Effect of captopril on left ventricular mass and function in hypertensive patients and in the rat.

Twenty-seven mild to moderate essential hypertensive patients were treated with captopril alone or combined with hydrochlorothiazide and left ventricular echocardiographic changes were evaluated after 1, 3 and 6 months. The left ventricular mass decreased slightly after 3 months, together with mean wall stress and total peripheral resistance, while the cardiac performance, as measured by fractional shortening and cardiac output, was unaffected. A high degree of individual variability was observed, and only 9 out of 20 patients examined after 3 months had a consistent reduction in left ventricular mass. The effect of captopril on the isomyosin composition was also evaluated in 4 normotensive rats after 12 weeks of drug administration. No interference with the physiological pattern was observed and no modifications of the biochemical and structural properties of the myocardium were detected.