sodium-pertechnetate-tc-99m and Heart-Diseases

Consecutive survivors of a first Q wave anterior myocardial infarction were studied to observe the impact of recombinant tissue-type plasminogen activator (rt-PA) therapy on the incidence and associations of left ventricular thrombus. Fifty-four patients received rt-PA within 4 hours after the onset of cardiac pain, followed by heparin infusion. Forty-four patients who did not qualify for rt-PA therapy but who were anticoagulated with heparin served as a control group. Two-dimensional echocardiography was performed in all patients on days 3 and 7 to detect thrombi and analyze wall motion. Ejection fraction was determined by radionuclide angiography in all patients on day 7. Apical thrombi were detected on day 3 in three patients (5.5%) who received rt-PA and in eight control patients (18%) (p less than 0.05). All patients with a thrombus had apical dyskinesis and 8 of 11 (73%) had an aneurysm. Of the 87 patients without thrombosis, apical dyskinesis and aneurysm were present in 42 (48%) and 11 (13%) patients, respectively (p less than 0.01). Ejection fractions and wall motion scores of patients without a thrombus were significantly better when compared with data from those with a thrombus. There were fewer patients with apical dyskinesis (17 of 54) in the group receiving rt-PA therapy compared with the control group (36 of 44) (p less than 0.01). Ejection fractions and wall motion scores were better in patients who received rt-PA compared with control subjects (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Echocardiography; Electrocardiography; Heart Diseases; Heart Ventricles; Humans; Incidence; Infusions, Intravenous; Middle Aged; Myocardial Infarction; Prospective Studies; Radionuclide Angiography; Recombinant Proteins; Sodium Pertechnetate Tc 99m; Stroke Volume; Thrombosis; Tissue Plasminogen Activator

123I-metaiodobenzylguanidine (MIBG), a tracer for sympathetic neuron integrity and function, was applied to 155 patients with various types of cardiac disease. The methods for quantification of MIBG and washout were studied as well as normal ranges. Heart-to-mediastinum average count ratio (H/M) correlated well with total heart count divided by injected activity (r = 0.60, P < 0.0001 and r = 0.72, P < 0.0001 for early and delayed images, respectively). Although as a whole left ventricular ejection fraction (LVEF) positively correlated with H/M ratio, decreased H/M ratio could be associated with normal LVEF, which may indicate that the MIBG activity was an independent variable compared with cardiac contractility. High washout rate was seen in various cardiac diseases, such as dilated cardiomyopathy, hypertrophic cardiomyopathy, ischaemic heart disease, hypertension, hypothyroidism and arrhythmia. The increased washout seems to be nonspecific to disease type, but is a common feature of damaged or failing myocardium.

Topics: 3-Iodobenzylguanidine; Erythrocytes; Gated Blood-Pool Imaging; Heart Diseases; Humans; Iodine Radioisotopes; Iodobenzenes; Middle Aged; Radionuclide Angiography; Reference Values; Sodium Pertechnetate Tc 99m; Stroke Volume; Sympatholytics; Ventricular Function, Left

A phantom was devised to validate scintigraphically determined left ventricular ejection fractions (LVEFs) and cardiac chamber volumes in the following simulated cardiac situations: normal contraction, moderately impaired left ventricular contraction, severely impaired left ventricular contraction, mitral regurgitation, and cardiomyopathy. The phantom, assembled from anatomically realistic cardiac chambers, simulated contraction and expansion using individual chamber pumps coordinated by a microcomputer. Scintigraphic studies were performed by sequential imaging of [99mTc]pertechnetate introduced into each chamber. The images were analyzed like conventional clinical studies, using both automatic and manual techniques. Scintigraphic techniques correlated with chamber volumes that were determined by weight to yield the following regression formulae: LVEF (by automatic method 1) = 1.08 x LVEF (by weight) -5.11; LVEF (by automatic method 2) = 1.00 x LVEF (by weight) -3.15; and LVEF (by manual method) = 1.04 x LVEF (by weight) -5.08 ml (Correlation coefficients greater than 0.98). The absolute left ventricular volumes (LVVs), determined by scintigraphy, correlated well with LVVs determined by weight. These correlations were performed with separations between the center of the left ventricle and the collimator varying from 5 cm to 9 cm. The regression formulae for 5, 7, and 9 cm distances were: LVV (by counts) = 0.99 x LVV (by weight) + 0.13, LVV (by counts) = 1.04 x LVV (by weight) + 9.08, LVV (by counts) = 0.88 x LVV (by weight) + 15.25, respectively. At 9 cm, slight volumetric underestimation occurred, as predicted from the work of Fearnow et al., possibly because of oversubtraction of background. Thus, this phantom provides a useful tool for validating scintigraphic cardiac blood-pool studies simulating a wide range of clinically relevant situations.

