Consequences of reversal of hypertensive cardiac hypertrophy by captopril on left ventricular pumping ability and performance.

ABSTRACT

Left ventricular hypertrophy can be reversed by treatment of hypertension with captopril but the consequences of this regression are not yet fully described. We studied the maximal capacity of the hypertrophied and hypertrophy-reversed ventricle to generate pressure during transient total occlusion of the aorta, and also the left ventricular end-diastolic pressure required to meet this maximal effort. Two-kidney, one clip Goldblatt (renal hypertensive rats; RHR) hypertension was induced in 17 Wistar rats, eight of which were treated with captopril (RHR-C 50 mg/kg given orally) from the fourth to the eighth week. Sham-operated controls (SC) remained untreated, or were treated with similar doses of captopril (SC-C). Significantly lower heart weights were found in RHR-C than in RHR (2.88 +/- 0.15 versus 2.38 +/- 0.04; P less than 0.001). During transient total occlusion of the aorta, the maximal intraventricular pressure developed in RHR-C was not significantly different from that in RHR, but left ventricular end-diastolic pressure was significantly less in RHR-C than in RHR (21.4 +/- 2.2 versus 34.3 +/- 3.8; P less than 0.01). The analysis of pressure-volume characteristics of the hypertrophied left ventricles and those in which hypertrophy was reversed revealed similar compliances between these two groups. Our data suggest that there was a mechanical improvement in the heart function after reversal of left ventricular hypertrophy.