Right ventricular ejection fraction in patients with acute anterior and inferior myocardial infarction assessed by radionuclide angiography

Recovery of right ventricular function following repair of acute ventricular septal defect

Ventricular septal defect is a serious complication of acute myocardial infarction with a high mortality rate. Right ventricular dysfunction, which frequently accompanies septal defect, can be due to several etiologies. We describe two cases of septal defect following infarction, with sequential studies of right and left ventricular function. Right ventricular infarction was found in both patients. Postoperatively, the right ventricular ejection fraction improved significantly. The pathophysiology and expectation for recovery are discussed.

Radionuclide assessment of right ventricular ejection fraction: a comparison of first pass studies with 133Xe and 99Tcm

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.

The role of right ventricular systolic dysfunction and elevated intrapericardial pressure in the genesis of low output in experimental right ventricular infarction

To elucidate the pathophysiology of severe right ventricular infarction (RVI), isolated RVI was produced in 15 dogs with the pericardium intact or open. After RVI in dogs with the pericardium intact, RV systolic pressure decreased by 27%, aortic pressure by 29% and cardiac output by 34%. RV transmural pressure, RV end-diastolic size and intrapericardial pressure increased, left ventricular transmural pressure and end-diastolic size decreased and the diastolic pressures equalized. Pericardiotomy after RVI resulted in increased ventricular transmural pressures and diastolic size, improved cardiac output and resolution of equalized diastolic pressures. RVI in dogs with the pericardium open resulted in similar changes, but of lesser magnitude and without equalization of diastolic pressures. These results indicate that reduced left ventricular preload due to impaired RV systolic function contributes to low cardiac output in RVI. Elevated intra-pericardial pressure further reduced left ventricular preload and produces equal diastolic pressures.

Hemodynamic correlates of right ventricular ejection fraction measured with gated radionuclide angiography

Right ventricular function was studied in 60 patients with equilibrium gated radionuclide angiography. The mean (+/- standard deviation) right ventricular ejection fraction in 20 normal subjects was 53 +/- 6 percent, a value in agreement with previous data from both radionuclide and contrast angiographic studies. This value was similar (55 +/- 7 percent) in 11 patients with coronary artery disease but normal left ventricular function. Radionuclide measurements of right ventricular ejection fraction were correlated with right heart hemodynamics. There was a significant negative linear correlation between right ventricular ejection fraction and mean pulmonary arterial pressure (r = -0.82) and between right ventricular ejection fraction and right ventricular end-diastolic pressure (4 = -0.67). Furthermore, patients with elevated right ventricular end-diastolic pressure and mean pulmonary arterial pressure had a more severely depressed ejection fraction than did those with an elevated mean pulmonary arterial pressure alone. Thus, an abnormal value for right ventricular ejection fraction by gated radionuclide angiography in the absence of primary right ventricular volume overload suggests abnormal right heart pressures, whereas a normal value excludes severe pulmonary arterial hypertension or an elevated right ventricular end-diastolic pressure.

Right Ventricular function in aortic and mitral valve disease

Radionuclide ventriculography of the right heart was performed in 56 patients within two weeks of cardiac catheterization using a gated first-pass technique. Thirteen patient served as normal controls, and 43 patients had severe aortic or mitral valve disease or both, 35 of whom subsequently underwent valve surgery. Right ventricular ejection fraction (RVEF) and the presence of central venous reflux was determined and related to catheterization findings. In normal patients, RVEF was 60 plus or minus 7 percent (mean plus or minus 1 SD). In patients with valvular disease, the RVEF was below the normal range in only 2/14 (14 per cent) when right ventricular peak systolic pressures were less than 50 mm Hg, compared with 16/29 (55 percent) with an RVEF below normal when right ventricular peak systolic pressures greater than 50 mm Hg (P less than .05). In contrast, there was no relation of right ventricular ejection fraction to ventricular filling pressure in valvular heart disease patients. There was no difference in early postoperative course in patients with normal or reduced ejection fraction. Central venous systolic reflux was not presented in normal patients, but was present in 3/12 (25 percent) and 22/25 (88 percent); P less than 0.1) of patients with right ventricular systolic pressures below and above 55 mm Hg, respectively, including all ten patients with documented tricuspid regurgitation. Radionuclide assessment of right ventricular function in patients with aortic or mitral valve disease or both provides information that cannot be inferred from right-sided pressure measurements.

Noninvasive radiographic assessment of cardiovascular function in acute and chronic respiratory failure

Noninvasive radiographic techniques have provided a means of studying the natural history and pathogenesis of cardiovascular performance in acute and chronic respiratory failure. Chest radiography, radionuclide angiocardiography and thallium-201 imaging, and M mode and cross-sectional echocardiography have been employed. Each of these techniques has specific uses, attributes and limitations. For example, measurement of descending pulmonary arterial diameters on the plain chest radiograph allows determination of the presence or absence of pulmonary arterial hypertension. Right and left ventricular performance can be evaluated at rest and during exercise using radionuclide angiocardiography. The biventricular response to exercise and to therapeutic interventions also can be assessed with this approach. Evaluation of the pulmonary valve echogram and echocardiographic right ventricular dimensions have been shown to reflect right ventricular hemodynamics and size. Each of these noninvasive techniques has been applied to the study of patients with respiratory failure and has provided important physiologic data.