Topics: Heart; Heart Diseases; Heart Ventricles; Models, Cardiovascular; Models, Structural; Myocardial Contraction; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Stroke Volume

Volume-pressure relationship and compliance of human systemic veins were estimated quantitatively and noninvasively using radionuclide. The effect of nitroglycerin (NTG) on these parameters was examined. Plethysmography with radionuclide (RN) was performed using the occlusion method on the forearm in 56 patients with various cardiac diseases after RN angiocardiography with 99mTc-RBC. The RN counts-venous pressure curve was constructed from (1) the changes in radioactivity from region of interest on the forearm that were considered to reflect the changes in the blood volume of the forearm, and (2) the changes in the pressure of the forearm vein (fv) due to venous occlusion. The specific compliance of the forearm veins (Csp.fv; (1/V).(delta V/delta P] was obtained graphically from this curve at each patient's venous pressure (Pv). Csp.fv was 0.044 +/- 0.012 mmHg-1 in class I (mean +/- SD; n = 13), 0.033 +/- 0.007 mmHg-1 in class II (n = 30), and 0.019 +/- 0.007 mmHg-1 in class III (n = 13), of the previous NYHA classification of work tolerance. There were significant differences in Csp.fv among the three classes. The systemic venous blood volume (Vsv) was determined by subtracting the central blood volume, measured by RN-angiocardiography, from total blood volume, measured by the indicator dilution method utilizing 131I-human serum albumin. Systemic venous compliance (Csv) was calculated from Csv = Csp.fv.Vsv. The Csv was 127.2 +/- 24.8 ml.mmHg-1 (mean +/- SD) in class I, 101.1 +/- 24.1 ml.mmHg-1 in class II and 62.2 +/- 28.1 ml.mmHg-1 in class III. There were significant differences in Csv among the three classes. The class I Csv value was calculated to be 127.2 +/- 24.8 ml.mmHg-1 and the Csv/body weight was calculated to be 2.3 +/- 0.7 ml.mmHg-1.kg-1 of body weight, which was very close to the values for Csv reported previously by other investigators in animal experiments. The administration of NTG caused the RN counts - venous pressure curve to become steeper and shift upward. It increased Csv significantly in all cases.

Topics: Adult; Aged; Blood Volume; Compliance; Erythrocytes; Female; Forearm; Heart Diseases; Humans; Male; Middle Aged; Nitroglycerin; Plethysmography; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Veins; Venous Pressure

To improve the accuracy of Doppler echocardiographic indices of left ventricular filling, we derived two indices of instantaneous transmitral flow with the use of Doppler velocities and M-mode echocardiography. These indices were calculated from the product of pulsed Doppler mitral velocities and either the excursion of the anterior mitral leaflet or the separation of both mitral leaflets as measures of the changing mitral orifice area. The derived flow indices and the mitral velocities alone were compared to left ventricular filling as determined by radionuclide ventriculography in 24 patients. When compared as areas under the matched decile divisions of the derived filling sequences by linear regression analysis, the relationship for combined Doppler and M-mode versus radionuclide left ventricular filling was closer to the line of identity (slope = 0.98 and 0.94 using the anterior mitral leaflet and both mitral leaflets, respectively, both p = NS versus the line of identity) than was the relationship for mitral velocities alone versus radionuclide left ventricular filling (slope = 0.74, p less than 0.05 versus the line of identity). The instantaneous mitral volume flow indices more closely resemble the time course and shape of radionuclide left ventricular filling curves than do mitral velocities alone, and the application of these indices should assist the quantitative description by Doppler echocardiography of left ventricular filling.

