Suppression of ventricular arrhythmias resulting from acute coronary artery ligation in rat by imipramine

The potential antiarrhythmic activity of imipramine against ventricular arrhythmias induced by coronary artery ligation in rats has been investigated and compared with procainamide. Imipramide (1 and 5 mg/kg-1) or procainamide (5 and 10 mg/kg-1) or solvent were injected intravenously 30 min before ligation. Imipramine reduced the total number of ventricular ectopic beats as well as the incidence and duration of ventricular tachycardia and ventricular fibrillation. The drug did not significantly affect the blood pressure but reduced the heart rate. The antiarrhythmic activity of imipramine is postulated to be due to a quinidine-like effect and/or alpha-adrenergic blocking activity. The study confirms the potential utility of imipramine as an antiarrhythmic drug.