[Effect of captopril in left ventricular failure during the acute stage of myocardial infarction].

The oral inhibitor of the converting enzyme of angiotensin has previously been used successfully in the treatment of chronic cardiac failure. Its action as an arterial and venous vasodilator and in significantly reducing the heart rate which we have previously reported, led us to assess its effects in left ventricular failure during acute myocardial infarction. The effects of captopril were compared with those of isosorbide dinitrate in 10 patients with left ventricular failure during acute myocardial infarction. An arterial and venous vasodilatation was obtained with both drugs. Captopril induced a greater fall in left ventricular filling pressures and significantly reduced the heart rate, leading to a slight increase in left ventricular systolic work index. Pulmonary arterial resistances decreased more significantly with captopril whilst systemic arterial resistances fell equally. The left ventricular function curve was shifted to the left by both captopril and isosorbide dinitrate, but only captopril induced an upward shift and only captopril caused very significant reductions in the rate-pressure product. The plasma renin activity of these patients was high but the correlation with the vasodilator effect was poor. There was little change in medium-term survival (50% mortality). These results indicate that captopril may be a valuable drug in the treatment of left ventricular failure in acute myocardial infarction. However, its oral presentation makes it difficult to determine the optimal dose.