Effects of captopril in patients with chronic obstructive pulmonary disease and secondary pulmonary hypertension.

Ten patients with chronic obstructive pulmonary disease (COPD) with normal left ventricular function were given a single dose of captopril (0.25 mg/kg). Mean systemic arterial pressure, heart rate and coronary flow to the right ventricle were reduced significantly after captopril. In contrast captopril did not cause a significant fall in pulmonary arterial pressure or pulmonary vascular resistance. We conclude that captopril fails to produce haemodynamic benefits in such hypoxic patients and that angiotensin II is not playing a significant role in maintaining pulmonary vasoconstriction.