Intravenous xenon- 133 for the determination of radionuclide first pass right ventricular ejection fraction

The use of intravenous xenon- 133 for determination of radionuclide first pass right ventricular ejection fraction is described. First pass determinations of right ventricular ejection fraction were made with both xenon- 133 and technetium-99m in 13 subjects (15 right ventricular ejection fraction determinations); results obtained with xenon- 133 show an excellent correlation (r = 0.98, p less than 0.002) with results obtained using technetium-99m. Because of rapid pulmonary elimination of xenon- 133 from the body, the use of this radioisotope allows multiple first pass right ventricular ejection fraction determinations within a short period of time, without significant radiation exposure for the patient.

A report of Uhl's disease in identical adult twins: evaluation of right ventricular dysfunction with echocardiography and nuclear angiography

The first example of Uhl's disease affecting identical adult twins is reported, offering support for the contention that a congenital developmental defect or hereditable tendency is the responsible cause. In one case, echocardiography and nuclear angiography proved to be valuable in making the diagnosis. Uhl's disease in the adult should be suspected among cases of isolated right ventricular enlargement and failure complicated by ventricular dysrhythmias. The diagnosis may be made using a combination of noninvasive tests, obviating the need for cardiac catheterization.

Monitoring cardiac function with nuclear techniques

Noninvasive imaging with radioactive tracers has become widely used since its introduction in the early 1970s. Improvements continue to be made in the techniques and the clinical applications. Much of the information provided by these techniques is new. The first transit studies are used mainly in the evaluation of pulmonary transit time, detection of intracardiac shunting, evaluation of right ventricular function, measurement of ejection fraction and detection of wall motion abnormalities at rest and after exercise. The gated blood pool study is found to be most useful in assessment of global left ventricular function, regional wall motion, valve regurgitation and right ventricular function. The techniques of nuclear cardiac imaging are noninvasive, simple, successfully performed in almost 100 percent of cases. They are easy to interpret, able to be quantified and able to be almost totally automated. Their use is likely to become more widespread in the future.

Angiotensin infusion effects on left ventricular function. Assessment in normal subjects and in patients with coronary disease

Radionuclide multigating of the cardiac cycle was employed to assess effects of angiotensin infusion on left ventricular function. In six normal subjects, angiotensin infusion decreased heart rate (HR) from 72 +/- SEM 2 to 57 +/- 2 beats/min (P less than 0.001); while systolic blood pressure (BP) increased from 119 +/- 2 to 178 +/- 1 mm Hg (P less than 0.001), and ejection fraction (EF) declined from 58 +/- 1 to 47 +/- 2 percent (P less than 0.05). In contrast, in 11 normal subjects, supine exercise increased HR and systolic BP by 55 and 49 percent, whereas EF increased from 64 +/- 1 to 71 +/- 1 (P less than 0.001). In ten patients with CAD, angiotensin infusion produced no change in HR, increased systolic BP by 34 percent, and decreased EF by 11 percent. Angiotensin infusion induced left ventricular depression in normal subjects and in patients with CAD. It cannot substitute for exercise in intervention radionuclide ventriculography.

Right and left ventricular dysfunction in patients with chronic obstructive lung disease. Assessment by first-pass radionuclide angiography

To evaluate the relationship between right and left ventricular function in patients with obstructive lund disease, we studied 10 normal subjects (group 1) and 37 patients with chronic obstructive pulmonary disease by first pass radionuclide angiography. These 37 patients were divided into three groups: nine with mild chronic obstructive pulmonary disease (group 2), 20 with severe chronic obstructive pulmonary disease (group 3) and eight with severe chronic obstructive pulmonary disease and primary left ventricular disease (group 4). In each subject right ventricular ejection fraction (RVEF), left ventricular ejection fraction (LVEF) and ejection fraction during first third of systole (first third LVEF) were calculated. (For table: see text.) p less than 0.05 versus 1. All subjects in group 2 had normal left ventricular and right ventricular function. In group 3, 11 of 10 (55 per cent) had a low RVEF and three of 20 (15 per cent) a low LVEF. However eight of 20 in this group (40 per cent) had a depressed first-third LVEF. The correlation between decline in RVEF and first-third LVEF was good r = 0.73. We conclude that (1) certain indices of early systolic left ventricular ejection are abnormal in many patients with chronic obstructive pulmonary disease and correlate with the decline in right ventricular function; (2) this is not seen in patients with mild chronic obstructive pulmonary disease and is worse in patients with underlying left-sided heart disease.

