ROC curves for prediction of functional recovery measured 0.66 +/- 0.01. Segments with > or =50% uptake and impaired but detectable wall thickening determined by gated SPECT had a significantly higher likelihood for functional improvement compared with segments with absent wall thickening (P < 0.05). There was no difference in segments with <50% tracer retention. There was good agreement for ejection fraction measurements by MRI and gated SPECT (mean ejection fraction 32 +/- 12 versus 34 +/- 11; r = 0.71, P < 0.001).. Regional 99mTc-tetrofosmin uptake provided high sensitivity but limited specificity for prediction of functional recovery after revascularization, leading to fair overall accuracy. Wall thickening assessment derived from gated SPECT may improve the specificity of 99mTc-tetrofosmin uptake for prediction of functional recovery but not the sensitivity in low-flow areas. In addition to the assessment of global function, gated data acquisition can be helpful to improve the overall accuracy of 99mTc-tetrofosmin SPECT for prediction of functional recovery after bypass surgery.

Topics: Coronary Artery Bypass; Coronary Disease; Electrocardiography; Female; Heart; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Predictive Value of Tests; Radiopharmaceuticals; ROC Curve; Sensitivity and Specificity; Tomography, Emission-Computed, Single-Photon; Ventricular Dysfunction, Left

We compared dipyridamole technetium-99m (Tc-99m) tetrofosmin and thallium-201 (Tl-201) single-photon emission computed tomographic (SPECT) imaging with respect to the detection rate of perfusion abnormalities in 26 patients with angiographic coronary artery disease (CAD).. Experimental studies have shown that myocardial extraction of Tc-99m tetrofosmin is lower than that of Tl-201 at high flow rates, resulting in less severe defects with vasodilator stress. It is uncertain whether this results in a lower sensitivity than Tl-201 for detecting coronary stenoses with vasodilator stress in patients.. Twenty-six patients with CAD underwent both dipyridamole Tl-201 and Tc-99m tetrofosmin SPECT. Tomographic images were scored for initial defects and the presence of reversibility. Defect magnitude was computer quantitated.. Of the 26 patients, 25 had defects on both Tl-201 and Tc-99m tetrofosmin SPECT images. Of 340 segments analyzed, 102 had defects by Tl-201 and 92 by Tc-99m tetrofosmin (p = NS). Whereas Tl-201 detected 27 fixed defects in 12 patients, Tc-99m tetrofosmin identified 37 fixed defects in 14 patients (p = NS). In contrast, Tl-201 identified more reversible and partially reversible defects than did Tc-99m tetrofosmin (89 vs. 55, p = 0.002). The average defect magnitude (percent normal) was similar for defects concordantly graded as fixed (38 +/- 3.0% for Tl-201 vs. 42 +/- 4% [mean +/- SEM] for Tc-99m tetrofosmin, p = NS). The average defect magnitude for defects concordantly graded as completely reversible was significantly more severe on Tl-201 than on Tc-99m tetrofosmin (49 +/- 3% vs. 58 +/- 3%) SPECT images. A significantly greater defect magnitude for Tl-201 was also found for defects concordantly classified as partly reversible (30 +/- 4% for Tl-201 vs. 45 +/- 5% for Tc-99m tetrofosmin).. With dipyridamole stress, 1) at least one defect was seen on both Tl-201 and Tc-99m tetrofosmin SPECT images; 2) Tc-99m tetrofosmin SPECT identified fewer reversible defects than did Tl-201, but showed a similar number of fixed defects; 3) the magnitude of reversible defects seen on Tc-99m tetrofosmin images was less, whereas fixed defects were similar for both tracers; 4) reversible defects seen on Tl-201 and not on Tc-99m tetrofosmin SPECT images were predominantly regions perfused by mild coronary stenoses.

Topics: Adult; Aged; Angina Pectoris; Blood Pressure; Chi-Square Distribution; Coronary Angiography; Coronary Circulation; Coronary Disease; Dipyridamole; Electrocardiography; Heart Rate; Humans; Image Processing, Computer-Assisted; Male; Middle Aged; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Sensitivity and Specificity; Thallium Radioisotopes; Tomography, Emission-Computed, Single-Photon; Vasodilator Agents

In this report, a patient with 100% RCA stenosis and prominent collaterals, in which TI-201 rest/redistribution and Tc-99m tetrofosmin infusion imaging findings were compatible with viable myocardium in contrast to Tc-99m tetrofosmin bolus imaging is presented. Viability was confirmed with improvement of wall motion and perfusion 3 months after revascularization. Infusion of Tc-99m tetrofosmin rather than a bolus injection may be a more reliable technique in the identification of severely ischemic but viable myocardium.

Topics: Coronary Disease; Heart; Humans; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Thallium Radioisotopes; Tomography, Emission-Computed, Single-Photon

The purpose of this study was to determine the biodistribution of 99mTc-tetrofosmin during intravenous infusion of adenosine triphosphate (ATP) and to evaluate the potential diagnostic value of myocardial tomography with 99mTc-tetrofosmin during ATP infusion for the detection of coronary artery disease.. Myocardial 99mTc-tetrofosmin imaging with ATP infusion and coronary arteriography were performed on 65 patients with suspected coronary artery disease. ATP was infused intravenously at a rate of 0.16 mg/kg/min for 5 min, and 370 MBq of 99mTc-tetrofosmin was injected 3 min after the start of ATP infusion. Myocardial SPECT imags were obtained 60 min later. Then, 740 MBq of 99mTc-tetrofosmin was administered at rest, and myocardial SPECT was repeated. Regional uptakes of 99mTc-tetrofosmin were scored from 4, normal, to 0, no activity. Serial 5-min planar images were obtained in the anterior projection at 15, 30, 45 and 60 min after the 99mTc-tetrofosmin injection in 10 patients. Heart-to-lung and heart-to-liver count ratios were defined from the serial planar images.. Adverse effects of ATP infusion were mild and transient. A heart-to-lung ratio after ATP infusion was high even at 15 min (3.40 +/- 0.33) and gradually increased with time. A heart-to-liver ratio after ATP was 0.53 +/- 0.40 at 15 min and increased with time. A heart-to-liver ratio reached 0.99 +/- 0.25 (p < 0.01) after 45 min and 1.32 +/- 0.36 (p < 0.01) after 60 min. The sensitivity and specificity for detecting coronary artery disease by myocardial SPECT with ATP were 89% (39/44) and 86% (18/21), respectively.. This study shows the favorable biodistribution of 99mTc-tetrofosmin after intravenous infusion of ATP. A one-day imaging protocol of 99mTc-tetrofosmin tomography with ATP is feasible and has high diagnostic accuracy for coronary artery disease.

Topics: Adenosine Triphosphate; Aged; Coronary Angiography; Coronary Disease; Female; Heart; Humans; Infusions, Intravenous; Liver; Lung; Male; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Sensitivity and Specificity; Tomography, Emission-Computed, Single-Photon

Comparative studies of thallium-201 (201Tl) and 99Tcm-tetrofosmin for the detection of ischaemic heart disease (IHD) have previously been reported. These 201Tl and 99Tcm-tetrofosmin studies were usually performed separately with different exercise loads at an interval of several days. Here, we used a dual-isotope technique with exercise myocardial SPET (single photon emission tomography) in 17 patients with IHD and 10 patients with normal coronary arteries. The triple-energy window (TEW) method was applied for cross-talk correction. SPET imaging was performed at 10 and 70 min (S1 and S2) after the injection of 99Tcm-tetrofosmin (222 MBq) and 201Tl (74 MBq) at peak exercise to determine the optimal imaging time of 99Tcm-tetrofosmin. The S2 value was obtained 35 min after the subject drank a glass of milk to accelerate hepatobiliary clearance. Twenty-five minutes after S2, 37 MBq of 201Tl were reinjected at rest and SPET imaging (S3) was performed. Immediately after S3, 666 MBq of 99Tcm-tetrofosmin were reinjected and SPET imaging (S4) was performed 50 min later. Representative short and vertical long axis tomograms were divided into 17 segments. Each segment was assessed using a 4-point scoring system. The defect score was defined as the sum of each segmental score. The defect scores for imaging at exercise were 14.3 +/- 11.4 for 201Tl at S1, 11.4 +/- 8 for 99Tcm-tetrofosmin at S1 and 9.7 +/-9.8 for 99Tcm-tetrofosmin at S2 (P < 0.01), respectively. The washout rate of 99Tcm-tetrofosmin for the first hour was 15.5 +/- 7.3% and 11.8 +/- 7.7% (P < 0.01), respectively, for the normal and ischaemic segments. The image quality of 201Tl at S1 was almost equivalent to that of 99Tcm-tetrofosmin at S1/S2. The overall sensitivity and specificity for the detection of ischaemia was 94% and 82% for 201Tl at S1, 89% and 86% for 99Tcm-tetrofosmin at S1, and 88% and 95% for 99Tcm-tetrofosmin at S2, respectively. The overall accuracy was 86%, 88% and 92%, respectively. The myocardial viability score was 7.4 +/- 7.1 for 201Tl at S3 and 5.8 +/- 7.0 for 99Tcm-tetrofosmin at S4 (P < 0.01). The results indicate that the diagnostic accuracy of 99Tcm-tetrofosmin for myocardial ischaemia is almost equivalent to that of 201Tl as assessed by dual SPET imaging, and that the optimal imaging time for 99Tcm-tetrofosmin is within 10-35 min (S1) after exercise.

Topics: Coronary Disease; Coronary Vessels; Exercise Test; Humans; Metabolic Clearance Rate; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Reference Values; Reproducibility of Results; Thallium Radioisotopes; Tomography, Emission-Computed, Single-Photon

The aim of this study was to determine the utility of 99Tcm-tetrofosmin cardiac imaging in patients with previous myocardial infarction and with significant coronary artery disease (CAD) compared with that of 201Tl cardiac imaging. Sixteen patients (14 males, 2 females) were studied by same-day exercise-rest 99Tcm-tetrofosmin imaging and exercise, rest and reinjection 201Tl cardiac imaging. For each study, semi-quantitative visual analysis was performed in 20 segments using a 4-point scale. The regional distribution and defect reversibility with the two tracers were compared with the results of coronary angiography. A total of 320 segments were analysed. There was a statistically significant concordance between the numbers of fixed and reversible segments in both studies in myocardial segments supplied by totally occluded coronary arteries (Group 1), as well as in segments supplied by significantly stenosed coronary vessels (Group 2). The exercise and rest uptake of both 99Tcm-tetrofosmin and 201Tl in myocardial segments supplied by totally occluded coronary arteries with poor collateral flow was significantly lower compared with segments supplied by totally occluded coronary arteries with efficient collateral flow (P < or = 0.05). When the uptake of both tracers was analysed according to each major vascular territory, the mean exercise and rest uptake grades of 99Tcm-tetrofosmin and 201Tl were similar. There was also no significant difference in defect reversibility between the two tracers. Discordant results were observed in the territory of the right coronary artery in Group 1 (mean exercise grade of 99Tcm-tetrofosmin = 2.26 +/- 0.7 and of 201Tl = 1.92 +/- 0.8; P < or = 0.001) and in Group 2 (mean grade of 99Tcm-tetrofosmin = 0.79 +/- 0.65 and of 201Tl = 0.95 +/- 0.65; P < or = 0.05). The results of the present study indicate that the overall diagnostic utility of 99Tcm-tetrofosmin in the identification of individual stenosed vessels is comparable with 201Tl in both patients with totally occluded coronary arteries and those with significantly stenosed vessels. The regional distribution of both tracers was lower in myocardial segments supplied by totally occluded coronary arteries with poor collateral flow.

