[Comparative study on use of angiotensin-converting enzyme inhibitors and cardiac glycosides in the treatment of cardiac insufficiency].

The efficacy of captopril (capoten) and digoxin was comparatively studied in long-term randomized, double blind trials of 22 male patients with postinfarction cardiosclerosis, functional classes I-III and preserved sinus rhythm. The optimal doses of the drugs proved to be small (0.31 and 35 mg/day of digoxin and capoten, respectively). No adverse effects were noted. The mortality rate was 10 and 16.7% with digoxin and captopril, respectively. The drugs equally improved the functional class by 0.51 and 0.45 and VO2 max by 1.5 and 1.7 ml/min. Digoxin had a mild effect on heart rate (-8.4%) and ejection fraction (+5.7%) and deteriorated diastolic relaxation, by slowing down the early peak of transmitral Doppler spectrum by 16.2%. Captopril significantly improved diastolic function by increasing the early peak by 17.2%. No significant changes in left ventricular sizes were recorded. The clinical efficacy of captopril was explained by a significant decrease in angiotension II (70%) and norepinephrine (40%) levels and by associated normalization of baroreflex regulation. Digoxin insignificantly affected the levels of angiotensin II and norepinephrine, but improved the baroreceptor regulation of sympathetic control impaired in chronic heart failure. It is concluded that extracardiac mechanisms play a major role in the action of not only captopril, but digoxin in the treatment of patients with postinfarct cardiosclerosis and chronic heart failure with sinus rhythm.