Topics: Aged; Aged, 80 and over; Blood Flow Velocity; Echocardiography; Echocardiography, Doppler; Heart; Heart Diseases; Humans; Male; Middle Aged; Mitral Valve; Radionuclide Imaging; Sodium Pertechnetate Tc 99m

To investigate the relation between left ventricular chamber dynamics in humans and the quantitative analysis of the histologic and biochemical characteristics of left ventricular endomyocardial biopsy material, 15 patients with a wide range of ventricular function were studied. The pressure-volume relation was determined using simultaneous gated radionuclide angiography, echocardiography and micromanometer pressure. The derived chamber dynamics were then compared with quantitative histologic data (percent fibrosis and cell diameter) and adenosine triphosphate content measurements obtained from the left ventricular biopsy specimen obtained at the time of the pressure-volume studies. The measures of systolic function correlated linearly with high energy phosphate content. The adenosine triphosphate/protein ratio (nanomoles) was shown to parallel ejection fraction (r = 0.81), peak ejection rate (r = -0.73) and peak positive maximal rate of rise in left ventricular pressure (dP/dt) (r = 0.79). No correlation was observed between these variables and the percent fibrosis or cell diameter. Variable results were found in comparing the diastolic properties of the left ventricle with the biopsy data. In general, the high energy phosphate content correlated with measures of active relaxation, but not with the passive filling characteristics of the left ventricle. The adenosine triphosphate/protein ratio was linearly related to peak negative dP/dt (r = -0.74) and the peak filling rate (r = 0.76) but correlated less well with other measures of active and passive diastolic filling. No correlation was found between any diastolic variable and the percent fibrosis or cell diameter.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Adenosine Triphosphate; Adult; Biopsy; Cardiac Catheterization; Echocardiography; Female; Heart Diseases; Heart Ventricles; Humans; Male; Middle Aged; Myocardial Contraction; Myocardium; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Stroke Volume

Three main nuclear medicine methods are used in paediatric cardiology: sequential first-pass radionuclide imaging of the cardiac cavities, radionuclide equilibrium ventriculography and radionuclide myocardial imaging. Valuable functional information is obtained, and invasive explorations can be avoided in an ever increasing number of cases. Of particular interest is left-to-right shunt measurement which indicates that atrial septal defects must be surgically corrected when the pulmonary/systemic flows ratio (QP/QS) is above 2. This technique is also useful to evaluate the tightness of repairs in ventricular and atrial septal defects. Radionuclide studies of the right and left ventricles may detect dysfunction in one or the other cavity. The left ventricular ejection fraction is reduced in myocardiopathy an in aortic or mitral valve diseases seen at a late stage. The right ventricular function is often abnormal, notably during exercise, after repair of the tetralogy of Fallot and after atrial correction of complete transposition of the great arteries. An altered ejection fraction in patients with single ventricle is also a sign of deterioration. Right ventricular diastolic overload evaluated by radionuclide equilibrium ventriculography correlates with the QP/QS ratio value in atrial septal defects and with the inducibility of ventricular tachycardia by endocavitary pacing in repaired tetralogy of Fallot. Thallium 201 myocardial imaging provides information on myocardial ischaemia, notably that associated with congenital abnormalities of the coronary arteries. Its use had now been extended, albeit with some limitations, to the evaluation of right ventricular systolic overload. Other radionuclide techniques are being developed with new tracers: Kryton 81m for studies of the right ventricle, short-lived radionuclides for first-pass studies, Iodine 123-labelled fatty acids for myocardial imaging. More recently, some substrates, such as deoxyglucose, have been labelled with positron emitters permitting in vivo metabolic studies.