Topics: Adult; Aged; Coronary Disease; Female; Heart; Humans; Male; Middle Aged; Myocardial Infarction; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Reproducibility of Results; Thallium Radioisotopes; Tomography, Emission-Computed, Single-Photon

We investigated the use of visual and quantitative technetium 99m tetrofosmin ECG-gated single-photon emission tomography (SPET) for the assessment of regional myocardial wall thickening (WT) and left ventricular (LV) ejection fraction (EF) in comparison with gated magnetic resonance imaging (MRI) in patients with a low angiographic LVEF. Gated SPET using 99mTc-labelled flow tracers offers potential for simultaneous assessment of myocardial perfusion and LV function. Few data are available on the use of visual and quantitative gated SPET in patients with low LVEF. In this study 21 patients with low angiographic LVEF (mean 37%+/-5%) were studied. Resting gated 99mTc-tetrofosmin SPET and gated MRI were performed within 48 h. WT was assessed by visual interpretation (five point score) and quantitative analysis based on count increase. There was good agreement for EF measurements by MRI and gated SPET (mean EF: 33%+/-12% vs 35%+/-11%, r = 0.86, P<0.001). Areas under receiver operator characteristic curves (AUC) for differentiation between MRI WT score points ranged from 0.60 to 0.66 for visual SPET WT analysis, from 0.59 to 0.71 for delta count increase values and from 0.46 to 0.60 for % WT, indicating substantial overlap between WT categories. Absolute agreement for visual WT between MRI and gated SPET ranged from 25% to 57% (kappa 0.03-0.25) depending on tracer uptake, and was limited in areas with moderate to severe perfusion defects (kappa 0.03-0.13). It is concluded that gated SPET provided reliable estimates of regional WT and global function in patients with low angiographic LVEF.

Topics: Coronary Angiography; Coronary Disease; Electrocardiography; Female; Heart; Humans; Image Processing, Computer-Assisted; Magnetic Resonance Imaging; Male; Middle Aged; Myocardial Contraction; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Stroke Volume; Tomography, Emission-Computed, Single-Photon; Ventricular Dysfunction, Left

The purpose of this study was to evaluate the diagnostic value of Tc-99m tetrofosmin SPECT myocardial perfusion scintigraphy rest/stress and stress/rest protocols for the assessment of coronary artery disease (CAD).. 65 patients underwent both rest and stress SPECT imaging in a one-day protocol and coronary angiography within 2 months before or after scintigraphy. Scintigraphic data was obtained according to two different protocols; 1) rest-stress (n = 18) and 2) stress-rest (n = 47).. Scintigraphic evidence for myocardial ischaemia was found in 36 patients (55%). The overall sensitivity to detect CAD (> 50% luminal stenosis) was 94% (34/36), specificity 66% (19/24), positive predictive value 77%, negative predictive value 90%. The sensitivity to detect CAD for protocols 1 and 2 were 100% and 93%, specificity 56% and 70%, positive predictive value 69% and 81% and negative predictive value 100% and 88%, respectively. The left anterior descending coronary artery showed a sensitivity (overall, protocol 1 & 2) of 78%, 75% (3/4) and 79% (15/19) and a specificity of 71%, 64% (9/14) and 75% (21/28). The right coronary artery showed a sensitivity (overall, protocol 1 & 2) of 91%, 100% (6/6) and 88% (14/16) and a specificity of 70%, 92% (11/12) and 61% (19/31). The left circumflex coronary artery showed a sensitivity (overall, protocol 1 & 2) of 50%, 67% (2/3) and 46% (6/13) and a specificity of 94%, 100% (15/15) and 91% (31/34).. Tc-99m tetrofosmin appears to be a valuable tool in predicting significant CAD. The sensitivity and the positive predictive value are high, making this test highly appropriate for the diagnosis of CAD. The diagnostic value of the individual coronary arteries is high to moderate. No significant differences were found between both protocols.

Topics: Adult; Aged; Aged, 80 and over; Blood Flow Velocity; Coronary Angiography; Coronary Disease; Electrocardiography; Exercise Test; Female; Follow-Up Studies; Humans; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Predictive Value of Tests; Radiopharmaceuticals; Rest; Tomography, Emission-Computed, Single-Photon

Short acquisition protocols for gated single-photon emission tomography (SPET) myocardial perfusion imaging are desirable for sequential imaging to evaluate the myocardial response during pharmacological intervention. In this study a less than 5 min gated SPET acquisition protocol is proposed. Perfusion characteristics (defect severity) and left ventricular ejection fraction (LVEF), end-diastolic and end-systolic volumes (EDV, ESV), wall motion (WM) and wall thickening (WT) were calculated, checked for reproducibility and compared with data obtained using a standard gated SPET acquisition protocol. Gated SPET images were recorded in 20 patients starting 60 min after the administration of 925 MBq technetium-99m tetrofosmin at rest. The 5 min gated SPET studies were acquired with a three-head camera equipped with Cardiofocal collimators. This protocol was repeated twice. In addition gated SPET studies were acquired according to a standard protocol using parallel-hole collimators. The severity of perfusion defects was quantified on polar maps using the non-gated image data and a normal database. LVEF, EDV, ESV, WM and WT were calculated from the gated images. The agreement between 5-min and standard gated SPET acquisitions was excellent for all investigated parameters. The reproducibility of repeated 5-min acquisitions for the quantification of perfusion defect severity was excellent (r=0.97). The agreement for segmental WT scores between repeated 5-min gated SPET acquisitions was good: kappa=0.71; major differences in segmental classification were observed in 2.5%. For WM a good agreement was found for segments with a tracer uptake >/=30% of the maximum: kappa=0.65, major differences =7.7%. Excellent reproducibility was found for LVEF, EDV and ESV measurements: r=0.97, 0.99 and 0.99, respectively. It is concluded that fast gated SPET perfusion studies acquired in less than 5 min yield accurate and reproducible measurements of myocardial perfusion and function (global and regional). In addition the results obtained with the 5-min gated SPET protocol correlate well with those obtained using a standard acquisition protocol.

Topics: Coronary Disease; Female; Gamma Cameras; Heart; Humans; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Reproducibility of Results; Time Factors; Tomography, Emission-Computed, Single-Photon; Ventricular Function, Left

Increased pulmonary 201TlCl (Tl) uptake during exercise has been used as a marker of multivessel critical stenosis. We studied whether pulmonary 99mTc-Tetrofosmin (TF) uptake measurement during exercise is useful as an additional indicator for the detection of coronary artery disease. Pulmonary to myocardial uptake ratio (P/M) measured by TF scintigraphy during exercise were compared with findings of coronary angiography in eighty one patients with ischemic heart disease and also P/M measured with Tl in twenty one cases. TF P/M level in the patients with triple vessel disease was higher than that in the patients with no coronary stenosis, single vessel disease and double vessel disease. However, there was no significant correlation between TF P/M and the severity of coronary artery stenosis. Inverse correlation was observed between TF P/M and left ventricular ejection fraction (LVEF) (r = 0.29, p < 0.01). TF P/M in the patients less than 50% of LVEF was significantly higher than that in the patients over 50% of LVEF (p = 0.05). TF P/M was well correlated with Tl P/M (r = 0.86). In conclusion, quantitative TF P/M during exercise was thought to be useful indicator for the evaluation of coronary artery disease.

Topics: Aged; Coronary Disease; Exercise Test; Female; Heart; Humans; Lung; Male; Middle Aged; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Radionuclide Imaging; Radiopharmaceuticals; Stroke Volume

After reading Part III of this series of nuclear cardiology articles, the technologist should be able to: (a) compare and contrast radiopharmaceuticals used for myocardial perfusion imaging; (b) describe imaging protocols used for detecting coronary artery disease; and (c) describe imaging patterns seen following reconstruction of myocardial images.

Topics: Coronary Circulation; Coronary Disease; Coronary Vessels; Electrocardiography; Exercise Test; Female; Heart; Humans; Image Processing, Computer-Assisted; Male; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Technetium Tc 99m Sestamibi; Thallium Radioisotopes; Tomography, Emission-Computed, Single-Photon; Vasodilator Agents; Ventriculography, First-Pass

The purpose of this study was to assess the efficacy of attenuation-corrected (AC) technetium-99m (99mTc)-tetrofosmin single-photon emission computed tomography (SPECT) in detecting viable myocardium compared to 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET).. The role of 99mTc-labeled perfusion tracers in the assessment of myocardial viability remains controversial. Attenuation artifacts affect the diagnostic accuracy of SPECT images.. Twenty-four patients with coronary artery disease (mean left ventricular ejection fraction 30%) underwent resting 99mTc-tetrofosmin SPECT and FDG PET imaging. Both AC and non-attenuation-corrected (NC) SPECT images were generated.. Using a 50% threshold for viability by FDG PET, the percentage of concordant segments of viability between 99mTc-tetrofosmin and FDG on the patient basis increased from 79.8%+/-14.0% (mean+/-SD) on the NC images to 90.8%+/-10.6% on the AC images (p=0.002). The percentage of 99mTc-tetrofosmin defect segments within PET-viable segments, an estimate for the degree of underestimation of viability, decreased from 19.8%+/-15.2% on the NC images to 9.7%+/-12.6% on the AC images (p=0.01). Similar results were obtained when a 60% threshold was used to define viability by FDG PET. When the anterior-lateral and inferior-septal regions were separately analyzed, the effect of attenuation correction was significant only in the inferior-septal region.. The results indicate that AC 99mTc-tetrofosmin SPECT improves the detection of viable myocardium mainly by decreasing the underestimation of viability particularly in the inferior-septal region, although some underestimation/overestimation of viability may still occur even with attenuation correction.

