Hemodynamic effects of intravenous bepridil in patients with normal left ventricular function

Calcium-channel blockers are known to have depressant effects on atrioventricular (AV) nodal conduction and myocardial contractility. Because of these known depressant effects, bepridil hydrochloride, a new, long-acting, antianginal and antiarrhythmic calcium-channel blocker, was administered intravenously to patients without heart failure to determine acute hemodynamic effects. The patients studied had normal ventricular function, were without electrocardiographic conduction disturbances and were taking no drug except sublingual nitroglycerin for at least 24 hours before bepridil infusion. The study protocol included right- and left-sided cardiac catheterization with infusion of bepridil at 2 mg/kg for 15 minutes followed by 1 mg/kg for 15 minutes in 10 patients, and infusion of bepridil at 3 mg/kg for 15 minutes followed by 1 mg/kg for 15 minutes in 8 patients. Pressures, Fick cardiac output, resistances, left ventricular (LV) dP/dt, LV stroke work index and rate-pressure product of the left ventricle were monitored. There were no significant changes during bepridil infusion at either dose for cardiac output, systemic vascular and pulmonary vascular resistances, LV stroke work index, heart rate, arterial blood pressure and rate-pressure product. There was mild depression of LV dP/dt during bepridil infusion. Further, LV end-diastolic pressure, pulmonary capillary wedge pressure and pulmonary arterial pressures were significantly increased during bepridil infusion. There were no apparent changes in AV nodal or intraventricular conduction during bepridil infusion. We conclude that bepridil appears to be a safe drug for intravenous administration despite mild depression of myocardial function in patients with normal baseline hemodynamic function who are not receiving concomitant beta-blocker therapy.