Left ventricular performance after intravenous infusion of captopril in patients with congestive heart failure.

BACKGROUND

Although oral administration of captopril, an angiotensin-converting enzyme inhibitor, is effective for the treatment of congestive heart failure (CHF), the effect of its intravenous (iv) administration is not well known.

METHODS AND RESULTS

Ten patients (age range 48-72 years), with CHF belonging to the second and third NYHA class, were given an iv bolus of 25 mg of captopril. Before and 30 minutes after the infusion of captopril, a number of parameters of the left ventricular function were evaluated by echocardiography IREX 3 M-B Mode. Eight patients showed a significant improvement of left ventricular performance indices. In fact, the ejection fraction (13.8%, p < 0.05), the cardiac output (24%, p < 0.001), the circumferential shortness fraction (29.9%, p < 0.05), and the fraction shortening (16.0%, p < 0.005) increased significantly, whereas the end-systolic diameter (21%, p < 0.001), the endsystolic stress (23.8%, p < 0.01) and the left ventricle ejection time (4.8%, p < 0.05) decreased significantly. Systolic and diastolic blood pressure values also underwent a significant reduction by 17% and 11% (p < 0.01 and p < 0.05 respectively). No evident correlation between the improvement of the left ventricular function and the basal renin rates was noticed.

CONCLUSIONS

A significant improvement of parietal kinesis was observed especially in those segments which showed movement abnormalities (hypokinesia and akinesia) and in many cases this was detected by M-B Mode echocardiography. Our findings may be the result of the following factors: 1) reduction of parietal stress; 2) increased district coronary flow; 3) inhibition of tissue renin-angiotensin-aldosterone system; and 4) "scavenging" action exerted by the SH group of captopril.