Topics: Aged; Aged, 80 and over; Coronary Disease; Female; Fluorodeoxyglucose F18; Heart; Humans; Male; Middle Aged; Myocardial Contraction; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Tomography, Emission-Computed; Tomography, Emission-Computed, Single-Photon

Dobutamine stress testing is increasingly used for the diagnosis and functional evaluation of coronary artery disease. However, the relationship between myocardial perfusion abnormalities and complications of the test has not been studied.. We studied the hemodynamic profile, safety and feasibility of dobutamine (up to 40 microg/kg/min)-atropine (up to 1 mg) stress myocardial perfusion SPECT imaging (with 201TI, 99mTc-MIBI or tetrofosmin) in a consecutive series of 1076 patients (age = 59 +/- 11 yr, 50% with previous myocardial infarction) referred for evaluation of myocardial ischemia.. No infarction or death occurred during the test. The test was considered feasible (achievement of 85% of the target heart rate or an ischemic endpoint) in 1005 patients (94%). Hypotension (systolic blood pressure drop > or = 40 mm Hg) occurred in 37 patients (3.4%). Independent predictors were higher baseline systolic blood pressure (p < 0.0001), number of ischemic segments (p < 0.05) and age (p < 0.05). Supraventricular tachyarrhythmias occurred in 48 patients (4.4%). Independent predictors were fixed perfusion defect (infarction) score (p < 0.005) and age (p < 0.05). Ventricular tachycardia occurred in 41 patients (3.8%). Independent predictors were infarction score (p < 0.01) and male gender (p < 0.05). All arrhythmias terminated spontaneously or after metoprolol administration.. Dobutamine-atropine myocardial perfusion scintigraphy is a feasible method for the evaluation of coronary artery disease with a safety profile and feasibility comparable to those reported for dobutamine stress echocardiography. Patients with more severe fixed perfusion abnormalities are at a higher risk of developing tachyarrhythmias during the test.

Topics: Atropine; Coronary Disease; Dobutamine; Feasibility Studies; Female; Heart; Humans; Hypotension; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Risk Factors; Safety; Tachycardia; Technetium Tc 99m Sestamibi; Thallium Radioisotopes; Tomography, Emission-Computed, Single-Photon

The role of Tc-99m tetrofosmin single-photon emission tomography (SPECT) in the evaluation of myocardial perfusion before and 6 months after successful percutaneous transluminal coronary angioplasty (PTCA) was assessed in 41 consecutive patients (32 men and 9 women). Twenty-five patients had one-vessel disease, 14 had two-vessel disease, and 2 had three-vessel disease. Thirty-six patients had dilation of one vessel and five patients dilation of two stenosed vessels, with a total of 46 dilated vessels. All patients underwent coronary angiography both before PTCA and 6 months after revascularization. Restenosis was angiographically demonstrated in 16 (39%) patients and 16 (34.8%) vessels. Tc-99m tetrofosmin myocardial SPECT was 81.3% sensitive and 88% specific for the detection of restenosis in the group of patients with a positive predictive value of 81.3% and a negative predictive value of 88%. Sensitivity, specificity, positive predictive value, and negative predictive value were 81.3%, 90%, 76.5%, and 89.7%, respectively, for restenosis detection in specific vessels. It was concluded that most patients who underwent successful PTCA (34 of 41, or 82.9%) had significant (P < 0.001) improvement in their scan image 6 months after the angioplasty, and that Tc-99m tetrofosmin myocardial SPECT is an excellent tool to follow these patients because it can detect restenosis accurately and noninvasively.

Topics: Adult; Aged; Angioplasty, Balloon, Coronary; Coronary Angiography; Coronary Disease; Female; Heart; Humans; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Recurrence; Tomography, Emission-Computed, Single-Photon

Both radionuclide perfusion tracers and contractile response to dobutamine have been used to identify hibernating myocardium. The aim was to compare 201Tl (thallium) single photon emission CT (SPECT), 99mTc-tetrofosmin (tetrofosmin) SPECT, and dobutamine cine MRI for identifying regions of reversible myocardial dysfunction.. Thirty patients with 3-vessel coronary artery disease and impaired left ventricular function (mean LVEF, 24.0%; SD, 8.3%) scheduled for coronary bypass grafting were recruited. All underwent rest/dobutamine stress (5 to 10 microg . kg-1 . min-1) cine MRI, stress/rest tetrofosmin SPECT, and stress/redistribution and separate-day rest/redistribution thallium SPECT before surgery. Stress/redistribution thallium SPECT and resting MRI were repeated after surgery. In a 9-segment model, SPECT images were scored visually for tracer uptake, which was also measured from a polar plot of myocardial counts. MRI was scored visually for endocardial motion, myocardial thickening, and thickness. Five patients died before follow-up, and 2 declined postoperative investigation. In the remaining 23 patients, mean LVEF increased from 24.0% (SD, 8.3%) to 29.7% (SD, 11.1%) (P<0.05). Of 207 segments analyzed, 145 had significantly abnormal wall motion before surgery, and 82 of these improved function after revascularization. The criteria for predicting recovery of severely hypokinetic segments on preoperative imaging were tracer uptake graded "moderately reduced" or better, or positive inotropic response on dobutamine MRI. Late-rest thallium images showed the highest sensitivity (76%), compared with stress-redistribution thallium (68%) and rest tetrofosmin (66%) (P<0.05). All 3 tracer techniques were nonspecific (44%, 51%, and 49%, respectively). Redistribution of thallium after the resting injection was insensitive (18%) but highly specific (83%). Inotropic response to dobutamine was also insensitive (50%) but specific (81%).. Radionuclide uptake is a sensitive but nonspecific predictor of myocardial functional recovery, whereas dobutamine MRI is specific but insensitive.

Topics: Adult; Aged; Cardiotonic Agents; Coronary Disease; Dobutamine; Exercise Test; Female; Humans; Magnetic Resonance Imaging, Cine; Male; Middle Aged; Myocardial Stunning; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Thallium Radioisotopes; Tomography, Emission-Computed, Single-Photon; Ventricular Function, Left

Patients with acute coronary syndrome require accurate diagnosis and treatment. We found that emergency myocardial scintigraphy with 99mTc-tetrofosmin was useful for diagnosis in 2 patients with acute coronary syndrome. The first patient was a 66-year-old man, who was hospitalized with chest discomfort at rest. Blood tests, electrocardiography, and echocardiography revealed no unusual findings. Myocardial scintigraphy with 99mTc-tetrofosmin disclosed moderately reduced uptake extending from the anterior wall to the apex. Coronary arteriography revealed 75% stenosis of the left main trunk. He was diagnosed as having unstable angina pectoris and coronary bypass surgery was performed. The second patient was a 61-year-old man, who was hospitalized with chest discomfort. Slight leukocytosis and flat T waves in leads V5 and V6 on electrocardiogram were detected, but echocardiographic findings were not abnormal. Myocardial scintigraphy with 99mTc-tetrofosmin revealed a defect in the posterolateral wall. Coronary arteriography showed total obstruction of #14, and a diagnosis of acute myocardial infarction was established. PTCA of #14 was performed to achieve reperfusion.

Topics: Aged; Angioplasty, Balloon, Coronary; Coronary Artery Bypass; Coronary Disease; Heart; Humans; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon

Nitrates can be used to improve resting myocardial blood flow in patients with severe coronary artery disease. This may enhance tracer uptake during rest myocardial perfusion imaging. Recent studies using nitrates at rest have shown increased detection of reversible ischaemia in this patient group with the 201Tl and 99Tcm perfusion tracers MIBI and tetrofosmin. However, it is not always possible to assess the severity of coronary artery disease before the rest injection and therefore whether a patient would benefit from nitrate administration. To improve the sensitivity for the detection of reversible ischaemia and to avoid a repeat study with nitrates (especially in patients with 'fixed' defects), a protocol in which all patients routinely receive nitrates prior to the rest injection is required. This prospective study evaluated the effect of nitrate administration prior to rest imaging in a randomly selected group of patients. Thirty patients selected at random from routine referrals had stress, rest and rest + GTN tetrofosmin imaging on three separate days. Changes in reversibility between the rest and rest + GTN images were assessed both visually and using semi-quantitative analysis. Defects at stress were seen in 43 coronary artery territories, 33 of which were reversible at rest and 37 reversible at rest + GTN. Of these 43 defects, 82% demonstrated either increased or the same degree of reversibility at rest + GTN imaging compared to standard rest imaging. All defects with reduced reversibility at rest + GTN imaging (i.e. the remaining 18%) were, however, still reversible compared to the stress images. Some of this reduced reversibility may be due to attenuation artefacts. We conclude that the routine use of GTN with rest tetrofosmin imaging will result in increased detection of ischaemic areas with no loss of sensitivity or specificity.

Topics: Administration, Sublingual; Adult; Aged; Coronary Disease; Coronary Vessels; Exercise Test; Female; Heart; Humans; Male; Middle Aged; Myocardial Ischemia; Nitroglycerin; Organophosphorus Compounds; Organotechnetium Compounds; Radionuclide Imaging; Radiopharmaceuticals; Sensitivity and Specificity; Vasodilator Agents

The aim of this study was to compare technetium-99m labelled tetrofosmin and sestamibi myocardial perfusion single-photon emission tomography (SPET) with one common sestamibi reference file for bull's eye imaging, with quantitation of the extent and severity of perfusion defects. Twenty patients suspected or known to have coronary artery disease participated in the study. Patients first underwent routine sestamibi myocardial SPET over 2 days, receiving doses of 400-600 MBq at stress and 600-800 MBq at rest. Then within the same week a 1-day tetrofosmin myocardial SPET study was performed, with a dose of 300 MBq at stress, followed 2.5 h later by a dose of 750 MBq at rest. Bull's eye images were generated for visual evaluation. Black-out defects according to the Cequal software analysis were only recorded if they comprised more than 10 pixels in men and 20 in women. According to the Cequal program, extent score and severity scores were expressed as number of pixels and deviations below reference limits. Five patients had normal myocardial SPET imaging with both radiotracers, while 15 had reversible, irreversible or partially reversible defects. The concordance of the results was high. The only two significant differences were that one patient had a reversible defect which appeared to be located in different myocardial regions (LAD vs RCA), and another patient had a defect that was partially reversible with sestamibi but irreversible with tetrofosmin. The results showed very high correlation coefficients for the extent and severity scores (linear correlation coefficient values of 0.99 and 0.94, respectively). In conclusion, it appears that changing between sestamibi and tetrofosmin has little influence on the interpretation of bull's eye images from the data file of a common reference population using one of the tracers.

Topics: Coronary Disease; Dipyridamole; Exercise Test; Female; Heart; Humans; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Reference Values; Technetium Tc 99m Sestamibi; Tomography, Emission-Computed, Single-Photon; Vasodilator Agents

This study investigates the value of ECG-gated 99mTc-tetrofosmin SPECT in the assessment of resting left ventricular (LV) function by comparison with cine MRI.. Twenty-eight patients were recruited prospectively from those referred for routine myocardial perfusion scintigraphy. Eight had three-vessel coronary artery disease, two had two-vessel disease, five had single-vessel disease and thirteen had not previously undergone coronary angiography. Twelve patients had previous myocardial infarction. After i.v. injection at rest of 750 MBq 99mTc-tetrofosmin, ECG-gated tomograms (16 frames per cardiac cycle) were acquired after 30 min. A nine-segment model of the LV was used and images were interpreted by two observers independently. Wall motion was assessed using a six-point scale (including unclassified where no judgment was possible), and systolic wall thickening was assessed from count changes through the cycle using a five-point scale. Tracer uptake was scored using a four-point scale. Diastolic wall thickness was assessed using a four-point scale. Cine magnetic resonance images were acquired in the same planes and analyzed in an identical fashion.. There was good overall agreement between the techniques for wall motion, thickness and thickening (kappa = 0.55-0.66), although 15 of the 252 (6%) segments were unclassified on radionuclide imaging. While there was absolute agreement in the assessment of all parameters in 10 patients with normal wall motion by MRI, agreement was less good in the 8 patients with three-vessel disease and poor left ventricular function (mean LVEF = 26%, mean LVEDV = 241 ml) (kappa = 0.37-0.48). Where tracer uptake was normal, there was good agreement between imaging, techniques (kappa = 0.64-0.75), but where uptake was absent or nearly absent, agreement was poor (kappa = 0-0.61), and 15 of 22 segments were unclassified on SPECT.. Gated 99mTc-tetrofosmin imaging provides an accurate assessment of myocardial wall motion, thickening and thickness in normal left ventricles but is less valuable in poorly functioning ventricles. Six percent of segments could not be assessed because of inadequate tracer uptake.

