[Skip to Content]
[Skip to Content Landing]
July 23, 1982

Antiarrhythmic Effects of Tricyclic Antidepressants

Author Affiliations

Western Psychiatric Institute and Clinic Pittsburgh

JAMA. 1982;248(4):429. doi:10.1001/jama.1982.03330040023022

To the Editor.—  We would like to add imipramine hydrochloride and the other tricyclic antidepressants to the list of newer antiarrhythmic drugs described by Drs Nademanee and Singh (1982;247:217). A standard antidepressant drug for more than 20 years, imipramine has been recently shown to have significant antiarrhythmic effects.1,2 In one study of depressed patients with more than ten premature ventricular contractions (PVCs) per hour, arrhythmia suppression was greater than 90% in ten of 11 patients.2 Based on studies done with animal models,3,4 imipramine and its metabolites shorten action-potential duration, similar to lidocaine or mexiletine, and decrease conduction velocity and maximal velocity, like procainamide hydrochloride or quinidine sulfate. Imipramine would therefore be considered a class 1 antiarrhythmic drug. Although other clinically used tricyclic antidepressants share these properties,3 it seems possible, partly based on our experience, that imipramine has the greatest antiarrhythmic potency.The half-life of imipramine is