Effects of captopril on abnormalities of the peripheral circulation and respiratory function in patients with severe heart failure.

Limb blood flow and respiratory function were compared in ten patients with severe heart failure inadequately controlled by diuretics and normal control subjects matched for age and sex. Both forearm and calf blood flow, at rest and after exercise, were lower in the patients than in the control subjects. Oxygen consumption during submaximal exercise was also lower in the patients and minute ventilation was higher. Captopril, administered in a single-blind controlled study to the patients, resulted in an improvement in these abnormalities, with the exception of oxygen consumption. It also improved exercise tolerance and reduced perceived exertion during exercise. Captopril is effective treatment for severe heart failure and improves some of the peripheral haemodynamic and respiratory abnormalities.