Topics: Adult; Aged; Coronary Disease; Electrocardiography; Female; Gated Blood-Pool Imaging; Humans; Magnetic Resonance Imaging, Cine; Male; Middle Aged; Myocardial Contraction; Observer Variation; Organophosphorus Compounds; Organotechnetium Compounds; Prospective Studies; Radiopharmaceuticals; Reproducibility of Results; Stroke Volume; Tomography, Emission-Computed, Single-Photon; Ventricular Function, Left

This study was undertaken to 1) compare the regional myocardial tracer distributions between rest technetium (Tc)-99m tetrofosmin and rest-redistribution thallium (Tl)-201 images in patients with coronary artery disease and left ventricular dysfunction; and 2) assess the comparative values of these agents for predicting functional recovery after revascularization.. Tc-99m tetrofosmin is a new myocardial perfusion imaging agent, but its role for detecting viable myocardium is still unclear.. Thirty-six patients with coronary artery disease and left ventricular dysfunction underwent rest Tc-99m tetrofosmin, rest-redistribution Tl-201 and gated blood pool scintigraphy. In 21 patients with successful revascularization confirmed by follow-up angiography, gated blood pool scintigraphy was repeated after revascularization. Optimal threshold cutoffs to separate reversible from irreversible dysfunction were determined by receive operating characteristic analysis.. Regional Tc-99m tetrofosimin activity highly correlated with redistribution Tl-201 activity (r = 0.93). The diagnostic performance for predicting functional recovery, as measured by the area under the receiver operating characteristic curves, measured 0.66 +/- 0.07 (mean +/- SD) for Tc-99m tetrofosmin and 0.67 +/- 0.07 for Tl-201 (p = 0.60, 96.7% power to detect difference in area of 0.10). The optimal threshold cutoffs for viability were considered to be 50% of peak activity for Tc-99m tetrofosmin and 55% of peak activity for Tl-201. The positive and negative predictive values for reversible dysfunction were, respectively, 69% and 82% for Tc-99m tetrofosmin and 69% (p = 0.99 vs. Tc-99m tetrofosmin) and 71% (p = 0.66 vs. Tc-99m tetrofosmin) by Tl-201.. The diagnostic performance of quantitative rest Tc-99m tetrofosmin imaging in predicting functional recovery after revascularization is comparable to that of rest-redistribution Tl-201.

Topics: Aged; Angioplasty, Balloon, Coronary; Case-Control Studies; Coronary Artery Bypass; Coronary Disease; Female; Gated Blood-Pool Imaging; Heart; Humans; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Predictive Value of Tests; Prospective Studies; Radiopharmaceuticals; ROC Curve; Thallium Radioisotopes; Tomography, Emission-Computed, Single-Photon; Ventricular Dysfunction, Left

A comparison was performed between technetium-99m tetrofosmin myocardial perfusion tomography at baseline and after nitrate administration, using a 2-day protocol, and rest-reinjection thallium-201 single-photon emission tomography (SPET) studies in order to assess whether nitrates enhance the detection of viable myocardium with 99mTc-tetrofosmin. Fifteen patients with coronary artery disease, previous myocardial infarction and a left ventricular ejection fraction <40% underwent 201Tl rest-injection and 99mTc-tetrofosmin baseline-postnitroglycerin (0.4 mg sublingually) SPET studies, within 48 h. Tomograms based on the three spatial planes were divided into 15 segments and regional tracer uptake was quantitatively analysed. Viability was defined as presence of tracer uptake >/=50% of peak activity on baseline studies or after reversibility. The percentage of peak activity of 99mTc-tetrofosmin at baseline correlated with that of 201Tl (r=0.82, P <0.001). On baseline 99mTc-tetrofosmin studies, 73 of the 225 segments that were analysed had <50% of peak activity. Fifteen percent of these segments showed reversibility after nitrate administration, with an increase in 99mTc-tetrofosmin uptake from 40%+/-9% to 57%+/-9% of peak activity (P=0.003). All reversible segments after nitrate administration had viability criteria on 201Tl studies, but 20 segments that were non-viable on 99mTc-tetrofosmin studies were viable on 201Tl studies. Using a threshold value of >/=40% of peak activity, only seven segments remained non-viable on 99mTc-tetrofosmin studies. Overall agreement between 99mTc-tetrofosmin with nitrates and 201Tl-reinjection regarding the presence of myocardial viability was 90%. Detection of myocardial viability with 99mTc-tetrofosmin was enhanced after nitrate administration, correlating with viability criteria observed on thallium studies.

Topics: Case-Control Studies; Coronary Disease; Female; Heart; Humans; Male; Middle Aged; Nitroglycerin; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Thallium Radioisotopes; Time Factors; Tomography, Emission-Computed, Single-Photon; Vasodilator Agents; Ventricular Dysfunction, Left

In patients with coronary artery disease (CAD), differentiation between severely ischemic but potentially viable myocardium and irreversibly infarcted tissue is clinically important, particularly when revascularization procedures are considered. Although thallium (TI) cardiac imaging has been shown to be a good tool for investigating myocardial viability in CAD, this tracer shows physical limitations, such as a low photon energy and long half-life. We assessed the results of a rest TI-201/stress Tc-99m tetrofosmin protocol in subjects with prior anterior myocardial infarction. All of the patients had an akinetic or dyskinetic area and more than 75% stenosis in the left anterior descending artery. All of the patients underwent revascularization after the examination. We evaluated the improvement in wall motion after revascularization using the centerline method with contrast left ventricular angiography. Fourteen patients showed reversible defects with the rest TI-201/stress Tc-99m tetrofosmin protocol or in additional TI-201 24 h redistribution images. All 14 patients showed a significant improvement in wall motion after revascularization. Dual-isotope rest TI-201/stress Tc-99m tetrofosmin single photon emission tomography data, acquired separately, may give fast and complete information about myocardial perfusion during stress and at rest, and on about myocardial viability.

Topics: Aged; Coronary Artery Bypass; Coronary Disease; Exercise Test; Female; Heart; Humans; Male; Middle Aged; Myocardial Contraction; Myocardial Infarction; Myocardial Ischemia; Myocardial Reperfusion; Myocardium; Organophosphorus Compounds; Organotechnetium Compounds; Thallium Radioisotopes; Tissue Survival; Tomography, Emission-Computed, Single-Photon

This study compared the results of adenosine 99mTc-tetrofosmin cardiac tomography with those of adenosine echocardiography in identifying patients with coronary artery disease (CAD) and in localizing individual stenosed, coronary vessels.. Twenty-six consecutive patients with suspected or known CAD had simultaneous adenosine (140 micrograms/Kg/min intravenously) 99mTc-tetrofosmin tomography and two-dimensional echocardiography. All patients had coronary angiography within 4 wk from imaging studies. Regional 99mTc-tetrofosmin activity was quantitatively measured in 78 coronary vascular territories and echocardiographic left ventricular function was assessed in corresponding regions.. At coronary angiography one patient had normal coronary vessels, 12 patients one-vessel and 13 had multivessel disease (> or = 50% luminal stenosis). Among the 25 patients with CAD, 22 showed perfusion defects at adenosine 99mTc-tetrofosmin tomography (sensitivity 88%) and 17 had abnormal echocardiographic study (sensitivity 68%, p < 0.05 versus 99mTc-tetrofosmin). Agreement for the identification of patients with CAD between adenosine 99mTc-tetrofosmin tomography and echocardiography was observed in 21 (81%) of the total 26 patients, with a kappa value of 0.45. Overall sensitivity, specificity and diagnostic accuracy for detection of individual stenosed vessels were 79%, 88% and 83% for 99mTc tetrofosmin and 57%, 68% and 61% (all p < 0.05 versus 99mTc-tetrofosmin) for echocardiography. Concordance between adenosine 99mTc-tetrofosmin tomography and echocardiography in the detection of individual stenosed coronary vessels was observed in 57 (73%) of the 78 vascular territories, with a kappa value of 0.36.. Adenosine-induced coronary vasodilation associated with quantitative 99mTc-tetrofosmin tomography is more accurate than adenosine echocardiography in identifying patients with CAD and in detecting individual stenosed coronary vessels.

Topics: Adenosine; Adult; Coronary Disease; Coronary Vessels; Echocardiography; Female; Heart; Hemodynamics; Humans; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Sensitivity and Specificity; Tomography, Emission-Computed, Single-Photon; Vasodilation; Vasodilator Agents

Irregular photon attenuation may limit the diagnostic accuracy of myocardial single-photon emission tomography (SPET). The aim of this study was to quantify the potential benefit of attenuation correction by simultaneous emission and transmission imaging for the detection of coronary artery disease (CAD) of vessels supplying the inferoposterior wall segments. In 25 male patients with >/=50% stenoses of the right coronary artery and/or circumflex artery but without significant narrowing of the left anterior descending artery, stress studies using technetium-99m tetrofosmin (400 MBq) were carried out with and without attenuation correction. A dual-head camera with L-shaped detector positioning was equipped with two scanning gadolinium-153 line sources. Tomograms were reconstructed and quantified using circumferential count rate profiles of myocardial activity (two in each patient). The profiles were compared with the respective normal ranges obtained from a database of 25 male patients with a <10% likelihood of CAD. In patients without CAD, the maximal differences in count density of different wall segments were reduced from 29.0% in non-corrected (NC) studies to 9.5% in attenuation-corrected (AC) studies. In particular, the inferoposterior and septal wall segments were represented by significantly increased relative count densities after attenuation correction. The effects of attenuation correction proved independent of body mass. In patients with CAD, segmental count densities were abnormal in 84% of the NC studies and 100% of the AC studies. In single-vessel disease the stenotic vessel was identified in 66% of cases by NC studies and in 100% by AC studies. In AC studies, the extent and depth of defects exceeded those in NC studies. For the detection of CAD of the right coronary artery, the receiver operating characteristic (ROC) curves relating to the AC studies demonstrated improved discrimination capacity (P<0.05). ROC analysis of CAD detection yielded normalcy rates of 82% (NC) and 94% (AC) for the circumflex artery and 65% (NC) and 97% (AC) for the right coronary artery area at a sensitivity level of 95%. It is concluded that attenuation correction using the above system may enhance the diagnostic accuracy of myocardial SPET when inferoposterior wall segments are to be evaluated.