Clinical setting and prognostic significance of high degree atrioventricular block in acute inferior myocardial infarction: a study of 144 patients

High degree AV block occurred in 144 of 843 patients consecutively admitted because of acute inferior myocardial infarction and was associated with more extensive myocardial damage and a higher mortality rate, as compared to those without AV block. Patients with power failure at the time of appearance of high degree AV block and a ventricular rate of less than 50 per minute, seemed to profit from pacemaker therapy. By contrast in patients with power failure and a ventricular rate of more than 50 per minute, pacemaker insertion did not affect immediate prognosis.

Radionuclide wall motion study and ejection fraction in clinical practice

Assessment of ventricular function is important in diagnosis and as a predictor of survival in many cardiopulmonary disorders, and analysis of ventricular function is one of the oldest applications of radioactive tracers in medicine. A sequence of parallel developments in instrumentation, radiopharmaceuticals, and nuclear medicine computers has allowed implementation of accurate, sensitive, noninvasive techniques for analysis of both right and left ventricular function. Techniques, indications, applications, and information that can be obtained are discussed.

Complimentary roles of cardiac ultrasound and cardiovascular nuclear medicine

This review is directed at the clinically useful highlights of ultrasound and radionuclide testing in adults with coronary and valvular heart disease, intracardiac shunts, and hypertrophic and congestive cardiomyopathies. As a clinical toto, the radionuclide procedures are currently more useful than ultrasound examination in evaluating patients with known or suspected coronary artery disease. This includes both primary diagnosis and the more accurate estimation of left ventricular function in the presence of segmental asynergy. In patients with valvular disease, the radionuclide procedures are only indirectly useful, while the ultrasound examination is more often diagnostic. These two techniques are complimentary to one another in their ability to noninvasively evaluate and monitor both chamber size and ventricular function in virtually all patients. Recent research involving noninvasive ventricular imaging during physiologic and pharmacologic intervention holds promise for a more sophisticated noninvasive approach to patient management.

Response of right ventricular ejection fraction to upright bicycle exercise in coronary artery disease

The right ventricular (RV) response to exercise was assessed in 32 patients with angiographically documented coronary artery disease and in 14 normal controls without cardiopulmonary disease. The relationships between exercise RV reserve, exercise left ventricular (LV) reserve, and the presence of proximal right coronary stenosis were also evaluated. RV and LV ejection fractions were determined using first-pass radionuclide angiocardiograms. The normal response to exercise was at least a 5% absolute increase in RV and LV ejection fractions. In the group with coronary artery disease, RV ejection fraction either decreased or remained the same with exercise (abnormal exercise RV reserve) in 19 of 32 patients. LV exercise reserve was abnormal in 26 of 32 patients. All 19 patients with abnormal exercise RV reserve had abnormal exercise LV reserve, and all six patients with normal LV reserve had normal RV reserve. There was a significant linear relationship between the direction and magnitude of change from rest to exercise of LV ejection fraction and RV ejection fraction (r = 0.77). In contrast, the RV response to exercise was not primarily dependent upon the presence or absence of proximal right coronary stenosis. These data suggest that abnormal exercise RV reserve occurs frequently in coronary artery disease and that the concomitant LV response to exercise appears to be its major determinant.

Role of right ventricular infarction in cardiogenic shock associated with inferior myocardial infarction

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Cardiovascular nuclear medicine: an overview

Some of the available cardiovascular nuclear medicine methods are incompletely validated, and others are incompletely developed. They are, however, of very great potential in diagnostic cardiology, and in patient management. A new era of clinical research and acute care monitoring has been opened by serial, noninvasive, hemodynamic measurements of right ventricular as well as left ventricular function. Stress testing has become more specific, and should, with future developments, become more specific, and should, with future developments, become more sensitive, using radionuclide procedures. Serious quality control and validation questions concerning thallium stress testing must be addressed. Intracoronary injection of radiogases has great potential, although minimal present application. Emission computerized tomography will be an important research tool. Compartmental analysis modeling of first pass tracer injections has much to offer, but is not yet validated. Present growth rate of these procedures is very rapid. Fully developed, cardiovascular nuclear medicine may become the largest component of clinical nuclear medicine practice.

First-pass radionuclide assessment of right and left ventricular performance in patients with cardiac and pulmonary disease

First-pass radionuclide angiocardiography allows noninvasive determination of right and left ventricular performance from a single study. Analysis is made from the high frequency components of the regional radionuclide time-activity curves. Both regional and global ventricular performance can be assessed at rest and during exercise. Sequential studies can be performed to evaluate therapeutic interventions. This technique has been applied in a broad spectrum of patients with cardiac and pulmonary disease and has been shown to have major clinical impact.

Instrumentation and data processing in cardiovascular nuclear medicine: evaluation of ventricular function

Cardiovascular nuclear medicine encompasses a variety of clinical procedures. Some of these procedures place demands on the imaging and data processing equipment that far exceeds those associated with other nuclear medicine procedures. This paper is devoted to an evaluation of the imaging and data processing requirements for two of the more demanding studies in cardiovascular nuclear medicine--first transit and gated equilibrium measurement of ventricular function. Imaging instrumentation and collimation, computer system hardware, and computer acquisition and analysis software are each treated as they apply to these procedures.