Topics: Cardiac Output; Child; Child, Preschool; Heart; Heart Defects, Congenital; Heart Diseases; Heart Ventricles; Humans; Infant; Infant, Newborn; Pulmonary Circulation; Radiation Dosage; Radioisotopes; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Thallium

Topics: Adolescent; Adult; Brain Death; Brain Diseases; Cerebrovascular Circulation; Child; Child, Preschool; Female; Heart Diseases; Humans; Image Processing, Computer-Assisted; Male; Middle Aged; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Time Factors

Topics: Heart Diseases; Humans; Scintillation Counting; Sodium Pertechnetate Tc 99m; Stroke Volume

Five studies were conducted to examine the degree of variability to be expected during the use of the non-imaging nuclear probe (BIOS Inc.) under a variety of clinical conditions. Comparison of the ejection fraction (EF) readings between the nuclear probe and a gamma camera showed good agreement, with the nuclear probe tending to underestimate lower, and overestimate higher camera EF values [mean (S.D.) difference, 0.84% (6.06)]. A comparison of two nuclear probes showed a small mean (S.D.) difference of EF readings of 0.063% (2.26). EF readings obtained in normal subjects 6 weeks apart were reproducible and differed by a mean (S.D.) of 0.23% (4.42). The administration of placebo to 10 normal subjects followed by sequential measurements for 4 h produced EF changes large enough to mimic a clinical effect, the largest hourly change observed being 5.4%, indicating the need for strict placebo control in interventional experiments. Data on four patients with heart failure showed small non-significant EF changes in the 1 h after placebo administration but a wide intra-subject range of ejection time and time to peak filling measurements. This highlights the problem of accurate, reproducible cursor placement in such patients. The nuclear probe is a portable, low cost instrument which produces accurate EF measurements when compared with the gamma camera.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Heart; Heart Diseases; Heart Function Tests; Humans; Middle Aged; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Stroke Volume

The relationship between radionuclide and thermodilution measurement of stroke volumes (SV) was investigated in 30 patients without valvular regurgitation or intracardiac shunt (group A) at rest and during exercise. Both attenuated radionuclide right ventricular (RV) and left ventricular (LV) SV measurements correlated well with the SV determined by the thermodilution method (r = 0.87 and r = 0.93, all P less than 0.001). The reliability of the radionuclide method to estimate SV was evaluated prospectively in two additional groups of patients. In 11 patients without valvular regurgitation or intracardiac shunt (group B) the radionuclide RVSV and LVSV closely approximated to thermodilution SV at rest and during exercise. In 15 patients with aortic regurgitation (group C) the radionuclide stroke volume ratio correlated well with the angiographic regurgitant fraction. Thus, both RVSV and LVSV and the severity of aortic regurgitation can be reliably measured with gated radionuclide ventriculography.

Topics: Cardiac Output; Coronary Disease; Erythrocytes; Female; Heart; Heart Diseases; Heart Failure; Humans; Male; Middle Aged; Physical Exertion; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Stroke Volume; Thermodilution

A prospective study was carried out to evaluate the role of radionuclide angiocardiography (CEF) in accessing subclinical cardiotoxicity secondary to Adriamycin (doxorubicin) therapy in 73 women with gynecologic malignancies. Based on the findings of this study, the authors conclude that all patients should have an initial CEF before Adriamycin therapy. In patients with an initial CEF of greater than or equal to 55, frequent determinations are not necessary unless there is a significant decrease from the initial CEF. Patients with low normal initial CEF or significant difference between the initial CEF and minimum CEF should have CEF studies performed at more frequent intervals. Patients who develop below normal CEF should have Adriamycin withheld and CEF should be repeated at more frequent intervals. If the CEF returns to normal Adriamycin therapy can be reinstated. Patients requiring continuation of Adriamycin past 550 mg/m2, can safely do so as long as the CEF values remain normal.

