Antiarrhythmic effect of a new class 1 antiarrhythmic drug, AN-132, on ventricular arrhythmias in beagles.

Using two-stage coronary-ligation-, digitalis- and adrenaline-induced ventricular arrhythmias in beagles, antiarrhythmic effects of AN-132 were examined, and the minimum effective plasma concentration for each arrhythmia model was determined. AN-132 suppressed all the arrhythmias, and the minimum effective plasma concentrations for arrhythmias induced by 24-hour coronary ligation, 48-hour coronary ligation, digitalis, and adrenaline were 3.4-4.6, 1.5-2.3, 0.83, and 9.3 micrograms/ml, respectively. The concentration for adrenaline-induced arrhythmia was significantly higher than that of 24-hour coronary ligation arrhythmia, and it was also higher than that of digitalis arrhythmia. This pharmacologic profile is similar to those of pirmenol and mexiletine. Since AN-132 had no deleterious effects on the hemodynamics and the central nervous system, it may become a clinically useful antiarrhythmic drug.