Preservation of the end-systolic pressure/end-systolic dimension relation following pindolol in congestive heart failure.

Beta blockade may adversely affect inotropic state of the ventricle, resulting in exacerbation of congestive heart failure in subjects with reduced ventricular function. In normal subjects, ventricular contractility appears to be preserved following administration of beta blockers with intrinsic sympathomimetic activity (ISA). The inotropic state of the ventricle was assessed in seven subjects with congestive heart failure (mean ejection fraction = 23 +/- 5%) before and after administration of the ISA beta blocker, pindolol, with the use of the noninvasively derived end-systolic pressure/end-systolic dimension (ESP/ESD) relation. The mean slope of the ESP/ESD relation was 36.3 +/- 20.4 mm Hg/cm at baseline and increased to 45.0 +/- 25.2 mm Hg/cm following five consecutive 10 mg oral doses of pindolol (p = ns). Other simultaneously derived inotropic indices that included percent fractional shortening, mean delta P/delta T, velocity of circumferential fiber shortening, and preejection period-to-left ventricular ejection time ratio showed directionally similar changes toward a mild increase in contractility. These results indicate that the slope of the left ventricular ESP/ESD relation is not altered following repeated dosing with pindolol in subjects with congestive heart failure. This reflects a preservation of inotropic state following administration of this ISA beta blocker in a population with severely compromised ventricular function.