Topics: Adult; Aged; Coronary Vessels; Doxorubicin; Female; Heart Diseases; Humans; Middle Aged; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Stroke Volume

Resting multigated blood-pool studies were performed on 61 patients without arrhythmias and data were simultaneously acquired to two computer systems. Using one computer, manual ejection fraction (EF) was calculated by two trained observers. EF was also calculated from the other computer using a commercially available fully automated program; quality control (QC) images were routinely obtained to evaluate correct left-ventricular center location, background region assignment, or gross edge mispositioning. When errors were noted, the automated analysis was reprocessed with operator intervention. Forty-eight of the 61 studies (78%) produced adequate QC images. Operator redefinition of the left ventricular center and background of the 13 QC failures raised the automated success level to 92%. Correlation of the manual EF by two observers was excellent (r = 0.969). The automated EF measurements correlated well with the average observer's (r = 0.898). An improved version of software reduced the QC failures from 13 to 10. Operator assisted automated processing gave the success rate of 94%. The remaining 6% of patients required manual processing to obtain a correct ejection fraction. Our normal range for manual EF is greater than or equal to 0.50 and our corresponding normal range for this group of patients using the automated program was greater than or equal to 0.44. Based on greater than or equal to 0.44, four patients with a low manual EF had a normal automated EF. All four patients had cardiac disease but there was no evidence of abnormal cardiac function. The fully automated program provided good correlation with manual EF and can remove some of the subjectivity in manual edge determination. However, QC images must be carefully examined and the normal EF range for the automated program must be determined.

Topics: Adult; Aged; Cardiac Output; Computers; Erythrocytes; Female; Heart; Heart Diseases; Humans; Male; Middle Aged; Quality Control; Radionuclide Imaging; Reference Values; Sodium Pertechnetate Tc 99m; Stroke Volume

The mitral valve E-point septal separation (EPSS) is widely used as an M-mode echocardiographic indicator of normal or abnormal left ventricular ejection fraction. Other M-mode echocardiographic estimates of left ventricular function (eg, fractional shortening) have limited utility in the presence of abnormal septal motion. The utility of EPSS was investigated in predicting a normal or abnormal ejection fraction in 27 patients with reversed septal motion, and to compare these results with 103 patients with normal septal motion. It was determined that EPSS is valid as an indicator of the presence of a normal or abnormal ejection fraction regardless of abnormalities of septal motion.

Topics: Cardiac Output; Echocardiography; Female; Heart Diseases; Heart Septum; Heart Ventricles; Humans; Male; Middle Aged; Mitral Valve; Radionuclide Imaging; Retrospective Studies; Sodium Pertechnetate Tc 99m; Stroke Volume

Gold-195m, a radionuclide with a short half life (30.5 s) was used to quantify left to right intracardiac shunts. The results of this method were compared with those obtained with technetium-99m, a method that was validated against oximetry. In five patients the pulmonary to systemic flow ratio (greater than 3:1) obtained by both radionuclides indicated that the level of shunting was too high to be measured accurately. In one patient fragmentation of the bolus meant that no satisfactory gamma fit could be obtained. In the remaining 16 patients there was no significant difference between two successive 195mAu studies. The agreement between 99mTc results and 195mAu results was excellent. Oxygen administration, straight leg raising exercise, and the use of oblique projections did not affect the values of the pulmonary to systemic flow ratio. The technique of quantification of intracardiac shunts by 195mAu gives reproducible and accurate results and the low radiation dose means that it is suitable for use in children with suspected left to right shunts.

Topics: Adolescent; Adult; Blood Flow Velocity; Child; Gold Radioisotopes; Heart Diseases; Humans; Middle Aged; Oximetry; Radiation Dosage; Radionuclide Imaging; Sodium Pertechnetate Tc 99m

Forty-one patients (25 male, 16 female) were studied by RNCA in our institution. There were 42 rest studies and 24 stress studies (66 studies total). Sixteen patients were normal, 15 had ASHD, seven had a cardiomyopathy, and three had left-sided valvular regurgitation. Each study was preprocessed using both the standard nine-point smoothing method and Fourier filtering. Amplitude and phase images were also generated. Both preprocessing methods were compared with respect to image quality, border definition, reliability and reproducibility of the LVEF, and cine wall motion interpretation. Image quality and border definition were judged superior by the consensus of two independent observers in 65 of 66 studies (98%) using Fourier filtered data. The LVEF differed between the two processes by greater than .05 in 17 of 66 studies (26%) including five studies in which the LVEF could not be determined using nine-point smoothed data. LV wall motion was normal by both techniques in all control patients by cine analysis. However, cine wall motion analysis using Fourier filtered data demonstrated additional abnormalities in 17 of 25 studies (68%) in the ASHD group, including three uninterpretable studies using nine-point smoothed data. In the cardiomyopathy/valvular heart disease group, ten of 18 studies (56%) had additional wall motion abnormalities using Fourier filtered data (including four uninterpretable studies using nine-point smoothed data). We conclude that Fourier filtering is superior to the nine-point smooth preprocessing method now in general use in terms of image quality, border definition, generation of an LVEF, and cine wall motion analysis. The advent of the array processor makes routine preprocessing by Fourier filtering a feasible technologic advance in the development of the RNCA study.