Topics: Algorithms; Coronary Disease; Gamma Cameras; Heart; Humans; Image Processing, Computer-Assisted; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Predictive Value of Tests; Radiopharmaceuticals; ROC Curve; Sensitivity and Specificity; Tomography, Emission-Computed, Single-Photon

The aim of this study was to determine the diagnostic accuracy of technetium-99m tetrofosmin myocardial imaging for the localization of coronary artery stenoses of different degrees of severity. Stress-rest single-photon emission tomography (SPET) was performed on separate days in 80 patients (64 males, 16 females; mean age 61 years; 43 patients with previous myocardial infarction; 18 patients with pharmacological stress), within 6 months of coronary angiography. Scintigraphic images were blindly and independently evaluated by three observers. Coronary stenosis was defined as a >50% narrowing in luminal diameter; severe stenosis was defined as a proximal stenosis of >75% or a peripheral stenosis of >90%. Coronary angiography revealed normal coronary arteries or insignificant coronary stenosis in 13 patients and significant coronary stenoses in 67 patients. The sensitivity and specificity of 99mTc-tetrofosmin SPET in respect of severely stenosed vessels were, respectively, 80% and 65% for the left anterior descending artery (LAD), 100% and 46% for the right coronary artery (RCA) and 58 and 78% for the left circumflex artery (LCx) territories. Considering all the significantly stenosed vessels, a significant decrease in sensitivity was observed for LAD territories (to 59%, P=0.05), and a nonsignificant decrease for RCA (88%) and LCx (47%) territories while specificity values remained essentially unchanged. No significant changes in sensitivity or specificity were observed when regions with previous myocardial infarction were excluded. In conclusion, the sensitivity of 99mTc-tetrofosmin SPET for the localization of individual stenosed vessels is only moderate when all significant stenoses are considered, but the ability of this technique to predict the location of severe coronary artery stenoses seems satisfactory, with the exception of the low specificity in respect of RCA territories.

Topics: Coronary Angiography; Coronary Disease; Exercise Test; Female; Heart; Humans; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Sensitivity and Specificity; Tomography, Emission-Computed, Single-Photon

Clinical studies have shown a comparable coronary stenosis detection rate between 99mTc-tetrofosmin and 201Tl but with smaller defect magnitudes for 99mTc-tetrofosmin. The goals of this study were to measure the first-pass extraction fraction (EF) of 99mTc-tetrofosmin in canine myocardium and to compare 99mTc-tetrofosmin with 201Tl uptake during adenosine-induced vasodilatation in dogs with various degrees of coronary stenosis.. EF was calculated in 4 anesthetized, open-chest dogs after intracoronary administration of 125I-labeled albumin and 99mTc-tetrofosmin. In another 16 dogs with either critical (n=6) or mild (n= 10) left anterior descending coronary artery (LAD) stenoses, 201Tl and 99mTc-tetrofosmin were administered during adenosine infusion (250 microg x kg(-1) x min(-1)). Dogs were killed 5 minutes later, and tracer activities were determined by ex vivo imaging of heart slices and by well counting. Mean 99mTc-tetrofosmin EF was 54.0+/-3.7%. In the 6 critical-stenosis dogs, the LAD-to-left circumflex artery (LCx) microsphere flow ratio was 0.22+/-0.02 with adenosine. The LAD-to-LCx activity ratios were 0.37+/-0.04 for 201Tl and 0.67+/-0.05 for 99mTc-tetrofosmin (P<.01). For the 10 mild-stenosis dogs, the LAD-to-LCx flow ratio was 0.44+/-0.05. The 201Tl activity ratio was 0.58+/-0.04, compared with 0.81+/-0.04 for 99mTc-tetrofosmin (P<.01). Thus, in both groups, 99mTc-tetrofosmin uptake underestimated the flow disparity more than 201Tl. Similarly, magnitudes of ex vivo image defects were significantly greater for 201Tl than for 99mTc-tetrofosmin in both groups.. In this canine model, relative underperfusion with adenosine stress is better resolved with 201Tl than with 99mTc-tetrofosmin and may be explained by the lower EF for 99mTc tetrofosmin. With clinical imaging, greater 201Tl attenuation and redistribution may lessen this advantage.

Topics: Adenosine; Animals; Biological Transport; Coronary Circulation; Coronary Disease; Dogs; Heart; Models, Biological; Myocardium; Organophosphorus Compounds; Organotechnetium Compounds; Radionuclide Imaging; Reference Values; Regional Blood Flow; Thallium Radioisotopes; Tissue Distribution; Vasodilation

Topics: Adult; Aged; Aged, 80 and over; Coronary Circulation; Coronary Disease; Exercise Test; Female; Humans; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Sensitivity and Specificity; Tomography, Emission-Computed, Single-Photon

The clinical usefulness of a new myocardial perfusion imaging agent, technetium-99m tetrofosmin, was assessed in 58 patients for a total of 76 times (mean age 9.7 years, 1-15 years) including 20 with and 26 without significant coronary stenotic lesions in Kawasaki disease. Pharmacological (dobutamine or adenosine triphosphate disodium) or exercise stress technetium-99m tetrofosmin single photon emission computed tomography was performed under stress and at rest on the same day. The sensitivity for detection of stress-induced perfusion defects by this method was 90% (18/ 20) and the specificity was 85% (22/26). The dose was 9.3 +/- 2.5 MBq/kg under stress and 18.7 +/- 5.6 MBq/kg at rest. No significant correlation was recognized between the dose and the image quality. Adequate image quality was provided by projection time 20-40 sec per frame. Increased liver accumulation was seen in 24% (18/76), especially in younger and pharmacological stress cases. The acquisition starting time after tetrofosmin injection was 58.4 +/- 18.7 min in the negative increased liver accumulation group and 43.7 +/- 18.3 min in the positive group (p < 0.01). We recommend that the following protocol is used for pediatric imaging. 1) The standard tetrofosmin dose is rougly 10 MBq/kg (upper limit 370 MBq) at stress and the double dose for the rest imaging. 2) SPECT projection time of 20-40 sec per frame. 3) In practice, the patient should be fasting prior to stress injection, and the imaging should be done 1 hour after eating. The rest injection should be done immediately thereafter, and the rest image should be obtained 1 hour later.

Topics: Adolescent; Child; Child, Preschool; Coronary Circulation; Coronary Disease; Female; Heart; Humans; Infant; Male; Mucocutaneous Lymph Node Syndrome; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon

We reported a 47-year-old female with congestive heart failure (CHF) of unknown origin. In this case, it was suggested that 123I-BMIPP and 99mTc-tetrofosmin myocardial SPECT images were useful in the diagnosis of CHF of unknown origin. She had complained of easy fatigability and dyspnea on effort since Sep. 1995. She was admitted to our hospital because of worsening of symptoms in Dec. 1995. Slightly decreased uptake in anterior, lateral and apical walls was recognized in 99mTc-tetrofosmin SPECT images, meanwhile 123I-BMIPP SPECT images showed markedly reduced uptake in the same areas. This discordance in the distribution between 123I-BMIPP and 99mTc-tetrofosmin myocardial SPECT suggested that CHF was not due to dilated cardiomyopathy, but ischemic myocardial disease. Coronary angiography revealed 90% stenosis at the just proximal of left coronary artery. This case was diagnosed an isolated coronary ostial stenosis with CHF, because she was menstruated middle aged woman and did not have a history of aortitis syndrome, syphilis and coronary risk factor before.

Topics: Coronary Disease; Fatty Acids; Female; Heart Failure; Humans; Iodine Radioisotopes; Iodobenzenes; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon

Nineteen patients with angina were recruited in this study for comparison of two 1-day protocols (stress-4h rest and rest-4-h stress) and a 2-day protocol of technetium-99m tetrofosmin single-photon emission tomography (SPET). All of them underwent coronary angiography before or after the study. Exercise stress-rest study and rest-stress study were performed on two consecutive days. Delayed imaging was performed before the rest injection on the 2nd day. The stress study on the 1st day and rest study on the 2nd day were considered as a 2-day protocol. The 1-day stress-rest protocol had a sensitivity of 100% (18/18) and an accuracy of 100% (19/19) in diagnosing ischaemic heart disease. The 1-day rest-stress protocol had a sensitivity of 94.4% (17/18) and an accuracy of 94.7% (18/19). These differences were not statistically significant (P=0.5 for sensitivity and accuracy). There was also no statistically significant difference between the two protocols in the diagnosis of ischaemic heart disease in individual artery territories. For the left descending artery, sensitivity was 88.2% (15/17) vs 76.5% (13/17) (P=0.48) for the stress-rest and rest-stress studies respectively. For the left circumflex artery, sensitivity was 90% (9/10) vs 80% (8/10) (P=1) and specificity was 66.7% (6/9) vs 77.8% (7/9) (P=1) respectively. For the right coronary artery, the sensitivity was 100% (16/16) vs 94% (15/16) (P=1) respectively, while the specificity was 33.3% (1/3) in both studies. Three hundred and forty-two myocardial segments were analysed. The stress-rest and 2-day protocols showed no statistically significant difference in the overall identification of segments with reversible ischaemia (48/141 segments vs 48/141 segments) or in respect of individual artery territories. There was also no significant difference in the identification of reversible ischaemic segments between the rest-stress and 2-day protocols (48/141 segments vs 34/135 segments, P=0.14). Abdominal activity was seen in 36 studies and interpretation was affected in five of them. Five patients with 24-h delayed images were evaluated and 24 segments with washout were identified. It is concluded that 99mTc-tetrofosmin is a valuable new tracer in the investigation of ischaemic heart disease. The 1-day stress-rest protocol is as good as the 1-day rest-stress protocol in diagnosing coronary heart disease. The 1-day protocols and the 2-day protocol display no difference in identifying segments with reversible is

Topics: Adult; Aged; Coronary Disease; Female; Heart; Humans; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Time Factors; Tomography, Emission-Computed, Single-Photon

Defect size on exercise-rest technetium (Tc)-99m tetrofosmin myocardial perfusion imaging was compared with that on exercise-reinjection thallium-201 imaging with 20 patients with 1-vessel coronary artery disease. In each patient, exercise-reinjection thallium-201 single-photon emission computed tomography (SPECT) and exercise-rest Tc-99m tetrofosmin SPECT imaging were performed. For visual analysis of the obtained SPECT images, the left ventricular myocardium was divided into 20 segments based on 3 short-axis slices from the apical, middle, and basal ventricular levels. For quantitative analysis, a square region of interest was placed on the center of each segment which was used for visual analysis, and relative regional activity to the normal reference region was calculated for each segment. By visual interpretation of the images, exercise Tc-99m tetrofosmin imaging showed a smaller defect size than exercise thallium-201 imaging (6.9 +/- 3.9 vs 8.8 +/- 3.0 segments, p <0.01). In contrast, rest Tc-99m tetrofosmin imaging showed a defect size similar to that on reinjection thallium-201 imaging (5.9 +/- 3.6 vs 5.6 +/- 3.9 segments, p = NS). Similarly, the mean defect sizes during exercise determined by quantitative analysis were smaller on Tc-99m tetrofosmin SPECT than those on thallium-201 SPECT at all tested threshold cutoff points ranging from 50% to 70%, whereas there were no significant differences in defect sizes between rest Tc-99m tetrofosmin and reinjection thallium-201 imaging. These data indicate that exercise Tc-99m tetrofosmin SPECT defect size determined either by visual analysis or by quantitative analysis may be smaller than on exercise thallium-201 SPECT.

