Effects of ACE inhibition on left ventricular dimensions and haemodynamics in systemic hypertension: a radionuclide and echocardiographic study

The aim of this study was to assess the effects of Angiotensin Converting Enzyme (ACE) inhibition on cardiac systolic and diastolic parameters and left ventricular muscle mass in hypertensive patients. For this purpose 30 patients (22 female and eight male) with mild to moderate essential hypertension, aged 47 +/- 2 years, were treated with enalapril maleate (MK 421, an ACE inhibitor) for six weeks. They underwent M-mode and Doppler echocardiography and radionuclide ventriculography at the beginning and after six weeks of enalapril treatment. In this study all patients treated with the ACE inhibitor enalapril responded with a significant decrease in mean arterial pressure (p < 0.001). A significant reduction in left ventricle and mass index were shown after six weeks of treatment with enalapril (p < 0.01). Total peripheral resistance and end-systolic stress decreased in the same time course (p < 0.001). Ejection fraction increased in both examinations after six weeks of therapy with enalapril, but this increase was not statistically significant. In radionuclide examinations, time to peak filling rate decreased significantly after six weeks of enalapril therapy (p < 0.02). Despite these improvements in cardiac systolic and diastolic parameters, cardiac output and stroke volume decreased slightly after enalapril treatment. We concluded that enalapril improves diastolic and systolic parameters in LV function but causes slight decreases in cardiac output and stroke volume in addition to lowering blood pressure.