technetium-tc-99m-tetrofosmin and Myocardial-Ischemia

Bone marrow-derived stem cells (BMSC) may represent a viable option for patients with myocardial ischemia refractory to conventional treatments.. In 5 patients (4 males and 1 female, mean age 64 +/- 8 years) with untreatable angina pectoris (Canadian Cardiovascular Society Class III/IV), myocardial segments with stress-induced ischemia as assessed by gated single-photon emission computed tomography were injected with 4 to 12 million CD133+ BMSC. Cells were injected into the myocardium (2 anterior, 2 lateral, 1 inferior wall) through minimally invasive approaches (left minithoracotomy [n = 4] and subdiaphragmatic approach [n = 1]). At baseline, at 6 months and at 1 year of follow-up, an exercise test, gated single-photon emission computed tomography (SPECT), 2-D echocardiography and coronary angiography were performed to assess exercise capacity, myocardial perfusion, LV function and coronary anatomy.. Intramyocardial injection of autologous CD133+ BMSC cells was safe. No early or long-term complications were observed. After an average of 3.8 weeks from cell inoculation, all patients experienced a significant improvement of CCS class (from 3.8 to 1.8 at 6 months) and serial SPECT documented improvements of rest and stress perfusion in the injected territories at 6 months from operation. In 3 cases, coronary angiography showed an increase in the collateral score of the target areas. Clinical improvements still persist unchanged in 4 out of 5 cases at a mean of 36.5 months postoperatively.. After stand-alone BMSC transplantation for refractory myocardial ischemia, we observed long-term clinical and perfusion improvements in the absence of adverse events.

Topics: AC133 Antigen; Aged; Angina Pectoris; Antigens, CD; Female; Glycoproteins; Hematopoietic Stem Cell Mobilization; Humans; Injections; Male; Mesenchymal Stem Cell Transplantation; Middle Aged; Myocardial Ischemia; Neovascularization, Physiologic; Organophosphorus Compounds; Organotechnetium Compounds; Peptides; Pilot Projects; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon; Transplantation, Autologous

Cardiovascular disease is the most frequent cause of death and disability in diabetes, and the morbidity and mortality for coronary artery disease (CAD) in this population is two to four times higher than in nondiabetic subjects. Traditional risk factors do not fully explain the level of cardiovascular risk, and coronary disease events are often silent in diabetic patients. Thus, research has recently focused on improving the risk assessment of an individual patient with new tools in an effort to better identify subjects at highest risk and in need of aggressive management. Cardiovascular imaging has proven very helpful in this regard. Traditional methods to assess CAD are based on detection of obstructive luminal disease responsible for myocardial ischemia. However, acute coronary syndromes often occur in the absence of luminal stenoses. Hence, the utilization of imaging methodologies to visualize atherosclerosis in its presymptomatic stages has received mounting attention in recent years. In this article, we review the current literature on the utility of traditional imaging modalities for obstructive CAD (nuclear and echocardiographic stress testing) as well as atherosclerosis plaque imaging with carotid intima-media thickness and coronary artery calcium for risk stratification of diabetic patients.

Topics: Cardiovascular Diseases; Coronary Artery Disease; Diabetes Complications; Diabetes Mellitus; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Echocardiography, Stress; Humans; Magnetic Resonance Angiography; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Radiography; Risk Management; Technetium Tc 99m Sestamibi; Thallium Radioisotopes; Tomography, Emission-Computed, Single-Photon; Tunica Intima; Tunica Media

Topics: Coronary Circulation; Heart; Humans; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Predictive Value of Tests; Prognosis; Radiopharmaceuticals; Technetium Tc 99m Sestamibi; Thallium Radioisotopes; Tissue Survival; 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

In patients undergoing regadenoson SPECT myocardial perfusion imaging (MPI), it is unknown how soon and at which dose intravenous aminophylline can be administered to reverse regadenoson-related adverse effects without blunting stress-induced myocardial ischemia.. In patients undergoing regadenoson-stress SPECT-MPI, the intravenous administration of 75 mg of aminophylline as early as 90 seconds after radioisotope injection does not seem to attenuate the burden of myocardial ischemia.

Topics: Administration, Intravenous; Aged; Aminophylline; Double-Blind Method; Drug Administration Schedule; Exercise Test; Female; Follow-Up Studies; Humans; Male; Middle Aged; Myocardial Ischemia; Myocardial Perfusion Imaging; Organophosphorus Compounds; Organotechnetium Compounds; Prospective Studies; Purines; Pyrazoles; Tomography, Emission-Computed, Single-Photon

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

Real-time perfusion (RTP) contrast echocardiography can be used during adenosine stress echocardiography (ASE) to evaluate myocardial ischemia. We compared two different types of RTP power modulation techniques, angiomode (AM) and high-resolution grayscale (HR), with 99mTc-tetrofosmin single-photon emission computed tomography (SPECT) for the detection of myocardial ischemia.. Patients with known or suspected coronary artery disease (CAD), admitted to SPECT, were prospectively invited to participate. Patients underwent RTP imaging (SONOS 5500) using AM and HR during Sonovue(R) infusion, before and throughout the adenosine stress, also used for SPECT. Analysis of myocardial perfusion and wall motion by RTP-ASE were done for AM and HR at different time points, blinded to one another and to SPECT. Each segment was attributed to one of the three main coronary vessel areas of interest.. In 50 patients, 150 coronary areas were analyzed by SPECT and RTP-ASE AM and HR. SPECT showed evidence of ischemia in 13 out of 50 patients. There was no significant difference between AM and HR in detecting ischemia (p = 0.08). The agreement for AM and HR, compared to SPECT, was 93% and 96%, with Kappa values of 0.67 and 0.75, respectively (p < 0.001).. There was no significant difference between AM and HR in correctly detecting myocardial ischemia as judged by SPECT. This suggests that different types of RTP modalities give comparable data during RTP-ASE in patients with known or suspected CAD.

Topics: Adenosine; Aged; Coronary Circulation; Echocardiography; Exercise Test; Female; Humans; Male; Middle Aged; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Reproducibility of Results; Sensitivity and Specificity; Tomography, Emission-Computed, Single-Photon

Although the accurate detection of ischemic etiology is important in the management of patients with severe left ventricular (LV) dysfunction, it is difficult to determine using a non-invasive strategy. The present study investigates whether perfusion and regional functional abnormalities identified by quantitative electrocardiographic gated single-photon emission computed tomography (QGS) at rest can detect ischemic LV dysfunction in patients with severe LV dysfunction.. Rest QGS with (99m)Tc-tetrofosmin was performed on 54 consecutive patients with LV ejection fraction of

Topics: Adult; Aged; Aged, 80 and over; Clinical Protocols; Coronary Circulation; Electrocardiography; Female; Gated Blood-Pool Imaging; Humans; Male; Middle Aged; Movement; Myocardial Contraction; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; ROC Curve; Stroke Volume; Tomography, Emission-Computed, Single-Photon; Ventricular Dysfunction, Left

To test the association of early post-stress lung/heart ratio (LHR) of 99mTc tetrofosmin radioactivity with gated-SPECT findings and angiographic results.. We studied 158 consecutive patients, with stress/rest 99mTc tetrofosmin myocardial SPECT and coronary angiography. Rest scans were obtained as gated SPECT and the left ventricular ejection fraction and end diastolic volume were calculated. To evaluate myocardial ischaemia, we calculated the summed stress score, summed rest score and summed difference score indices. For the LHR calculation, we acquired an anterior image, 4-6 min after radiotracer injection at stress; LHR was defined as mean counts/pixel in the lung region of interest divided by the mean counts/pixel in the myocardial region of interest.. An early post-stress LHR value of 0.500 was defined as the upper normal limit. The most significant correlation (P<0.001) was observed among early post-stress LHR, summed stress score and the number of stenosed vessels. The incidence of multi-vessel coronary artery disease in the subgroup of patients with increased values of early post-stress LHR, was significantly higher than in the normal group (81% vs. 42%, P<0.001). There was a significant difference (P<0.001) of the early post-stress LHR value between patients with normal coronary arteries or one-vessel disease and patients with multi-vessel disease. Early post-stress LHR was an independent predictor of multi-vessel coronary artery disease (coefficient 1.85, SD 0.16, P<0.001), with an incremental value for its identification.. Our results suggest that early post-stress 99mTc tetrofosmin LHR appears to be a useful index of extensive myocardial ischaemia dysfunction and multi-vessel coronary artery disease.

Topics: Aged; Aged, 80 and over; Coronary Artery Disease; Coronary Vessels; Exercise Test; Female; Heart; Humans; Image Interpretation, Computer-Assisted; Lung; Male; Middle Aged; Myocardial Ischemia; Myocardium; Organophosphorus Compounds; Organotechnetium Compounds; Radionuclide Imaging; Radiopharmaceuticals; Reproducibility of Results; Sensitivity and Specificity; Statistics as Topic

Cell therapy has recently been introduced to treat patients with refractory angina. Because most studies have only included short-term follow-up, the effects of cell therapy over a longer period are unknown.. In 25 patients (mean age 64 +/- 10 years, 21 men) with refractory angina, a total of 84 +/- 29 x 10(6) bone marrow-derived mononuclear cells was injected intramyocardially in regions with ischemia on technetium-99m tetrofosmin single-photon emission computed tomography. Anginal symptoms and quality of life were evaluated at baseline and at 3, 6, and 12 months. Gated single-photon emission computed tomography was performed at baseline and at 3 and 12 months to assess myocardial perfusion and left ventricular function.. Bone marrow cell injection was performed without any complication. At 7 months, one patient died of intracranial hemorrhage. Canadian Cardiovascular Society class improved from 3.4 +/- 0.5 to 2.3 +/- 0.6 at 3 months, 2.4 +/- 0.6 at 6 months, and 2.7 +/- 0.8 at 12 months (P < .01). Quality of life improved from 53% +/- 10% to 71% +/- 11% at 3 months, 72% +/- 14% at 6 months, and 68% +/- 14% at 12 months (P < .01). The number of segments with ischemia per patient decreased from 4.7 +/- 3.3 to 2.1 +/- 2.6 at 3 months and 1.6 +/- 2.5 at 12 months (P < .01). Left ventricular ejection fraction increased from 47% +/- 13% to 53% +/- 17% at 3 months and 51% +/- 17% at 12 months (P < .01). Regional wall motion improved from 5.9 +/- 1.7 to 6.6 +/- 2.2 mm at 3 months and 6.4 +/- 2.0 mm at 12 months (P = .01).. Autologous bone marrow cell injection in patients with ischemia is safe and results in a sustained beneficial effect on anginal symptoms, myocardial perfusion, and left ventricular function.

Topics: Aged; Angina Pectoris; Bone Marrow Transplantation; Chronic Disease; Coronary Circulation; Female; Follow-Up Studies; Heart; Humans; Injections; Male; Middle Aged; Monocytes; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon; Transplantation, Autologous; Treatment Outcome; Ventricular Function, Left

We sought to determine the prognostic value of myocardial contrast echocardiography (MCE) in patients with known or suggested coronary artery disease compared with technetium-99m sestamibi single photon emission computed tomography (SPECT)-myocardial perfusion imaging (MPI).. The prognostic value of SPECT-MPI is well established for patients with coronary artery disease. It is less well defined by MCE.. In all, 51 consecutive patients with suggested coronary artery disease prospectively underwent MCE and SPECT-MPI at baseline and after dipyridamole infusion. MCE and SPECT-MPI were independently analyzed for myocardial perfusion. Cardiac events during the follow-up period were determined, and event-free survival was calculated for MCE and SPECT-MPI techniques separately.. MCE (log rank P < .005) and SPECT-MPI (log rank P < .05) demonstrated equivalent event-free survival. The negative predictive value for events for both MCE and SPECT-MPI was 100%.. MCE accurately classifies patients at risk for cardiac events and provides prognostic information comparable with validated SPECT-MPI techniques.

Topics: Adult; Aged; Coronary Vessels; Disease-Free Survival; Echocardiography; Female; Humans; Male; Middle Aged; Myocardial Ischemia; Ontario; Organophosphorus Compounds; Organotechnetium Compounds; Prognosis; Radiopharmaceuticals; Risk Assessment; Risk Factors; Single-Blind Method; Survival Rate; Tomography, Emission-Computed, Single-Photon

To assess if myocardial perfusion scintigraphy (MPS) at rest can be of value in elucidating myocardial perfusion, ischaemia and perioperative myocardial infarction (PMI) associated with coronary artery bypass graft (CABG) surgery.. This was a prospective randomized study of patients undergoing elective CABG. Forty-eight patients in the control group underwent serial ECG recordings and measurements of CK-MB and cTnT. Fifty-four patients in the study group were additionally examined with MPS preoperatively and 2-4 days and 6 weeks postoperatively.. The study showed a highly significant (p < 0.001) improvement in myocardial radionuclide uptake from preoperatively to 2-4 days postoperatively. Judged from ECG and enzymatic changes, two control patients and one study patient only had PMI and no additional cases of PMI were demonstrated by MPS.. MPS at rest showed that CABG significantly improved myocardial perfusion, by demonstrating an increase in radionuclide uptake. In diagnosing PMI, we found that MPS provided no additional information beyond cardiac biochemical markers and ECG changes.

Topics: Adult; Aged; Aged, 80 and over; Biomarkers; Coronary Artery Bypass; Coronary Circulation; Creatine Kinase, MB Form; Elective Surgical Procedures; Electrocardiography; Female; Follow-Up Studies; Gamma Cameras; Humans; Male; Middle Aged; Myocardial Infarction; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Prospective Studies; Radionuclide Imaging; Radiopharmaceuticals; Time Factors; Treatment Outcome; Troponin T

(18)F-fluorodeoxyglucose (FDG) positron-emission tomography (PET) is assumed to be the most useful method of evaluating the viability of the myocardium, but its use is limited by the need for a cyclotron. In the present study, the ability of a combination of (99m)Tc-tetrofosmin (TF) and (123)I-beta-methyliodophenyl pentadecanoic acid (BMIPP) single-photon emission computed tomography (SPECT), a combination of (18)F-FDG PET and (123)I-BMIPP SPECT, and a combination of (18)F-FDG PET and (99m)Tc-TF SPECT were compared to predict functional improvement of ischemic myocardium after a large acute myocardial infarction (AMI).. Ten patients with large AMI were studied by (99m)Tc-TF SPECT, (123)I-BMIPP SPECT and (18)F-FDG PET within 3 weeks. Six months later, (99m)Tc-TF imaging was performed. All patients underwent successful revascularization, and had no restenosis. Regional tracer uptake was scored using a 4-point scale in 20 segments of the SPECT and PET images. When the defect score of (123)I-BMIPP SPECT exceeded the defect score of (99m)Tc-TF SPECT or (18)F-FDG PET by 1 point or more, and when the defect score of (99m)Tc-TF SPECT exceeded the defect score of (18)F-FDG PET by 1 point or more, the segment was considered to show mismatching. When the defect score was the same in 2 tracers, the segment was considered to show matching. (99m)Tc-TF imaging at 3 weeks and 6 months used quantitative gated SPECT (QGS) to score wall motion using a 6-point scale (-1= dyskinesis, 0= akinesis, 1= severe hypokinesis, 2= moderate hypokinesis, 3= mild hypokinesis, and 4= normokinesis). The sensitivity of the combination of (123)I-BMIPP and (99m)Tc-TF imaging in predicting functional improvement was 61%, that of (18)F-FDG PET and (123)I-BMIPP SPECT was 94%, and that of (18)F-FDG PET and (99m)Tc-TF SPECT was 76%. The specificity of the combination of (123)I-BMIPP and (99m)Tc-TF imaging in predicting functional improvement was 83%, that of (18)F-FDG PET and (123)I-BMIPP SPECT was 40%, and that of (18)F-FDG PET and (99m)Tc-TF SPECT was 49%. The accuracy of the combination of (123)I-BMIPP and (99m)Tc-TF imaging in predicting functional improvement was 70%, that of (18)F-FDG PET and (123)I-BMIPP SPECT was 71%, and that of (18)F-FDG PET and (99m)Tc-TF SPECT was 63%.. The combination of (123)I-BMIPP and (99m)Tc-TF imaging is a practical modality for predicting the functional improvement of ischemic myocardium after a large AMI.

Topics: Aged; Drug Combinations; Fatty Acids; Female; Humans; Iodine Radioisotopes; Iodobenzenes; Male; Middle Aged; Myocardial Infarction; Myocardial Ischemia; Myocardial Revascularization; Organophosphorus Compounds; Organotechnetium Compounds; Predictive Value of Tests; Radiopharmaceuticals; Sensitivity and Specificity; Severity of Illness Index; Tomography, Emission-Computed, Single-Photon; Treatment Outcome

Regadenoson, a selective A2A adenosine receptor agonist, was evaluated for tolerability and effectiveness as a pharmacological stress agent for detecting reversible myocardial hypoperfusion when combined with single-photon emission computed tomography (SPECT).. Adenosine and dipyridamole are nonselective adenosine agonists currently used as pharmacologic stressors. Despite proven safety, these agents often cause undesirable side effects and require a continuous infusion.. This Phase II, multicenter, open-label trial was conducted in 36 patients who had demonstrated ischemia on a 6-min adenosine SPECT imaging study within the previous 2 to 46 days. Patients received regadenoson as a rapid intravenous bolus dose of 400 microg (n = 18) or 500 microg (n = 18). The radiopharmaceutical was then delivered within one minute. The SPECT images were acquired in a standard manner and uniformly processed at a central laboratory. Regadenoson and adenosine studies were presented in random order and interpreted blindly with a 17-segment model by three observers. Additionally, quantitative analysis was performed with 4D-MSPECT software (University of Michigan, Ann Arbor, Michigan).. Overall agreement for the presence of reversible hypoperfusion was 86%. The 400-mug dose was better tolerated. Overall, regadenoson was well-tolerated; side effects (e.g., chest discomfort, flushing, dyspnea) were generally mild in severity and self-limiting. High-grade atrioventricular block and bronchospasm were not observed.. Regadenoson is well-tolerated and seems as effective as adenosine for detecting and quantifying the extent of hypoperfusion observed with SPECT perfusion imaging. Phase III clinical trials are now underway, given the promise of regadenoson's reduced side effects and simplicity of bolus administration.

Topics: Adenosine; Adenosine A2 Receptor Agonists; Electrocardiography; Heart; Humans; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Pilot Projects; Purines; Pyrazoles; Radiopharmaceuticals; Technetium Tc 99m Sestamibi; Tomography, Emission-Computed, Single-Photon

We used myocardial fractional flow reserve (FFR(myo)) and coronary flow reserve (CFR) to estimate cut-off values for assessment of the functional severity of coronary stenosis and myocardial ischemia, and we tested the usefulness of coronary blood hemodynamic measurements before and after plain old balloon angioplasty (POBA) and coronary artery bypass graft surgery (CABG).. Fractional flow reserve and CFR are useful for assessing the functional severity of coronary artery stenosis, coronary microvascular dysfunction, and myocardial ischemia during cardiac catheterization in adults. However, there have been no reports on the use of these measurements in children with Kawasaki disease (KD).. The study group included 128 patients with 314 coronary branches. The subjects were classified into three groups: normal coronary group, with 206 branches; abnormal coronary artery without ischemia group, with 58 branches; and ischemia group, with 50 branches.. In each branch, CFR and FFR(myo) were significantly lower in the ischemia group than in the other groups. Cut-off values for assessing the functional severity of coronary stenosis and CFR were approximately equal to those obtained for adults (CFR: <2.0; FFR(myo): <0.75). We obtained very high sensitivity and specificity for estimating myocardial ischemia using CFR and FFR(myo) (CFR: 94.0% and 98.5%, respectively; FFR(myo): 95.7% and 99.1%, respectively). Both CFR and FFR(myo) were reliable indicators of coronary hemodynamics before and after POBA and CABG.. Together, CFR and FFR(myo) provide a useful index for assessing the functional severity of coronary artery stenosis and myocardial ischemia and estimating the effectiveness of POBA and CABG in children with KD, the same as they do for adults.

Topics: Angioplasty, Balloon; Blood Flow Velocity; Case-Control Studies; Child; Coronary Artery Bypass; Coronary Circulation; Coronary Stenosis; Female; Humans; Male; Mucocutaneous Lymph Node Syndrome; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Sensitivity and Specificity; Tomography, Emission-Computed, Single-Photon; Ultrasonography, Interventional

To evaluate the results of surgical treatment of patients with ischemic heart disease in combination with intraoperative intramyocardial introduction of the human gene VEGF165 (angiostimulin).. Twenty four patients enrolled in the study were examined using 12-lead ECG, echocardiography, treadmill exercise test, single-photon emission computed tomography of the myocardium with Tc-99m-tetrophosmine, fluorodesoxyglucose (FDG) positron-emission tomography of the myocardium, selective coronarography. Out of 24 patients, 10 patients have been reexamined so far. The effect of the treatment was assessed by the data obtained at the treadmill test, transthoracic echocardiography, myocardial scintigraphy and FDG.. All the patients demonstrated a clinical response. The class of effort angina improved, the dose of the prescribed nitric drugs was decreased, exercise tolerance and total stress time rose, quality of life improved. Myocardial scintigraphy registered reduction of the total area and better accumulation of the radiopharmaceutical under load and at rest 3 and 6 months after the operation including myocardial areas which had not been revacularised at coronary artery bypass grafting but had been treated with the preparation of the human gene VEGF165.. The results of the study suggest that therapeutic angiogenesis may be an alternative impact on those myocardial areas which are supplied by the affected but ineligible for bypass grafting coronary arteries.

Topics: Collateral Circulation; Combined Modality Therapy; Coronary Angiography; Echocardiography; Electrocardiography; Exercise Test; Female; Fluorodeoxyglucose F18; Humans; Male; Middle Aged; Myocardial Ischemia; Myocardial Revascularization; Organophosphorus Compounds; Organotechnetium Compounds; Quality of Life; Tomography, Emission-Computed, Single-Photon; Treatment Outcome; Vascular Endothelial Growth Factor A

In order to compare the diagnostic ability of pulsed tissue Doppler and myocardial perfusion Single Photon Emission Computed Tomography (SPECT) in patients with a history of unstable coronary artery disease, CAD, 26 patients, 22 men and four women, age 47-76 years, were investigated in a prospective study, 5-10 day after an episode of unstable angina. Tissue Doppler and two-dimensional echocardiography were performed during dobutamine stress testing and myocardial scintigraphy after bicycle exercise and at rest. Patients with a normal SPECT had higher peak systolic velocity during dobutamine infusion, 18.9 +/- 4.1 cm s(-1), than patients with ischaemia, 12.2 +/- 3.8 cm s(-1) (P<0.001) or scar, 8.8 +/- 3.0 cm s(-1) (P<0.01). In a territorial analysis the difference in peak systolic velocity between areas with a normal and abnormal SPECT was less apparent. Failure to achieve >/=13 cm s(-1) in mean-peak systolic velocity was the most accurate criterion for detection of significant CAD on SPECT. We conclude that pulsed tissue Doppler can be used for objective quantification of left ventricular wall motion during dobutamine stress testing and for identification of patients with CAD on SPECT but not for identification of regional ischaemia.

Topics: Aged; Coronary Artery Disease; Dobutamine; Echocardiography, Doppler, Pulsed; Echocardiography, Stress; Exercise Test; Feasibility Studies; Female; Humans; Image Interpretation, Computer-Assisted; Male; Middle Aged; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon; Ventricular Dysfunction, Left

123I-15-(p-iodophenyl)-3-(R,S)-methylpentadecanoic acid (BMIPP) and 99mTc-tetrofosmin (TET) are widely used for evaluation of myocardial fatty acid metabolism and perfusion, respectively. ECG-gated TET SPECT is also used for evaluation of myocardial wall motion. These tests are often performed on the same day to minimize both the time required and inconvenience to patients and medical staff. However, as 123I and 99mTc have similar emission energies (159 keV and 140 keV, respectively), it is necessary to consider not only scattered photons, but also primary photons of each radionuclide detected in the wrong window (cross-talk). In this study, we developed and evaluated the effectiveness of a new scatter and cross-talk correction imaging protocol.. Fourteen patients with ischemic heart disease or heart failure (8 men and 6 women with a mean age of 69.4 yr, ranging from 45 to 94 yr) were enrolled in this study. In the routine one-day acquisition protocol, BMIPP SPECT was performed in the morning, with TET SPECT performed 4 h later. An additional SPECT was performed just before injection of TET with the energy window for 99mTc. These data correspond to the scatter and cross-talk factor of the next TET SPECT. The correction was performed by subtraction of the scatter and cross-talk factor from TET SPECT. Data are presented as means +/- S.E. Statistical analyses were performed using Wilcoxon's matched-pairs signed-ranks test, and p < 0.05 was considered significant.. The percentage of scatter and cross-talk relative to the corrected total count was 26.0 +/- 5.3%. EDV and ESV after correction were significantly greater than those before correction (p = 0.019 and 0.016, respectively). After correction, EF was smaller than that before correction, but the difference was not significant. Perfusion scores (17 segments per heart) were significantly lower after as compared with those before correction (p < 0.001).. Scatter and cross-talk correction revealed significant differences in EDV, ESV, and perfusion scores. These observations indicate that scatter and cross-talk correction is required for one-day acquisition of 123I-BMIPP and 99mTc-tetrofosmin SPECT.

