A single intravenous dose of ivabradine, a novel I-f inhibitor, lowers heart rate but does not depress left ventricular function in patients with left ventricular dysfunction

This randomized, single-blind, placebo-controlled study investigated the effect of ivabradine, a novel heart rate-lowering agent, on echocardiographic indices of left ventricular (LV) systolic function in patients with regional ( coronary artery disease) or global ( cardiomyopathy) LV dysfunction. Patients were randomized on an unequal basis to receive ivabradine 0.25 mg/kg (n = 31) or placebo ( n = 13) by intravenous infusion. Resting heart rate was reduced by a mean of 17.6 +/- 4.7% with ivabradine and 1.5 +/- 5.8% with placebo. The mean maximum decrease in LV ejection fraction was 0.2% with ivabradine and 1.7% with placebo. Fractional shortening and stroke volume were also fully preserved after ivabradine administration. Thus, a single intravenous dose of ivabradine produced a substantial reduction in resting heart rate without affecting LV function in patients with regional or global LV dysfunction. Copyright (C) 2003 S. Karger AG, Basel.