Topics: Aged; Constriction, Pathologic; Coronary Disease; Coronary Vessels; Exercise Test; Female; Heart; Humans; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Thallium Radioisotopes; Tomography, Emission-Computed, Single-Photon

The aim of this study was to evaluate the accuracy of quantitative 1-day exercise-rest technetium-99m tetrofosmin tomography in the identification of patients with coronary artery disease (CAD) and in the detection of individual stenosed coronary vessels. Sixty-one patients with suspected CAD who underwent coronary angiography and 13 normal volunteers were studied. All patients were submitted to two i.v. injections of 99mTc-tetrofosmin, one at peak exercise (370 MBq) and the other (1110 MBq) at rest 3 h after exercise (images 15-30 min after injection for both studies). All patients with CAD (>/=50% luminal stenosis) (n=50) had an abnormal 99mTc-tetrofosmin tomogram. Only one patient without significant coronary narrowing showed abnormal findings. Overall sensitivity, specificity and diagnostic accuracy in the detection of individual stenosed vessels were 77%, 93% and 85%, respectively. Sensitivity and diagnostic accuracy in the identification of individuals stenosed coronary vessels were significantly higher (P<0.05) in patients with single-vessel disease (n=21) than in those with multivessel disease (n=29). Sensitivity, specificity and accuracy for detecting individual diseased vessels were similar in patients without previous myocardial infarction (n=26) and in those with previous myocardial infarction (n=35). In myocardial territories related to non-infarcted areas (n=128), sensitivity and specificity in the detection of stenosed vessels were 70% and 95%, respectively. In infarcted areas (n=55), sensitivity and specificity in the detection of stenosed vessels were 85% (P=NS vs non-infarcted areas) and 75% (P<0.05 vs non-infarcted areas), respectively. Finally, sensitivity was significantly lower (P<0.05) in vascular territories supplied by vessels with moderate stenosis (50%-75%) than in those supplied by vessels with severe stenosis (>75%). The results of this study demonstrate that quantitative 1-day exercise-rest 99mTc-tetrofosmin single-photon emission tomographic imaging is a suitable and accurate technique to identify patients with CAD and to detect individual stenosed coronary vessels.

Topics: Case-Control Studies; Coronary Angiography; Coronary Disease; Exercise Test; Female; Heart; Humans; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Sensitivity and Specificity; Time Factors; Tomography, Emission-Computed, Single-Photon

Technetium-99m-tetrofosmin uptake was compared to that of 201Tl in the setting of low flow and systolic dysfunction.. In nine open-chested dogs, a severe left anterior descending (LAD) coronary artery stenosis resulted in a 54.3% mean flow reduction and decreased left ventricular thickening from 21% +/- 1% to -3 +/- 2%. After 30 min, 37 MBq (1 mCi) of 201Tl and microspheres were injected and initial and 2-hr redistribution images acquired. Two hours later, 370 MBq (10 mCi) of 99mTc-tetrofosmin and microspheres were injected and an image was obtained. LAD: left circumflex (LCX) count ratios for both tracers and flows were calculated by well counting postmortem, and 201Tl and 99mTc-tetrofosmin defect magnitudes were determined by quantitative image analysis.. LAD:LCx flow ratios were similar during 201Tl and 99mTc-tetrofosmin injections (0.48 +/- 0.04 versus 0.49 +/- 0.05, p = n.s.). Final 201Tl activity (0.66 +/- 0.04) was significantly higher than 99mTc-tetrofosmin (0.55 +/- 0.05; p < 0.05). LAD/LCx 99mTc-tetrofosmin image defect count ratio was similar to 201Tl defect count ratio on the initial rest 201Tl scan (0.57 +/- 0.03 versus 0.56 +/- 0.02, p = ns), but significantly less than 201Tl defect count ratio at 2 hr (0.57 +/- 0.03 versus 0.65 +/- 0.02, p < 0.05).. In a low-flow model with profound systolic dysfunction, myocardial 99mTc-tetrofosmin uptake ( > 50%) reflective of viability was observed in the asynergic zone perfused by the stenotic LAD.

Topics: Animals; Coronary Circulation; Coronary Disease; Dogs; Heart; Image Processing, Computer-Assisted; Microspheres; Organophosphorus Compounds; Organotechnetium Compounds; Radionuclide Imaging; Systole; Thallium Radioisotopes; Ventricular Dysfunction, Left

Standard exercise thallium-201 (201Tl)-redistribution protocols for the detection of coronary artery disease take about 4 h to complete. This is inconvenient for both patients and staff. The higher energy technetium-99m (99Tcm) emissions permit immediate imaging after 201Tl with minimal crosstalk. This study assessed exercise gated planar 201Tl scintigraphy (55 MBq) followed by rest gated planar 99Tcm-tetrofosmin scintigraphy (250 MBq) in 32 patients. The results showed a high sensitivity for the detection of coronary disease (100%) in this highly selective group of patients. In order to diagnose myocardial infarction accurately, it was necessary to view the gated 201Tl images and assess regional wall motion in a defect zone. This gave a specificity of 88% and a sensitivity of 71% for the prediction of myocardial infarction on the angiographic ventriculogram. Stress 201Tl/rest 99Tcm-tetrofosmin is a useful short protocol for patients unable to complete the full 4-h exercise 201Tl-redistribution study.

Topics: Adult; Aged; Clinical Protocols; Coronary Angiography; Coronary Disease; Evaluation Studies as Topic; Exercise Test; Female; Humans; Male; Middle Aged; Myocardial Infarction; Organophosphorus Compounds; Organotechnetium Compounds; Radionuclide Imaging; Sensitivity and Specificity; Thallium Radioisotopes

Tc-99m tetrofosmin is a lipophilic, cationic perfusion imaging agent that changes to Tl-201 in detecting coronary artery disease during exercise testing. The purpose of this study is to evaluate the usefulness of Tc-99m tetrofosmin dipyridamole stress imaging combined with low level exercise for the detection of coronary artery disease. We examined 42 patients and 10 normal volunteers who also underwent coronary angiography. A one-day protocol was used: in the stress study, 296 MBq of tetrofosmin was injected and in the rest study 888 MBq was injected. After intravenous administration of dipyridamole (0.142 mg/kg/min for 4 minutes), the patient was exercised on a bicycle ergometer for 3 min (25 Watts). Tetrofosmin was injected 2 minutes after dipyridamole infusion during the exercise. Single photon emission computed tomographic images were obtained 30 minutes after the tracer injection. Images were interpreted as abnormal in 36 of 42 patients with coronary artery disease, and normal in all of 10 normal volunteers. The overall sensitivity of detection of coronary artery disease was 83.3% and the normalcy rate was 100%. The diagnostic values for the detection of significant stenosis in the three major arteries were: LAD sensitivity 83%, specificity 92%; LCX sensitivity 47%, specificity 91%; RCA sensitivity 75%, specificity 83%. Of the 66 arteries with more than 50% stenosis, 48 arteries were correctly identified. Of the 36 with more than 70% stenosis, 31 were identified. Scintigraphic evidence of multivessel disease was found in only 9 patients (50%). A protocol of Tc-99m tetrofosmin SPECT combined with low level exercise after dipyridamole is therefore useful for the detection of the coronary artery disease.

Topics: Adult; Coronary Disease; Dipyridamole; Exercise Test; Female; Heart; Humans; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Reference Values; Tomography, Emission-Computed, Single-Photon; Vasodilator Agents

Recent work has shown that rest 99Tcm-sestamibi uptake may underestimate the amount of perfused myocardium, suggesting infarct tissue in some instances when myocardium is hypoperfused but which will benefit from revascularization. Administration of nitrates before a resting 99Tcm-sestamibi injection has been shown to increase tracer uptake. We have used 99Tcm-tetrofosmin as a myocardial perfusion agent and imaged 30 patients at stress, rest and again at rest following administration of sublingual nitrates. All patients had angiographically demonstrated severe coronary artery disease and 27 patients had previous infarction. Twenty-one patients were stressed on a treadmill and nine using intravenous dobutamine. Images were analysed using both a visual and semi-quantitative analysis. Defects were observed in 39 coronary artery territories on stress 99Tcm-tetrofosmin imaging, 23 appearing fixed on standard rest imaging. Twelve (52%) of these defects showed reversibility on rest with glyceryl trinitrate (GTN) imaging and increased reversibility was seen in 62% of defects reversible at rest. We conclude that, in patients with severe coronary artery disease and fixed rest defects, GTN given prior to the rest injection appears to improve the detection of ischaemic hypoperfused myocardium.

Topics: Administration, Sublingual; Adult; Aged; Coronary Angiography; Coronary Disease; Exercise Test; Female; Humans; Male; Middle Aged; Myocardial Ischemia; Nitroglycerin; Organophosphorus Compounds; Organotechnetium Compounds; Radionuclide Imaging; Vasodilator Agents

To investigate whether tetrofosmin uptake is affected by myocardial viability as has been noted for 201Tl and sestamibi, we analyzed the initial and delayed distribution patterns of tetrofosmin in a rat coronary artery occlusion-reperfusion model.. Animals were intubated and ventilated, and their arterial pressures were monitored. A left thoracotomy was performed. After 1-hour occlusion and 1-hour reperfusion of a major branch of the circumflex artery, 201Tl and either tetrofosmin or sestamibi were injected intravenously. Radiolabeled microspheres were used to document the area at risk and reperfusion. Five minutes or 1 hour after administration of the diffusible tracers, the animals were killed. Tracer distribution was determined by use of segmental tissue analysis, and tissue viability was determined by use of histochemical staining. Both the initial and delayed retention of tetrofosmin were sensitive to myocardial viability, as shown by significantly lower uptake (30 +/- 14%) and retention (24 +/- 12%) of tetrofosmin in the nonviable segments compared with the viable segments. In addition, the initial myocardial distribution of tetrofosmin was similar to that noted for 201Tl, but after 1 hour of tracer circulation, the tetrofosmin tissue distribution appeared unchanged compared with the initial regional blood flow distribution. This is in direct contrast to our present observations of significant 201Tl redistribution and some changes in sestamibi distribution as well.. The clinical implication of these observations suggests that initial and delayed imaging after tetrofosmin administration would reflect both the initial regional blood flow pattern and myocardial viability.

