Immediate effects of captopril in acute left ventricular failure secondary to myocardial infarction

Abstract. In eight patients with acute left ventricular failure secondary to myocardial infarction the haemo-dynamic effects of captopril (25 mg), an orally active converting enzyme inhibitor, were measured. Haemo-dynamic modifications were maximal at 60 min and lasted for 2–3 h. Pulmonary wedge pressure fell from 23–5± 4.9(mean ± SD)to 16–8 ± 4.7 mmHg(P<0–01), cardiac output rose from 3–24 ± 1 to 4–05 ± 0–91 1/min (P<001). Systemic vascular resistance decreased from 27–34 ± 3–81 to 17.52 ± 1–65 mmHg min 1^-1 (P<001). Mean arterial pressure fell from 89.6 ± 13.9 to 75.7±0 16.3 mmHg (P<0001) while heart rate was not significantly modified. Six patients who had high pretreatment plasma renin activity values responded by a decrease in ventricular filling pressure and/or an increase in cardiac output. One patient with normal initial plasma renin activity value showed similar haemodynamic effects. These data suggest that in the short term captopril is a vasodilator with both arterial and venous effects and improves cardiac function in acute left ventricular failure secondary to myocardial infarction.