Hemodynamic effects of penticainide (CM 7857), a novel class I antiarrhythmic drug--comparison with disopyramide

Penticainide (CM 7857) is a new class I antiarrhythmic agent, which has been shown to suppress ventricular arrhythmias by a specific effect on repolarization, shortening the action potential duration. To assess acute hemodynamic effects of penticainide and to compare them to those of disopyramide, 20 patients with normal left ventricular function were studied by simultaneous left and right heart catheterization before as well as 5 and 30 min after intravenous drug administration (1.5 mg/kg for both compounds) in a randomized fashion. After penticainide, a maximal negative inotropic effect was noted at the end of the 5 min infusion, as reflected by reductions in stroke index and parameters of contractility despite increases in vascular resistances. These changes returned to baseline after 30 min except for ejection fraction, which was still lower than at baseline. After disopyramide, similar hemodynamic drug effects were observed that were greater than after penticainide, leading to a moderate tachycardia immediately after drug infusion. In addition, all parameters of contractility as well as stroke index were still significantly reduced 30 min after disopyramide, but not after penticainide. Thus, the hemodynamic profiles of both drugs tested were similar, but the negative inotropic effect of penticainide was less marked and of shorter duration than that of disopyramide in an equipotent antiarrhythmic dose. Penticainide may therefore be used in treatment of acute ventricular arrhythmias, but it should be administered with caution in patients with depressed left ventricular function.