Disparate structural effects on left and right ventricles by angiotensin-converting enzyme inhibitors and calcium antagonists in essential hypertension

Abstract

Reduced left ventricular (LV) mass and wall thicknesses with angiotensin-converting enzyme (ACE) inhibitors and calcium antagonists occur in essential hypertension. Experimental studies have shown that reduction in LV mass is related to hemodynamic as well as nonhemodynamic factors that may influence LV and also right ventricular (RV) structure. Sixty-eight patients with essential hypertension were studied echocardiographically 4 to 8 weeks after antihypertensive therapy was initiated. LV dimensions and wall thicknesses, as well as RV free wall thickness, were measured using 2-dimensionally guided techniques. Patients were divided in 2 groups: those receiving either ACE inhibitors or calcium antagonists. This short-term therapeutic period produced similar hemodynamic changes and reductions in LV mass in both groups. In these 2 groups of patients, we found opposite effects in RV free wall thickness. Thus, RV wall thickness increased from 0.44 ± 0.02 to 0.56 ± 0.02 cm (p <0.01) after therapy in the calcium antagonist group, whereas no change was found in the ACE inhibitor group (0.36 ± 0.04 vs 0.34 ± 0.04). These structural changes suggest that ACE inhibitors and calcium antagonists produce dissimilar effects on cardiac cell growth and growth reversal, which may be mediated through different nonhemodynamic effects after short-term therapy.