Captopril effects on pulmonary and systemic hemodynamics in chronic cor pulmonale.

A placebo-controlled single-blind study on acute effects of captopril on hypoxic pulmonary hypertension was performed in 15 patients with severe chronic obstructive lung disease recovering from right heart failure. Ten patients received active drug (25 mg captopril orally), five patients received placebo and served as control subjects. Before drug administration, there was no difference in lung function data and pulmonary hemodynamics between patients in both groups. Captopril produced highly significant fall in systemic arterial pressure. No change in breathing frequency, minute ventilation, and pulmonary gas exchange was observed. There was no significant change in studied variables after placebo. The presented data suggest that captopril does not decrease pulmonary vascular resistance in patients with hypoxic pulmonary hypertension. A fall in pulmonary wedge pressure reflects a decrease in left ventricular afterload.