Left ventricular mass regression after aortic valve replacement measured by ultrafast computed tomography.

Left ventricular mass and function were measured using ultrafast computed tomography, and were correlated with clinical status in 17 patients with aortic stenosis and/or insufficiency undergoing aortic valve replacement or balloon valvuloplasty. Wall mass was 159 +/- 38 gm/m2 initially, decreased 25% to 116 +/- 29 gm/m2 at 4 month (p less than 0.001), and decreased a total of 34% to 105 +/- 33 gm/m2 at 8 months after valve repair. By 8 months not only was the mean wall mass within the normal range, but only three patients retained abnormal hypertrophy. Ejection fraction increased 8% (p = 0.06). Clinical function improved in all patients, with only three patients remaining outside of New York Heart Association functional class 1 at 8 months. Regression of ventricular mass into the normal range correlated with attainment of class 1 functional status (p less than 0.02), despite a lack of increase of ejection fraction. The single patient followed for 8 months after valvuloplasty had minor wall mass regression and minor clinical improvement.

The relationship between left ventricular systolic function and congestive heart failure diagnosed by clinical criteria.

There is no uniformly accepted clinical definition for congestive heart failure (CHF), although criteria have been published by various groups. There is also no reference standard for CHF, although left ventricular ejection fraction (LVEF) gives a quantitative assessment of systolic function and is useful in predicting prognosis. To determine the relationship between LVEF and clinically diagnosed CHF, we compared resting LVEF determined by radionuclide ventriculography with diagnosis of CHF by clinical criteria in 407 patients, based on clinical data collected by a cardiology fellow. Of 153 patients with a low LVEF (less than or equal to 0.40), 30 (20%) met none of the criteria for CHF. Conversely, of 204 patients with normal LVEF (greater than or equal to 0.50), 105 (51%) met at least one of the criteria. We conclude that different criteria for CHF will have varying utility depending on the population being examined, and that a combination of clinical features and an objective measure of cardiac performance is needed to diagnose CHF.

Systolic and diastolic performance in normal human subjects as measured by ultrafast computed tomography.

Ultrafast computed tomography (ultrafast-CT) is a minimally invasive imaging modality with very short acquisition time and excellent anatomic definition. It shows promise of providing precise measurement of right and left ventricular volumes, left ventricular mass, and left ventricular diastolic function with a single test. We expand on the knowledge regarding normal humans by studying ten normal volunteers in the short axis. Cardiac volumes and mass (mean +/- 1 S.D.) were as follows: 1) left ventricle: end-diastolic volume index (ml/m2) = 61 +/- 15, end-systolic volume index (ml/m2) = 19 +/- 7, stroke volume index (ml/m2) = 43 +/- 9, cardiac index (liters/min/m2) = 2.7 +/- .5, ejection fraction (%) = 70 +/- 7, end-diastolic mass (g/m2) = 95 +/- 15; 2) right ventricle: end-diastolic volume index (ml/m2) = 76 +/- 19, end-systolic volume index (ml/m2) = 35 +/- 13, stroke volume index (ml/m2) = 40 +/- 8, cardiac index (liters/min/m2) = 2.6 +/- .5, ejection fraction (%) = 55 +/- 6. Stroke volume index differed by 1.6 +/- 2.0 ml/m2 between ventricles. Measurement of global and segmental left ventricular diastolic function revealed: 1) Peak filling rate (end-diastolic volumes/second): global = 2.29 +/- .40, base = 1.78 +/- .49, midventricle = 2.49 +/- .57, apex = 3.13 +/- .39 (P less than .001, base vs. apex; P less than .01, base vs. midventricle and midventricle vs. apex); 2) time to peak filling rate (msec): global = 193 +/- 24, base = 192 +/- 20, midventricle = 194 +/- 26, apex = 190 +/- 19 (P = NS between levels).(ABSTRACT TRUNCATED AT 250 WORDS)

The clinical use of nuclear exercise tests.