Topics: Aged; Aged, 80 and over; Artifacts; Fatty Acids; Female; Heart Failure; Humans; Iodine Radioisotopes; Iodobenzenes; Male; Middle Aged; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Phantoms, Imaging; Radiopharmaceuticals; Reproducibility of Results; Scattering, Radiation; Sensitivity and Specificity; Tomography, Emission-Computed, Single-Photon

Because of damage to cardiomyocytes and the contractile apparatus, contractile reserve may be observed less frequently in hibernating than in stunned myocardium. The aim of this study was to assess the presence of contractile reserve in response to dobutamine infusion in a large group of patients with stunned and hibernating myocardium.. A total of 198 consecutive patients with ischemic cardiomyopathy (left ventricular ejection fraction < or = 40%) underwent resting 2-dimensional echocardiography to assess regional contractile dysfunction. On the basis of assessment of perfusion (with (99m)Tc-tetrofosmin SPECT) and glucose use (with (18)F-FDG SPECT), dysfunctional segments were grouped. Dysfunctional segments with normal perfusion were classified as stunned. Dysfunctional segments with a perfusion defect were classified as hibernating when a perfusion-(18)F-FDG mismatch was present. Dysfunctional segments with a perfusion defect were classified as scar tissue when a perfusion-(18)F-FDG match was present; these segments were subdivided into nontransmural and transmural scars. Contractile reserve was evaluated by dobutamine stress echocardiography.. Dobutamine-induced contractile reserve was more frequently found in stunned than in hibernating myocardium (61% vs. 51%, respectively; P < 0.01). Only 14% of the scarred segments improved in wall motion during dobutamine infusion, significantly less than stunned or hibernating myocardium (P < 0.001). Nontransmural scars exhibited contractile reserve more frequently than did transmural scars.. The progressive reduction of contractile reserve in stunned, hibernating, and scarred myocardium supports the hypothesis that stunning, hibernation, and scarring are not circumscript pathophysiologic entities but represent gradual ultrastructural damage on the myocyte level.

Topics: Dobutamine; Echocardiography; Female; Fluorodeoxyglucose F18; Heart; Humans; Male; Middle Aged; Myocardial Contraction; Myocardial Infarction; Myocardial Ischemia; Myocardial Stunning; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Single-Blind Method; Stress, Physiological; Tomography, Emission-Computed, Single-Photon; Ventricular Dysfunction, Left

It is not known whether pretreatment with nicorandil, an ATP-sensitive K+ channel (K(ATP)channel) opener, induces a preconditioning effect independent of increased collateral recruitment.. Forty-four patients with angina who underwent percutaneous transluminal coronary angioplasty (PTCA) to proximal left anterior descending artery (LAD) stenosis were randomly allocated for pretreatment with an intravenous injection of 80 g/kg nicorandil 5 min before initial ballooning (n=22) or saline (n=22). 99mTc tetrofosmin was injected during balloon inflation, quantitative analysis of occlusion images by SPECT was conducted, and the defect severity score (SS) was calculated. An ECG was recorded during the 2-min inflation to calculate the sum of ST elevation (sigmaST).. SigmaST levels were significantly reduced in patients with nicorandil pretreatment compared with control patients (control:1.89+/-0.85 mV nicorandil:1.24+/-0.57 mV, p=0.0052). However, no difference was observed in defect severity (control: 79.0+/-32.5, nicorandil: 98.7+/-48.9 ns). A close correlation was observed between SS and sigmaST in both groups (nicorandil group R(2)=0.505, control group R(2)=0.599). A multivariate regression model demonstrated that both defect severity (p<0.0001) and pretreatment with nicorandil (p<0.001) were significantly related to the level of sigmaST, suggesting a cellular protective effect against ischaemia by nicorandil, independent of myocardial blood flow.. Nicorandil pretreatment resulted in the induction of myocardial preconditioning independent of the severity of ischaemia.

Topics: Aged; Angioplasty, Balloon, Coronary; Calcium Channel Agonists; Collateral Circulation; Coronary Stenosis; Female; Humans; Ischemic Preconditioning, Myocardial; Male; Middle Aged; Myocardial Ischemia; Myocardial Revascularization; Nicorandil; Organophosphorus Compounds; Organotechnetium Compounds; Radionuclide Imaging; Radiopharmaceuticals; Vasodilator Agents

The aim of this study was to assess the influence of incremental nitroglycerin infusion (NTG+Inf) on the myocardial uptake of 99mTc-tetrofosmin (TF) in order to determine whether nitrates enhance the detection of viable myocardium with TF in patients with coronary artery disease (CAD) and left ventricular dysfunction. Fifty patients (39 males, 11 females; 54 +/- 11 years) with previous myocardial infarction and left ventricular dysfunction, who had been referred for coronary revascularization procedures, were studied. Myocardial single-photon emission tomography (SPET) images were obtained 1 h after injection of 750 MBq TF at baseline and after NTG+Inf, using a 2 day protocol. NTG+Inf was performed starting at 0.4 microg x kg(-1) x min(-1), with equal increments every 5 min up to 2 microg x kg(-1) x min(-1). Within 1 week of the TF study, rest-redistribution (R-RD) 201Tl SPET was performed after the injection of 111 MBq 201Tl. For each study, quantitative analysis was performed in 17 segments. Viability was defined as the presence of tracer uptake of > 50% of the peak activity on baseline studies or reversibility. There was significant correlation between quantitative regional RD 201Tl activity and TF activity after NTG+Inf (r = 0.90, P < 0.001). Of the 131 segments with severely reduced tracer uptake on resting TF images, 34 (26%) were reversible, showing increased tracer uptake after NTG+Inf (from 41%+/-7% to 57%+/-12% of peak activity; P < 0.001). All reversible segments after NTG+Inf had viability criteria on 201Tl studies. There was 95% concordance between TF with NTG+Inf and RD 201Tl imaging with regard to the presence of myocardial viability. We conclude that TF imaging with incremental NTG+Inf improves the detection of ischaemic but viable myocardium, correlating with the viability criteria observed on 201Tl studies. When the advantages of TF imaging are considered, rest TF imaging with NTG+Inf may be a practical diagnostic protocol in patients with CAD and left ventricular dysfunction who are being considered for revascularization.

Topics: Adult; Aged; Coronary Artery Disease; Female; Humans; Infusions, Intravenous; Male; Middle Aged; Myocardial Infarction; Myocardial Ischemia; Nitroglycerin; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Reproducibility of Results; Sensitivity and Specificity; Severity of Illness Index; Statistics as Topic; Thallium; Tomography, Emission-Computed, Single-Photon; Ventricular Dysfunction, Left

The effect of adenosine and exercise on gated SPET left ventricular ejection fraction (LVEF), end diastolic volume (EDV) and end systolic volume (ESV) has not been fully investigated. The aim of the study was to compare functional measurements obtained in one-day adenosine rest and two-day stress-rest protocols in relation to ischaemia.. Out of 226 consecutive patients examined with submaximal treadmill stress-rest 700 MBq Tc-99m MIBI, 26 were chosen to match those subjected to adenosine (140 micro g/kg/min) enhanced by a low level exercise protocol (300 MBq and 700 MBq Tc-99m tetrofosmin for stress and rest respectively). All images were acquired on a double head system and were gated using 8 frames, 25 s per frame.. ED and ES volumes increased after adenosine but decreased after treadmill resulting in the post-stress LVEF being significantly greater than after adenosine, 60 +/- 11 v. 51 +/- 13% (p < 0.01). This was caused by the smaller post-stress ESV in the treadmill group 40 +/- 20 v. 51 +/- 34, p < 0.05. In non-ischaemic scans the LVEF was greater (61 +/- 8 v. 51 +/- 14, p < 0.01) and EDV and ESV smaller after both stress and rest.. The adenosine test may have an opposite influence on the EDV and ESV in comparison to the submaximal treadmill test and therefore the left ventricular function measurements after adenosine infusion should be interpreted carefully and may not represent those acquired after physical exercise. In the gated SPET scans showing ischaemia the post-stress EDV and ESV may be greater and the LVEF lower than at rest.

Topics: Adenosine; Aged; Exercise Test; Female; Gated Blood-Pool Imaging; Humans; Male; Middle Aged; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Reproducibility of Results; Sensitivity and Specificity; Technetium Tc 99m Sestamibi; Tomography, Emission-Computed, Single-Photon; Ventricular Dysfunction, Left

The present study evaluates left ventricular performance during exercise by ECG-gated myocardial perfusion SPECT with short-time data collection.. The study population consisted of 10 healthy volunteers (Group N) and 9 patients with ischemic heart disease (Group I). Seven patients in Group I had a history of prior myocardial infarction. Rest ECG-gated SPECT was performed 40 min after an injection of Tc-99m-tetrofosmin (555-740 MBq). After resting data acquisition, Group N underwent up to two 5-min stages of exercise (75 and 125 watts) on a detachable bicycle ergometer. The Group I patients all underwent symptom-limited, maximal testing on the ergometer. ECG-gated SPECT data were acquired from both groups for 3 min at rest and during the last 3 min of each exercise stage.. Significant increases occurred in LVEF from rest to peak stress in both groups (from 55.4 +/- 5.8 to 66.6 +/- 4.1% in group N, p < 0.0001; from 49.0 +/- 12.8 to 56.7 +/- 13.8% in Group I, p < 0.001). The LVESV values significantly decreased to peak stress in Group N (from 49.9 +/- 13.1 to 37.8 +/- 10.0 ml, p < 0.0001), whereas LVEDV did not change (from 110.6 +/- 18.9 to 112.0 +/- 19.0 ml). In contrast, the LVESV values at rest and under peak stress were similar in Group I (from 52.6 +/- 23.9 to 51.7 +/- 31.4 ml) and LVEDV in Group I at peak exercise tended to increase (from 102.8 +/- 36.7 to 111.3 +/- 39.0 ml). The changes in LVESV from rest to peak stress were significantly different between Groups N and I (-12.1 +/- 6.3 vs. -0.9 +/- 11.6 ml, p < 0.02).. ECG-gated SPECT with short-time data collection can assess left ventricular function during exercise and may offer useful information for evaluating patients with ischemic heart disease.

Topics: Adult; Aged; Exercise Test; Female; Gated Blood-Pool Imaging; Humans; Male; Middle Aged; Myocardial Infarction; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Reproducibility of Results; Rest; Sensitivity and Specificity; Tomography, Emission-Computed, Single-Photon; Ventricular Dysfunction, Left

The clinical feasibility of both dual-isotope single photon emission tomography (SPET) and gated SPET have been described. The present study evaluates the feasibility of combining gated SPET with exercise 201Tl/rest 99mTc-tetrofosmin dual-isotope SPET corrected for scatter. Ninety-one patients with known or suspected coronary artery disease underwent cardiac catheterization and coronary angiography. Twenty-nine of them underwent exercise 201Tl/rest 99mTc-tetrofosmin dual-isotope SPET with a second 201Tl injection 3 h after the initial 201Tl injection (protocol 1). We then segregated a Bull's eye polar map into three coronary artery territories and quantified the relative regional uptake. The remaining 62 patients underwent exercise 201Tl/rest 99mTc-tetrofosmin dual-isotope SPET combined with gated SPET. We visually evaluated exercise and rest images from the three coronary artery territories. Left ventricular (LV) function was assessed globally by means of the LV ejection fraction and regionally by means of visual scoring analysis, compared with left ventriculography (LVG). The correlation between rest 99mTc-tetrofosmin and 201Tl reinjection images in 87 areas of coronary artery territory (r=0.89, P<0.01) and in 13 infarcted areas (r =0.94, P<0.01) was very close in protocol 1. The overall values for vessel-related sensitivity, specificity and accuracy were 88%, 79% and 82%, respectively, in protocol 2. The correlation between gated SPET and LVG was significant and linear with respect to the LV ejection fraction (r=0.77, P<0.01). The wall motion score from visual evaluation in gated SPET revealed a close overall agreement with LVG (concordance rate, 88%; kappa, 0.670). Exercise 201Tl/rest 99mTc-tetrofosmin dual-isotope SPET with scatter correction for assessing the coronary artery disease offers excellent diagnostic accuracy and the additional gated SPET provides useful information about LV function similar to that for LVG. This sequential protocol requires only 2 h to generate much useful clinical information.

Topics: Aged; Cardiac Catheterization; Coronary Artery Disease; Coronary Circulation; Feasibility Studies; Female; Gated Blood-Pool Imaging; Heart; Humans; Male; Middle Aged; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Perfusion; Radiopharmaceuticals; Stroke Volume; Thallium Radioisotopes; Ventricular Function, Left

This study investigated the utility of optional thallium-201 (201Tl) imaging for detecting myocardial viability in the stress 99Tcm-tetrofosmin/rest 201Tl dual-isotope protocol. Seventy-nine patients with old myocardial infarction and 25 patients with acute myocardial infarction underwent acquisition of three consecutive 201Tl images (early, intermediate and delayed) using the dual-isotope protocol. A polar map was created and defect scores (extent and severity) were determined by comparison with normal control data. Fluorodeoxyglucose positron emission tomography was also performed in 16 patients with old myocardial infarction. In patients with old infarction, the severity score decreased significantly from the early to the intermediate images, and decreased further on the delayed images. In patients with acute infarction, the score increased from the early to the intermediate images, but not on the delayed images. Regional uptake on the delayed images showed a better correlation with the fluorodeoxyglucose images than that on the early images. Redistribution on the delayed images was exclusively observed in the myocardial segments with less uptake than that estimated by fluorodeoxyglucose. In conclusion, addition of delayed 201Tl imaging to the dual-isotope protocol could improve the sensitivity for detecting myocardial viability.

Topics: Aged; Exercise Test; Female; Fluorodeoxyglucose F18; Heart; Humans; Image Processing, Computer-Assisted; Male; Middle Aged; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Rest; Thallium; Thallium Radioisotopes; Tomography, Emission-Computed

This study describes a new 1-day protocol with Tc-99m tetrofosmin that requires only 100 minutes to obtain both stress and resting cardiac images by using a double-injection and subtraction method.. This procedure was performed in 48 consecutive patients. Rest-rest double injections were performed in eight patients (five men, three women; mean age, 69 +/- 9.8 years ) to evaluate count and image reproducibility (subprotocol A), and stress-rest and additional resting perfusion images (true rest) were done on a different day in 11 patients (five men, six women; mean age, 63 +/- 5.9 years) to confirm the validity of the new protocol (subprotocol B).. Image quality scores of the resting image were excellent (35 of 48, or 72.9%), good (7 of 48, or 14.6%), fair (3 of 48, or 6.3%), and poor (3 of 48, or 6.3%). The scintigraphic findings with the new protocol corresponded closely with those of angiography in 26 of 34 cases (76.5%), with a tendency for underestimation (in 5 of 34 cases, or 14.7%) rather than overestimation (in 3 of 34 cases, or 8.8%). In subprotocol A, count reproducibility between the two resting images was excellent (r = 0.95; P < 0.0001); and in subprotocol B, the early-rest images were concordant visually and quantitatively with the true rest images (r = 0.89, P < 0.0001).. Although there are some limitations, this protocol can be used as a routine stress-rest protocol.

Topics: Aged; Aged, 80 and over; Biological Transport; Clinical Protocols; Coronary Angiography; Data Interpretation, Statistical; Exercise Test; Feasibility Studies; Female; Heart; Humans; Male; Middle Aged; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Patient Compliance; Radiopharmaceuticals; Sensitivity and Specificity; Subtraction Technique; Tomography, Emission-Computed, Single-Photon

We developed a new diagnostic method for simultaneously evaluating myocardial ischemia, myocardial viability and ventricular function in less than 90 minutes by combined use of rest thallium-201 (Tl) SPECT and exercise Tc-99m tetrofosmin (TF) first pass and SPECT. The subjects were 9 healthy controls, 19 angina pectoris patients, and 19 old myocardial infarction patients, in all of whom coronary angiography had been performed. Rest Tl myocardial SPECT was performed first, and was followed by exercise TF myocardial SPECT. We also performed first pass radionuclide angiography by TF during maximum exercise on a bicycle ergometer to assess the left ventricular ejection fraction (LVEF). The total examination time was less than 90 minutes. SPECT diagnosis was performed by semi-quantitative analysis. LVEF below 55% was regarded as abnormal. In the patients with angina pectoris, analysis according to the coronary artery showed that the diagnostic accuracy of SPECT was 85.0% for ischemia in the region of the left anterior descending branch (LAD), 87.5% for the left circumflex branch (LCX) and 77.8% for the right coronary artery (RCA). The accuracy of diagnosis for angina pectoris was 82.1%, as determined by SPECT alone, and rose to 89.3% when the LVEF levels were also taken into consideration. In the patients with old myocardial infarction, the diagnostic accuracy of SPECT was 84.2% for the LAD, 92.3% for the LCX and 85.0% for the RCA. Analysis by patients showed that the accuracy of diagnosis for myocardial infarction was 85.7%, as determined by SPECT alone. The diagnostic accuracy, however, rose to 89.3% when the LVEF levels also were taken into consideration. In conclusion, it was demonstrated that this combined diagnostic method was highly reliable for evaluating ischemic heart disease within a short time.

Topics: Aged; Coronary Angiography; Exercise; Female; Humans; Male; Middle Aged; Myocardial Infarction; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Radionuclide Ventriculography; Reproducibility of Results; Sensitivity and Specificity; Thallium Radioisotopes; Tomography, Emission-Computed, Single-Photon

99Tcm-tetrofosmin is a new myocardial perfusion agent that has excellent physical and pharmacokinetic characteristics for performing tomographic myocardial perfusion studies. The aim of this study was to compare the behaviour of 99Tcm-tetrofosmin and 201Tl in the assessment of ischaemia and viability in patients with previous myocardial infarction. Twenty consecutive patients who had suffered infarction and been referred for assessment of ischaemia and myocardial viability were enrolled into the study. Each patient underwent two stress tests performed no more than 10 days apart, one with a 201Tl exercise-reinjection-redistribution method and one with a 99Tcm-tetrofosmin short protocol (exercise-rest). The results were quantified using polar maps to represent images for stress, rest and reversibility. The post-stress images showed there was a slight tendency to overestimate defect size with 99Tcm-tetrofosmin in the lateral region (P < 0.006). We found no significant differences between the two tracers when comparing reversibility. The same defect size at rest were obtained when the maps for 201Tl with uptake of 50% were compared with those for 99Tcm-tetrofosmin with uptake of 45%. Agreement between the two agents for assessment of viability was 93%. We conclude that the quantitative assessment of myocardial ischaemia and uptake of 99Tcm-tetrofosmin at rest are comparable to those obtained with 201Tl in patients who have suffered myocardial infarction.

Topics: Adult; Aged; Coronary Circulation; Exercise Test; Female; Heart; Humans; Image Processing, Computer-Assisted; Male; Middle Aged; Myocardial Ischemia; Myocardium; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Stress, Physiological; Thallium Radioisotopes; Tomography, Emission-Computed, Single-Photon

Myocardial ischemia and myocardial infarction are the most serious complications of coronary artery lesions in children with Kawasaki disease (KD). Therefore, early detection and treatment of myocardial ischemia in patients with KD is essential. We studied the effectiveness of percutaneous transluminal coronary angioplasty (PTCA) in patients with silent myocardial ischemia detected by dobutamine stress 99mTc myocardial scintigraphy (TMS), body surface mapping (BMS), and signal-averaged ECG late potentials (ELP).. Eight of 76 asymptomatic patients with a coronary stenosis >25% and a positive dobutamine stress test were considered to have silent myocardial ischemia. All eight patients had >95% stenoses demonstrated by coronary angiography (CAG) just before PTCA. After PTCA, CAG showed that all of the coronary artery stenoses had been reduced to <50%. Additionally, intravascular ultrasonography (IVUS) performed in five patients before and after PTCA demonstrated adequate dilation of the coronary stenosis after PTCA. All eight patients underwent dobutamine stress TMS, BMS, and ELP 2 to 3 months after PTCA, which demonstrated no regions of myocardial ischemia. Approximately 6 months later, CAG was performed in all eight patients, and only one patient had developed restenosis.. PTCA effectively dilates stenotic coronary arteries in children with KD. Moreover, dobutamine stress TMS, BMS, and ELP are useful for detecting silent myocardial ischemia and estimating the effectiveness of PTCA. Furthermore, IVUS is useful for evaluating the severity of coronary artery lesions before and after PTCA in patients with KD.

Topics: Adolescent; Angioplasty, Balloon, Coronary; Body Surface Potential Mapping; Cardiotonic Agents; Child; Child, Preschool; Coronary Angiography; Dobutamine; Electrocardiography; Evaluation Studies as Topic; Exercise Test; Humans; Infant; Male; Mucocutaneous Lymph Node Syndrome; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon; Ultrasonography, Interventional

The aim of this study was to investigate the accuracy of quantitative one-day exercise-rest 99mTc tetrofosmin tomography in the identification of patients with suspected coronary artery disease (CAD) and in the detection of single stenosed coronary vessels. Sixty-one patients with suspected CAD and submitted to coronary angiography were examined. All patients were given 2 i.v. injections of 99mTc tetrofosmin, one at peak exercise (370 MBq) and the other (1110 MBq) at rest 3 hours after exercise (images 15-30 min after injection for both studies). All patients with CAD (> or = 50% luminal stenosis) (n = 50) had abnormal 99mTc tetrofosmin tomogram (100% sensitivity). Only one patient without CAD had abnormal 99mTc tetrofosmin tomogram (91% specificity). Overall sensitivity, specificity, and diagnostic accuracy in the detection of single stenosed vessels were 77%, 93% and 85%, respectively. No significant differences among single vascular areas were observed. Sensitivity and diagnostic accuracy in the identification of single stenosed coronary vessels were significantly higher (p < 0.05) in the patients with single-vessel disease (n = 21) than in those with multivessel disease (n = 29). Sensitivity, specificity and diagnostic accuracy in detecting single diseased vessels were similar in the patients without (n = 26) and in those with previous myocardial infarction (n = 35). The results of this study demonstrate that quantitative one-day exercise-rest 99mTc tetrofosmin SPECT imaging is a suitable and accurate technique to identify patients with suspected CAD and to detect single stenosed coronary vessels.

Topics: Adult; Coronary Vessels; Female; Humans; Male; Middle Aged; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Reproducibility of Results; Sensitivity and Specificity; Tomography, Emission-Computed, Single-Photon

Technetium-99m tetrofosmin is a new myocardial perfusion imaging agent that accumulates rapidly and shows slow clearance from the myocardium. Dynamic acquisition and SPECT imaging were performed in a total of 26 patients. Using exercise-rest protocol, the single-photon emission computed tomography (SPECT) findings of 130 myocardial segments were classified as infarction, ischemia and partial filling and compared to those with 201Tl. Complete concordance of findings was obtained in 108 segments (83%) between images with 99mTc tetrofosmin and 201Tl. Partial filling was observed in 24 segments with 201Tl and 14 segments with tetrofosmin, showing a greater number of ischemic regions in 201Tl. However, in comparison with coronary arteriography (n = 19), overall sensitivity and specificity for detecting coronary artery stenosis (> or = 75%) was 15 of 25 (0.60) and 27 of 32 (0.84), respectively, which did not differ significantly from those of 201Tl, which was 18 of 25 (0.72) and 27 of 32 (0.84), respectively. Graphic analysis that assumes unidirectional transfer of the tracer was applied to initial dynamic changes and uptake constant k and distribution volume V were computed. Multiple vessel disease and congestive heart failure showed a low perfusion index (k/V), and may be used in this type of tracer with unidirectional uptake. This preliminary study in the clinical trial showed the usefulness of 99mTc tetrofosmin as a myocardial perfusion imaging agent.

Topics: Coronary Angiography; Exercise Test; Heart; Humans; Image Processing, Computer-Assisted; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Sensitivity and Specificity; Thallium Radioisotopes; Time Factors; Tomography, Emission-Computed, Single-Photon

The Covid-19 pandemic led to a complete renewal of clinical activities of Italian hospitals. During the lockdown, all hospitals in Italy had to suspend non-urgent clinical activities. The prolonged suspension of elective activities could have caused a series of problems.. A new ad hoc protocol was designed. Single-day fast-imaging protocol with regadenoson-stress 99mTc-tetrofosmin imaging was preferred. Patients were contacted by phone 4 days before the test and answered to a questionnaire which will be repeated on the day of the exam. Body temperature <37.5 degrees C and no Covid-19 symptoms were necessary to enter the unit. Patients wore surgical mask and gloves. Social distancing was maintained throughout the examination. Healthcare professionals wore a personal protective equipment.. A total of 46 patients were studied from April 7 to May 15, 2020, before the publication of the recommendations from ASNC and SNMMI. None of the patients experienced complications. Follow-up of patients discharged was carried by phone. No Covid-19 infection symptoms were reported. On May 18, 2020 all the healthcare providers of nuclear cardiology department underwent serological testing IgG and IgM and none were positive.. Strict ad hoc hygiene protocol for Covid-19 pandemic avoids diagnostic-therapeutic delay and lengthening of waiting lists. Our experience confirms that pursuing WHO recommendations and recent indication of ASNC and SNMMI is safe for both health providers and patients. Moreover, the incidence of significant inducible ischemia rises when correct stratification of patients is performed.