Topics: Adult; Aged; Angina Pectoris; Cardiomyopathy, Dilated; Coronary Disease; Female; Filtration; Fourier Analysis; Heart; Heart Diseases; Heart Valve Diseases; Humans; Male; Middle Aged; Myocardial Contraction; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Technetium; Tin Polyphosphates

Topics: Coronary Disease; Heart Diseases; Heart Function Tests; Humans; Radioisotope Dilution Technique; Radionuclide Imaging; Sodium Pertechnetate Tc 99m

Electrocardiographic gating provides an alternative method of acquiring first pass radionuclide ventriculograms from both ventricles. This report details the methods of acquisition and analysis, provides validation and reproducibility data, and describes applications of gated first pass radionuclide ventriculography using a count-based method. Left ventricular ejection fractions measured by gated first pass were correlated quite closely with gated blood pool ventriculography (n = 43; r = 0.95) but less well with contrast angiography (n = 23; r = 0.72). The right ventricular ejection fractions measured by gated first pass compared favorably with gated blood pool ventriculography (n = 32; r = 0.93). When one observer processed the images two times, the reproducibilities of RVEF (n = 10; r = 0.99) and LVEF (n = 10; r = 0.88) were excellent. Similarly, when two observers processed the images independently, the reproducibilities of RVEF (n = 11; r = 0.99) and LVEF (n = 11; r = 0.98) were excellent. The first pass studies were obtained in a right anterior obliquity, which provided the best atrioventricular chamber separation and provided a different view of global ventricular function and segmental wall motion from that provided by the standard blood pool views.

Topics: Adolescent; Adult; Aged; Cardiomyopathies; Female; Heart Diseases; Heart Valve Diseases; Humans; Male; Methods; Middle Aged; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Stroke Volume

Although equilibrium radionuclide angiographic measurement of right ventricular ejection fraction (RVEF) has been validated in patients with coronary artery disease, the accuracy of this technique has not been demonstrated in patients with other cardiac diseases which may result in RV pressure and/or volume overload. The accuracy of three methods of equilibrium radionuclide analysis for measuring RVEF was compared in several subgroups of patients with a variety of cardiac diseases, including congenital and valvular heart disease, cor pulmonale, and cardiomyopathy. It was concluded that RVEF may be accurately derived by equilibrium radionuclide ventriculography in patients with a wide variety of cardiac diseases, including those resulting in RV volume and/or pressure overload. Accuracy varies depending on analysis method and the nature of the hemodynamic derangement.

Topics: Adult; Aged; Cardiac Output; Female; Heart Diseases; Humans; Male; Methods; Middle Aged; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Stroke Volume

The phase and amplitude images derived from multiple gated blood pool studies of the heart have been used to aid the delineation of the boundary of the left ventricle. The results of left ventricular ejection fraction (LVEF) using this method have been compared with those obtained using edge detection algorithms, dual region of interest techniques, and x-ray contrast ventriculography, in a series of patients with well documented left ventricular wall motion. The results indicate that the sole use of phase and amplitude images does not improve the correlation or accuracy of LVEF estimation in relation to those obtained by x-ray contrast ventriculography, and that the dual region of interest technique is likely to remain the preferred method.

