[Effects of cordarone on the contractile function of the left ventricle]

Acute intravenous administration of cordarone in a dose of 5 mg/kg was demonstrated to decrease the mean values of the peak increase rate in left ventricular pressure, circulatory myocardial fiber shortening velocity, ejection fraction, and specific peripheral vascular resistance by 19.5, 12.3, 10.3, and 26.2%, respectively. Less marked changes occurred in stroke and cardiac outputs. The effects were more pronounced during a more rapid intravenous administration of the agent, as well as in patients with lower myocardial contractility. Chronic administration of oral cordarone in doses of 200 to 300 mg a day had a low effect on cardiac hemodynamic parameters. Sinus bradycardia was significant in reducing the cardiac output (-10.8%). All the patients displayed prolonged Q-T interval that was maximally apparent in patients with the baseline prolonged interval (+13.1%).