Topics: Aged; Aged, 80 and over; Body Temperature; Cardiology; COVID-19; Female; Hospitals; Humans; Incidence; Infection Control; Italy; Male; Middle Aged; Myocardial Ischemia; Nuclear Medicine; Occupational Exposure; Organophosphorus Compounds; Organotechnetium Compounds; Patient Safety; Personal Protective Equipment; Physical Distancing; Surveys and Questionnaires; Tomography, Emission-Computed, Single-Photon

Regadenoson Stress Echocardiography (RSE) can detect myocardial ischemia, and its diagnostic accuracy should be evaluated. We sought to investigate the agreement between RSE and gated-SPECT myocardial perfusion imaging (MPI) and appraise its diagnostic accuracy. Consecutive patients (n = 202) referred for non-invasive evaluation of myocardial ischemia, with (38.6%) or without a previous coronary artery disease (CAD) diagnosis, were enrolled. Both tests were performed simultaneously. Invasive coronary angiography (CA) is considered the gold standard. The mean age was 70.9 (9.8) years, and 59.9% were male. The prevalence of cardiovascular risk factors (arterial hypertension [81.7%], diabetes mellitus [37.6%], hypercholesterolemia [71.8%], and smoking [18.8%]) was high. Forty-four patients (21.8%) had a non-interpretable electrocardiogram, 15 (34.1%) of them were a result of ventricular paced-rhythm, while 29 (65.9%) were a result of advanced left ventricular branch block. The overall agreement between both diagnostic techniques was good: Gwet's AC1 0.66 (CI95% 0.55 to 0.76), and it was higher in patients without a previous CAD diagnosis: 0.76 (CI95% 0.65 to 0.87). In the biased sample (those who underwent CA), RSE and nuclear study sensitivity was 0.50 and 0.78 and specificity was 0.75 and 0.75, respectively. We noted a dramatic reduction in sensitivity for RSE after debiasing (debiased sensitivity of 0.16), and the negative predictive value was similar to the biased and debiased samples. RSE is in strong agreement with gated-SPECT MPI. However, its low sensitivity and negative predictive value preclude its use as a bedside test to detect myocardial ischemia.

Topics: Aged; Cardiac-Gated Imaging Techniques; Comorbidity; Echocardiography, Stress; Female; Heart Disease Risk Factors; Humans; Male; Middle Aged; Myocardial Ischemia; Myocardial Perfusion Imaging; Organophosphorus Compounds; Organotechnetium Compounds; Predictive Value of Tests; Prevalence; Purines; Pyrazoles; Radiopharmaceuticals; Reproducibility of Results; Smoking; Technetium Tc 99m Sestamibi; Tomography, Emission-Computed, Single-Photon; Vasodilator Agents

Myocardial perfusion imaging (MPI) is a useful modality to rule out myocardial ischaemia in patients presenting with chest pain. In nursing mothers imaging with radioisotope is usually avoided but under certain circumstances it is unavoidable. We present the case of a 45-year-old woman with chest pain, who underwent MPI for assessment of ischaemia. The scan showed anterior artefact due to diffuse breast uptake in both the breasts, as the patient was a lactating mother. The case highlights the importance of breast uptake of radioisotope in the lactating mother on MPI and the necessary steps which need to be taken if radiotracer is injected into a lactating woman.

Topics: Breast; Exercise Test; Female; Humans; Lactation; Middle Aged; Myocardial Ischemia; Myocardial Perfusion Imaging; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon

The goal of this study was to evaluate the prevalence of depression and anxiety in patients subjected to myocardial perfusion imaging (MPI) with 99mTc tetrofosmin stress-rest single-photon emission computer tomography (SPECT), and their impact on their cardiological events or disease.. Patients referred to the Nuclear Medicine Department for 99mTc tetrofosmin myocardial MPI-SPECT were asked to fulfill the Zung Self-Rating Depression Scale (ZDS) and Hamilton anxiety questionnaire (HAQ). Among 213 patients who completed the ZDS and HAQ, 80 patients (59 males and 21 females) were selected for this study because they had no known psychological disease, other disease that could influence psychological status, or use of narcotic drugs. Collected data from MPI and psychological status were subsequently analyzed.. Among all 80 patients, 52 patients (65%) had abnormal MPI of whom 28/52 (53.8%) exhibited either depression, anxiety or both, and 28 (35%) patients had normal MPI of whom 10/28 (35.7%) had abnormal psychological status. The higher number of patients with abnormal psychological status in association with abnormal MPI was noted predominantly in patients with previously established coronary artery disease. A correlation was also noted between obesity, cardiac heredity and depression or anxiety in patients with abnormal MPI.. Patients that exhibit depression, anxiety, or both, have high rates of myocardial ischemia, and thus are at risk for subsequent cardiological events.

Topics: Aged; Anxiety; Depression; Female; Humans; Male; Middle Aged; Myocardial Ischemia; Myocardial Perfusion Imaging; Organophosphorus Compounds; Organotechnetium Compounds; Prognosis; Tomography, Emission-Computed, Single-Photon

The aim of the present study was to assess the additional value of systolic wall thickening to myocardial perfusion in diagnosing myocardial stunning induced by dipyridamole infusion. We selected 52 ischemic patients (43 males; mean age 65.5 ± 7.64), with CAD documented by angiography. Ischemia was defined as a summed difference score ≥ 5. All patients underwent a 2-day gated perfusion SPECT protocol. The patients received a dose of 740 MBq of 99mTc-tetrofosmin after stress and at rest.. The post-stress LVEF was significantly lower than rest LVEF (48.3% ± 14.5% vs. 50.7% ± 15%; P = 0.0001). The wall thickening summed difference score was 3.97 ± 3.84 (P = 0.0001). At a multivariate regression analysis, only WT-SDS as independent variable was significantly correlated with myocardial ischemia (SDS) (P = 0.001). We divided patients according to SDS in those with mild (SDS < 8) and severe (SDS ≥ 8) ischemia. WT-SDS, but not ∆LVEF, was significantly different between groups.. WT-SDS showed a better correlation with the degree of ischemia than the depression in the global function of the left ventricle. It allowed to better identify the stunning phenomenon in patients submitted to pharmacological stress.

Topics: Aged; Cardiac-Gated Single-Photon Emission Computer-Assisted Tomography; Dipyridamole; Female; Humans; Male; Middle Aged; Myocardial Ischemia; Myocardial Stunning; Organophosphorus Compounds; Organotechnetium Compounds; Predictive Value of Tests; Radiopharmaceuticals; Vasodilator Agents

Transposition of the great arteries is a congenital heart defect defined by an abnormal connection between the aorta, pulmonary artery, and the ventricles, resulting in parallel systemic and pulmonary circulations. Long-term follow-up data of patients who underwent correction via an arterial switch operation have recently shown that as a result of re-implantation of the coronary arteries in the neo-aorta, coronary stenosis and occlusion are relatively common complications. In this report, we discuss two cases illustrating the added value of myocardial perfusion imaging (MPI) and cardiac CT for the assessment of these patients. Based on the available literature we conclude that MPI and cardiac CT are excellent non-invasive methods to evaluate coronary anatomy and myocardial function also in this specific group of patients.

Topics: Adolescent; Coronary Angiography; Coronary Stenosis; Coronary Vessels; Exercise; Heart; Heart Ventricles; Humans; Male; Myocardial Ischemia; Myocardial Perfusion Imaging; Organophosphorus Compounds; Organotechnetium Compounds; Radionuclide Imaging; Risk; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed; Transposition of Great Vessels

Using myocardial perfusion scintigraphy (MPS), an increase in left ventricular (LV) volumes or a decrease in ejection fraction (EF) from rest to stress may be clinically important. The variation in these measures between the low-dose stress acquisition and high-dose rest acquisition in a one-day stress-rest protocol has not been established. We assessed the reproducibility of gated volumetric indices between stress and rest and the normal variation in ungated TID ratio for a one-day stress-rest. Two thousand and one hundred and fifty eight (2158). Gated data were analyzed for 621 patients without inducible hypoperfusion. Mean EF at rest was slightly higher than after stress (62.4% ± 10.3% vs 61.2% ± 10.4%, P < 0.001), and the standard deviation of the difference was 5.2% (95% CI 4.9% to 5.5%). Ungated volumes were available for 992 non-ischaemic patients. The upper 95% CI for TID ratio was 1.23. This increased from 1.20 to 1.37 between the highest and lowest deciles of rest ungated volume.. Using a one-day stress-rest

Topics: Aged; Confidence Intervals; Coronary Artery Disease; Exercise Test; Female; Humans; Male; Middle Aged; Myocardial Ischemia; Myocardial Perfusion Imaging; Organophosphorus Compounds; Organotechnetium Compounds; Reproducibility of Results; Retrospective Studies; Stroke Volume; Technetium Tc 99m Sestamibi; Tomography, Emission-Computed, Single-Photon; Ventricular Function, Left

Dual-energy computed tomography (DECT) can be used for visual determination of iodine distribution in the myocardium (iodine image); however, the accuracy and reproducibility of the process remains debatable. Because of the low contrast-to-noise ratio of CT, we hypothesized that quantitative measurement may be more accurate for detecting myocardial ischemia. In this study, we evaluated our quantitative method by comparing it with visual analysis using Tc-tetrofosmin (TF) stress-rest single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) as the reference standard.. Forty-three patients who had a significant stenosis on cardiac rest DECT and had received Tc-TF stress-rest SPECT MPI within 1 month were retrospectively analyzed. The regions of interest were set on iodine images in accordance with the American Heart Association (AHA) 17-segment model (a total of 731 segments). The regions of interest values were divided by the amount of iodine (mg) per unit weight (kg) and defined as perfusion value (perfusion value analysis). All segments were also visually analyzed and receiver operating characteristic curve analysis performed to identify the superior analysis.. The receiver operating characteristic curve analysis showed that perfusion value analysis is significantly superior to visual analysis [the area under the curve: 0.921 (95% confidence interval, 0.860-0.981) versus 0.685 (95% confidence interval, 0.580-0.791), respectively, P<0.05], with 93.8% sensitivity, 99.1% specificity, 98.9% accuracy, 83.3% positive predictive value, and 99.7% negative predictive value (P<0.01).. Quantitative analysis of the iodine image of rest DECT, called perfusion value analysis, is more accurate than visual analysis when compared with Tc-TF SPECT MPI as the reference standard.

Topics: Aged; Evaluation Studies as Topic; Female; Humans; Iodine; Male; Myocardial Ischemia; Myocardial Perfusion Imaging; Organophosphorus Compounds; Organotechnetium Compounds; Radiography, Dual-Energy Scanned Projection; Radiopharmaceuticals; Reference Standards; Reproducibility of Results; Rest; Sensitivity and Specificity; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed

At present, the choice of noninvasive testing for a diagnosis of significant coronary artery disease (CAD) is ambiguous, but nuclear myocardial perfusion imaging with single-photon emission tomography (SPECT) or positron emission tomography (PET) and coronary computed tomography angiography (CCTA) is predominantly used for this purpose. However, to date, prospective head-to-head studies are lacking regarding the diagnostic accuracy of these imaging modalities. Furthermore, the combination of anatomical and functional assessments configuring a hybrid approach may yield improved accuracy.. To establish the diagnostic accuracy of CCTA, SPECT, and PET and explore the incremental value of hybrid imaging compared with fractional flow reserve.. A prospective clinical study involving 208 patients with suspected CAD who underwent CCTA, technetium 99m/tetrofosmin-labeled SPECT, and [15O]H2O PET with examination of all coronary arteries by fractional flow reserve was performed from January 23, 2012, to October 25, 2014. Scans were interpreted by core laboratories on an intention-to-diagnose basis. Hybrid images were generated in case of abnormal noninvasive anatomical or functional test results.. Hemodynamically significant stenosis in at least 1 coronary artery as indicated by a fractional flow reserve of 0.80 or less and relative diagnostic accuracy of SPECT, PET, and CCTA in detecting hemodynamically significant CAD.. Of the 208 patients in the study (76 women and 132 men; mean [SD] age, 58 [9] years), 92 (44.2%) had significant CAD (fractional flow reserve ≤0.80). Sensitivity was 90% (95% CI, 82%-95%) for CCTA, 57% (95% CI, 46%-67%) for SPECT, and 87% (95% CI, 78%-93%) for PET, whereas specificity was 60% (95% CI, 51%-69%) for CCTA, 94% (95% CI, 88%-98%) for SPECT, and 84% (95% CI, 75%-89%) for PET. Single-photon emission tomography was found to be noninferior to PET in terms of specificity (P < .001) but not in terms of sensitivity (P > .99) using the predefined absolute margin of 10%. Diagnostic accuracy was highest for PET (85%; 95% CI, 80%-90%) compared with that of CCTA (74%; 95% CI, 67%-79%; P = .003) and SPECT (77%; 95% CI, 71%-83%; P = .02). Diagnostic accuracy was not enhanced by either hybrid SPECT and CCTA (76%; 95% CI, 70%-82%; P = .75) or by PET and CCTA (84%; 95% CI, 79%-89%; P = .82), but resulted in an increase in specificity (P = .004) at the cost of a decrease in sensitivity (P = .001).. This controlled clinical head-to-head comparative study revealed PET to exhibit the highest accuracy for diagnosis of myocardial ischemia. Furthermore, a combined anatomical and functional assessment does not add incremental diagnostic value but guides clinical decision-making in an unsalutary fashion.

Topics: Computed Tomography Angiography; Coronary Angiography; Female; Fractional Flow Reserve, Myocardial; Humans; Male; Middle Aged; Multimodal Imaging; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Positron-Emission Tomography; Radiopharmaceuticals; Sensitivity and Specificity; Tomography, Emission-Computed, Single-Photon

471 patients had images adequate for total 17-segment scoring. There were 48 ArEs (10.2%). Neither. The presumption of a monotonic increase in ArE risk with increasing summed

Topics: 3-Iodobenzylguanidine; Arrhythmias, Cardiac; Causality; Comorbidity; Female; Heart Failure; Humans; Incidence; Internationality; Male; Middle Aged; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Prognosis; Radiopharmaceuticals; Reproducibility of Results; Risk Factors; Sensitivity and Specificity; Single Photon Emission Computed Tomography Computed Tomography; Survival Rate

We investigated if image- and diagnostic quality in SPECT MPI could be maintained despite a reduced acquisition time adding Depth Dependent Resolution Recovery (DDRR) for image reconstruction. Images were compared with filtered back projection (FBP) and iterative reconstruction using Ordered Subsets Expectation Maximization with (IRAC) and without (IRNC) attenuation correction (AC).. Stress- and rest imaging for 15 min was performed on 21 subjects with a dual head gamma camera (Infinia Hawkeye; GE Healthcare), ECG-gating with 8 frames/cardiac cycle and a low-dose CT-scan. A 9 min acquisition was generated using five instead of eight gated frames and was reconstructed with DDRR, with (IRACRR) and without AC (IRNCRR) as well as with FBP. Three experienced nuclear medicine specialists visually assessed anonymized images according to eight criteria on a four point scale, three related to image quality and five to diagnostic confidence. Statistical analysis was performed using Visual Grading Regression (VGR).. Observer confidence in statements on image quality was highest for the images that were reconstructed using DDRR (P<0·01 compared to FBP). Iterative reconstruction without DDRR was not superior to FBP. Interobserver variability was significant for statements on image quality (P<0·05) but lower in the diagnostic statements on ischemia and scar. The confidence in assessing ischemia and scar was not different between the reconstruction techniques (P = n.s.).. SPECT MPI collected in 9 min, reconstructed with DDRR and AC, produced better image quality than the standard procedure. The observers expressed the highest diagnostic confidence in the DDRR reconstruction.

Topics: Adenosine; Adult; Aged; Algorithms; Bicycling; Cardiac-Gated Imaging Techniques; Electrocardiography; Exercise Test; Female; Humans; Image Interpretation, Computer-Assisted; Male; Middle Aged; Myocardial Ischemia; Myocardial Perfusion Imaging; Observer Variation; Organophosphorus Compounds; Organotechnetium Compounds; Predictive Value of Tests; Radiopharmaceuticals; Reproducibility of Results; Single Photon Emission Computed Tomography Computed Tomography; Vasodilator Agents

Two-dimensional echocardiographic left ventricular (LV) global longitudinal strain (GLS) after ST-segment elevation myocardial infarction (STEMI) is moderately correlated with infarct size and reflects the residual LV systolic function. This correlation may be influenced by the presence of myocardial ischemia. The present study investigated how myocardial ischemia modulates the correlation between LV GLS and infarct size determined with single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) in patients with first STEMI treated with primary coronary intervention. A total of 1,128 patients (age 60 ± 11 years) who underwent SPECT MPI for the evaluation of infarct size and residual ischemia were evaluated. LV GLS was measured on transthoracic echocardiography. The time interval between echocardiography and SPECT MPI was 1 ± 1 month. A moderate correlation between echocardiographic LV GLS and infarct size on SPECT MPI was observed (r = 0.58, p <0.001). This correlation was weakened by the presence or extent of ischemia; in the group of patients without ischemia, the correlation between LV GLS and infarct size on SPECT MPI was r = 0.66 (p <0.001), whereas in patients with mild or moderate-to-severe ischemia, the correlations were r = 0.56 and 0.38, respectively (both p <0.001). Moderate-to-severe myocardial ischemia was independently associated with more impaired LV GLS after adjusting for infarct size, age, diabetes mellitus, and hypertension (β 0.60, 95% confidence interval 013 to 1.06). In conclusion, the presence of myocardial ischemia after STEMI impacts on the correlation between echocardiographic LV GLS and infarct size measured on SPECT MPI. Residual ischemia is independently associated with more impaired LV GLS.

Topics: Echocardiography; Female; Humans; Image Interpretation, Computer-Assisted; Male; Middle Aged; Myocardial Infarction; Myocardial Ischemia; Myocardial Perfusion Imaging; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Retrospective Studies; Tomography, Emission-Computed, Single-Photon; Ventricular Dysfunction, Left

Background Previous studies revealed a relatively high prevalence of electrocardiographic findings indicative for myocardial ischemia in asymptomatic athletes undergoing pre-participation screening. Myocardial perfusion scintigraphy is generally considered a valuable diagnostic and prognostic modality and often used for further diagnostic evaluation in these subjects. However, data on the diagnostic accuracy of myocardial perfusion scintigraphy in athletes are scarce. Objectives The main purpose of this study was to investigate the positive predictive value of myocardial perfusion scintigraphy for detection of coronary artery disease in asymptomatic athletes with abnormal exercise testing results during pre-participation screening. The secondary aim was to evaluate the prognostic value of myocardial perfusion scintigraphy. Methods Electronic charts of asymptomatic athletes who underwent myocardial perfusion scintigraphy following an abnormal exercise testing were retrospectively reviewed. Myocardial perfusion scintigraphy and exercise testing studies were revised. Athlete characteristics and cardiovascular risk factors were evaluated. Results One hundred and forty-three athletes were included. 29 athletes (20%) showed concordant abnormal exercise testing and myocardial perfusion scintigraphy results. Coronary imaging was performed in 20 of these 29 athletes. Four athletes showed significant coronary artery disease (positive predictive value = 20%). The positive predictive value increased to 33% when athletes were selected who should have undergone exercise testing according to the guideline recommendations. During a mean follow-up interval of 4.7 ± 2.2 years, eight cardiac events occurred. Athletes with an abnormal myocardial perfusion scintigraphy result had a fourfold increased risk at a future cardiac event (2.9%/year versus 0.75%/year, p = 0.031). Conclusions The positive predictive value of myocardial perfusion scintigraphy for the detection of significant coronary artery disease in asymptomatic athletes with a positive exercise testing result is low, even in a selection of athletes with a relatively high cardiovascular risk. Although an abnormal myocardial perfusion scintigraphy result was associated with a fourfold higher annual event rate, the absolute annual event rate in this group was still low. Efforts should be made to develop better diagnostic strategies to evaluate asymptomatic athletes with abnormal exercise testing results during pre-part

Topics: Adult; Athletes; Computed Tomography Angiography; Coronary Angiography; Coronary Artery Disease; Coronary Circulation; Exercise Test; Female; Humans; Male; Middle Aged; Myocardial Ischemia; Myocardial Perfusion Imaging; Organophosphorus Compounds; Organotechnetium Compounds; Predictive Value of Tests; Prognosis; Radiopharmaceuticals; Reproducibility of Results; Retrospective Studies; Risk Assessment; Risk Factors; Time Factors

The purpose of this study was to examine the prognostic significance of uptake patterns on quantitative myocardial (123)I-mIBG and (99m)Tc-tetrofosmin SPECT imaging in heart failure (HF) subjects and to assess the differences between patients with ischaemic and non-ischaemic HF.. Results of quantitative analyses of (123)I-mIBG myocardial SPECT, alone and in combination with (99m)Tc tetrofosmin SPECT, were studied in 619 ischaemic (I) and 319 non-ischaemic (NI) HF subjects from the ADMIRE-HF trial. Cardiac and all-cause mortality data for 2-year follow-up were collected in the extension study (ADMIRE-HFX) and were examined in relation to extent and severity of voxel-based defects, the number of myocardial segments with significant dysinnervation (derived score ≥2), and (123)I-mIBG/(99m)Tc tetrofosmin mismatch quantitation. Cox proportional hazards and survival analyses were used to identify higher and lower risk groups and to define thresholds for optimal discrimination between the two. Two-year all-cause and cardiac mortality were not significantly different between IHF and NIHF subjects. Mortality was higher in patients with dysinnervation involving >50% of the myocardium. Highest cardiac mortality risk for IHF subjects was seen with perfusion defects involving 20-40% of the myocardium. By comparison, NIHF subjects with smaller perfusion abnormalities (<20% of myocardium), but with a large discrepancy between (123)I-mIBG and (99m)Tc tetrofosmin defect sizes, were at highest risk of cardiac death.. Prognostic significance of patterns of (123)I-mIBG and MPI uptake differ between IHF and NIHF subjects. SPECT imaging may provide new insights into underlying disease processes in HF, including the degree of dysinnervation in areas with preserved myocardial perfusion in non-ischaemic HF patients.

Topics: 3-Iodobenzylguanidine; Aged; Female; Follow-Up Studies; Heart Failure; Humans; Male; Middle Aged; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Prognosis; Radiopharmaceuticals; Survival Analysis; Tomography, Emission-Computed, Single-Photon

Although liposomes hold promise for cancer therapy, the effectiveness of treating myocardial ischemia by promoting angiogenesis has yet to be proved. Nanoliposomes loaded with therapeutic agents can effectively target ischemic myocardium via enhanced permeability and retention. Surface polyethylene glycol (PEG) modification can further facilitate effective targeting by prolonging liposomal circulation. This study aimed to determine whether PEGylated nanoliposomes are effective in facilitating targeted drug delivery and treating myocardial ischemia.. Rats subjected to 30min of myocardial ischemia were given (99m)Tc-hexamethylpropyleneamine oxime- or (99m)Tc-diethylenetriamine pentaacetate-labeled liposomes with mean diameters of ~100nm or ~600nm with or without PEG modifications to determine the extent of myocardial uptake in the different conditions. Therapeutic effectiveness was assessed by studying changes in myocardial perfusion defects with (99m)Tc-tetrofosmin autoradiography and vascular density with immunohistochemistry at 7days post-treatment.. The liver and spleen showed the largest capacity for liposome uptake. Uptake by the liver and spleen was more pronounced when the liposomes were larger. Conversely, myocardial liposome uptake was significantly greater when the liposomes were ~100nm rather than ~600nm in diameter. Surface modification with PEG significantly augmented myocardial uptake of ~100nm liposomes. PEG modification did not affect the size dependence. To investigate therapeutic efficacy, hearts subjected to ischemia received PEGylated nanoliposomes encapsulated with angiogenic peptides. Our data demonstrated that PEGylated nanoliposomes loaded with angiogenic peptides improved myocardial perfusion defects and increased vascular density. A 10-fold increase in liposomal concentration did not further benefit myocardial ischemia.. Liposomal angiogenic formulation with size control and PEG modification may be effective treatment strategy for myocardial ischemia. Increasing the concentration of liposomes does not necessarily benefit myocardial ischemia.

Topics: Angiogenic Proteins; Animals; Capsules; Coronary Circulation; Dose-Response Relationship, Drug; Liposomes; Male; Myocardial Ischemia; Neovascularization, Physiologic; Organophosphorus Compounds; Organotechnetium Compounds; Polyethylene Glycols; Radionuclide Imaging; Rats; Rats, Sprague-Dawley; Tissue Distribution

Coronary artery lesions in Kawasaki disease invasively assessed by coronary angiography. Evaluation of myocardial perfusion by single-photon emission computed tomography may identify the haemodynamic significance of coronary lesions.. To evaluate diagnostic accuracy of dipyridamole stress technetium-99 m tetrofosmin, single-photon emission computed tomography as a possible alternative to invasive coronary angiography for detection and follow-up of myocardial ischaemia in patients with Kawasaki disease, and pre- and post-coronary bypass grafting.. Coronary angiography and single-photon emission computed tomography were performed on 21 patients who were classified into three groups - group I (stenosis), group II (giant aneurysms), and group III (small aneurysms). Of the 21 patients, 16 (groups I and II) patients with myocardial perfusion defects, who underwent coronary bypass grafting, were followed up with single-photon emission computed tomography.. In group I, all patients had significant coronary stenosis and 100% of them had perfusion defects in the anterior and septal walls. In group II, all patients had giant aneurysms and 83% of them had inferior and inferolateral perfusion defects. In group III, all patients had small aneurysms and 100% of them had normal perfusion. Pre-coronary bypass grafting myocardial ischaemic defects disappeared in all patients after surgery. Sensitivity, specificity, and accuracy of single-photon emission computed tomography were 94, 100, and 95%, respectively.. Technetium-99 m tetrofosmin single-photon emission computed tomography can be applied as an accurate non-invasive diagnostic technique for detecting myocardial perfusion defects with coronary artery lesions, and to show improved or even normalised perfusion of the myocardium in patients after surgical revascularisation.

