DISPARATE STRUCTURAL EFFECTS ON LEFT-AND-RIGHT-VENTRICLES BY ANGIOTENSIN-CONVERTING ENZYME-INHIBITORS AND CALCIUM-ANTAGONISTS IN ESSENTIAL-HYPERTENSION

Reduced left ventricular (LV) mass and wall thick nesses with angioten sin-converting enzyme (ACE) inhibitors and calcium antagonists occur i n essential hypertension. Experimental studies have shown that reducti on in LV mass is related to hemodynamic as well as nonhemodynamic fact ors that may influence LV and also right ventricular (RV) structure. s ixty-eight patients with essential hypertension were studied echocardi ographically 4 to 8 weeks after antihypertensive therapy was initiated . LV dimensions and wall thicknesses, as well as RV free wall thicknes s, were measured using 2-dimensionally guided techniques. Patients wer e divided in 2 groups: those receiving either ACE inhibitors or calciu m antagonists This short-term therapeutic period produced similar hemo dynamic changes and reductions in LV mass in both groups. In these 2 g roups of patients, we found opposite effects in RV free wall thickness . Thus, RV wall thickness increased from 0.44 +/- 0.02 to 0.56 +/- 0.0 2 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 ca lcium antagonists produce dissimilar effects on cardiac cell growth an d growth reversal, which may be mediated through different nonhemodyna mic effects after short-term therapy.