1 Vasodilator therapy is used widely for the treatment of congestive heart failure irrespective of its origin. The acute and long-term effects of captopril were studied in 50 patients with congestive heart failure due to valvular incompetence, hypertension, cardiomyopathy, and ischaemic heart disease. Haemodynamic studies were performed in all patients. In those with valvular incompetence, regurgitation fractions were measured cineangiographically. In patients with ischaemic heart disease coronary sinus blood flow was assessed by a thermodilution technique. During clinical follow-up patients were studied by non-invasive techniques including electrocardiography, echocardiography and chest radiography.
2 In the short-term studies, left ventricular filling pressure, total peripheral resistance, and end-diastolic and end-systolic volumes decreased after captopril, while cardiac output, stroke volume, and ejection fraction increased. Valvular regurgitation fraction was assessed in 10 patients with aortic or mitral insufficiency. In every patient the regurgitation fraction decreased. Coronary blood flow was measured in eight patients with severe ischaemic heart disease. In three patients it remained constant and in the other five patients it decreased. At the same time a highly significant decrease of myocardial oxygen consumption was measured.
3 During long-term treatment clinical improvement occurred in most of the patients. This was documented by a reduction of ventricular diameters in hypertensive heart disease as well as in valvular incompetence. These values remained constant in congestive cardiomyopathy despite clinical improvement. Serious hypotensive episodes were observed in eight patients with valvular stenosis or complex congenital cardiac abnormalities.
4 Captopril is therefore an effective vasodilator for the treatment of congestive heart failure. In patients with intact left ventricular function captopril should not be given because severe hypotensive episodes may occur. Ischaemic heart disease with congestive heart failure is no contraindication for treatment with captopril because the reduction in myocardial blood flow is balanced by the reduced myocardial oxygen consumption.