Topics: Child; Child, Preschool; Coronary Angiography; Coronary Artery Bypass; Dipyridamole; Female; Humans; Male; Mucocutaneous Lymph Node Syndrome; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon; Treatment Outcome; Vasodilator Agents

Direct ischemia imaging with F18-FDG can potentially overcome many limitations of SPECT-MPS inherent to "cold imaging". We compared SPECT-MPS with exercise F18-FDG PET in detection of ischemia in patients with suspected CAD.. 45 patients with clinical suspicion of CAD without the history of myocardial infarction were prospectively included. All patients underwent Tc-99m tetrofosmin SPECT-MPS and exercise F18-FDG PET imaging within 7 days of SPECT-MPS, and both modalities were compared with coronary angiography for detecting ischemia.. 27 patients had an abnormal coronary angiography (at least one coronary artery with stenosis >50%). Exercise F18-FDG performed better than SPECT-MPS in LAD and LCX territory with comparably good performance in RCA territory. Exercise F18-FDG performed better in single-vessel disease and equally good in multi-vessel disease compared to SPECT-MPS. Performance of exercise 18F-FDG study was significantly better than SPECT-MPS (P = .0014) in the analysis of the 81 vascular territories in the 27 patients with abnormal coronary angiography. Performance of exercise F18-FDG was significantly better than SPECT-MPS in detecting ischemia in suspected CAD patients.. Exercise F18-FDG imaging is a potentially useful ischemia imaging modality which offers the advantages of direct ischemia imaging in CAD patients.

Topics: Adult; Aged; Constriction, Pathologic; Coronary Angiography; Coronary Artery Disease; Female; Fluorodeoxyglucose F18; Humans; Image Processing, Computer-Assisted; Male; Middle Aged; Myocardial Infarction; Myocardial Ischemia; Myocardial Perfusion Imaging; Organophosphorus Compounds; Organotechnetium Compounds; Prospective Studies; Radionuclide Imaging; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon; Young Adult

We set out to develop normal databases and prospectively validate abnormality criteria for a low-dose Tc-99m tetrofosmin myocardial perfusion SPECT protocol using the 530c CZT camera.. All patients received 6 mCi rest/20 mCi stress doses of Tc-99m tetrofosmin. Rest and stress images were obtained over 7-9 and 5-7 minutes according to the chest size. Low-dose CT of the chest was obtained on a standalone CT scanner. Forty patients with very low likelihood (LLK) of coronary artery disease (CAD) were used to define the normal count distributions. The abnormality criteria were prospectively validated in 55 patients who had coronary angiography and in 40 patients with LLK of CAD.. The results for quantitative non-attenuation-corrected (AC) and AC analysis and visual analysis were as follows: sensitivity of 79%, 85%, and 92% (P = NS) and specificity of 44%, 75%, and 56% (P = NS), respectively. The normalcy rates for quantitative non-AC and AC analyses and visual analysis were 95%, 98%, and 98% (P = NS).. We have developed non-AC and AC normal databases for low-dose rest/stress Tc-99m tetrofosmin myocardial perfusion SPECT protocol using the 530c CZT camera. The per-patient diagnostic performance of quantitative analyses is not significantly different from visual analysis by an experienced reader.

Topics: Aged; Coronary Angiography; Coronary Artery Disease; Exercise Test; Female; Humans; Male; Middle Aged; Myocardial Ischemia; Myocardial Perfusion Imaging; Organophosphorus Compounds; Organotechnetium Compounds; Prospective Studies; Radiopharmaceuticals; Reproducibility of Results; Sensitivity and Specificity; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed

To investigate the relationships between regional adrenergic innervation heterogeneity, myocardial perfusion, and contractile function obtained by means of a low-dose imaging protocol with a cadmium-zinc-telluride (CZT) dedicated camera.. Twenty-eight patients with or without ischaemic heart disease underwent (123)I-metaiodobenzylguanidine (MIBG) planar scintigraphic and CZT early and delayed evaluations followed by (99m)Tc-tetrofosmin rest gated CZT with a single-day protocol. The heart-to-mediastinum ratio and the washout rate were computed from planar (123)I-MIBG images. The summed (123)I-MIBG defect scores (SS-MIBG) were semi-quantitatively assessed from CZT images. The summed rest score (SRS), summed motion score (SMS), and summed thickening score (STS) were quantitated from (99m)Tc-tetrofosmin images.. Sixteen patients showed a depressed left ventricular systolic function [ejection fraction (EF)<50%]. They presented higher SRS (P = 0.007), SMS (P < 0.001), STS (P < 0.001), and early SS-MIBG (P = 0.007) values than those with normal contractile function. Interestingly, higher early SS-MIBG values, index of regional sympathetic innervation heterogeneity, clustered with more elevated SRS (P = 0.023), and more impaired measures of regional and global left ventricle systolic function, i.e. SMS (P = 0.046), STS (P = 0.014), and EF (P = 0.027). At multivariate analysis, a higher SRS (P = 0.039) remained the only independent predictor of more elevated early SS-MIBG values. In the 20 of 28 ischaemic patients, the correlations between early SS-MIBG and SMS (P = 0.017) and also STS (P = 0.036) were further confirmed. The effective dose of the investigation was 4.2 ± 0.72 mSv.. An altered early SS-MIBG, assessed with a low-dose imaging protocol and a CZT cardiac camera, identifies patients with more impaired myocardial perfusion and contractile function.

Topics: 3-Iodobenzylguanidine; Adrenergic Neurons; Aged; Cadmium; Female; Heart; Humans; Male; Middle Aged; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Radiographic Image Interpretation, Computer-Assisted; Radiopharmaceuticals; Tellurium; Tomography, Emission-Computed, Single-Photon; Zinc

We have previously reported that 35% CO2 challenge induced myocardial ischemia in 81% of coronary artery disease (CAD) patients with comorbid panic disorder (PD) and previous positive nuclear exercise stress tests. However, it is yet unclear whether this is the case among CAD patients with PD and normal nuclear exercise stress test results. We hypothesized that a potent mental stressor such as a panic challenge among CAD patients with PD would also induce ischemia in patients with normal exercise stress tests.. Forty-one coronary artery disease patients with normal nuclear exercise stress tests (21 patients with PD and 20 without PD) were submitted to a well-established panic challenge test (with 1 vital capacity inhalation of a gas mixture containing 35% CO2 and 65% O2) and injected with Tc-99m-tetrofosmin (Myoview), upon inhalation. Single photon emission computed tomography imaging was used to assess per-panic challenge reversible myocardial ischemia and HR, BP, and a 12 lead ECG was continuously measured during the procedure.. Fifty-eight percent of panic disorder patients (12/21) had a panic attack during the panic challenge vs 15% (3/20) of controls (p=0.005). Only 10% of patients in each group displayed myocardial ischemia per panic challenge.. These findings suggest that panic attacks among panic disorder patients with lower-risk coronary artery disease may not confer a risk for myocardial ischemia.

Topics: Administration, Inhalation; Adult; Aged; Carbon Dioxide; Coronary Artery Disease; Exercise Test; Female; Humans; Male; Middle Aged; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Panic; Panic Disorder; Radiopharmaceuticals; Risk; Tomography, Emission-Computed, Single-Photon

To determine whether chitosan hydrogel nanoparticles loaded with vascular endothelial growth factor (VEGF) peptides (81-91 fragments) capable of targeting the ischemic myocardium enhance angiogenesis and promote therapeutic effects and whether radionuclide image-guided dosage control is feasible.. Experimental procedures and protocols were approved by the Institutional Animal Care and Use Committee. Rats (n = 32, eight per group) were subjected to myocardial ischemia (control group) and received chitosan hydrogel nanoparticles with VEGF165 proteins (chitosan VEGF) or VEGF81-91 peptides (chitosan peptides) via apical puncture. Ischemic hearts receiving chitosan without angiogenic factors served as the chitosan control. Myocardial perfusion was examined 7 days after surgery by using technetium 99m ((99m)Tc) tetrofosmin (37 MBq) autoradiography, and changes in vascular density with immunohistochemical staining were reviewed. Kruskal-Wallis test and Bonferroni corrected Mann-Whitney U test were used for multiple comparisons. Wilcoxon signed rank test was used to compare myocardial retention of (99m)Tc chitosan.. Thirty minutes of myocardial ischemia resulted in perfusion defects (median, 54%; interquartile range [IQR], 41%-62%). Chitosan VEGF decreased perfusion defect extent (median, 68%; IQR, 63%-73%; P = .006 vs control) and increased vascular density (median, 81 vessels per high-power field; IQR, 72-100; P = .009 vs control). Administration of chitosan peptides reduced the degree of perfusion defects (median, 66%; IQR, 62%-73%; P = .006 vs control) and increased vascular density (median, 82 vessels; IQR, 78-92; P = .006 vs control). The effects of chitosan peptides on perfusion and vascular density were comparable to those seen with chitosan VEGF proteins (P = .713 and P = .833, respectively). Chitosan radiolabeled with (99m)Tc was administered twice at reperfusion with a 1-hour interval to determine whether image-guided dosage control is feasible. The hearts initially retained 4.6% (IQR, 4.1%-5.0%) of (99m)Tc chitosan administered and 9.2% (IQR, 6.6%-12.7%; P = .068) with subsequent injection.. VEGF peptides have angiogenic potential and resulted in therapeutic effectiveness. Adjunct use of single photon emission computed tomography was also demonstrated for individualized treatment of myocardial ischemia by further tailoring the therapeutic dosing. Online supplemental material is available for this article.

Topics: Animals; Autoradiography; Chitosan; Hydrogels; Immunohistochemistry; Male; Molecular Imaging; Myocardial Ischemia; Myocardial Reperfusion; Nanoparticles; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Rats; Rats, Sprague-Dawley; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed; Vascular Endothelial Growth Factor A

It is well known that silent myocardial ischemia (SMI) often complicates patients with cerebral infarction and that stroke patients often die of ischemic heart disease. Therefore, it is considered important to treat myocardial ischemia in stroke patients. This study investigated SMI complicating Japanese patients with fresh stroke, using (99m)Tc-tetrofosmin myocardial scintigraphy with pharmacologic stress testing to elucidate their clinical manifestations. This study included 41 patients (26 men, mean age 76.0 ± 10.7 years) with acute cerebral infarction and no history of coronary artery disease. All patients underwent (99m)Tc-tetrofosmin myocardial scintigraphy with intravenous administration of adenosine to diagnose SMI. Of the 41 patients, myocardial ischemia was confirmed in 17 patients (41.5%). Atherosclerotic etiology was the major cause of stroke in the ischemia(+) group and embolic origin was the major cause in the ischemia(-) group. Patients with myocardial ischemia had a higher incidence of diabetes mellitus (52.9 vs 20.8%; P = 0.0323) and more than two conventional cardiovascular risk factors (64.7 vs 25.0%; P = 0.0110) compared with the nonischemic patients. Infarction subtype of atherosclerotic origin was an independent positive predictor of asymptomatic myocardial ischemia in patients with stroke. These findings indicate that the prevalence of asymptomatic myocardial ischemia is relatively high, especially in patients with stroke of atherosclerotic origin. Therefore, it is beneficial for us to narrow the target population who are at the highest risk when screening for SMI in Japanese patients with acute cerebral infarction.

Topics: Acute Disease; Adenosine; Aged; Cerebral Infarction; Coronary Angiography; Diagnosis, Differential; Exercise Test; Female; Follow-Up Studies; Humans; Incidence; Japan; Male; Myocardial Ischemia; Myocardial Perfusion Imaging; Organophosphorus Compounds; Organotechnetium Compounds; Prognosis; Radiopharmaceuticals; Retrospective Studies; Risk Factors; Tomography, Emission-Computed, Single-Photon; Vasodilator Agents

Hypertrophic cardiomyopathy (HCM) patients often develop left--ventricular subendocardial ischaemia, a cause of chest symptoms, despite normal epicardial coronary arteries. The aim of this study was to examine whether ultrasonic tissue characterization or late gadolinium enhancement on cardiac magnetic resonance imaging can detect subendocardial ischaemia in patients with HCM.. Subendocardial ischaemia was quantified on exercise Tc-99m tetrofosmin myocardial scintigraphy in 29 non-obstructive HCM patients with asymmetric septal hypertrophy. Ultrasonic tissue characterization using cyclic variation of integrated backscatter (CV-IB) and late gadolinium enhancement on cardiac magnetic resonance imaging were analysed separately in the right halves and the left halves of the ventricular septum in relation to subendocardial ischaemia. Subendocardial ischaemia was identified in 17 (59%) patients. The ratio of CV-IB in the right-to-left halves of the ventricular septum was significantly higher in patients with subendocardial ischaemia (1.19 ± 0.10) than those without (0.84 ± 0.10, P = 0.04). The optimal cutoff for the detection of subendocardial ischaemia was the ratio of CV-IB >1.0, with a sensitivity of 80%, specificity of 71%, and accuracy of 76%. On the other hand, late gadolinium enhancement was not associated with subendocardial ischaemia in our cohort.. Ultrasonic tissue characterization using CV-IB separately in the right and left halves of the ventricular septum, but not late gadolinium enhancement on magnetic resonance imaging, provided useful information in detecting subendocardial ischaemia in patients with HCM. Ultrasonic tissue characterization may be useful in selecting patients who will benefit from medications to relieve chest symptoms.

Topics: Cardiomyopathy, Hypertrophic; Contrast Media; Echocardiography; Exercise Test; Female; Gadolinium DTPA; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Radionuclide Imaging; Radiopharmaceuticals

To evaluate the incremental prognostic value of (99m)Tc-tetrofosmin early poststress lung/heart ratio (eLHR) and to assess the optimal cut-off value.. We studied 503 patients (aged 61.3 years/SD = 8.6 years, 302 men) with stress/rest (99m)Tc-tetrofosmin myocardial gated-single photon emission computed tomography and coronary angiography. To evaluate myocardial ischemia, the summed stress score, summed rest score, and summed difference score indices were calculated. For the eLHR calculation, an anterior image was acquired 4-6 min after radiotracer injection at stress; eLHR was defined as the mean counts/pixel in the lung region of interest divided by the mean counts/pixel in the myocardial region of interest. The incremental prognostic value of eLHR was evaluated by a significant increase in the global χ(2) of the Cox proportional hazard model that included clinical, exercise, angiographic, and scintigraphic variables. Using the receiver operating characteristic analysis, the optimal cut-off of eLHR for the prediction of cardiac events was determined.. During the follow-up period, hard cardiac events occurred in 50 (9.9%) and soft cardiac events in 61 (12.1%) patients. Receiver operating characteristic curve analysis showed that the optimal cut-off of eLHR for the prediction of cardiac events was 0.51, with a sensitivity of 78.4% and specificity of 72.2%. The area under the curve was 0.82 (95% confidence interval: 0.77-0.87). Multiple Cox regression analysis revealed that eLHR more than 0.51 (hazard ratio = 7.78; 95% confidence interval: 5.00-12.11) provided incremental prognostic value over clinical exercise testing and scintigraphic data for cardiac events.. A (99m)Tc-tetrofosmin eLHR value larger than 0.51 added incremental value to other variables for the prediction of cardiac events.

Topics: Cardiac-Gated Single-Photon Emission Computer-Assisted Tomography; Exercise Test; Female; Follow-Up Studies; Humans; Male; Middle Aged; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Prognosis; Radiopharmaceuticals; Sensitivity and Specificity

SPECT myocardial perfusion imaging (MPI) is commonly used for comprehensive interpretation of metabolic PET FDG imaging in ischemic dysfunctional myocardium. We evaluated the difference in scan interpretation introduced by CT attenuation correction (CTAC) of SPECT MPI in patients undergoing viability characterization by (99m)Tc SPECT MPI/PET FDG. In 46 consecutive patients (mean age 64, range 36-83 years) with dysfunctional myocardium, we analyzed viability from combined SPECT MPI and PET FDG scanning without attenuation correction (NC) and with CTAC for SPECT MPI. FDG uptake was classified in groups of percent uptake using the segment with maximum tracer in SPECT perfusion uptake as reference. Viability patterns were categorized as normal, mismatch, mild match and scar by relative comparison of SPECT and PET. Applying CTAC introduced a different reference segment for the normalization of PET FDG study in 57% of cases. As a result, the flow-metabolism pattern changed in 28% of segments, yielding a normal, mismatch, mild match and scar pattern in 462, 150, 123, and 47 segments with NC and 553, 86, 108, and 35 with CTAC, respectively (P = 0.001). Thus, by introducing CTAC for SPECT MPI 25% of segments originally classified as scar were reclassified and the number of normal segments increased by 20%. Introducing CTAC decreased by 54% the number of patients with possible indication for revascularization, from 26/46 to 12/46 (P < 0.001). Different interpretation of myocardial viability can be observed when using CTAC instead of NC SPECT MPI as reference for PET FDG scans.

Topics: Adult; Aged; Aged, 80 and over; Coronary Circulation; Coronary Stenosis; Female; Fluorodeoxyglucose F18; Humans; Image Interpretation, Computer-Assisted; Male; Middle Aged; Myocardial Ischemia; Myocardial Perfusion Imaging; Myocardium; Organophosphorus Compounds; Organotechnetium Compounds; Positron-Emission Tomography; Predictive Value of Tests; Radiopharmaceuticals; Severity of Illness Index; Switzerland; Tissue Survival; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed

Artificial neural networks interpretation of myocardial perfusion scintigraphy (MPS) has so far been based on image data alone. Physicians reporting MPS often combine image and clinical data. The aim was to evaluate whether neural network interpretation would be improved by adding clinical data to image data. Four hundred and eighteen patients were used for training and 532 patients for testing the neural networks. First, the network was trained with image data alone and thereafter with image data in combination with clinical parameters (age, gender, previous infarction, percutaneous coronary intervention, coronary artery bypass grafting, typical chest pain, present smoker, hypertension, hyperlipidaemia, diabetes, peripheral vascular disease and positive family history). Expert interpretation was used as gold standard. Receiver operating characteristic (ROC) curves were calculated, and the ROC areas for the networks trained with and without clinical data were compared for the diagnosis of myocardial infarction and ischaemia. There was no statistically significant difference in ROC area for the diagnosis of myocardial infarction between the neural network trained with the combination of clinical and image data (95.8%) and with image data alone (95.2%). For the diagnosis of ischaemia, there was no statistically significant difference in ROC area between the neural network trained with the combination of clinical and image data (87.9%) and with image data alone (88.0%). Neural network interpretation of MPS is not improved when clinical data are added to perfusion and functional data. One reason for this could be that experts base their interpretations of MPS mainly on the images and to a lesser degree on clinical data.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Child; Coronary Circulation; Europe; Female; Humans; Image Interpretation, Computer-Assisted; Male; Middle Aged; Myocardial Ischemia; Myocardial Perfusion Imaging; Neural Networks, Computer; Organophosphorus Compounds; Organotechnetium Compounds; Predictive Value of Tests; Radiopharmaceuticals; Reproducibility of Results; ROC Curve; Tomography, Emission-Computed, Single-Photon; Young Adult

Elevated transient ischemic dilatation (TID) ratio during myocardial perfusion imaging (MPI) is described as a marker of severe CAD, even in acquisitions with normal perfusion. This was initiated to explore the effects of stressor type on the TID. Additionally the relation between the TID and other functional parameters, such as end diastolic volume (EDV), end systolic volume (ESV), and left ventricle ejection fraction (LVEF), heart rate (HR), and severity of ischemia, was evaluated.. A total of 299 consecutive patients referred for a 2-day stress/rest MPI protocol were included. Patients were stressed with either adenosine (n = 164) or exercise (n = 135). MPI data were analyzed with an automated software tool to determine TID, EDV, ESV, LVEF, SSS, and SDS. The SDS was used to quantify the degree of ischemia, with a SDS > or = 3 considered ischemic.. Comparison of the adenosine and exercise stressed population revealed significant differences, especially in parameters derived from the poststress acquisition. Within the exercise stressed population, TID was proportional with the SDS (R(2) = .12); whereas the adenosine population did not show such a relation (R(2) = .001). Difference in HR between rest and poststress acquisitions showed high levels of linear regression with TID values of both the adenosine (R(2) = .41) and exercise (R(2) = .29) stressed population.. In an exercise stressed population, TID is determined by both the degree of ischemia and the heart-rate difference between the two acquisition moments. TID within the adenosine population was found to be highly proportional with the HR, rather than with the degree of ischemia.

Topics: Adenosine; Aged; Automation; Coronary Artery Disease; Exercise; Female; Heart; Heart Rate; Humans; Male; Middle Aged; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Perfusion; Radionuclide Imaging; Retrospective Studies; Ventricular Function, Left

We investigated whether myocardial perfusion imaging (MPI) can demonstrate the effect of classical preconditioning.. 21 patients with documented coronary artery disease (stenosis>or=70%) underwent two exercise stress tests (EST) with concomitant MPI, using TL-201 for the first and tetrofosmin-Tc-99m for the second. A third MPI was performed at rest, using Tc-99m. Total defect score was derived by summing tracer uptake in a 17 segments left ventricle model, graded on a 5-point scale. Tomographic images were also analyzed quantitatively, to derive the total defect size.. Maximum ST depression did not differ significantly between the two EST (2.2+/-1 vs 2.2+/-1 mm, p=NS), however in the second EST longer times for onset of ischemic changes (228+/-94 vs 265+/-103 s, p=0.01) and appearance of angina (282+/-153 vs 328+/-177 s, p=0.04) were observed. Exercise perfusion abnormalities were significantly lower in the second MPI, in terms of both total defect score (19.2+/-11.5 vs 10+/-10.4, p<0.0001) and total defect size (28.3+/-16.9 vs 13.8+/-15.8, p<0.0001).. Significant improvement in perfusion pattern was demonstrated in the second MPI, accompanied by delayed appearance of ischemic manifestations. The improvement in myocardial perfusion extends far beyond the changes that can be attributed to differences in myocardial uptake between tracers, reflecting the effect of classical preconditioning.

Topics: Aged; Coronary Artery Disease; Exercise Test; Female; Heart Ventricles; Humans; Ischemia; Ischemic Preconditioning; Male; Middle Aged; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Perfusion; Time Factors

To investigate negative contractile responses in the left ventricle during low-dose dobutamine (LDD) gated single-photon emission computed tomography (SPECT) in patients with ischemic cardiomyopathy.. Sixty-eight consecutive patients (mean age, 60 + or - 11 years; 7 male) with ischemic cardiomyopathy (i.e., left ventricular ejection fraction [LVEF] < or = 40%) were evaluated using gated-SPECT at rest and during LDD infusion. Associations between a negative contractile reserve (i.e., a > or = 1-grade improvement in wall thickening score with LDD infusion) and scintigraphic viability criteria and coronary angiography findings were analyzed.. Some 42.6% (29/68) of patients had a negative contractile reserve in one or more segments. In 14.7% (n=10), the LVEF decreased by > or = 4% with LDD. These patients had more segments with a negative contractile reserve (2.8 + or - 2.5 vs. 0.87 + or - 0.40; P=.042), and the cut-off value on receiver operating characteristic curve analysis was > or =2 segments with a negative contractile reserve (sensitivity 70%, specificity 74%, positive likelihood ratio 2.71, negative likelihood ratio 0.40). Some 94% (74/79) of segments with a negative contractile reserve were in viable myocardium (i.e. normal or viable on scintigraphy). Twelve of 17 segments with akinesia or severe hypokinesia and a negative contractile reserve satisfied scintigraphic viability criteria, with the majority (10/12) lying in territories supplied by a patent coronary artery.. A negative contractile reserve was not uncommon in patients with ischemic cardiomyopathy and was associated with a general decrease in left ventricular systolic function. It was observed mainly in myocardial segments that appeared viable on scintigraphy and were supplied by a patent coronary artery.

Topics: Aged; Cardiotonic Agents; Coronary Angiography; Dobutamine; Female; Gated Blood-Pool Imaging; Humans; Male; Middle Aged; Myocardial Contraction; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon; Ventricular Function, Left

Topics: Child; Coronary Angiography; Electrocardiography; Humans; Magnetic Resonance Imaging; Male; Myocardial Ischemia; Myocardial Perfusion Imaging; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon

Our goal was to validate myocardium at risk on T2-weighted short tau inversion recovery (T2-STIR) cardiac magnetic resonance (CMR) over time, compared with that seen with perfusion single-photon emission computed tomography (SPECT) in patients with ST-segment elevation myocardial infarction, and to assess the amount of salvaged myocardium after 1 week.. To assess reperfusion therapy, it is necessary to determine how much myocardium is salvaged by measuring the final infarct size in relation to the initial myocardium at risk of the left ventricle (LV).. Sixteen patients with first-time ST-segment elevation myocardial infarction received (99m)Tc tetrofosmin before primary percutaneous coronary intervention. SPECT was performed within 4 h and T2-STIR CMR within 1 day, 1 week, 6 weeks, and 6 months. At 1 week, patients were injected with a gadolinium-based contrast agent for quantification of infarct size.. Myocardium at risk at occlusion on SPECT was 33 +/- 10% of the LV. Myocardium at risk on T2-STIR did not differ from SPECT, at day 1 (29 +/- 7%, p = 0.49) or week 1 (31 +/- 6%, p = 0.16) but declined at week 6 (10 +/- 12%, p = 0.0096 vs. 1 week) and month 6 (4 +/- 11%, p = 0.0013 vs. 1 week). There was a correlation between myocardium at risk demonstrated by T2-STIR at week 1 and myocardium at risk by SPECT (r(2) = 0.70, p < 0.001), and the difference between the methods on Bland-Altman analysis was not significant (-2.3 +/- 5.7%, p = 0.16). Both modalities identified myocardium at risk in the same perfusion territory and in concordance with angiography. Final infarct size was 8 +/- 7%, and salvage was 75 +/- 19% of myocardium at risk.. This study demonstrates that T2-STIR performed up to 1 week after reperfusion can accurately determine myocardium at risk as it was before opening of the occluded artery. CMR can also quantify salvaged myocardium as myocardium at risk minus final infarct size.