Topics: Adult; Aged; Erythrocytes; Female; Heart Diseases; Heart Ventricles; Humans; Male; Middle Aged; Radiography; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Stroke Volume

A method was developed for determining the ratio of cardiopulmonary blood volume to stroke volume, in horses. The radioisotope 99 Tc (technetium 99m pertechnetate) was injected into the jugular vein as a bolus, which was then detected in the right and left ventricles consecutively by a scanning device consisting of a Na I crystal, a collimator, an amplifier and a discriminator. The radiocardiogram (RCG) and the ECG were recorded simultaneously by a two-channel writing device. The ratio of cardiopulmonary blood volume to stroke volume (cardiopulmonary flow index = CPFI) was then determined from the RCG and ECG tracings. Five categories of horses were examined, viz. Thoroughbreds in training, showjumpers in training, horses not in training, horses with cardiovascular disease and horses with chronic lung disease. The mean CPFI of the above categories were respectively 7.0 +/- 0.39, 7.3 +/- 0.45, 6.7 +/- 0.61, 9.8 +/- 1.30 and 6.2 +/- 0.47. The mean CPFI of the subjects with heart disease was significantly greater than the mean values of the other four categories (P less than 0.001). It was concluded that the CPFI was a reproducible physiological parameter in horses and that the value was significantly increased in our series of subjects with heart disease.

Topics: Animals; Blood Volume; Blood Volume Determination; Cardiac Output; Cardiac Volume; Coronary Circulation; Heart; Heart Diseases; Horse Diseases; Horses; Male; Physical Exertion; Pulmonary Circulation; Radionuclide Imaging; Reference Values; Sodium Pertechnetate Tc 99m; Stroke Volume

Topics: Cardiac Output; Cardiomyopathies; Coronary Circulation; Coronary Disease; Coronary Vessels; Heart; Heart Diseases; Heart Valve Diseases; Heart Ventricles; Humans; International Cooperation; Lung Diseases, Obstructive; Myocardial Infarction; Perfusion; Quality Control; Radionuclide Imaging; Reference Values; Societies, Medical; Sodium Pertechnetate Tc 99m; Terminology as Topic; Tomography, Emission-Computed; World Health Organization

A mathematical model is presented for the dynamics of a bolus of technetium-99m-labeled red blood cells through the left ventricle. It is used to correct for attenuation the count rate observed over the left ventricle during a conventional gated blood-pool study. The left-ventricular volumes are calculated from the corrected count rates and expressed as a percentage of total blood volume, or in absolute terms if a blood sample is obtained. The procedure is applied to a number of patients with nonvalvular cardiac disease. Cardiac volumes determined by the method are found to correlate well (r = 0.98) with those determined by contrast left ventriculography. The method is simple, requires no special equipment, and can be applied with existing computer software.

Topics: Adult; Aged; Cardiac Output; Erythrocytes; Female; Heart Diseases; Heart Ventricles; Humans; Male; Mathematics; Middle Aged; Models, Biological; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Stroke Volume; Technetium

Gold 195m (Au-195m) has a half-life of 30.5 sec and can be produced at the bedside from the parent mercury-195m (T 1/2 = 41.6 hr). The generator produced sterile pyrogen-free Au-195m with mercury breakthrough of 0.75 +/- 0.09 (s.e.m.) muCi per mCi of Au-195m. Approximately 20 to 25 mCi of Au-195m was produced per elution from a generator containing 155 mCi of Hg-195m. We compared first-pass resting Tc-99m angiograms with Au-195m angiograms in 28 patients. The correlation coefficient between the two studies was 0.92 over an ejection-fraction range from 0.22 to 0.83. In addition, we tested the reproducibility of Au-195m first-pass angiograms by performing two studies 3 min apart. In 25 patients with ejection fractions ranging from 0.20 to 0.78, the correlation coefficient between such pairs was 0.93. The nuclide is reliably and reproducibly produced, and its short half-life allows the performance of background-free sequential first-transit studies with unusually low radiation exposure to the patient.

