Influence of Sympathomimetic Pressor Drugs on Arrhythmias Caused by Multiple Stimuli

Abstract

A technic of administering successive stimuli to the heart at various ectopic foci was devised. Under normal circumstances the heart had sufficient power of integration to resist disorganization of its action by these multiple stimuli. Methoxamine, mephentermine and metaraminol had less tendency to increase vulnerability to fibrillation than did levarterenol under these conditions of stress. A new compound (Lilly #20522) blocked for a time the arrhythmia-producing action of levarterenol.