Topics: Animals; Coronary Circulation; Coronary Disease; Hemodynamics; Male; Myocardial Reperfusion; Myocardium; Nitroblue Tetrazolium; Organophosphorus Compounds; Organotechnetium Compounds; Rats; Rats, Sprague-Dawley; Staining and Labeling; Technetium Tc 99m Sestamibi; Thallium; Thallium Radioisotopes

A new method is described for precise quantitative analysis of the relative three-dimensional distribution of myocardial tracers. The system uses a 360 degrees elliptical sampling of radial slices to create activity profiles. These are then positioned onto a common centre at the same angular coordinates as the corresponding radial slice reconstruction planes to generate a two-dimensional polar summary display. Abnormal distribution is then identified by automatic comparison of the patient polar map with the threshold of a normal database defined on a pixel by pixel basis as the normal mean -2.5 SD. Our stress and rest databases currently comprise 34 and 24 studies for sestamibi and tetrofosmin respectively. The present method differs from currently available software in two major respects. First, radial slices are used rather than short-axis slices to minimize operator intervention and to allow quantitative evaluation of the left ventricle volume independent of the heart size and without truncation, in particular near the apex and at the base. This sampling scheme also results in a more homogeneous and sampling-independent partial volume effect. Secondly, quantitative analysis is improved by calculating perfusion defect severity, extent and size in a precise manner. Severity is evaluated relative to a standardized background measurement and to the mean normal value rather than to the threshold value. This parameter was underestimated up to a defect extent of 32 cm2 in our phantom studies. Calculation of defect extent takes into account the surface distortion resulting from planar projection by using pixel by pixel weighted factors but it is otherwise overestimated as a result of the limited resolution of the imaging system. Integrating defect severity and extent, our hypoperfusion index appeared to accurately estimate the true defect size in our phantom model (r=0.993). The reproducibility of analysis was 6.24% in phantom studies and 3.10% in patient studies including repeated acquisitions. Applied to a well-documented population of 80 patients, this method resulted in an 86% sensitivity and a 78% specificity for overall coronary artery disease detection with reference to the angiographic data.

Topics: Coronary Disease; Exercise Test; Female; Heart; Humans; Image Processing, Computer-Assisted; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Phantoms, Imaging; Radiopharmaceuticals; Reproducibility of Results; Sensitivity and Specificity; Technetium Tc 99m Sestamibi; Tomography, Emission-Computed, Single-Photon

Left ventricular ejection fraction (LVEF) can be derived from gated single-photon emission tomographic (SPET) myocardial perfusion studies using either manual or edge detection techniques. In the presence of severe perfusion defects, however, difficulties may be encountered. In this article a method based on the assumption that the average position of the myocardial wall can be localized by means of statistical analysis of the distribution count density, and not on edge detection, is used to measure LVEF. SPET myocardial perfusion images, gated in eight time bins, were recorded in 50 patients 60 min after the injection of 925 MBq technetium-99m tetrofosmin. Masking of non-myocardial structures and thresholding resulted in images in which only myocardial walls had significant non-zero values. The distance of the wall relative to the centre of the cavity was calculated in the three-dimentional space as the first moment of the count rate distribution along radii originating in the centre of the cavity. LVEF was calculated using, for each time bin, the sum of the cube of all distances as an estimate of the cavity volume. The method required minimal operator interventions and was successful in all patients, including those with severe perfusion defects. Intraobserver and interobserver variability was excellent, with regression coefficients of 0.97 and standard deviations of 4.5% and 4.7%, respectively. For 30 patients, the measurements were validated against planar equilibrium radionuclide angiography (ERNA) that was obtained within an interval of 1 week. LVEF ranged from 12% to 88%. Agreement between the two methods was excellent (LVEFERNA=1.05+0.92 LVEFGSPET, r=0.93, P=0.023, SEE=7.06). The Bland-Altman analysis did not show any apparent trend in the differences between ERNA and gated SPET over a wide range of ejection fractions. The standard deviation of the differences was 3. 1%. In addition no relationship was found between the two methods and the severity of perfusion defects. In conclusion, accurate measurements of LVEF are obtained from gated SPET perfusion images using a method based on statistical analysis of the count rate density. This method did not deteriorate even in the presence of severe perfusion defects and could therefore be used in following patients after myocardial infarction.

Topics: Aged; Coronary Disease; Feasibility Studies; Female; Gated Blood-Pool Imaging; Heart; Humans; Male; Middle Aged; Observer Variation; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Reproducibility of Results; Stroke Volume; Tomography, Emission-Computed, Single-Photon; Ventricular Function, Left

To investigate the role of sublingual nitrate plus 99Tcm-tetrofosmin infusion in the detection of severely ischaemic but viable myocardium, we selected 25 patients with coronary artery disease who had at least one fixed segmental defect during conventional stress-redistribution (ST-RD) 201Tl single photon emission tomographic (SPET) imaging. Reinjection (RI) and 24 h late redistribution (LRD) imaging were also performed. Within a week of 201Tl imaging, one-day rest-stress (R-ST) 99Tcm-tetrofosmin SPET was performed with the same stress levels. The following day, 99Tcm-tetrofosmin was infused over 1 h immediately after sublingual nitrate administration and SPET images (N + Inf) were acquired. Of 100 fixed defects on R-ST 99Tcm-tetrofosmin imaging, 15 were reversible on N + Inf 99Tcm-tetrofosmin imaging. There was 91% concordance between ST-RD/RI/LRD 201Tl and R-ST/N + Inf 99Tcm-tetrofosmin imaging regarding reversibility. We conclude that N + Inf 99Tcm-tetrofosmin imaging may be clinically useful in the detection of severely ischaemic but viable myocardium.

Topics: Administration, Sublingual; Adult; Aged; Cerebral Infarction; Coronary Disease; Exercise Test; Female; Heart; Humans; Infusions, Intravenous; Male; Middle Aged; Myocardial Ischemia; Nitrates; Organophosphorus Compounds; Organotechnetium Compounds; Physical Exertion; Radiopharmaceuticals; Thallium Radioisotopes; Tissue Distribution; Tomography, Emission-Computed

Coronary angiography is still the most reliable method for the detection of coronary artery disease. In this study we compared to this method the accuracy of 99mTc-Tetrofosmin myocardial SPECT.. Fifty two patients (38 male and 14 female) were studied with stress-rest 99mTc-Tetrofosmin myocardial SPECT. Two independent observers evaluated the uptake of the radiotracer using a score from 0 to 4. All patients underwent coronary angiography and the results were compared to SPECT findings. We considered as hemodynamic significant any obstruction greater than 50% and as ischemic any myocardial region with radiotracer uptake less than 4 at stress.. There was good segmental correspondence between tetrofosmin scintigram and angiography. Sensitivity 72.2-91.1%, specificity 80.0-88.2%, ppv 76.4-88.5% and npv 83.3-85.7%, depending on the obstructed vessel.. 99mTc-Tetrofosmin myocardial SPECT is a reliable alternative for the detection of CAD.

Topics: Adult; Aged; Coronary Angiography; Coronary Disease; Female; Hemodynamics; Humans; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Sensitivity and Specificity; Tomography, Emission-Computed, Single-Photon

Exercise first-pass radionuclide ventriculography provides valuable diagnostic and prognostic information in patients with coronary artery disease. In this procedure, motion correction of the images is commonly performed using a second external point source attached to the chest wall during exercise (dual-isotope method). Recently, a motion correction algorithm without an external point source (single-isotope method) was developed and the results compared with those of the dual-isotope method.. To examine the accuracy of the motion correction method, a phantom study was performed using a moving cardiac phantom with a motion speed of up to 169 cycle/min and motion amplitude up to 6 cm. Count fluctuation in the phantom region by motion was calculated as a coefficient of variation (CV). In the clinical study, time-activity curves of the left ventricular phase were created for quantitative assessment of variation as CV values of the ejection fraction in the central five cardiac cycles after correction by the two methods during exercise radionuclide ventriculography in 17 patients.. In the moving phantom, both the single- and dual-isotope methods reduced the CV values less than 10%. In the clinical study, the single-isotope method provided less CV value of ejection fraction (9.8% +/- 5.6%) than the dual-isotope method (24.8% +/- 10.5%) (p < 0.01), indicating less individual variation of ejection fraction values.. These data indicate that object motion can be accurately corrected in the moving phantom by both single- and dual-isotope methods. In clinical studies, the single-isotope method is more accurate.

Topics: Algorithms; Artifacts; Coronary Disease; Exercise Test; Feasibility Studies; Humans; Iodine Radioisotopes; Organophosphorus Compounds; Organotechnetium Compounds; Phantoms, Imaging; Stroke Volume; Ventriculography, First-Pass

Exercise-rest 99mTc-tetrofosmin myocardial perfusion images with a 2-day protocol was compared to exercise-redistribution-reinjection 201Tl images to assess the ability of 99mTc-tetrofosmin to detect viable myocardium.. We studied 25 patients with coronary artery disease and regional or global left ventricular dysfunction. Myocardial SPECT images with 99mTc-tetrofosmin were obtained 10 min after injection during exercise and 1 and 3 hr after rest injection. Within 1 wk of the 99mTc-tetrofosmin study, exercise-redistribution-reinjection 201Tl SPECT imaging was performed.. Visual analysis demonstrated concordance between 201Tl and 99mTc-tetrofosmin imaging for defect reversibility in 126 of 209 segments (60%), with initial defects on both exercise 201Tl and 99mTc-tetrofosmin images. In the remaining discordant 83 segments (40%), 73 (88%) appeared nonreversible on 99mTc-tetrofosmin imaging but were reversible on 201Tl imaging.. On the basis of defect reversibility by visual analysis, exercise-rest 99mTc-tetrofosmin imaging underestimates myocardial viability compared to 201Tl reinjection imaging. The identification of viable myocardium with both 99mTc-tetrofosmin and 201Tl can be greatly enhanced to a similar degree if the severity of reduction in activity within nonreversible defects is considered. These two agents may provide comparable information about myocardial viability by quantitative analysis of defect severity.

Topics: Coronary Disease; Exercise Test; Female; Heart; Humans; Image Processing, Computer-Assisted; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Thallium Radioisotopes; Time Factors; Tomography, Emission-Computed, Single-Photon

The aim of this study was to assess the potential role of 99mTc-tetrofosmin cardiac tomography in detecting totally occluded or severely stenosed coronary arteries.. Thirty-three patients (32 men, 1 woman; mean age, 52 +/- 9 yr) with chronic coronary artery disease (CAD) and left ventricular dysfunction (ejection fraction 40% +/- 12%) underwent resting 99mTc-tetrofosmin SPECT and coronary arteriography within 2 wk. Regional distribution of 99mTc-tetrofosmin activity was compared with the coronary anatomy. Tracer uptake was quantitatively analyzed in 22 segments for each patient. The activity in each segment was expressed as a percent of the peak activity.. A significant relationship between the degree of coronary artery stenosis and 99mTc-tetrofosmin uptake was observed (p = -0.64, p < 0.001). Technetium-99m-tetrofosmin uptake was lower (p < 0.001) in segments with 100% coronary occlusion with poor collateral flow (53% +/- 17%) compared to segments supplied by a vessel with 50%-99% coronary stenosis (75% +/- 20%) or a normal noncritically stenosed artery (85% +/- 10%). Furthermore, 99mTc-tetrofosmin uptake was lower (p < 0.01) in segments with 100% coronary occlusion with poor (53% +/- 17%) compared to those with good collateral flow (70% +/- 20%).. These results demonstrate that quantitative analysis of resting 99mTc-tetrofosmin regional uptake detects the majority of segments supplied by occluded coronary arteries with poor collateral flow and suggest that this tracer may be helpful in the diagnosis of acute myocardial infarction.