In the mid-1970s, after decades of clinical use, the utility of electrocardiographic exercise testing for the evaluation of patients with suspected ischemic heart disease was critically examined and questioned. Concurrent with this critique, two sophisticated, more expensive and powerful "nuclear" exercise tests were introduced sequentially for clinical use: myocardial perfusion imaging with thallium-201 and radionuclide ventriculography with technetium 99m. The published indications for the two tests are similar, and both have been shown to offer advantages over ECG stress testing in selected populations. However, few data are available regarding the comparative utility of thallium versus ventriculographic imaging. As part of a prospective study to assess the efficacy of cardiovascular nuclear medicine studies, we undertook the present analysis to assess the clinical evolution of these tests and to elucidate factors responsible for clinicians' choice for the often competing examinations. The study examined 213 consecutive patient referrals for thallium scintigraphy and 183 referrals for ventriculography, ranging from patients with no symptoms or highly non-specific chest pain syndromes (21% of referrals) to patients with proven coronary disease (28% of the referrals). Twenty-one percent of patients were referred to confirm the clinical impression that the patient did not have coronary disease, 40% to confirm its presence, and 37% to determine its severity. Analyses were undertaken to determine the factors that dictated a preference for thallium scintigraphy rather than ventriculography; only the physician's intent in testing and level of training were significant predictors for a particular nuclear test.

Sex bias in considering coronary bypass surgery.

Cardiovascular nuclear medicine exercise studies may serve as a screening method to be used in making decisions to refer patients for catheterization and coronary artery bypass surgery. In a study of 390 patients consecutively referred for nuclear exercise testing, abnormal results found in 31% of the women and in 64% of the men affected physicians' decisions to recommend catheterization in men only; 4% of the women with abnormal radionuclide scans were referred for catheterization compared with 40% of the men (p less than 0.001). this 10:1 ratio was independent of age. A multiple logistic regression analysis that controlled for age, previous myocardial infarction, presence of typical and atypical angina, and abnormal test results yielded an odds ratio of 6.3 for men. The male-to-female ratio of patients with coronary artery disease given abnormal results of a cardiovascular nuclear scan is only 2:1. Thus, the sex differential in decisions to refer patients for cardiac catheterization cannot be explained entirely by differences in the sensitivity of tests or the rates of coronary artery disease; it also cannot be explained by differential benefits from surgery. These findings raise the question of whether coronary artery bypass surgery is underused in women.

Nuclear scans: a clinical decision making tool that reduces the need for cardiac catheterization.

We have assessed the impact of cardiovascular nuclear medicine studies (CVNMS) on physicians' decisions to send patients with suspected ischemic heart disease (N = 439) on to cardiac catheterization at three Bronx hospitals. A change in management plans with respect to catheterization was observed in 31% of cases. Catheterization rates were reduced by 25% among patients referred for resting studies and by 49% for exercise studies (thallium perfusion or exercise wall motion studies). Results of CVNMS had little impact on catheterization decisions for resting study patients (N = 192). Among exercise study patients (N = 247), those with normal results had a relative reduction in catheterization post-CVNMS of 82% vs 27% for patients with abnormal results (p less than 0.001). However, impact of exercise CVNMS test results on post-CVNMS catheterization rates obtained for men only; women with abnormal exercise study results were much less likely to undergo subsequent catheterization (7.7%) than men with abnormal results (41.9%), p less than 0.005, independent of age. The apparent discrepancy in referral for catheterization based on sex needs to be investigated further.

Prosthetic valve visualization by cine-computed tomography: a case report.

The use of cine-computed tomography scanning is described in evaluating cardiac function in a patient with a bileaflet mitral valve prosthesis (St. Jude medical valve) and in a second patient with both mitral and aortic bileaflet prostheses. Both biventricular and prosthesis function were assessed successfully.

Signouts against medical advice from a coronary care unit.

Twenty-nine patients who were admitted to a Coronary Care Unit (CCU) but who subsequently discharged themselves against medical advice (AMA) were matched with a group of control patients who were admitted to the same unit but who remained in the hospital for the entire course of their treatment. The two groups were then compared on the basis of sociodemographic, medical, behavioral, and psychiatric variables. Results were that the AMA group differed significantly from the control group in a number of factors including age, number of previous AMA signouts, severity of medical problems, and self-reports of alcoholism and emotional difficulties. The relationship of these findings to the AMA behavior is discussed and intervention strategies are suggested.