Topics: Aged; Angioplasty, Balloon, Coronary; Contrast Media; Coronary Angiography; Female; Follow-Up Studies; Heart Ventricles; Heterocyclic Compounds; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Myocardial Infarction; Myocardial Ischemia; Myocardium; Organometallic Compounds; Organophosphorus Compounds; Organotechnetium Compounds; Predictive Value of Tests; Radiopharmaceuticals; Reproducibility of Results; Risk Assessment; Time Factors; Tomography, Emission-Computed, Single-Photon; Treatment Outcome

Topics: Angioplasty, Balloon, Coronary; Contrast Media; Coronary Angiography; Heart Ventricles; Heterocyclic Compounds; Humans; Magnetic Resonance Imaging; Myocardial Infarction; Myocardial Ischemia; Myocardium; Organometallic Compounds; Organophosphorus Compounds; Organotechnetium Compounds; Predictive Value of Tests; Radiopharmaceuticals; Reproducibility of Results; Risk Assessment; Time Factors; Tomography, Emission-Computed, Single-Photon; Treatment Outcome

This was a cross-sectional study in which the values of sensitivity and specificity of myocardial perfusion study with (99)mTc-Tetrofosmina protocol in a day after stimulation with dipyridamole were determined in a population of women. We also assessed the relationship with coronary vascular territories, based on coronary angiography.. We studied retrospective medical records of 202 women with suspected ischemic heart disease tested on myocardial perfusion who also underwent coronary angiography.. The values of sensitivity and specificity for the population were 87.16% and 81.48% respectively. For the coronary artery territory, the values of sensitivity and specificity for the DA artery were 68.75% and 77.78% respectively, while these were 60.0% and 81.51% for the Cx. Finally, the values for the CD were 69.88 and 72.27%, respectively.. The myocardial perfusion test stimulation/rest has a high diagnostic validity for the disease in women with suspected ischemic heart disease.

Topics: Aged; Cross-Sectional Studies; Female; Humans; Myocardial Ischemia; Myocardial Perfusion Imaging; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Retrospective Studies

Real-time perfusion (RTP) adenosine stress echocardiography (ASE) can be used to visually evaluate myocardial ischaemia. The RTP power modulation technique angio-mode (AM), provides images for off-line perfusion quantification using Qontrast software, generating values of peak signal intensity (A), myocardial blood flow velocity (beta) and myocardial blood flow (Axbeta). By comparing rest and stress values, their respective reserve values (A-r, beta-r, Axbeta-r) are generated. We evaluated myocardial ischaemia by RTP-ASE Qontrast quantification, compared to visual perfusion evaluation with 99mTc-tetrofosmin single-photon emission computed tomography (SPECT).. Patients admitted to SPECT underwent RTP-ASE (SONOS 5500) using AM during Sonovue infusion, before and throughout adenosine stress, also used for SPECT. Visual myocardial perfusion and wall motion analysis, and Qontrast quantification, were blindly compared to one another and to SPECT, at different time points off-line.We analyzed 201 coronary territories (left anterior descendent [LAD], left circumflex [LCx] and right coronary [RCA] artery territories) in 67 patients. SPECT showed ischaemia in 18 patients and 19 territories. Receiver operator characteristics and kappa values showed significant agreement with SPECT only for beta-r and Axbeta-r in all segments: area under the curve 0.678 and 0.665; P < 0.001 and < 0.01, respectively. The closest agreements were seen in the LAD territory: kappa 0.442 for both beta-r and Axbeta-r; P < 0.01. Visual evaluation of ischaemia showed good agreement with SPECT: accuracy 93%; kappa 0.67; P < 0.001; without non-interpretable territories.. In this agreement study with SPECT, RTP-ASE Qontrast quantification of myocardial ischaemia was less accurate and less feasible than visual evaluation and needs further development to be clinically useful.

Topics: Aged; Echocardiography; Exercise Test; Female; Humans; Image Interpretation, Computer-Assisted; Male; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Phospholipids; Radiopharmaceuticals; Reproducibility of Results; Sensitivity and Specificity; Sulfur Hexafluoride; Tomography, Emission-Computed, Single-Photon

The noninvasive differentiation of ischemic from nonischemic cardiomyopathy is clinically important. However, whether adenosine Tc-99m tetrofosmin SPECT can offer clear and accurate information was not known. The aim of this study is to investigate the usefulness of adenosine Tc-99m tetrofosmin SPECT in differentiation of ischemic from nonischemic etiology in patients with mild to severe LV systolic dysfunction and to compare the relationship between patients with mild LV systolic dysfunction and those with severe LV systolic dysfunction.. Seventy-five patients with chronic heart failure (LV ejection fraction 35%, group II (31 patients) had severe LV dysfunction, LVEF or=20%. Myocardial ischemia was defined by >or=70% stenosis in at least one vessel by coronary angiography.. : In group I, 4 (30.8%) of 13 patients with small defects, 1 (25.0%) of 5 patients with a medium defect, and 22 (84.6%) of 26 patients with large defects demonstrated myocardial ischemia documented by coronary angiography. The relationship between the extent of the SPECT defect and myocardial ischemia was statistically significant in the group I population (P < 0.001). However, in group II, 1 (33.3%) of 3 patients with small defect, 3 (33.3%) of 9 patients with medium defects, and 7 (36.8%) of 19 patients with large defects demonstrated myocardial ischemia confirmed by coronary angiography. There was no statistical relationship between the extent of the SPECT defect and myocardial ischemia in group II.. Adenosine Tc-99m tetrofosmin SPECT is a useful modality to differentiate ischemic from nonischemic etiology in patients with mild LV systolic dysfunction. However, other noninvasive approaches other this SPECT may be considered for confirming the etiology in patients with severe LV systolic dysfunction.

Topics: Aged; Cardiomyopathies; Coronary Angiography; Echocardiography; Female; Heart Failure; Humans; Male; Middle Aged; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Systole; Tomography, Emission-Computed, Single-Photon; Ventricular Dysfunction, Left

The prognostic value of ECG-gated rest 201Tl/stress 99mTc-tetrofosmin myocardial perfusion single-photon emission computed tomography for the prediction of acute coronary syndrome (ACS: myocardial infarction (MI) and unstable angina (UA)) and the implications of ejection fraction (EF) has not yet been defined in Japanese.. The 1,895 patients were followed up for the occurrence ACS. The mean follow-up interval was 26.9+/-15.5 months. The 142 patients with revascularization within 60 days were censored. Summed stress score (SSS) and summed difference score (SDS) were calculated. The 19 MI and 29 UA occurred (1.1% and 1.6%, respectively). Univariate Cox analysis showed that hypertension (Wald 5.09, p<0.05), poststress EF (Wald 10.9, p<0.01), SSS (Wald 12.4, p<0.001) and SDS (Wald 18.7, p<0.001) were significant predictors of ACS. Multivariate Cox analysis showed that hypertension (Wald 4.27, p<0.05) and SDS (Wald 8.59, p<0.01) were independent predictors. When multiple clinical risk factors (number of coronary risk factors > or =2), significant ischemia (SDS > or =4) and low EF (EF <45%) were applied to multivariate Cox analysis, the combination of significant ischemia and low EF showed the highest predictive value (Wald 11.9; p<0.001) for future ACS.. Poststress EF added incremental prognostic value for the prediction of ACS.

Topics: Acute Coronary Syndrome; Adenosine Triphosphate; Aged; Cardiac-Gated Single-Photon Emission Computer-Assisted Tomography; Coronary Artery Disease; Coronary Circulation; Exercise Test; Female; Humans; Hypertension; Japan; Kaplan-Meier Estimate; Male; Middle Aged; Multivariate Analysis; Myocardial Ischemia; Myocardial Perfusion Imaging; Myocardial Revascularization; Organophosphorus Compounds; Organotechnetium Compounds; Predictive Value of Tests; Proportional Hazards Models; Prospective Studies; Radiopharmaceuticals; Risk Assessment; Risk Factors; Stroke Volume; Thallium Radioisotopes; Time Factors; Treatment Outcome

The cardiovascular disease is the main cause of death among diabetic patients, which makes it crucial to identify the individuals at higher risk of cardiovascular events.. To evaluate the prognostic value of scintigraphy with gated single photon emission computed tomography (SPECT) in patients with diabetes mellitus (DM) and suspected coronary artery disease.. Retrospective study with 232 diabetic patients submitted to scintigraphy with gated SPECT. Perfusion Gated SPECT (scores and number of altered segments) as well as ventricular function parameters (ejection fraction, left ventricle (LV) volume and contractility) were evaluated. Cardiac death, acute ischemic coronary syndrome, revascularization procedures or encephalic vascular accident were considered future cardiovascular events. The uni- and multivariate analyses were carried out by the multiple logistic regression model (p< 0.05).. At the univariate analysis, age (p=0.02), chest angina (p=0.01), insulin therapy (p=0.02), myocardial perfusion abnormalities (p<0.0001), the number of segments involved (p=0.0001), the perfusion scores (p=0.0001), the ejection fraction (p=0.004), the final systolic volume (p=0.03) and the finding of segmental alteration at the left ventricle contractility (p<0.0001) were associated with future events at the univariate analysis. At the multivariate analysis, the male sex (p=0.007), age (p=0.03), angina (p=0.001), insulin therapy (p=0.007) and the SDS > 3 (p=0.0001) and the number of altered segments > 3 (p=0.0001) were predictors of cardiovascular events.. The myocardial scintigraphy with gated SPECT adds independent information to the stratification of the risk of future cardiovascular events in patients with DM and suspected coronary artery disease.

Topics: Adult; Age Factors; Aged; Aged, 80 and over; Angina Pectoris; Diabetes Mellitus; Epidemiologic Methods; Female; Humans; Insulin; Male; Middle Aged; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Prognosis; Radiopharmaceuticals; Sex Factors; Tomography, Emission-Computed, Single-Photon; Ventricular Function

In Japan, Diagnosis Procedure Combination (DPC) of hospitalization health-care costs has been introduced since 2004, and its introduction has been recently expanded also to general hospitals. In such situations, the role of nuclear cardiology as a gatekeeper for the diagnosis of ischemic heart disease is increasingly important. Thus, the present study was designed to determine which clinical risk for hard events after normal single-photon emission computed tomography (SPECT) images, identify the predictors of increased risk in patients with normal SPECT images based on the J-ACCESS study.. A total of 4,629 consecutively tested patients who underwent stress (99m)Tc-tetrofosmin SPECT at hospitals in Japan were included in the study. Based on SPECT image data, 1,862 participants had a summed stress score of or=49% in men, EF >or=55% in women), which is defined as selection criteria III (normal perfusion, ESV and EF). During the 3-year follow-up period, there was a total of 211 cardiac events (11.3%) in patients grouped in selection criteria I, 196 cardiac events (11.0%) in patients grouped in selection criteria II, and 189 cardiac events in patients grouped in selection criteria III (10.8%). The annual hard event rates were 0.81%, 0.67% and 0.63% in selection criteria I, II and III, respectively. Cox proportional hazard analysis showed that diabetes mellitus, age and hypertension were independent predictors of all cardiac events in all selection criteria.. Normal stress myocardial perfusion imaging in the Japanese population is associated with a low cardiac event risk. The prognosis results of a normal SPECT scan would be useful for better patient management.

Topics: Aged; Asian People; Exercise Test; Female; Follow-Up Studies; Humans; Japan; Kaplan-Meier Estimate; Male; Middle Aged; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Prognosis; Proportional Hazards Models; Radiopharmaceuticals; Risk Factors; Tomography, Emission-Computed, Single-Photon

Failure to reach 80% of maximal predicted heart rate (HR) during exercise may render a myocardial perfusion single photon emission computed tomography (SPECT) study non-diagnostic for ischemia detection. We sought to investigate the injection of atropine in patients who fail to achieve 80% of age-predicted HR during exercise performed for myocardial perfusion SPECT (MPS), defining its safety and efficacy to raise HR to adequate levels as well as its effect on MPS interpretation.. Between January 2002 and December 2004, we studied 3,150 consecutive patients (2,253 men and 897 women, mean age 55 +/- 6 years) who were referred to a single office-based nuclear cardiology laboratory for MPS using SPECT imaging. One milligram of atropine was administered to patients that were unable to continue because of fatigue before reaching minimal HR, without an ischemic response (group A, n = 397). The scintigraphic results for group A were compared with those of patients who spontaneously achieved target HR (group B, n = 2,753). In group A, mean HR before atropine injection was 119.5 +/- 13.6 beats per minute (bpm), and it increased up to 137.3 +/- 13.5 bpm after drug administration, with an incremental of 17.8 +/- 6.9 bpm (P < 0.0001). The mean percentage of age-related HR achieved in this group was 83.5 +/- 8.1%. In 302 of this patients (76.1%) more than 80% of their aged-related HR (86.9 +/- 5.1%) was attained. No major adverse effects occurred. When groups A and B were compared, baseline and peak HR, rate pressure product, and maximal metabolic equivalents achieved were higher in group B. There were no significant differences in the percentage of total positive perfusion studies between both groups: 210/397 patients (52.9%) in group A and 1,342/2,753 patients (48.7%) in group B (P = 0.39). Ischemia or ischemia plus scar was found in 112/397 patients (28.2%) in group A and in 923/2,753 patients (33.5%) of group B (P = 0.14).. Atropine added to exercise stress testing in patients who cannot achieve their 80% age-related HR is a safe, well-tolerated, and feasible method for MPS.

Topics: Arrhythmias, Cardiac; Atropine; Blood Pressure; Cholinergic Antagonists; Coronary Circulation; Exercise Test; Feasibility Studies; Female; Heart Rate; Humans; Male; Middle Aged; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Research Design; Severity of Illness Index; Tomography, Emission-Computed, Single-Photon

At present, 20-30% of patients do not respond to cardiac resynchronization therapy (CRT). In this study, the relation between the extent of viable myocardium and scar tissue vs. response to CRT was evaluated. In addition, the presence of scar tissue in the left ventricular (LV) lead position was specifically related to response to CRT.. A total of 51 consecutive patients with ischaemic heart failure and substantial LV dyssynchrony undergoing CRT were included. All patients underwent gated SPECT before CRT implantation to determine the extent of scar tissue and viable myocardium. Clinical and echocardiographic parameters were assessed at baseline and after 6 months of CRT. The results demonstrated direct relations between the response to CRT and the extent of viable myocardium and scar tissue. In addition, the 15 patients (29%) with transmural scar tissue (< 50% tracer activity) in the region of the LV pacing lead showed no improvement after 6 months of CRT.. The extent of scar tissue and viable myocardium were directly related to the response to CRT. Furthermore, scar tissue in the LV pacing lead region may prohibit response to CRT. Evaluation for viability and scar tissue may be considered in the selection process for CRT.

Topics: Aged; Cardiac Pacing, Artificial; Cicatrix; Electrocardiography; Female; Heart Failure; Humans; Male; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon; Treatment Outcome; Ventricular Dysfunction, Left

Diabetes is associated with abnormal function of the autonomic nervous system, while autonomic dysfunction is related to attenuated heart-rate recovery (HRR) after exercise testing. The purpose of this study was to test whether HRR could be a useful index of myocardial ischaemia in patients suffering from diabetes mellitus.. We included 206 consecutive patients in this study and excluded patients whose HRR value or the myocardial perfusion imaging could have been influenced by factors other than myocardial ischaemia. The value of HRR was defined as the decrease in the heart rate from peak exercise to 1 min after the termination of the exercise. All patients underwent SPECT myocardial perfusion imaging, combined with exercise testing and we calculated the summed stress score (SSS), summed rest score (SRS) and summed difference score (SDS) indexes.. Sixty patients had abnormal HRR value. A significant correlation was found between HRR 1 min after exercise and SSS (r=-0.64, P<0.001), SDS (r=0.56, P<0.001) and chronotropic variables. Patients with abnormal HRR value, had a higher frequency of other risk factors (besides diabetes) for CAD, were mostly taking cardioactive medications, had lower efficiency during treadmill testing, and presented more pathologic findings on the scintigram.. Our results suggest that myocardial ischaemia, as it is mainly assessed by myocardial perfusion imaging, has an important correlation with HRR in diabetic patients. HRR value 1 min after exercise may be considered as a useful index of the severity of myocardial ischaemia, in this cohort of patients.

Topics: Adult; Aged; Algorithms; Cohort Studies; Coronary Circulation; Diabetes Mellitus; Diabetic Angiopathies; Exercise; Exercise Test; Female; Heart; Heart Rate; Humans; Male; Middle Aged; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Regression Analysis; Thallium Radioisotopes; Tomography, Emission-Computed, Single-Photon

Bone marrow cell injection has been introduced to treat patients with ischemic heart disease. However, focal application of bone marrow cells may generate an arrhythmogenic substrate.. To assess the electrophysiological and arrhythmogenic effects of intramyocardial bone marrow cell injection in patients with chronic myocardial ischemia.. Bone marrow was aspirated in 20 patients (65+/-11 years, 19 male) with drug-refractory angina and myocardial ischemia. Electroanatomical mapping (NOGA, Biosense-Webster, Waterloo, Belgium) was performed during mononuclear cell isolation. Areas for cell injection were selected based on the localization of ischemia on SPECT. These areas were mapped in detail to evaluate local bipolar electrogram duration, amplitude and fragmentation. Mononuclear cells were injected in the ischemic area with the NOGA system. SPECT and electroanatomical mapping were repeated at 3 months. Holter monitoring was repeated at 3 and 6 months.. SPECT revealed a decrease in the number of segments with ischemia (3.5+/-2.5 vs. 1.1+/-1.0 at 3 months; P<0.01) and an increased left ventricular ejection fraction (44+/-13% vs. 49+/-17% at 3 months; P=0.02). The number of ventricular premature beats remained unchanged (10+/-24x10(2)/24h vs. 8+/-23x10(2)/24h at 3 months (P=NS) and 12+/-30x10(2)/24h at 6 months (P=NS)). At 3 months follow-up, bone marrow cell injection did not prolong electrogram duration (15.9+/-4.6 ms vs. 15.6+/-4.0 ms; P=NS), decrease electrogram amplitude (3.8+/-1.5 mV vs. 3.8+/-1.5 mV; P=NS), or increase fragmentation (2.0+/-0.5 vs. 1.9+/-0.4; P=NS).. Intramyocardial bone marrow cell injection does not increase the incidence of ventricular arrhythmias and does not alter the electrophysiological properties of the injected myocardium.

Topics: Aged; Angina Pectoris; Body Surface Potential Mapping; Bone Marrow Transplantation; Chronic Disease; Electrocardiography, Ambulatory; Electrophysiologic Techniques, Cardiac; Female; Follow-Up Studies; Heart Rate; Humans; Incidence; Male; Middle Aged; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Research Design; Stroke Volume; Tachycardia, Sinus; Tachycardia, Ventricular; Tomography, Emission-Computed, Single-Photon; Treatment Outcome; Ventricular Premature Complexes

N-terminal pro-b-type natriuretic peptide (NT pro-BNP) is a neurohormone synthesized predominantly in ventricular myocardium. In patients with symptoms of heart failure, elevation in NT pro-BNP accurately identifies ventricular dysfunction. However, NT pro-BNP levels are not specific for ventricular dysfunction in patients who do not have overt symptoms of heart failure, suggesting that other cardiac processes such as myocardial ischemia may also cause elevation in NT pro-BNP. The study was aimed to determine whether NT pro-BNP elevations are associated with myocardial ischemia.. One hundred and thirty patients (104 males, 26 females, mean age 61+12 years), with ST elevation acute myocardial infarction (STEMI) and preserved left ventricular ejection fraction (>45%) at echocardiography performed at entry, from February 2003 and February 2004 were enrolled. In all patients NT pro-BNP plasma levels were checked at entry and 4-5 days after symptoms onset. In addition, maximal or symptom-limited exercise treadmill test (Bruce protocol), and myocardial perfusion scintigraphy using [(99m)Tc]Tetrofosmin single photon emission computed tomography (SPECT) imaging were performed within 30 days of STEMI. Ischemia was defined as reversible perfusion abnormalities.. Of the 130 participants, 66 (51%) had inducible ischemia. Compared with patients in the lowest tertile, those in the highest tertile of NT pro-BNP had a greater significant risk of residual ischemia (odds ratio: 8.66; 95% CI, 3.90 to 19.24). Nevertheless patients in the highest tertile were older (64.19+/-10.80 years versus 55.90+/-9.67 years, P = 0.0001), had a lower left ventricular ejection fraction (49.70+13.46% versus 59.49+/-6.58%, P = 0.0001) and had a great rate of acute myocardial infarction (anterior acute myocardial infarction = 40.63% versus 25%).. Elevated levels of NT pro-BNP are associated with residual myocardial ischemia among patients with STEMI and preserved left ventricular ejection fraction, as demonstrated by perfusion defect on SPECT imaging, suggesting that these patients may need further evaluation for stratification of the future risk of fatal events. The observed association between NT pro-BNP levels and ischemia may explain because tests for NT pro-BNP are not specific for ventricular dysfunction among patients with coronary artery disease.

Topics: Adult; Aged; Aged, 80 and over; Biomarkers; Echocardiography, Stress; Electrocardiography; Exercise Test; Female; Humans; Logistic Models; Male; Middle Aged; Myocardial Infarction; Myocardial Ischemia; Natriuretic Peptide, Brain; Odds Ratio; Organophosphorus Compounds; Organotechnetium Compounds; Peptide Fragments; Predictive Value of Tests; Radiopharmaceuticals; Retrospective Studies; ROC Curve; Sensitivity and Specificity; Tomography, Emission-Computed, Single-Photon

To determine if T-wave normalization during exercise or dobutamine stress testing identified patients with myocardial ischemia as indicated by reversible perfusion defects.. Exercise or dobutamine stress tests with perfusion scintigraphy were performed in 1,173 patients with abnormal T-waves on their baseline electrocardiograms. The results of perfusion scintigraphy were compared in patients with and without stress-induced T-wave normalization.. Only 33 of 270 patients with reversible perfusion defects (12.2%) had T-wave normalization during stress while 76.4% of 140 patients who had T-wave normalization during stress did not have a reversible perfusion defect. Results were similar for patients who did or did not reach 85% of their maximal predicted heart rate, for patients with and without Q-wave infarction on the baseline EKG and for patients who did or did not have ischemic ST-segment depression during stress.. T-wave normalization during stress testing has low sensitivity and poor positive predictive value for stress-induced reversible myocardial ischemia.

Topics: Aged; Atropine; Blood Pressure; Cardiotonic Agents; Case-Control Studies; Dobutamine; Electrocardiography; Exercise Test; Female; Heart Conduction System; Heart Rate; Humans; Male; Middle Aged; Myocardial Ischemia; Myocardial Reperfusion; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Regression Analysis; Research Design; Retrospective Studies; Sensitivity and Specificity; Stress, Physiological; Technetium Tc 99m Sestamibi; Tomography, Emission-Computed, Single-Photon

The purpose of this study was to evaluate the reliability of left ventricular ejection fraction (LVEF) measured by quantitative gated SPECT (QGS). We compared the efficacy of LVEF assessment among Tc-99m tetrofosmin gated SPECT imaging, contrast left ventriculography (LVG), and first-pass radionuclide angiography (FP).. One-hundred and seven patients with ischemic heart disease underwent QGS and LVG simultaneously within 3 months, and 92 of the 107 patients also underwent FP at the same time.. QGS progressively overestimated LVEF at the lower range of end-systolic volume (ESV), especially in patients with small hearts. Moreover, the QGS technique systemically tended to underestimate LVEF in comparison with LVG. However, linear regression analysis demonstrated a good correlation between the LVEF values measured by QGS and those measured by both LVG (p<0.0001) and FP (p<0.0001).. Although QGS has a tendency to overestimate LVEF in patients with small hearts, and to systemically underestimate LVEF compared with LVG, this technique is still a reliable clinical tool for measurement of LVEF.

Topics: Aged; Female; Humans; Linear Models; Male; Middle Aged; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Radionuclide Angiography; Radionuclide Ventriculography; Radiopharmaceuticals; Reproducibility of Results; Tomography, Emission-Computed, Single-Photon; Ventricular Dysfunction, Left

Changes in high-frequency (HF) QRS components of the electrocardiogram (ECG) (150-250 Hz) are more sensitive than changes in conventional ST segments for detecting myocardial ischemia. We investigated the accuracy of 12-lead HF QRS ECG in detecting perfusion defects during adenosine tetrofosmin myocardial perfusion imaging (MPI).. 12-lead HF QRS ECG recordings were obtained from 45 patients before and during adenosine technetium Tc 99m tetrofosmin MPI tests. Before the adenosine infusions, recordings of HF QRS were analyzed according to a morphologic score that incorporated the number, type, and location of reduced amplitude zones (RAZs) present in the 12 leads. During the adenosine infusions, recordings of HF QRS were analyzed according to the maximum percentage changes (in both the positive and negative directions) that occurred in root mean square voltage amplitudes within the 12 leads. The best set of prospective HF QRS criteria had a sensitivity of 94% and a specificity of 83% for correctly identifying the MPI result. The sensitivity of simultaneous ST-segment changes (18%) was significantly lower than that of any individual HF QRS criterion (P < .001).. Analysis of 12-lead HF QRS ECG is highly sensitive and reasonably specific for detecting perfusion defects during adenosine MPI stress tests and significantly more sensitive than analysis of conventional ST segments.