Topics: Adult; Coronary Angiography; Coronary Disease; Coronary Vessels; Female; Heart; Humans; Male; Middle Aged; Myocardial Infarction; Organophosphorus Compounds; Organotechnetium Compounds; Tomography, Emission-Computed, Single-Photon

Technetium-99m tetrofosmin is a recently developed compound that clears from background organs rapidly. Tetrofosmin has a good correlation with 201Tl. This study assesses the feasibility and diagnostic accuracy of a combined protocol involving rest 201Tl SPECT and stress imaging with 99mTc-tetrofosmin.. Twenty-five patients (23 men, 2 women; aged 36-73 yr) with known coronary artery disease underwent the combined protocol. Twenty minutes after the resting injection of 201Tl, resting SPECT data were acquired using low-energy, high-resolution collimators. A stress test using adenosine infusion combined with low-level dynamic exercise was performed. The stress data were collected 20 min later. The reconstructed vertical long-axis, horizontal long-axis and short-axis slices were analyzed qualitatively. Analysis was carried out using nine segments of the left ventricle. The segments were reported either as fixed or reversible. The results were compared to coronary angiography results.. The sensitivity and specificity for the detection of diseased coronary vessels were 85% and 70% for the left anterior descending territory, respectively, 78% and 71% for the right coronary artery, and 69% and 70% for the left circumflex. Overall, the sensitivity was 80% and the specificity 70%.. Combined rest 201Tl/stress 99mTc-tetrofosmin SPECT provides a protocol of short duration which displays similar diagnostic accuracy to a protocol using tetrofosmin as a single agent.

Topics: Adult; Aged; Coronary Angiography; Coronary Disease; Exercise Test; Female; Humans; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Sensitivity and Specificity; Thallium Radioisotopes; Tomography, Emission-Computed, Single-Photon

Images recorded after intravenous administration of 99mTc-tetrofosmin were compared to those obtained with 201Tl in a series of 40 patients with angiographically documented coronary artery disease. These patients were part of a Phase II tetrofosmin study and presented anamnestic or laboratory evidence suggestive of ischemic heart disease.. Thirty-seven patients had one or more coronary obstructions greater or equal to 70% of luminal diameter. Three patients studied after bypass surgery or angioplasty had patent grafts, absence of disease progression or no significant restenosis. Twenty-six patients had evidence of previous myocardial infarction. All images were processed into a common display format by a core laboratory. They were identified by code and read by concensus of four investigators. Each segment was classified as normal or abnormal and these readings were combined and categorized into normal, reversible, fixed or mixed regional defects.. There was good segmental correspondence between thallium and tetrofosmin (kappa values ranged from 0.43 to 1.00). The ability of thallium and tetrofosmin to recognize and localize myocardial infarction was excellent, since corresponding abnormalities were present in respectively 24 and 25 of the 26 patients with previous myocardial infarction. Abnormalities in noninfarcted territories were recognized with both tracers in 16 of 28 patients presenting with coronary lesions involving vessels unrelated to the infarct.. In comparison to rest tetrofosmin, thallium redistribution shows more reversibility in areas with myocardial infarction but less reversibility in areas of myocardial ischemia. Current Phase II results suggest that tetrofosmin is a sensitive and reliable tracer for detecting myocardial infarction and ischemia. Results should be confirmed in a larger group of patients.

Topics: Aged; Coronary Angiography; Coronary Disease; Electrocardiography; Exercise Test; Female; Heart; Humans; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Radionuclide Imaging; Thallium Radioisotopes

To assess the clinical value of the 99mTc-labeled myocardial perfusion agent, 99mTc-tetrofosmin, the findings of stress and rest myocardial tomography were compared with those of stress and 3-hr delayed 201Tl tomography and coronary arteriography.. Twenty-five patients who had coronary arteriography were studied with both stress tetrofosmin and 201Tl tomography.. The image quality of tetrofosmin was superior to that of 201Tl despite a shorter acquisition time. Both the tetrofosmin and 201Tl studies were quite sensitive to detect coronary artery disease (100% and 95%, respectively) (p = ns). The two studies showed similar sensitivity (75% and 73%) and specificity (80% and 77%, respectively) for the detection of significant (> or = 75% diameter) coronary artery stenosis. Stress distribution of tetrofosmin tended to be slightly higher than that of 201Tl (% uptake: 63.3% +/- 13.5% versus 60.4% +/- 12.2%, p = 0.0006; uptake score: 2.33 +/- 1.03 versus 2.22 +/- 1.07, p = 0.007), indicating less defect contrast in the former. A high concordant rate (89%) of the stress perfusion score was observed between the two radiopharmaceuticals. Reversible perfusion abnormalities were observed to be similar between stress-rest tetrofosmin and stress-delayed 201Tl studies.. Stress tetrofosmin perfusion tomography is a valuable method to detect coronary artery disease and to assess tissue viability with accuracy similar to that of stress 201Tl tomography.

Topics: Aged; Coronary Angiography; Coronary Disease; Exercise Test; Female; Heart; Humans; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Sensitivity and Specificity; Thallium Radioisotopes; Tomography, Emission-Computed, Single-Photon

To clarify the usefulness of the combined assessment of exercise (EX)-induced abnormalities in myocardial perfusion and regional wall motion for detecting coronary artery disease (CAD), we carried out first-pass radionuclide angiography and myocardial perfusion imaging during EX and at rest by 99mTc-tetrofosmin. Twenty-four patients with angiographically proven CAD, 9 (Gp A) with single and 15 (Gp B) with multivessel disease, were studied. The sensitivity for the detection of CAD was 78% of Gp A, 73% of Gp B in planar image and 78%, 87% in SPECT image, respectively. When left ventricular ejection fraction and regional ejection fraction (rEF) were combined with the result of myocardial perfusion, sensitivity increased up to 89% of Gp A, 100% of Gp B. Diagnostic accuracy of LAD, LCX and RCA was 79%, 88% and 83%, respectively. Regional EF in ischemic areas decreased during EX in both Gps, particularly in Gp B. Regional EF in relatively normal perfusion areas did not significantly change in Gp A, but decreased in Gp B. These results suggest that 99mTc-tetrofosmin contributes to the improvement of sensitivity for CAD by combined assessment of EX-induced wall motion and myocardial perfusion abnormalities.

Topics: Aged; Coronary Disease; Exercise Test; Female; Gated Blood-Pool Imaging; Heart; Humans; Male; Middle Aged; Myocardial Contraction; Myocardial Reperfusion; Organophosphorus Compounds; Organotechnetium Compounds; Ventricular Function, Left

Technetium-99m (Tc-99m) tetrofosmin, a new myocardial perfusion imaging agent, was evaluated at exercise and rest in 50 patients with documented coronary artery disease to determine myocardial kinetics, redistribution and ideal imaging time. Planar imaging was performed at 5, 30, 60, 90, 120 and 240 minutes after an injection of Tc-99m tetrofosmin (8 to 10 mCi) at peak graded ergometric exercise. Reinjection (24 to 30 mCi) was performed at rest, 4 hours after the stress injection and also on a separate day, and imaging was repeated. All patients underwent thallium-201 (Tl-201) exercise and redistribution (4-hour) imaging. Perfusion defect to normal, and heart to lung ratios were calculated for exercise Tc-99m tetrofosmin images at each time point. The mean +/- SD defect to normal ratios were 0.75 +/- 0.10, 0.75 +/- 0.10, 0.74 +/- 0.09, 0.73 +/- 0.10, 0.73 +/- 0.10 and 0.72 +/- 0.10 at 5, 30, 60, 90, 120 and 240 minutes, respectively (p = NS), suggesting absence of redistribution. There was a significant increase in lung uptake of Tl-201 during exercise (p < 0.05), but not with Tc-99m tetrofosmin (p = NS). Washout of Tc-99m tetrofosmin was calculated in a subset of patients (n = 23). Rapid background clearance enabled postexercise diagnostic imaging as early as 5 minutes after injection. Myocardial retention curves after rest injection suggested that the optimal time for imaging was approximately 30 minutes later. Slow myocardial washout (4%/hour after exercise and 0.6%/hour after rest injection) enabled diagnostic images to be obtained up to 4 hours after each study.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Aged; Coronary Disease; Evaluation Studies as Topic; Female; Heart; Humans; Lung; Male; Middle Aged; Myocardium; Organophosphorus Compounds; Organotechnetium Compounds; Radionuclide Imaging; Thallium Radioisotopes

We compared 360 degrees data collection technique with 180 degrees technique in SPECT using a new myocardial perfusion imaging agent, 99mTc-Tetrofosmin. Eight patients were examined at stress and at rest on separate days. Following the injection of 555 MBq 99mTc-Tetrofosmin, 64 views of 15 sec each were collected during a 360 degrees rotation, and 32 views of 30 sec each during a 180 degrees rotation. The 180 degrees data collection provided superior images in sharpness in 14 of 16 scans. The interpretation was concordant in 123 of 128 regions (96.1%), and hypoperfusion was considered to be underestimated in 5 regions using the 360 degrees technique. It was suggested that the 180 degrees data collection technique is more effective in myocardial SPECT employing 99mTc-Tetrofosmin than the 360 degrees technique.

Topics: Aged; Coronary Disease; Data Collection; Female; Heart; Humans; Male; Middle Aged; Myocardium; Organophosphorus Compounds; Organotechnetium Compounds; Tomography, Emission-Computed, Single-Photon

To evaluate clinical value of 99mTc-1,2-bis[bis (2-ethoxyethyl)phosphino]ethane(99mTc-PPN1011) imaging for assessing coronary artery disease (CAD), 99mTc-PPN1011 SPECT imaging at post-exercise and at rest was compared with 201Tl SPECT imaging at post-exercise and 3 hours in 24 patients with CAD. The sensitivities for detecting CAD were 100% (21/21) by 99mTc-PPN1011 SPECT and 95% (20/21) by 201Tl SPECT. The sensitivities for detecting stenosed coronary arteries (> or = 75% stenosis) were similar between 99mTc-PPN1011 (68%) and 201Tl (66%). The similar specificity values were obtained by 99mTc-PPN1011 (80%) and 201Tl (77%). The patterns of abnormality (normal, ischemia and scar) were concordant between 99mTc-PPN1011 and 201Tl images in 20 of the 24 cases (83%) and 106 of the 120 segments (88%). In the simultaneous analysis of cardiac function by first pass radionuclide angiography with 99mTc-PPN1011, there was good correlation between left ventricular ejection fraction and perfusion score at rest (r = 0.70) and exercise (r = 0.80). The degrees of abnormality between perfusion and wall motion were similar in 56 of 66 segments (85%) at rest and 52 of 66 segments (79%) at exercise. We conclude that this agent is promising for the diagnosis and evaluation of coronary artery disease.

Topics: Aged; Coronary Disease; Female; Heart; Humans; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Physical Exertion; Stroke Volume; Thallium Radioisotopes; Tomography, Emission-Computed, Single-Photon; Ventriculography, First-Pass