Effect of the tetracyclic antidepressant drug maprotiline on cardiac electrophysiology in human volunteers.

The tetracyclic antidepressant drug maprotiline was given intravenously to seven healthy volunteers in order to evaluate its effect on sinus node automaticity, on the atrioventricular conduction system judged from Hisbundle electrograms, and on the repolarization of the right atrium and ventricle judged from the refractoriness and monophasic action potential duration. Sinus recovery time decreased after the drug, probably as a result of the anticholinergic action of maprotiline. No other significant changes were obtained. The electrophysiological effects of maprotiline on the atrium, AV-nodal conduction, and the ventricle seem less pronounced than those of tricyclic antidepressant drugs and this may explain the less pronounced arrhythmogenic effect of maprotiline.