Topics: Adenosine; Aged; Chest Pain; Coronary Circulation; Electrocardiography; Exercise Test; False Positive Reactions; Female; Humans; Male; Middle Aged; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Preoperative Care; Radionuclide Imaging; Radiopharmaceuticals; Regression Analysis; Sensitivity and Specificity; Signal Processing, Computer-Assisted; Vasodilator Agents

Intramyocardial injection of bone marrow cells has been proposed as a new therapeutic option for patients with chronic ischemic heart disease. We investigated whether autologous bone marrow-derived mononuclear cell injection into the myocardium of patients with drug-refractory ischemia reduces anginal symptoms, improves left ventricular (LV) function, increases myocardial perfusion, and alters the extent of scar tissue.. In 25 patients (mean age +/- SD, 64 +/- 10 y; 21 male) with drug-refractory angina pectoris (Canadian Cardiovascular Society [CCS] class III-IV), despite optimized medical therapy and without options for conventional revascularization, bone marrow was aspirated from the iliac crest. Mononuclear cell injections were targeted at myocardial regions with stress-induced ischemia on gated (99m)Tc-tetrofosmin SPECT. Anginal symptoms were reassessed at 3- and 6-mo follow-up. At baseline and 3-mo follow-up, gated (99m)Tc-tetrofosmin SPECT and (18)F-FDG SPECT were performed to assess LV function, LV volumes, myocardial perfusion (stress and rest, 17-segment model), and extent of scar tissue.. Mean CCS score improved from 3.4 +/- 0.6 at baseline to 2.3 +/- 0.6 at 3 mo (P < 0.01) and remained unchanged at 6 mo (2.3 +/- 0.6; P < 0.01 vs. baseline and P = not significant [NS] vs. 3 mo). Gated (99m)Tc-tetrofosmin SPECT demonstrated an increased LV ejection fraction (from 47.6% +/- 13.5% to 54.1% +/- 16.9%; P < 0.01) and a reduced LV end-systolic volume (from 81 +/- 68 mL to 75 +/- 70 mL; P < 0.01). Segmental regional wall thickening increased from 34% +/- 12% at baseline to 39% +/- 17% at 3-mo follow-up (P = 0.01). The number of segments with stress-inducible ischemia per patient decreased from 4.6 +/- 3.2 to 2.0 +/- 2.6 (P < 0.01). Both segmental stress and segmental rest score improved, although the improvement in stress score was more pronounced (decrease in segmental stress score 0.22 +/- 0.20 vs. decrease in segmental rest score 0.04 +/- 0.06; P < 0.01). Myocardial perfusion improved in 53% of the injected segments and in 13% of the noninjected segments (P < 0.01). The percentage of myocardial segments with some extent of scar remained unchanged at 3-mo follow-up (13% vs. 12%; P = NS).. Autologous bone marrow-derived mononuclear cell injection in patients with drug-refractory angina and chronic ischemia improves anginal symptoms, increases LV function, and predominantly enhances myocardial stress perfusion in injected segments, whereas the extent of myocardial scar tissue remains unchanged.

Topics: Aged; Angina Pectoris; Bone Marrow Transplantation; Chronic Disease; Drug Resistance; Fluorodeoxyglucose F18; Humans; Injections; Leukocytes, Mononuclear; Male; Middle Aged; Myocardial Ischemia; Myocardial Reperfusion; Myocardium; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon; Transplantation, Autologous; Ventricular Function, Left

The aim of this study was to assess the accuracy of stress 99m technetium tetrofosmin myocardial perfusion imaging for the diagnosis of in stent stenosis (ISS).. We studied 72 patients who underwent exercise or dobutamine stress 99m technetium tetrofosmin imaging, 0.9+/-0.5 years after percutaneous coronary interventions in which stents were deployed. Coronary angiography was performed within 3 months of the stress test. ISS was defined as > or =50% stenosis in a coronary segment with previous stenting. Significant coronary artery disease (CAD) was defined as > or =50% stenosis within or outside the stented coronary segment.. The stent was deployed in 1 coronary artery in 52 patients, and in 2 coronary arteries in 20 patients (a total of 92 detected in 42 (58%) patients (51 stents). Reversible perfusion abnormalities were present in 34 of patients with ISS (sensitivity=81%, CI 70-94). Regional sensitivity for diagnosis of stenosis per stent was 76% (CI 65-88), specificity was 83% (CI 71-94) and accuracy was 79% (CI 69-85). Reversible perfusion abnormalities were detected in > or =2 vascular distributions in 15 of 22 patients with multi-vessel CAD and in 5 of 50 patients without (sensitivity for identifying multivessel CAD=68%, CI 50-89; specificity=90%, CI 82-98; and accuracy=83%, CI 75-90).. Stress 99m technetium tetrofosmin myocardial perfusion imaging is a useful non-invasive technique for the diagnosis of in stent stenosis and extent of CAD in patients with previous percutaneous coronary artery interventions.

Topics: Adrenergic beta-Agonists; Angioplasty, Balloon, Coronary; Coronary Angiography; Coronary Artery Disease; Coronary Circulation; Coronary Restenosis; Dobutamine; Exercise Test; Female; Follow-Up Studies; Humans; Male; Middle Aged; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Predictive Value of Tests; Radiopharmaceuticals; Research Design; Sensitivity and Specificity; Stents; Time Factors; Tomography, Emission-Computed, Single-Photon

We evaluated the value of upsloping ST-segment depression in predicting the severity of myocardial ischemia. Comparison of the exercise electrocardiographic changes was made to myocardial perfusion images and coronary angiograms as the criteria for ischemia. We retrospectively reviewed 621 patients who underwent exercise technetium-99m tetrofosmin single photon emission computed tomography (SPECT) for the assessment of suspected or known coronary artery disease followed by coronary angiography within a 3-month period. The test sensitivity and specificity of 1 mm horizontal or downsloping ST depression in predicting reversible ischemia as assessed by gated SPECT imaging (GSI) were 65% and 87%, respectively. The corresponding values were 67% and 94% compared to coronary angiography. The sensitivity and specificity of gated SPECT imaging compared to coronary angiography were 78% and 89%. On the other hand when 1 mm upsloping ST depression at 70 ms past the J-point was regarded as abnormal, along with horizontal and downsloping, the sensitivity and specificity were 82% and 90% compared to myocardial perfusion imaging, and 77% and 92% as assessed by coronary angiography. We conclude that upsloping ST-segment depression is associated with an increased risk of coronary artery disease and is a valuable predictor of myocardial ischemia.

Topics: Coronary Angiography; Electrocardiography; Exercise Test; Humans; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Retrospective Studies; Sensitivity and Specificity; Tomography, Emission-Computed, Single-Photon

Exercise stress electrocardiography is the recommended method for cardiac evaluation of patients with normal electrocardiograms (ECGs). There are no data to indicate an independent value of myocardial perfusion imaging (MPI) in predicting mortality in these patients. This study assessed the value of exercise stress MPI in predicting mortality in patients with normal baseline ECGs. We studied 319 patients (55 +/- 10 years of age; 180 men) with normal ECGs by exercise stress technetium-99m tetrofosmin MPI. End points during follow-up were cardiac and all-cause mortalities and hard cardiac events. A normal scan was detected in 190 patients (60%). Myocardial perfusion abnormalities were fixed in 59 patients (18%) and reversible in 70 (23%). During a mean follow-up of 7 +/- 1.2 years, 46 patients (14%) died. Death was considered cardiac in 28 patients (9%). Nonfatal myocardial infarction occurred in 12 patients (4%). Annual cardiac death rates were 0.4% in patients with normal perfusion, and 2.7% in patients with reversible defects. Annual total mortality rates were 1.1% in patients with normal perfusion and 3.4% in patients with reversible defects. In a multivariate analysis model, reversible perfusion abnormalities were associated with cardiac death (RR 2.8, 95% confidence interval 1.6 to 5.1) and hard cardiac events (RR 2.7, 95% confidence interval 1.5 to 4.5). Perfusion abnormalities in multivessel distribution were predictive of all-cause mortality (RR 2, 95% confidence interval 1.4 to 3.2). ST-segment depression was not significantly associated with events. In conclusion, stress technetium-99m tetrofosmin MPI provides independent information for predicting cardiac and overall mortalities in patients with normal ECGs. Reversible perfusion abnormalities, but not ischemic electrocardiographic changes, are predictive of outcome in these patients.

Topics: Electrocardiography; Exercise Test; Female; Follow-Up Studies; Humans; Injections, Intravenous; Male; Middle Aged; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Prognosis; Radiopharmaceuticals; Retrospective Studies; Risk Factors; Severity of Illness Index; Survival Rate; Tomography, Emission-Computed, Single-Photon

Earlier studies have suggested a modest accuracy of stress thallium 201 myocardial perfusion imaging (MPI) for the diagnosis of coronary artery disease (CAD) in women. The accuracy of stress MPI with technetium 99m tetrofosmin has not been studied in women. The aim of this study was to assess the accuracy of stress Tc-99m tetrofosmin MPI for the diagnosis and localization of CAD in women.. We studied 88 women who underwent exercise or dobutamine stress Tc-99m tetrofosmin tomography and coronary angiography within 3 months. Significant CAD was defined as a stenosis 50% or greater in diameter in at least 1 major epicardial coronary artery. Myocardial perfusion abnormalities were detected in 44 of 53 patients with significant CAD and in 7 of 35 patients without significant CAD (overall sensitivity, 83% [95% confidence interval (CI), 73%-93%]; specificity, 80% [95% CI, 67%-93%]; and accuracy, 82% [95% CI, 74%-90%]). The sensitivity was 72% (18/25) in patients with single-vessel CAD and 93% (26/28) in patients with multivessel CAD. Perfusion abnormalities were detected in 2 or more vascular distributions in 20 of 28 patients with multivessel CAD and in 4 of 60 patients without multivessel CAD (sensitivity for the identification of multivessel CAD, 71% [95% CI, 55%-88%]; specificity, 93% [95% CI, 86%-98%]; and accuracy, 86% [95% CI, 79%-93%]). The sensitivity, specificity, and accuracy were 82%, 84%, and 83%, respectively, for the diagnosis of CAD in the left anterior descending artery; 77%, 84%, and 81%, respectively, for CAD in the right coronary artery; and 74%, 80%, and 78%, respectively, for CAD in the left circumflex artery.. Stress Tc-99m tetrofosmin MPI is an accurate noninvasive technique for the diagnosis and localization of CAD in women.

Topics: Aged; Coronary Angiography; Coronary Artery Disease; Coronary Stenosis; Female; Humans; Middle Aged; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Radionuclide Imaging; Radiopharmaceuticals; Reproducibility of Results; Tomography, X-Ray Computed

We report the case of a 14-year-old boy who developed Kawasaki disease at 5 months of age. The patient developed severe aneurysmal disease of both the left and right coronary arteries. He eventually developed total calcified occlusion of the right coronary artery despite long-term treatment with aspirin. Catheterisation showed no antegrade flow into the right coronary artery, with retrograde flow from the left coronary system into the right coronary. At the most recent follow-up he was asymptomatic, with normal exercise tolerance and a negative exercise stress test. Single-photon emission computed tomography (SPECT) myocardial perfusion imaging was carried out during stress and at rest using intravenous persantine (dipyridamole) and technetium-99m tetrofosmin. During stress, there were prominent left ventricular apical and anteroseptal defects, which normalised at rest. SPECT during stress and at rest may detect subclinical ischaemia and influence further management options in such patients.

Topics: Adolescent; Calcification, Physiologic; Clopidogrel; Coronary Vessels; Echocardiography, Stress; Exercise Test; Humans; Male; Mucocutaneous Lymph Node Syndrome; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Platelet Aggregation Inhibitors; Radiopharmaceuticals; Ticlopidine; Tomography, Emission-Computed, Single-Photon; Ventricular Outflow Obstruction

Laryngopharyngoesophagectomy and reconstruction by using stomach roll with retrocardiac anastomosis were performed in a 60-year-old man with hypopharyngeal cancer. Postoperative electrocardiogram showed marked ST-segment elevation in leads I and aVL and depression in leads II, III, aVF, and V1-6. However, the patient did not present with abnormal findings on physical examination and vital signs were normal. Further, the laboratory data were normal. Echocardiography was a poor technique, but the stomach roll was observed to be expanded due to wall edema with exudates and exerted pressure on the posterior side of the heart. These findings were also ascertained by contrast-enhanced chest computed tomography scanning. Technetium-99m-tetrofosmin myocardial scintigraphy clearly showed that coronary blood perfusion and left ventricular wall motion were quite normal. The characteristic electrocardiogram returned to a near-normal state, and the expanded stomach roll shrank back to its ordinary size after one week. Coronary angiography showed neither organic stenoses nor vasospasm. The physical pressure of the expanded stomach roll might have influenced the electrocardiogram findings.

Topics: Contrast Media; Coronary Angiography; Echocardiography; Electrocardiography; Esophagus; Humans; Middle Aged; Movement; Myocardial Infarction; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Stomach; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed

Evaluation of myocardial ischemia and viability is very important for the management of patients with a history of Kawasaki disease (KD). (99m)Tc-tetrofosmin myocardial perfusion scintigraphy combined with quantitative gated single photon computed emission tomography (QGS) gives us information, not only about perfusion, but also the percentage change in left ventricular wall thickness (%WT) and relative changes in left ventricular wall motion (LVM).. The subjects were 27 patients with a history of KD followed as outpatients at the National Cardiovascular Center, Osaka, Japan. Exercise-loaded QGS was performed on 21 patients, and dipyridamole- loaded QGS was performed in six patients younger than 7 years old.. Perfusion defects (PD) were observed in 12 patients. Of the 12 patients, four with old myocardial infarction (OMI) had decreased %WT. All patients with OMI showed a decrease in %WT in the areas where PD was seen on the image. The other eight patients without OMI showed no decrease in %WT. In non-infarcted cases, the %WT was normal in the PD-positive area.. It is possible to evaluate myocardial ischemia and viability in KD patients by comparing PD on the image with %WT determined by QGS using exercise or drug-loaded myocardial scintigraphy alone.

Topics: Adolescent; Adult; Child; Child, Preschool; Coronary Stenosis; Dipyridamole; Exercise Test; Female; Humans; Male; Mucocutaneous Lymph Node Syndrome; Myocardial Infarction; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Tissue Survival; Tomography, Emission-Computed, Single-Photon; Vasodilator Agents

Stress myocardial perfusion imaging is a useful method for evaluation of coronary artery disease (CAD) in patients with diabetes mellitus. However, its role in predicting all-cause mortality is not well defined. The aim of this study was to determine whether myocardial ischemia on stress myocardial perfusion imaging can predict all causes of death in patients with diabetes mellitus.. We studied 297 patients with diabetes mellitus and known or suspected CAD by exercise or dobutamine stress (99m)Tc-tetrofosmin myocardial perfusion tomographic imaging. Ischemia was defined as reversible perfusion abnormalities. The endpoints were death from any cause and hard cardiac events (cardiac death and nonfatal myocardial infarction).. An abnormal scan was detected in 179 (60%) patients. Myocardial perfusion abnormalities were fixed in 76 (26%) patients and were reversible in 103 (35%) patients. During a mean follow-up of 6 +/- 2.1 y, 80 (27%) patients died. Nonfatal myocardial infarction occurred in 14 (5%) patients. The annual mortality rate was 2.5% in patients with normal perfusion, 4.5% in patients with fixed defects, and 6% in patients with ischemia. The annual cardiac death rate was 4.2% in patients with ischemia and 2.6% in patients with fixed defects. In patients with normal perfusion, the annual cardiac death rate was 0.9% during the 5 y after the stress test. In a Cox multivariate analysis model, predictors of death were age, history of heart failure, peripheral vascular disease, and reversible perfusion defects.. Myocardial ischemia on stress (99m)Tc-tetrofosmin myocardial perfusion imaging is associated with an increased risk of all-cause mortality during long-term follow-up among patients with diabetes mellitus. Patients with normal perfusion have a lower mortality rate and may require less frequent follow-up stress perfusion imaging.

Topics: Cause of Death; Comorbidity; Diabetes Mellitus; Exercise Test; Female; Humans; Male; Middle Aged; Myocardial Ischemia; Netherlands; Organophosphorus Compounds; Organotechnetium Compounds; Prevalence; Prognosis; Radionuclide Imaging; Radiopharmaceuticals; Reproducibility of Results; Risk Assessment; Risk Factors; Sensitivity and Specificity; Survival Analysis; Survival Rate

Patients with hypertrophic cardiomyopathy (HCM) sometimes develop myocardial ischemia during exercise in the absence of coronary lesions. The relationship between myocardial ischemia and ST-segment depression was investigated during exercise testing in patients with HCM.. Regional hypoperfusion and/or transient left ventricular cavity dilation, a parameter of subendocardial hypoperfusion, were assessed on exercise 99mTc-tetrofosmin myocardial scintigraphy in 42 patients with non-obstructive HCM. The scintigraphic results were further correlated with the ST-segment responses to exercise.. Regional hypoperfusion or transient left ventricular cavity dilation were observed in 19 (45%) or 16(38%)patients with HCM, respectively. The incidence of ST-segment depression > or = 0.1 mV during exercise testing was similar in HCM patients with regional hypoperfusion, with transient left ventricular cavity dilation, and without hypoperfusion (42%, 38%, 38%, p = 0.95). Furthermore, exercise-induced ST-segment depression > or = 0.1 mV occurred similarly irrespective of symptoms, exercise tolerance, the degree or the site of hypertrophy, or the presence or absence of resting ST-segment depression.. ST-segment depression during exercise testing was common in patients with HCM, but seems to be an unreliable marker of myocardial ischemia as assessed by exercise scintigraphy.

Topics: Aged; Cardiomyopathy, Hypertrophic; Electrocardiography; Exercise Test; Female; Heart; Humans; Male; Middle Aged; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Radionuclide Imaging; Radiopharmaceuticals

This was an observational study carried out in the department of cardiology. Bangabandhu Shikh Mujib Medical University (BSMMU), Dhaka in collaboration with Institute of Nuclear Medicine (INM), Shabag, Dhaka during the period October 2002-March 2003. A total of 54 patients presenting with Canadian Cardiovascular Society (CCS) class I-II severity of chest pain with mean +/-SD age 49.88 +/- 8.44 yrs and having male to female ratio 5.75:1 were included in the study. The main objective of the study was to predict severity of myocardial ischemia by Exercise Tolerance Test (ETT) determined by Duke Treadmill Score (DTS) and by perfusion pattern observed following Single-Photon Emission Computed Tomography myocardial perfusion imaging (SPECT-MPI). All patients underwent ETT and then SPECT-MPI scan using Tc-99m-tetrofosmin in one-day stress and rest protocol. Coronary angiogram (CAG) was done with in six months of the perfusion study. After performing ETT, patients were categorized by DTS and myocardial perfusion studies were also stratified according to severity of perfusion defect. The formula used to calculate the score was: Exercise time- (5 x ST segment deviation)-(4 X Treadmill angina index). The angiographic findings (significant >50% stenosis) and perfusion defects in MPI were compared with the severity of DTS. There were 31 patients who had CAG proven (>50% luminal diameter narrowing) CAD and 23 patients free of CAD. After ETT patients were categorized by Duke Treadmill Score into high DTS 12 (22.22%) patients, intermediate DTS 20 (37.03%) patients low DTS 22 (40.74%) patients. In high DTS group 91.66% patients had perfusion defect, whereas in intermediate and low risk group it was 60% and 40.9% respectively. In high DTS group 91.66% of patients had angiographicaly proven CAD, 58.33% of them had triple vessel disease (TVD) while in intermediate and low risk groups angiographically proven CAD were 65% and 22.72% of whom TVD only in 15% & 0% respectively. The results of ETT using DTS score were satisfactorily correlated with SPECT-MPI scanning in high DTS subsets of patients only. It is therefore, suggested that patient of high risk DTS do not need for myocardial perfusion imaging study and should undergo CAG for further evaluation. But the intermediate and low risk groups were needed myocardial perfusion imaging study to guide for further evaluation.

Topics: Adult; Chest Pain; Exercise Test; Exercise Tolerance; Female; Humans; Male; Middle Aged; Myocardial Ischemia; Myocardial Reperfusion; Organophosphorus Compounds; Organotechnetium Compounds; Prospective Studies; Risk Assessment; Risk Factors; Severity of Illness Index; Tomography, Emission-Computed, Single-Photon

The aim of this study was to evaluate the significance of extension of exercise-induced ischemia toward apex of left ventricle.. After injections of technetium-99m tetrofosmin at peak ergometer exercise and thallium-201 at 3 min post-exercise, dual-isotope single photon emission computed tomography (SPECT) images were obtained simultaneously with cross-talk compensation using triple-energy window in 70 patients (65.8+/-9.5 years) with angiographically proven ischemic heart disease. The left ventricle was divided into a total of 18 areas in 3 levels of apical, middle, basal, and the extent and localization of ischemia to long axis of left ventricle were measured at peak exercise and 3 min into the recovery.. Of 57 patients with exercise-induced reversible ischemia, in 25 patients with the ischemia in 2 levels to long axis of left ventricle, the ischemia extended mainly to the middle and basal levels (p<0.0001) and was localized during recovery mainly in the basal level (p<0.0005). In 21 patients with the ischemia in all 3 levels, the ischemia was localized during recovery mainly to the middle and basal levels (p<0.05). The persistence of ischemia in apex at post-exercise reflected the delay of recovery from ischemia on the whole of left ventricle and was related to the enlargement of resting end-diastolic volume of left ventricle as compared to the quick recovery of ischemia in apex (p<0.0005 and p<0.05, respectively).. Although the ischemia recovers earliest in the peripheral apical level within exercise-induced ischemic territory, the delay of recovery from the ischemia in the apical level may be related to the development of heart failure, independent of intensity of occurred ischemia during exercise.

Topics: Aged; Cardiac Catheterization; Case-Control Studies; Coronary Stenosis; Exercise Test; Female; Heart; Heart Ventricles; Humans; Male; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Thallium Radioisotopes; Tomography, Emission-Computed, Single-Photon

The severity of exercise-induced painful ischemia and its recovery after the disappearance of pain are unknown. The aim of this study was to investigate the difference in severity of ischemia at both exercise and postexercise between painful ischemia and painless ischemia. After injections of technetium-99m tetrofosmin at peak ergometer exercise and thallium-201 at 3 minutes postexercise, dual-isotope single photon emission tomography was performed in 78 patients with angiographically proven ischemic heart disease. The extent of ischemic areas (the number of areas), the depth of ischemia in the ischemic area (the severity score of ischemia) and the extension of ischemia toward long axis of the left ventricle (the number of left ventricular levels with ischemic areas in apical, middle, and basal levels) at both exercise and postexercise were compared on the basis of the presence of pain and a history of diabetes mellitus (DM). The symptoms improved within 3 minutes postexercise in all painful ischemia patients. Of 59 patients with reversible ischemia, except for 4 painful ischemia patients with DM, the extent and depth of ischemia at postexercise were more severe in 14 painful ischemia patients without DM and 13 painless ischemia patients with DM than 28 painless ischemia patients without DM (extent; 2.9 +/- 1.7 areas, 3.5 +/- 2.8 areas versus 1.4 +/- 1.8 areas, P = 0.005, depth; 3.8 +/- 3.1 scores, 5.8 +/- 5.4 scores versus 1.9 +/- 3.0 scores, P = 0.0084, respectively) despite a comparable severity of ischemia at peak exercise (extent; 5.4 +/- 2.6 areas, 6.0 +/- 2.4 areas versus 4.3 +/- 3.3 areas, depth; 9.3 +/- 5.7 scores, 10.7 +/- 7.3 scores and 7.5 +/- 8.1 scores, all NS). The extension of ischemia toward long-axis of the left ventricle at both peak exercise and postexercise was more severe in the former 2 groups than the latter group (peak exercise; 2.4 +/- 0.6 levels, 2.5 +/- 0.7 levels versus 1.9 +/- 0.8 levels, P = 0.0263, postexercise: 1.8 +/- 0.7 levels, 1.5 +/- 0.9 levels versus 0.8 +/- 0.8 levels, P = 0.0014, respectively). The presence of chest pain is related to the extension of ischemia toward long-axis of the left ventricle, and the disappearance of pain was not related to the recovery of ischemia.

Topics: Aged; Angina Pectoris; Exercise; Exercise Test; Female; Humans; Male; Middle Aged; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Recovery of Function; Severity of Illness Index; Thallium Radioisotopes; Tomography, Emission-Computed, Single-Photon

Topics: Exercise Test; Female; Humans; Lupus Erythematosus, Systemic; Male; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Predictive Value of Tests; Risk Assessment; Sampling Studies; Scleroderma, Systemic; Sensitivity and Specificity; Severity of Illness Index; Tomography, Emission-Computed, Single-Photon

To assess the prevalence of myocardial viability by technetium-99m (Tc-99m)-tetrofosmin/fluorine-18-fluorodeoxyglucose (FDG) single photon emission computed tomography (SPECT) in patients with ischaemic cardiomyopathy.. A retrospective observational study.. Thoraxcenter Rotterdam (a tertiary referral centre).. 104 patients with chronic coronary artery disease and severely depressed left ventricular function presenting with heart failure symptoms.. Prevalence of myocardial viability as evaluated by Tc-99m-tetrofosmin/FDG SPECT imaging. Two strategies for assessing viability in dysfunctional myocardium were used: perfusion imaging alone, and the combination of perfusion and metabolic imaging.. On perfusion imaging alone, 56 patients (54%) had a significant amount of viable myocardium, whereas 48 patients (46%) did not. Among the 48 patients with no significant viability by perfusion imaging alone, seven additional patients (15%) had significantly viable myocardium on combined perfusion and metabolic imaging. Thus with a combination of perfusion and metabolic imaging, 63 patients (61%) had viable myocardium and 41 (39%) did not.. On the basis of the presence of viable dysfunctional myocardium, 61% of patients with chronic coronary artery disease and depressed left ventricular ejection fraction presenting with heart failure symptoms may be considered for coronary revascularisation. The combination of perfusion and metabolic imaging identified more patients with significant viability than myocardial perfusion imaging alone.