Topics: Gold Radioisotopes; Half-Life; Heart Diseases; Heart Ventricles; Humans; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Stroke Volume; Technetium; Technology, Radiologic

First pass radionuclide angiocardiography was utilized to calculate right and left ventricular ejection fraction in 74 infants and children. For the synchronization of radionuclide imaging with the cardiac cycle, the peaks and valleys of corrected ventricular time activity curve were adopted as the time reference points instead of R wave of electrocardiogram. Left ventricular ejection fractions obtained by the radionuclide technique correlated well with those derived from the contrast angiographic technique (r = 0.90), but right ventricular ejection fractions correlated less well (r = 0.74). This noninvasive technique appeared useful for evaluation of right and left ventricular ejection fraction.

Topics: Aortic Valve Insufficiency; Aortic Valve Stenosis; Cardiac Output; Cardiomyopathies; Child; Child, Preschool; Female; Heart Defects, Congenital; Heart Diseases; Humans; Infant; Male; Mitral Valve Insufficiency; Mucocutaneous Lymph Node Syndrome; Pulmonary Valve Insufficiency; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Stroke Volume; Syndrome; Technetium

The application of an edge detection algorithm (EDA) in defining the boundary of the left ventricle (LV) in multiple gated (MG) cardiac studies has been assessed by comparison of the left ventricular ejection fraction (LVEF) derived from X-ray contrast ventriculography (CV) in a series of patients. The results demonstrate good correlation between methods irrespective of the projection and LV status when an EDA is used, such that the correlation in anterior and left anterior oblique (45 degrees) views is 0.91 and 0.86 respectively.

Topics: Adult; Aged; Cardiac Output; Contrast Media; Female; Heart; Heart Diseases; Heart Ventricles; Humans; Male; Mathematics; Middle Aged; Radiography; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Stroke Volume; Technetium

A technique is presented for producing functional images derived from equilibrium gated blood pool studies as a means of diagnosing cardiac disease. These functional images are based on characteristics associated with the time variation of the count rate (the time domain) at each point of the image matrix rather than on the Fourier transform of the time-activity curve (the frequency domain) which has gained recent attention. As examples of this method, we present images which display the statistical variance of the time-activity curve at each pixel, corrected for the expected contribution due to random statistical fluctuation, and images which display the time at which each pixel reaches its minimum count value. Variance and time-to-minimum images are comparable to Fourier amplitude and phase images, respectively, and have been found to be useful in facilitating the diagnosis of wall motion abnormalities. A major advantage of time-domain analysis is the wide variety of features of potential clinical significance which may be investigated.

Topics: Fourier Analysis; Heart; Heart Diseases; Humans; Image Enhancement; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Technetium; Time Factors

Right ventricular ejection fraction (RVEF) was determine in 26 patients using the first pass radionuclide angiocardiography with 133Xe and 99Tcm as tracers. A good correlation (r = 0.88) was found. Duplicate determinations in 13 patients with 133Xe showed good reproducibility, the absolute value for the standard error of a single determination being 2.6% and the coefficient of variation 5.7%. In a reference group of 17 individuals RVEF was 49 +/- 5% (range 42-61%). It is concluded that 133Xe can be used for RVEF determinations. Due to the rapid elimination and the low radiation dose 133Xe is preferable when repeated determinations of RVEF are desired.

Topics: Adult; Cardiac Output; Heart; Heart Diseases; Heart Ventricles; Humans; Lung Diseases; Middle Aged; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Stroke Volume; Technetium; Xenon Radioisotopes

Quantitative radionuclide angiocardiography (QRAC) was performed with and without deconvolution analysis (DA) in 87 children with various heart disorders. QRAC shunt quantitation was possible without DA in 70% of the cases and with DA in 95%. Among 21 patients with prolonged bolus injections, quantitation of the shunt was possible in 52% of the cases without DA an in all cases with DA. Correlation between oximetry and QRAC with DA was better than between oximetry and QRAC without DA. It is concluded that QRAC with DA is a more reliable, noninvasive means for detection and quantitation of left-to-right cardiac shunts than QRAC without DA.

Topics: Adolescent; Cardiac Catheterization; Child; Child, Preschool; Evaluation Studies as Topic; Heart Diseases; Heart Septal Defects; Humans; Infant; Infant, Newborn; Injections, Intravenous; Mathematics; Oximetry; Pulmonary Circulation; Radioisotope Dilution Technique; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Technetium