Effects of cardiac medications on ventricular performance: Emphasis on evaluation with radionuclide angiography

Abstract

With the advent of radionuclide angiography (RNA) and quantitative two-dimensional echocardiography (2DE), a great deal of interest has been generated in the noninvasive evaluation of the effects of an increasing number of active cardiac medications on ventricular performance. In this review, the effects of acute and chronic administration of vasodilators and antianginal, antihypertensive, inotropic, and antiarrhythmic agents on left ventricular (LV) ejection fraction (EF), volume, and diastolic properties and, to a lesser extent, on right ventricular (RV) EF will be discussed. The effects of these pharmacologic agents on intracardiac pressures, systemic pressure, systemic and pulmonary artery resistance, and cardiac output have been extensively studied and will not be included in this review. Table I presents a summary of these studies. Several points should be emphasized; first, a statistically significant change in EF may not be clinically relevant, for example, a decrease in EF from 60 to 55 may be statistically significant but clinically irrelevant. Statistical analysis is used only to judge whether data from the study are consistent or inconsistent with a null hypothesis. Second, the change in EF is analyzed as the mean change before and after therapy. Such analysis does not reflect the reproducibility and variability in these measurements. In good laboratories, the interand intraindividual variability is less than 5 % , but each laboratory should establish its own reproducibility results. A more important point, however, is the reproducibility of results when measurements are separated by days or weeks. Sequential studies in normal