Topics: Coronary Circulation; Coronary Vessels; Female; Fluorodeoxyglucose F18; Humans; Male; Middle Aged; Myocardial Contraction; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Retrospective Studies; Tomography, Emission-Computed, Single-Photon; Ventricular Dysfunction, Left

To evaluate radiation-induced defects in myocardial perfusion imaging in early breast cancer patients treated with modern technique radiotherapy.. Twenty-four patients with left-breast tumours and 12 control patients with right-breast tumours, relapse-free since treatment for primary disease, who had undergone radiotherapy at least 5 years previously and with no history of ischaemic heart disease prior to radiotherapy underwent study. In left-breast patients, at least 1 cm of heart was required to have been in the treatment field. Patients underwent cardiac assessment and single photon emission computerized tomography myocardial perfusion imaging.. Myocardial perfusion tracer uptake was abnormal in 17 (70.8%) left-breast and two (16.7%) right-breast patients (P = 0.002). Of the 17 abnormal scans in left-breast patients, abnormalities were confined to the cardiac apex in 16 patients, and perfusion defects were reversible (n = 7), fixed (n = 7) or mixed (n = 3). Reversible perfusion defects that were not confined to the cardiac apex were observed in two right-breast patients. Left ventricular ejection fraction was normal in all 33 patients in whom it was measured, and no myocardial perfusion abnormalities were judged to require treatment or follow-up.. In this selected study population modern technique radiotherapy to the left breast was associated with a significantly greater number of myocardial perfusion abnormalities than radiotherapy to the right breast. These abnormalities were both reversible and irreversible, suggesting that radiotherapy can lead to both myocardial damage and to epicardial coronary disease. With a minimum of 5 years follow-up since treatment, no abnormalities were considered to be clinically significant.

Topics: Aged; Breast Neoplasms; Coronary Circulation; Female; Follow-Up Studies; Heart; Humans; Middle Aged; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Radiotherapy; Risk Factors; Tomography, Emission-Computed, Single-Photon

Stress nuclear imaging is the noninvasive technique currently used to detect coronary artery disease (CAD) in dialysis patients. Stress echocardiography is recognized as an alternative to stress nuclear imaging for the general population. The aim of this study is to assess the diagnostic accuracy of stress echocardiography for detecting myocardial ischemia in hemodialysis patients.. Stress echocardiography and stress technetium-99m-tetrofosmin (Myoview; Amersham International Plc) imaging were performed simultaneously for 66 asymptomatic hemodialysis patients in a single session, using a combination of high-dose dipyridamole and symptom-limited exercise. Coronary angiography was performed in 44 patients with at least one abnormal noninvasive test result or who were considered high-risk despite normal noninvasive test results.. Results for stress echocardiography were abnormal in 15 patients (22%); stress Myoview, in 14 patients (21%); and coronary angiography, in 12 patients (18%). The sensitivity of stress echocardiography for detecting myocardial ischemia (defined as stress Myoview defect) was 86%; specificity, 94%; positive predictive value, 80%; negative predictive value, 96%; and overall accuracy, 92%. The sensitivity of stress echocardiography for detecting CAD (defined as abnormal coronary angiography result) was 83%; specificity, 84%; positive predictive value, 67%; negative predictive value, 93%; and overall accuracy, 84%. Stress echocardiography and stress Myoview did not differ significantly in overall accuracy for detecting CAD (84% versus 91%; P = not significant).. In hemodialysis patients, combined dipyridamole-exercise echocardiography is an accurate method to detect both myocardial ischemia and CAD and represents an alternative to stress nuclear imaging.

Topics: Adult; Aged; Coronary Angiography; Coronary Artery Disease; Dipyridamole; Echocardiography, Stress; Exercise Test; Female; Humans; Male; Middle Aged; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Radionuclide Ventriculography; Radiopharmaceuticals; Renal Dialysis; Risk Assessment; Sensitivity and Specificity; Vasodilator Agents

We report the estimation of left ventricular systolic pressure (LVSP) by a left ventricular (LV) volume-time curve obtained from electrocardiogram (ECG) gated 99mTc-tetrofosmin single photon emission computed tomography (SPECT) using quantitative gated SPECT (QGS). LVSP was calculated based on the following parameters: LV volumes, velocity and acceleration of LV contraction, aortic valve area and density of blood. The first three parameters can be derived from ECG gated SPECT. In 16 patients, the LV volume-time curve was obtained from ECG gated SPECT by using QGS. LVSP was estimated by the above-mentioned theory. The values of estimated peak LVSP were compared with those measured from a pressure transducer. There was a correlation between the values of peak LVSP estimated by the LV volume-time curve and those measured by pressure transducer (r=0.69, P<0.01). Using QGS, LVSP and the systolic LV pressure-volume relationship could be estimated by the LV volume-time curve.

Topics: Algorithms; Angina Pectoris; Female; Gated Blood-Pool Imaging; Humans; Male; Middle Aged; Models, Cardiovascular; Myocardial Infarction; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Sensitivity and Specificity; Ventricular Function, Left; Ventricular Pressure

The purpose of this investigation was to compare the efficiency of two different imaging protocols using two different clinically available 99mTc labelled myocardial perfusion tracers. One thousand one hundred and thirty-four imaging studies were performed prospectively, using either 99mTc-tetrofosmin or 99mTc-sestamibi, alternating the use of each tracer for a total period of 8 months. 99mTc-tetrofosmin rest studies were performed with injections of 259MBq-370MBq and imaging 30 min later. Exercise studies were performed with injections of 777MBq-1.11GBq and imaging 20 min later. 99mTc-sestamibi studies used doses similar to those in the 99mTc-tetrofosmin studies. Imaging followed a standard procedure, at 60 min after rest injection, and 30 min after exercise. For patients undergoing pharmacological stress testing99mTc-sestamibi was imaged 45 min after injection and 99mTc-tetrofosmin was imaged 30 min after injection. Variables analysed were (1) injection-to-imaging time for the procedure, and (2) the number of repeated scans because of extra cardiac activity. The completion time for the rest study was significantly shorter for 99mTc-tetrofosmin compared to 99mTc-sestamibi (47.7+/-21.7 min vs 74.3+/-25.8 min P<0.0001). Likewise, the total study time was shorter for 99mTc-tetrofosmin compared to 99mTc-sestamibi (90+/-32.7 min vs 124+/-37 min, P<0.0001). More importantly, the number of repeated scans was higher with 99mTc-sestamibi compared to 99mTc-tetrofosmin, 21.4% vs 10%, P=0.001 for rest studies and 16.4% vs 7.9% P=0.001 [corrected] for rest and stress. It was concluded that, using a same day rest/stress protocol, 99mTc-tetrofosmin provided higher patient throughput with fewer repeat scans. These factors may be considered for efficiency improvement in nuclear cardiology laboratories using 99mTc perfusion tracers.

Topics: Adenosine; Exercise Test; Female; Humans; Male; Middle Aged; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Prospective Studies; Radiopharmaceuticals; Reproducibility of Results; Sensitivity and Specificity; Technetium Tc 99m Sestamibi; Time Factors; Tomography, Emission-Computed, Single-Photon

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 carried out stress 201Tl (Tl) and rest 99mTc-tetrofosmin (TF) myocardial scintigraphy with dual energy acquisition in 24 patients with suspected ischemic heart disease performed coronary arteriography and elucidated the sensitivity of this method. One hour after light meal eating, TF (555 MBq) was injected intravenously at rest and after 3 minutes from injection of TF exercise or pharmacologic stress was performed. During stress Tl (111 MBq) was injected intravenously before end-point or at adequate point of pharmacologic stress. Dual energy acquisition using triple energy windows (TEW) was started after 5 minutes (early) and 4 hours (delayed) from stress. The sensitivity (Sn), specificity (Sp) and accuracy (Ac) in diagnosis of non-infarcted branches by using Tl (early)-TF (rest) and Tl (early)-Tl (delayed) were 79% vs. 53% (Sn), 78% vs. 96% (Sp) and 79% vs. 71% (Ac) respectively. Accordance of uptake score of infarcted region between TF (rest) and Tl (delayed) was 70%. In conclusion, this protocol is seemed to be useful as usual protocol for detection of myocardial ischemia and viability during about only 1 hour.

Topics: Aged; Female; Heart; Humans; Male; Middle Aged; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Rest; Sensitivity and Specificity; Thallium Radioisotopes; Tomography, Emission-Computed, Single-Photon

Perfusion imaging combined with pharmacological stress is the study of choice in patients with ischaemic heart disease who are incapable of exercising. Some medical conditions, however, can preclude the use of pharmacological stress. In these particular situations, availability of a diagnostic test which allows for the assessment of ischaemic territory at rest would be desirable. With the purpose of providing a marker of reversible ischaemia, we evaluated myocardial iodine-123 metaiodobenzylguanidine (MIBG) uptake in regions with fixed and reversible defects defined by exercise/rest perfusion study. Fifty-four male patients with ischaemic heart disease and previous myocardial infarction were studied by means of exercise/rest tetrofosmin and MIBG single-photon emission tomography (SPET). Regional tracer uptake was quantified and expressed as a percentage of maximum peak activity. Areas with denervated but perfused myocardium and areas with ischaemic myocardium were calculated. Regions with<75% of peak activity in the exercise perfusion study were divided into two groups according to whether the increase in peak activity in the respective rest study was >10% (reversible regional defect) or <10% (fixed regional defect). These percentages were compared with the percentages of the innervation study. The area of the innervation defect was significantly larger when the perfusion defect was reversible than when it was fixed. In regions with reversible perfusion defects, the size of the area of denervated but perfused myocardium was similar to the size of the area of ischaemic myocardium. In regions with reversible defects, the percentage of myocardial MIBG uptake was not significantly different from the percentage of tetrofosmin uptake at exercise, while it was significantly lower than the percentage of tetrofosmin uptake at rest. In regions with fixed defects, the percentage of myocardial MIBG uptake was significantly lower than the percentage of tetrofosmin uptake at exercise and at rest. In patients who developed angina during exercise test, the area of denervated but perfused myocardium was significantly larger than in patients without angina (4.1+/-2.4 vs 3.4+/-2.5, P=0.02). The same trend was observed with regard to the size of the innervation defect (8.6+/-2.4 vs 5.7+/-2.2, P=0.02). It is concluded that when the use of pharmacological stress is not possible in patients incapable of exercising, rest studies with MIBG combined with rest myocardial perfusion

Topics: 3-Iodobenzylguanidine; Adult; Aged; Coronary Circulation; Exercise Test; Heart; Humans; Male; Middle Aged; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Rest; Sympathetic Nervous System; Tomography, Emission-Computed, Single-Photon

To determine the mechanism of myocardial ischemia in patients with sickle beta-thalassemia, we performed a scintigraphic evaluation of myocardial perfusion during exercise.. We studied 30 patients with sickle beta-thalassemia, (mean [+/-SD] age, 37 +/- 10 years) who had no electrocardiographic (ECG), radiographic, or echo-Doppler signs of pulmonary hypertension, left ventricular hypertrophy, or impaired contractility. All patients had a hemoglobin level greater than 7 g/dL. Treadmill exercise test was performed according to the Bruce protocol. Myocardial perfusion was assessed by single-photon emission computed tomography, using Tetrofosmin Tc-99 m Myoview as radiotracer, at peak exercise and again 4 hours later.. Eight patients (27%) developed stress-induced scintigraphic perfusion abnormalities that were reversible in all but 1 patient. Subsequent coronary angiograms were normal in all 8 patients. ST segment depression was seen during exercise in 5 of the 7 patients who had reversible perfusion defects. Except for a significantly greater white blood cell count, these 5 patients did not differ from the rest of patients by sex, age, hemoglobin level, percentage hemoglobin F, beta-thalassemia genotype, or risk factors for coronary artery disease. Three of the 5 patients with perfusion and ECG abnormalities (and another with only perfusion defects) developed a stress-induced sickling crisis.. Physical stress may induce myocardial ischemia in sickle beta-thalassemia patients with normal coronary arteries and elicit painful crises. The sickling process, activated by exercise, could be the common underlying mechanism.

Topics: Adult; Analysis of Variance; Anemia, Sickle Cell; beta-Thalassemia; Coronary Circulation; Exercise Test; Female; Humans; Male; Middle Aged; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Statistics, Nonparametric; Tomography, Emission-Computed, Single-Photon

Chest pain (CP) represents a frequent reason for presentation at the emergency department (ED). A large proportion of patients have non-diagnostic ECG on presentation, and in many cases several hours have elapsed since onset of symptoms. Acute rest myocardial scintigraphy (rest SPET) has been shown to have a relevant role in the detection of patients at risk for coronary events, but its sensitivity and negative predictive value are optimal only within the first 3 h following onset of symptoms. In those with delayed presentation, exercise SPET alone, as a screening approach, appears more promising, but its feasibility and diagnostic role in the ED are still unresolved. A total of 231 consecutive patients with a recent-onset (<24 h) first episode of CP had a negative first-line work-up including ECG, troponins, creatine kinase-MB and echocardiography. These patients were considered at low risk for short-term coronary events. Patients were studied with rest SPET if they presented <3 h after onset of CP and exercise SPET if they presented after > or =3 h. The end-points of the study were detection of significant coronary artery disease (CAD) by angiography and major coronary events or cardiac death at 6 months. Eighty patients (35%) underwent rest SPET, while 151 (65%) underwent exercise SPET. Two of the 159 patients with negative SPET had evidence of critical CAD at 6-month follow-up (one patient in the rest SPET group and one in the exercise SPET group; P=NS). Of the 72 patients (31%) with a positive scan, 34 (15%) had documented CAD (16 patients in the rest SPET group and 18 in the exercise SPET group; P=NS). Sensitivity, specificity, accuracy and predictive value were not statistically different between the two groups. In conclusion, the accuracy of exercise SPET in patients with CP and delayed presentation to the ED is comparable to that of validated rest SPET in patients with early presentation. Owing to the high negative predictive value (99%), exercise SPET is especially valuable as a screening tool for the exclusion of CAD in low-risk patients and implementation of early discharge.

Topics: Aged; Chest Pain; Electrocardiography; Emergency Service, Hospital; Exercise Test; Female; Heart; Humans; Male; Middle Aged; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Predictive Value of Tests; Radiopharmaceuticals; Risk Factors; Technetium Tc 99m Sestamibi; Tomography, Emission-Computed, Single-Photon

Electrocardiographically (ECG) gated myocardial SPECT with (99m)Tc-tetrofosmin has been used widely to assess left ventricular (LV) function. However, the accuracy of variables using ECG gated myocardial SPECT with beta-methyl-p-(123)I-iodophenylpentadecanoic acid (BMIPP) has not been well defined.. Thirty-six patients (29 men, 7 women; mean age, 61.6 +/- 15.6 y) with ischemic heart disease underwent ECG gated myocardial SPECT with (123)I-BMIPP and with (99m)Tc-tetrofosmin and left ventriculography (LVG) within 1 wk. LV ejection fraction (LVEF), LV end-diastolic volume (LVEDV), and LV end-systolic volume (LVESV) were determined on gated SPECT using commercially available software for automatic data analysis. These volume-related items on LVG were calculated with an area-length method and were estimated by 2 independent observers to evaluate interobserver validity. The regional wall motion with these methods was assessed visually.. LVEF was 41.1% +/- 12.5% on gated SPECT with (123)I-BMIPP, 44.5% +/- 13.1% on gated SPECT with (99m)Tc-tetrofosmin, and 46.0% +/- 12.7% on LVG. Global LV function and regional wall motion between both gated SPECT procedures had excellent correlation (LVEF, r = 0.943; LVEDV, r = 0.934; LVESV, r = 0.952; regional wall motion, kappa = 0.92). However, the correlations of global LV function and regional wall motion between each gated SPECT and LVG were significantly lower. Gated SPECT with (123)I-BMIPP showed the same interobserver validity as gated SPECT with (99m)Tc-tetrofosmin.. Gated SPECT with (123)I-BMIPP provides high accuracy with regard to LV function and is sufficiently applicable for use in clinical SPECT. This technique can simultaneously reveal myocardial fatty acid metabolism and LV function, which may be useful to evaluate various cardiac diseases.

Topics: Electrocardiography; Fatty Acids; Female; Heart; Humans; Iodine Radioisotopes; Iodobenzenes; Linear Models; Male; Middle Aged; Myocardial Contraction; Myocardial Ischemia; Myocardium; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon; Ventricular Function, Left

A high number (30%-50%) of reversible defects have been detected early after coronary balloon angioplasty. Inadequate luminal enlargement despite a good angiographic appearance has been suggested as a possible mechanism of these perfusion abnormalities, and some reports have shown better coronary flow reserve after coronary stent implantation than after balloon dilatation. The primary objective of this study was to evaluate the frequency of early ischemic defects detected by maximal exercise (plus dipyridamole) with (99m)Tc-tetrofosmin SPECT after successful coronary angioplasty with stent implantation. A secondary objective was to determine the prognostic value of these early ischemic defects.. Thirty patients without previous myocardial infarction who successfully underwent 1-vessel coronary angioplasty with stent implantation were studied. Maximal-exercise (99m)Tc-tetrofosmin myocardial SPECT, with simultaneous dipyridamole if exercise was suboptimal, was performed at 6 +/- 1 d (mean +/- SD) after percutaneous transluminal coronary angioplasty. At 8 +/- 3 mo, all patients were followed up clinically, and 77% of them underwent follow-up angiography.. The percentage of stenosis decreased from 68.5% +/- 12.6% of luminal diameter to 9.3% +/- 8.8% after stent implantation, and minimal luminal diameter increased from 0.89 +/- 0.36 mm to 2.85 +/- 0.45 mm. Mild-to-moderate reversible myocardial defects in the territory of the dilated artery were detected in 5 patients (17%), with no angiographic or procedural differences occurring between them and patients without ischemic defects. At follow-up, the target lesion revascularization rates depending on the presence or absence of early ischemic defects were 40% and 8%, respectively (P = 0.18). Angiographic restenosis occurred in 3 of 4 patients who had early ischemic defects and underwent follow-up angiography and in 3 of 19 patients who had no early ischemic defects and underwent follow-up angiography (restenosis rate, 75% and 16%, respectively; P < 0.05).. Coronary angioplasty with stent implantation is associated with a 17% rate of ischemic defects early after the procedure. Patients with early myocardial perfusion defects after coronary stent implantation had a high rate of restenosis.

Topics: Angioplasty, Balloon, Coronary; Coronary Angiography; Coronary Restenosis; Dipyridamole; Exercise Test; Female; Follow-Up Studies; Humans; Incidence; Male; Middle Aged; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Prognosis; Radiopharmaceuticals; Stents; Time Factors; Tomography, Emission-Computed, Single-Photon

According to improvement of SPECT system, ECG-gated SPECT with 201TlCl have been applied to the left ventricular volumetry. In this study 24 patients without ischemia demonstrated by stress (99mTc-TF) and rest (201TlCl) dual-isotope ECG-gated myocardial SPECT were enrolled. To evaluate left ventricular volumetry using 201Tl ECG-gated SPECT data, the left ventricular end diastolic volumes (EDV) were compared between Quantitative Gated SPECT (QGS) and Emory Cardiac Toolbox (ECT) as well as between dual-isotopes based on the same ECG-gated data. The EDV values with 99mTc data (EDVTc) using QGS were well correlated with those using ECT (r = 0.96, p < 0.0001). Both QGS and ECT demonstrated well correlation between EDVTc (r = 0.98, p < 0.0001) and the EDV value with 201Tl (EDVTl) (r = 0.93, p < 0.0001). However, QGS processing induced significantly lower EDVTl compared with EDVTc. In contrast, EDVTl were significantly higher than EDVTc in ECT performance. The QGS errors subtracting EDVTl from EDVTc were more evident according to the left ventricular volume increase. On the other hand, ECT error showed no tendency associated with the left ventricular volume. From these results, a careful strategy for selection of tracers and softwares should be necessary to assessment of quantitative values derived from ECG-gated SPECT data because of interaction with softwares, tracers, and subjects.

Topics: Adult; Aged; Algorithms; Electrocardiography; Female; Gated Blood-Pool Imaging; Humans; Male; Middle Aged; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Software; Thallium; Thallium Radioisotopes; Tomography, Emission-Computed, Single-Photon; Ventricular Function, Left

Case 1 involved a 52-year-old man with angina chest pain at rest and case 2 involved a 63-year-old woman with chest oppression at rest. An electrocardiogram (ECG) showed negative T wave in III and aVF leads in case 1, and complete atrioventricular block and ST segment depression in II, III, aVF, and V5-6 leads in case 2. In both cases, 99mTc-tetrofosmin myocardial SPECT showed reduced uptake in the inferior and posterior wall. Although bath patients' left coronary arteriographies were normal, right coronary arteriographies revealed severely delayed filling of contrast medium without significant narrowing of epicardial coronary arteries, suggesting microembolism or microvascular vasospasm. An intracoronary infusion of isosorbide dinitrate did not improve the delayed filling of contrast medium or ST segment depression on ECG. Soon after intracoronary infusion of diltiazem in case 1 and nicorandil in case 2, coronary arterial flows were normalized, chest symptoms disappeared, and ECG findings were normalized. The next day, both patients' 99mTc-tetrofosmin myocardial SPECT showed normal uptake. These findings suggest that myocardial ischemia in these cases might be explained as having been caused by microvascular spasm.

Topics: Calcium Channel Blockers; Diltiazem; Female; Heart; Humans; Male; Microvascular Angina; Middle Aged; Myocardial Ischemia; Nicorandil; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon; Treatment Outcome; Vasodilator Agents

Topics: Fatty Acids; Fluorodeoxyglucose F18; Humans; Iodine Radioisotopes; Iodobenzenes; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Technetium Tc 99m Sestamibi; Tomography, Emission-Computed; Tomography, Emission-Computed, Single-Photon

The dual-isotope technique (rest 201Tl and stress 99mTc-sestamibi) is useful to assess myocardial perfusion in coronary disease patients. 99mTc-labeled tetrofosmin is a radiopharmaceutical whose characteristics are similar to sestamibi. Thus, we decided to use it to detect reversible myocardial hypoperfusion in patients with a background of myocardial infarction and ischemia. A sequential dual-isotope scintigraphy (3 mCi rest 201Tl and 25 mCi stress 99mTc-tetrofosmin) with 24-hour 201Tl redistribution (RD) was performed in 20 patients with previously confirmed myocardial infarction and clinical and ergometric signs of ischemia. Each patient also underwent a stress-redistribution protocol with redistribution at 4 and 24 hours post injection with 201Tl scintigraphy within two weeks of the first study. The qualitative uptake analysis showed no significant differences in the number of myocardial segments with severe reduction of tracer uptake on stress that improved at rest or in RD images, even if 24-hour RD images were considered. The quantitative global uptake analysis showed a similar defect reversibility with both protocols; however if 24-hour RD images were considered the uptake improvement was significant only when compared with the rest 201Tl images in dual-isotope scintigraphy protocol (75+/-8% vs. 81+/-9% of peak activity, rest vs. 24-hour RD; p<0.01) and not when compared with the 4-hour RD in the 201Tl scintigraphy. On the other hand, when only the segments with severely reduced uptake (<50% of peak activity) were analyzed, the 24-hour RD improved myocardial uptake significantly (p<0.001 vs. rest and vs 4-hour RD) in both protocols. We conclude that a sequential dual-isotope rest 201Tl/stress 99mTc-tetrofosmin scintigraphy is comparable with stress-redistribution 201Tl scintigraphy to detect reversible myocardial hypoperfusion; however in both cases, the addition of 24-hour images increases its usefulness in severely hypoperfused segments, if the uptake of the radiopharmaceutic is quantified.

Topics: Adult; Aged; Exercise Test; Female; Humans; Male; Middle Aged; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Radionuclide Imaging; Radiopharmaceuticals; Rest; Thallium Radioisotopes

We encountered a patient with hypertrophic cardiomyopathy complicated with exercise-induced myocardial ischemia. Exercise-stress 99mTc-tetrofosmin imaging demonstrated reversible ischemia in the lateral wall, whereas resting fatty acid imaging with a new beta-methyl branched fatty acid analogue, I-123-15-(p-iodophenyl)-9-(R,S)-methylpentadecanoic acid (123I-9-MPA), showed impaired uptake and accelerated washout kinetics in the inferoapical and posteroseptal walls but not in the ischemia-related region. These findings suggest that the metabolic derangement is closely related to cardiomyopathy per se rather than exercise-induced myocardial ischemia in this patient with hypertrophic cardiomyopathy and a spastic coronary lesion so that myocardial perfusion and 123I-9-MPA imagings may contribute to clarifying the etiological background of impaired myocardial fatty acid metabolism.

Topics: Aged; Cardiomyopathy, Hypertrophic; Coronary Vasospasm; Exercise Test; Fatty Acids; Heart; Humans; Iodobenzenes; Male; Myocardial Ischemia; Myocardium; Organophosphorus Compounds; Organotechnetium Compounds; Radionuclide Imaging; Radiopharmaceuticals

It has been reported that quantitative gated SPECT (QGS) has revealed post-stress dysfunction of the left ventricle (LV) 30 minutes after a stress test. The purpose of this study was to determine whether post-stress dysfunction of LV is still present one hour after an exercise stress test. The subjects comprised 152 patients (124 males and 28 females, mean age 59 +/- 10 years). Exercise stress myocardial scintigraphy was performed using a one-day, stress and rest protocol. 99mTc labeled myocardial perfusion tracer, tetrofosmin, 370 MBq was injected at the end-point of a supine ergometer stress test for stress imaging. ECG gated SPECT was carried out 1 hour after injection. Three hours later, 740 MBq to 1100 MBq of 99mTc labeled myocardial perfusion tracer was injected for rest imaging. ECG gated SPECT was again performed 1 hour after injection. We divided the subjects into four groups according to the severity score of defects on the stress image and the presence or absence of fill-in; normal (NOR, n = 59), myocardial infarct (MI, n = 65), small ischemia (S-IS, n = 13) and large ischemia (L-IS, n = 15). Post-stress dysfunction is defined according to two criteria: 1) rest LVEF--post-stress LVEF > or = 5% and 2) post-stress ESV--rest ESV > or = 5 ml. The frequency of post-stress dysfunction was 3.4%, 9.1%, 23.1% and 40% in NOR, MI, S-IS and L-IS, respectively. Post-stress LV dysfunction was found to be more frequent in the large ischemia group. In conclusion, post-stress dysfunction was present 1 hour after the stress test and was more frequent in the large ischemia group.

Topics: Aged; Electrocardiography; Exercise Test; Female; Heart; Humans; Male; Middle Aged; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Time Factors; Tomography, Emission-Computed, Single-Photon; Ventricular Dysfunction, Left

A pharmacological adenosine-tri-phosphoric acid (ATP) stress test has been used in patients who can not perform an enough exercise stress test. However, falling blood pressure during the stress test and increased liver uptake of the tracer are often found in patients undergoing the ATP test. To prevent these phenomena, a combination of ATP stress test and low workload exercise test (ATP & EX) is proposed. The usefulness of this newly developed stress test was elucidated from two viewpoints. Firstly, the changes of hemodynamic parameters were measured in 34 patients: 17 undergoing ATP alone and 17 undergoing ATP & EX. Systolic blood pressure fell from 150 +/- 20 mmHg to 126 +/- 16 mmHg (p < 0.05) for ATP alone. However, it changed from 141 +/- 19 mmHg to 149 +/- 31 mmHg (ns) for ATP & EX. There was a significant fall in systolic blood pressure (> 30 mmHg) in 58.8% for ATP alone and 5.9% for ATP & EX (p < 0.01). Secondly, the ROI count in the liver and heart on an anterior projection image were measured in 38 patients: 11 undergoing ATP alone, 13 undergoing ATP & EX, and 14 undergoing an ergometer exercise test (EX). The ROI count in the liver at 60 minutes after tracer injection were 29.0 +/- 10.7 count/pixel, 21.4 +/- 5.2 count/pixel, 18.3 +/- 4.5 count/pixel for ATP alone, ATP & EX and EX, respectively. The activities for ATP & EX and EX were lower than that for ATP alone (p < 0.05 and p < 0.01). Thus, ATP & EX decreased the rates of the fall of systolic blood pressure and decreased liver uptake of the tracer compared with ATP alone. In conclusion, ATP & EX is a useful stress method for myocardial perfusion scintigraphy in patients who can not perform the enough exercise stress test.

Topics: Adenosine Triphosphate; Aged; Blood Pressure; Exercise Test; Female; Heart; Humans; Liver; Male; Middle Aged; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon

To investigate the role of technetium-99m (99mTc) tetrofosmin single-photon emission Computed Tomography (SPECT) associated with nitrate administration in the detection of hypoperfused but still viable myocardium in patients with chronic coronary artery disease and left ventricular (LV) dysfunction.. Twenty-two patients (mean age 54 +/- 11 years) with coronary artery disease, previous myocardial infarction and LV dysfunction (LV ejection fraction 38 +/- 13%) were examined. On different days all patients underwent 99mTc tetrofosmin (740 MBq) SPECT under control conditions at rest and after sublingual nitroglycerin administration (10 mg). Regional tetrofosmin activity was quantitatively measured in 22 myocardial segments per patient. In each segment, tracer uptake was expressed as a percentage of the region with the peak activity.. Under control conditions, 267 myocardial segments (55%) showed normal tetrofosmin uptake (> 70% of peak activity), 107 segments (22%) showed a moderate reduction (51-70%) and 110 segments (23%) a severe reduction (< or = 50%) in tracer uptake. Among the 110 segments with a severe reduction in tetrofosmin uptake, 20 (18%) showed increased tracer uptake > or = 10% of after nitrate administration (from 44 +/- 5% to 58 +/- 3%, p < 0.0001). The remaining 90 (82%) segments with a severe reduction in tetrofosmin uptake did not show any change after nitroglycerin administration (from 38 +/- 9% to 39 +/- 8%, p = ns).. In patients with chronic coronary artery disease and LV dysfunction, tetrofosmin cardiac SPECT associated with sublingual nitrate administration allows the detection of severely hypoperfused but still viable myocardium.

Topics: Adult; Aged; Chronic Disease; Heart; Hemodynamics; Humans; Male; Middle Aged; Myocardial Ischemia; Nitroglycerin; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Time Factors; Tomography, Emission-Computed, Single-Photon; Vasodilator Agents; Ventricular Dysfunction, Left

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

Topics: Adult; Cold Temperature; CREST Syndrome; Female; Heart; Heart Diseases; Humans; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Tomography, Emission-Computed, Single-Photon

To evaluate the effect of left ventricular (LV) size on the calculation of LV function from gated myocardial SPECT with Emory and Cedars-Sinai programs, we performed 99mTc-tetrofosmin gated SPECT on 49 patients with ischemic heart disease. End-diastolic volume (EDV), end-systolic volume (ESV), and ejection fraction (EF) were semi-automatically calculated by each program. All patients underwent left ventriculography (LVG) within 3 months before and after the SPECT study. We grouped the patients into 22 with a calculated ESV obtained from LVG of over 50 ml (group A) and 27 with an ESV value of 50 ml or below (group B). We then compared the ESV values from gated SPECT with those from LVG in each group. In group A, the ESV from both Emory and Cedars-Sinai programs similarly correlated well with those from LVG (r = 0.92 and r = 0.93, respectively), but in group B, the ESV calculated from the Cedars-Sinai program correlated less with those from LVG (r = 0.53) than those from the Emory program did (r = 0.70). The calculated LV volumes had more errors in the Cedars-Sinai program than in the Emory program, when a patient had a small heart.

Topics: Adult; Aged; Angina Pectoris; Automation; Diastole; Female; Gated Blood-Pool Imaging; Humans; Image Processing, Computer-Assisted; Male; Middle Aged; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Regression Analysis; Systole; Tomography, Emission-Computed, Single-Photon; Ventricular Function, Left

The goal of this study was to determine whether 99mTc-tetrofosmin can assess regional flow heterogeneity when injected during sustained coronary artery occlusion and to estimate the degree of myocardial salvage and viability during coronary reperfusion.. In protocol 1, 99mTc-tetrofosmin, 201 TI and microspheres were injected during total left anterior descending (LAD) coronary artery occlusion in five anesthetized open-chested dogs. Protocol 2 dogs underwent LAD occlusion for either 60 min (n = 7) or 180 min (n = 6) followed by 105 min of reperfusion. 99mTc-tetrofosmin (10 mCi), 201TI (1 mCi) and microspheres were injected 90 min after reflow. In both protocols, myocardial 99mTc-tetrofosmin and 201TI activities were quantified from regions of interest on ex vivo images and by in vitro well counting.. In protocol 1, there was a linear relationship between 201TI (r = 0.96) and 99mTc-tetrofosmin (r 0.92) activities and microsphere flow during the occlusion. In protocol 2, the LAD/left circumflex (LCx) defect count ratios for 99mTc-tetrofosmin and 201TI from images of myocardial slices were comparable in dogs undergoing either 1 or 3 h of LAD occlusion and 105 min of reperfusion. Similarly, the LAD/LCx in vitro count ratios were comparable between 201TI and 99mTc-tetrofosmin in 1 and 3 h occluded dogs, and significantly lower than the reperfusion flow when these tracers were injected. Uptake of both tracers was depressed to a greater extent in areas of severe ischemic damage.. These data suggest that administration of 99mTc-tetrofosmin during coronary occlusion accurately delineates the flow heterogeneity. When given after reperfusion, 99mTc-tetrofosmin uptake was significantly reduced in reperfused, infarcted areas and was reflective of viability and the degree of myocardial salvage in addition to reperfusion flow. These experimental studies validate the clinical use of 99mTc-tetrofosmin for assessing persistent coronary artery occlusion, and infarct size and myocardial viability after reperfusion.

Topics: Animals; Coronary Circulation; Dogs; Heart; Hemodynamics; Microspheres; Myocardial Ischemia; Myocardial Reperfusion; Myocardium; Organophosphorus Compounds; Organotechnetium Compounds; Radionuclide Imaging; Radiopharmaceuticals; Thallium Radioisotopes

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

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

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

We measured the uptake of technetium-99m tetrofosmin (99m Tc) and thallium-201 (201 TI) in areas of healed transmural myocardial infarction and in the regions of acute peri-infarction ischemia.. Anesthetised pigs with a 1-month old transmural infarction elicited by permanent ligature of the left anterior descending (LAD) coronary artery below the first branch underwent one hour of proximal LAD occlusion followed by injection of 99m Tc-tetrofosmin and 201TI either in the left atrium (GI, n= 19) or in the jugular vein (GII, n = 6). Twelve other pigs (GIII) with similar acute peri-infarction ischemia received 99m Tc-tetrofosmin and 201Tl into the left ventricle during cardiocirculatory arrest to rule out the effect of coronary collaterals. Radiotracer counting was determined in samples from normal, acute ischemic and necrotic regions.. Uptake of 99m Tc-tetrofosmin and 201 Tl was greater in the infarct scar (median % of normal tissue: 20 for 99m Tc and 8.6 for 201 Tl in GI; 22 and 15 in GII) than in acute ischemic myocardium (3.2 and 2.5 in GI; 6.4 and 3.3 in GII). Radiotracer injection in arrested hearts (GIII) depicted a similar pattern (median % of injected dose: 6.2 for 99m Tc and 10 for 201Tl in the scar; 2.3 and 4.0 in acute ischemia; 2.9 and 3.5 in normal tissue). The infarcted region showed connective tissue and lack of viable myocardium.. A 1-month old infarct scar with no viable myocardial tissue can take up significant fractions of 99mTc-tetrofosmin and 201Tl even in the absence of coronary collateral perfusion. Data suggest that the infarct scar can extract these radiotracers from the intraventricular blood.

Topics: Animals; Myocardial Infarction; Myocardial Ischemia; Myocardium; Organophosphorus Compounds; Organotechnetium Compounds; Radioisotopes; Radionuclide Imaging; Radiopharmaceuticals; Swine; Thallium Radioisotopes

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

Due to stable myocardial retention and technetium imaging characteristics, 99mTc-tetrofosmin has been considered potentially useful for acute chest pain imaging. Tetrofosmin also has favorable biokinetics with reported rapid liver clearance, 5 min poststress and 30-45 min post-rest injection. Since comparable data are not available, the effect of time on liver clearance was evaluated in patients with acute chest pain.. One hundred six patients received an intravenous injection of 25-30 mCi 99mTc-tetrofosmin to evaluate acute chest pain. SPECT imaging was performed 15-120 min after injection of the tracer. Patient images were grouped according to the time of acquisition after acute injection: 15-30 min, 31-45 min, 46-60 min, 61-90 min and > 90 min. Quantitative analysis was performed of a similar anterior projection for each patient consisting of 6 X 6-pixel region of interest over the myocardium and adjacent liver. Average counts per pixel were determined and a heart/liver (H/Li) ratio was calculated.. The mean H/Li ratio was < 1.0 for patient images acquired 15-45 min after injection, and > 1.0 for patient images acquired after 45 min. The difference was statistically significant (p < 0.05).. Quantitative analysis suggests that the optimal imaging time should be at least 45 min after the injection of 99mTc-tetrofosmin to allow adequate liver clearance before image acquisition of acute chest pain syndromes.

Topics: Aged; Angina Pectoris; Evaluation Studies as Topic; Female; Heart; Humans; Image Processing, Computer-Assisted; Injections, Intravenous; Liver; Male; Metabolic Clearance Rate; Middle Aged; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Time Factors; Tomography, Emission-Computed, Single-Photon

Simultaneous assessment of stress perfusion and rest function is possible with gated single photon emission computed tomography (SPECT) using stress injected technetium-99m (99mTc) tetrofosmin (TF). The feasibility of dipyridamole stress electrocardiographic gated myocardial SPECT (GSPECT) with TF was examined as an alternative to conventional stress/rest imaging. Fifty-one patients underwent stress GSPECT. 740 MBq of TF was administered 3 min after dipyridamole infusion. GSPECT acquisition was performed one hour after the injection. Additional rest SPECT was performed on another day only in patients with abnormal perfusion on stress images. Perfusion and thickening were analyzed visually on 17 segments of the left ventricle. Percentage of wall thickening (%WT) was also calculated in 17 segments of the polar map. Thirty-two of 51 patients (63%) had normal stress perfusion and normal rest thickening. Nineteen of 51 patients (37%) had abnormal perfusion on stress images. Among 157 abnormal perfusion segments of the 19 patients, 139 segments (89%) had thickening and the rest (11%) had no thickening. %WT was higher in the reversible segments with or without thickening. There was better agreement for the identification of normal segments and the presence of reversibility between stress GSPECT and the conventional stress/rest study in patients without previous myocardial infarction than in those with previous myocardial infarction (89% vs 79%). These results suggest that stress GSPECT may substitute for conventional stress/rest perfusion study in patients without previous myocardial infarction, allowing shorter examination time and lower cost. However, stress GSPECT does not replace the need for rest perfusion study in patients with previous myocardial infarction, because of underestimation of viability, but %WT may eliminate this underestimation.

Topics: Aged; Dipyridamole; Electrocardiography; Female; Gated Blood-Pool Imaging; Humans; Male; Middle Aged; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; 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

A 64-year-old man visited our hospital with a complaint of exertional chest discomfort. Exercise electrocardiography revealed ST segment depression in the V4-V6 leads, and exercise thallium myocardial scintigraphy demonstrated myocardial ischemia in the area of the right coronary artery, suggesting effort angina. Diagnostic coronary angiography revealed an anomalous origin of the right coronary artery from the left sinus of Valsalva and 90% organic stenosis at the proximal portion. We performed percutaneous transluminal coronary angioplasty (PTCA), but repeat PTCA was required 3 months later because of restenosis. Follow-up angiography 1 year later showed regression of the stenotic lesion to less than 50% diameter compared with the data obtained 3 months after the second PTCA. However, exercise 99mtechnetium-tetrofosmin myocardial scintigraphy disclosed obvious myocardial ischemia in the inferior region. These results suggested that the myocardial ischemia in this particular patient was caused not only by the organic stenosis but also by the anatomic anomaly which might reduce coronary blood flow during exercise. Such patients should be followed up cautiously with much more sophisticated methodology.

Topics: Angioplasty, Balloon, Coronary; Constriction, Pathologic; Coronary Vessel Anomalies; Heart; Humans; Male; Middle Aged; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Radionuclide Imaging; Sinus of Valsalva

Non-invasive assessment of ischemic heart disease requires information of both LV function and myocardial perfusion. Recently, ECG-gated myocardial SPECT with technetium-labeled radiopharma-ceuticals can provide both of them. Gated myocardial SPECT were performed in thirty-three patients with cardiac disease using a two-headed rotating gamma camera system (ADAC; VERTEX), 30-60 minutes after resting injection of 555-740 MBq of 99mTc-Tetrofosmin. Then, the SPECT data were used to determine the LV epi- and endocardial surface, and LV volume for measurement of LVEF was calculated automatically. This entire computational process required only 210 seconds per 16 frame study. Interobserver agreement of EF values obtained from gated SPECT was excellent (r = 0.996, n = 10, p < 0.01). LVEFs obtained from gated SPECT showed good correlation to those calculated from radionuclide ventriculography (MUGA) (r = 0.91, p < 0.01). In conclusion, this automatic method using gated myocardial SPECT data was considered to be useful for assessment of LV function with reproducibility.

Topics: Aged; Cardiac Volume; Electrocardiography; Endocardium; Female; Gated Blood-Pool Imaging; Heart; Humans; Male; Middle Aged; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Pericardium; Systole; Tomography, Emission-Computed, Single-Photon; Ventricular Function, Left

Myocardial perfusion scintigraphy with wall motion analysis is known to enhance accuracy in diagnosing ischemic heart disease. The purpose of this study is to determine the best method to evaluate regional wall motion in a gated planar perfusion study. Planar gated 99mTc tetrofosmin (GTF) study in two projections was performed after rest-exercise sequence SPECT studies (n = 29). To evaluate wall motion, cine-mode display, wall thickening, and inverted tetrofosmin studies including ventricular inner border tracing, segmental wall shortening and functional images were used. The results were compared with gated blood-pool (GBP) study in the same projections. In the GTF study, functional image identified asynergy significantly better than cinematic display. The best correlation between GTF and GBP studies was observed with functional images of phase and amplitude, with complete visual agreement seen in 145 of 168 (86%) segments. With quantitative analysis by means of regions of interest (n = 280), a good correlation was observed between GTF and GBP regarding regional amplitude (r = 0.78), regional phase (r = 0.84), average left ventricular phase (r = 0.91) and standard deviation of phase values (r = 0.90). The value for the count-based "ejection fraction" derived from inverted GTF showed insufficient correlation to that of the GBP study (r = 0.69). Functional imaging with myocardial perfusion imaging is a simple and effective means to evaluate ventricular asynergy. Similar diagnostic criteria to gated blood-pool imaging and comparable diagnostic accuracy are advantages of this approach.

Topics: Aged; Aged, 80 and over; Evaluation Studies as Topic; Female; Gated Blood-Pool Imaging; Heart; Heart Ventricles; Humans; Male; Middle Aged; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Tomography, Emission-Computed, Single-Photon; Ventricular Function; Ventricular Function, 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

We calculated an increase of myocardial 99mTc-tetrofosmin uptake during exercise from resting condition, which was thought to reflect coronary flow reserve, and assessed whether this method enhanced the detection of coronary artery disease (CAD). Exercise myocardial SPECT was performed using 99mTc-tetrofosmin with one-day method (exercise-rest) in 26 patients. Twenty-one patients were suspected to have ischemic heart disease and 5 were control patients. A polar map was used to evaluate the increase in counts after exercise. The parameter of % uptake increase was obtained by the ratio of exercise and resting myocardial counts. The uptake was corrected for administration dose and time decay between the exercise and rest studies. The sensitivity for detecting patients with significant coronary stenosis by visual evaluation and % uptake increase map was 60% and 90%, respectively. In 5 patients, % uptake increase map detected stenosed coronary artery lesions that could not be detected by visual analysis. We concluded that the % uptake increase map combined with conventional SPECT images enhanced the detectability of coronary artery disease and the evaluation of the degree of coronary flow reserve.

Topics: Adult; Aged; Aged, 80 and over; Exercise Test; Female; Humans; Male; Middle Aged; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon

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 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

ECG-gated dual-isotope acquisition protocol involving rest imaging with 201Tl and stress 99mTc-tetrofosmin (TF) SPECT was designed for the simultaneous assessment of rest/stress myocardial perfusion and rest ventricular systolic function. This study assessed the feasibility and diagnostic accuracy of this protocol. Forty-five patients underwent the dual-isotope SPECT protocol. Twenty minutes after resting injection of 111 MBq of 201Tl, 370 MBq of 99mTc-TF was administered at a peak exercise. The dual-isotope gated SPECT acquisition was performed 1 hour later. Then, the regional count increase rate (%WT) of 99mTc-TF from end-diastole end-systole was calculated using an automated method which was developed for quantification of regional wall thickening based on circumferential profile analysis in our laboratory. Myocardial perfusion and contractility analysis was carried out using 8 segments of left ventricle with comparison of coronary angiographical findings. The sensitivity and specificity for the detection of diseased coronary vessels (> = or 75% stenosis) were 76% and 94%, respectively. Infarcted regions showing reversible defect had significantly greater %WT as compared with those with fixed defects (63 seg; 12.7 +/- 6.1% vs. 36 seg; 8.9 +/- 7.2%, p < 0.01). In conclusion, this dual-isotope protocol has some advantages; i.e., shortening an examination time, having the exact registration of stress/rest perfusion, and simultaneous evaluation of resting regional wall thickening.

Topics: Coronary Angiography; Electrocardiography; Female; Gated Blood-Pool Imaging; Heart; Humans; Male; Middle Aged; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Thallium Radioisotopes; Tomography, Emission-Computed, Single-Photon; Ventricular Function, Left

Technetium-99m-tetrofosmin is a 99mTc-labeled perfusion tracer demonstrating promise for myocardial perfusion imaging. To determine if 99mTc-tetrofosmin tracks myocardial flow over a pathophysiologic range, the initial myocardial uptake and clearance of 99mTc-tetrofosmin relative to microsphere flow were evaluated in a canine model of ischemia during pharmacological vasodilatation.. Six open-chest dogs were subjected to complete left anterior descending coronary artery occlusion. Dogs were injected with 99mTc-tetrofosmin and radiolabeled microspheres during pharmacological stress. Coincident with radiotracer injection, dynamic planar imaging and arterial sampling were performed to assess 99mTc-tetrofosmin clearance from blood, myocardium, lung and liver. Fifteen minutes after injection, hearts were excised for well counting of myocardial 99mTc-tetrofosmin activity and flow.. Myocardial 99mTc-tetrofosmin activity correlated linearly with microsphere flow (r = 0.84). Relative 99mTc-tetrofosmin activity underestimated flow at higher flow ranges (> 2.0 ml/min/g) and overestimated flow in low flow ranges (< 0.2 ml/min/g). Technetium-99m-tetrofosmin cleared rapidly from the blood and was retained in the myocardium. Resting target-to-background activity ratios (heart:lung = 3.57 +/- 1.01; heart:liver = 0.58 +/- 0.04) were acceptable 10 min after injection.. Our experimental data support both the validity of 99mTc-tetrofosmin as a myocardial perfusion tracer and the use of early poststress 99mTc-tetrofosmin imaging for the assessment of myocardial perfusion in man.

Topics: Adenosine; Animals; Coronary Circulation; Dogs; Heart; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Radionuclide Imaging

99mTc-tetrofosmin myocardial perfusion imagings under different protocols were performed at rest and stress on the same day. In the stress/rest protocol, the exercise study was carried out first, and then the rest one followed. Eight patients were involved in the stress/rest protocol. Seven patients were examined in the reverse, rest/stress protocol. In any protocols, the injection interval was 3 hours, and injection doses in the first and second studies were 370 MBq and 740 MBq, respectively. Myocardial counts were obtained by placing region of interest over the myocardial walls in short axial SPECT images. Based on myocardial counts from the first injection and the wash-out rate of tetrofosmin, we calculated, at the second imaging, counts caused from the first injection. Approximately 20-25% of counts in the second study were found to be caused from the residual radiotracer. The residual radiotracers affected the interpretation of imagings of two patients we examined: one with marked reversible ischemia examined in the stress/rest protocol and the other with mild ischemic change examined in the rest/stress one. Our results suggested that some modifications of studies, such as the increase in the injection intervals or the reduce of the first-to-second dose ratio, might be necessary to conduct the same day protocols.

Topics: Exercise Test; Heart; Humans; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Rest; Tomography, Emission-Computed, Single-Photon

99mTc-tetrofosmin is a lipophilic, cationic diphosphine which has been developed for myocardial imaging. We examined 9 patients with ischemic heart disease including 3 angina pectoris (AP), 4 old myocardial infarction (OMI), 1 AP with OMI and 1 syndrome X. One patient was examined before and after operation. 370 MBq of 99mTc-tetrofosmin was injected during exercise and 740 MBq at rest. And 74 MBq of 201Tl myocardial exercise and redistribution scintigraphy was also performed to compare with 99mTc-tetrofosmin myocardial scintigraphy. SPECT, multiple gated SPECT and anterior planar images were obtained in all cases. We calculated percent wall thickening (%WT) using multiple gated SPECT images. There was a decreased lung uptake in 99mTc-tetrofosmin planar images compared to 201Tl myocardial scintigraphy. Liver and Biliary system uptake in 99mTc-tetrofosmin images was decreased with intake of milk. Segmental comparison of SPECT images showed an agreement in 9/10 of the segment between 201Tl and 99mTc-tetrofosmin. We could obtain excellent quality of multiple gated SPECT images in all patients. We could calculate percent wall thickening (%WT) in all patients. We conclude that 99mTc-tetrofosmin myocardial scintigraphy should provide usefulness for detection of ischemic myocardium as same as 201Tl myocardial scintigraphy, although the biologic characteristics of two agents were different. These data and excellent quality of multiple gated SPECT images suggest that 99mTc-tetrofosmin is a new 99mTc agent for evaluation of patients with ischemic heart disease.

Topics: Exercise Test; Female; Heart; Humans; Male; Middle Aged; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Thallium Radioisotopes; Tomography, Emission-Computed, Single-Photon

Myocardial perfusion imaging with Tc-99 m-1,2-bis (bis (2-ethoxyethyl) phosphino) ethane (Tc-99 m-tetrofosmin) was performed in 26 patients with ischemic heart disease (IHD) or suspected to have IHD. The agent was administered both at rest and at peak exercise. Exercise and rest studies were performed on the same day or on different days. The injected dose ranged from 296 MBq-740 MBq. Image quality was adequate for diagnosis, and was superior to that of T1-201 scintigraphy. Results from the tetrofosmin imaging corresponded well with findings of T1 scintigraphy, with a segmental concordance of 87%. Sensitivity and specificity were 70% and 93%, respectively. Our results suggested that tetrofosmin could be a promising Tc-99m labeling agent for the evaluation of myocardial perfusion.

Topics: Evaluation Studies as Topic; Humans; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Thallium Radioisotopes; Tomography, Emission-Computed, Single-Photon