The Action of Cardiac Glycosides on Experimental Auricular Flutter

Abstract

The effect of cardiac glycosides on auricular flutter produced by the method of Rosenblueth and Garcia Ramos is studied. In the denervated heart these drugs produce an increase in the effective refractory period, a decrease in conduction velocity and excitability. The flutter is reverted to a sinus rhythm because of the increase in the effective refractory period. In the innervated heart these glycosides can change the auricular flutter to auricular fibrillation. This change is mediated through the vagus since atropine or cutting the vagi promptly reverts the fibrillation to a sinus rhythm. The change from auricular flutter to fibrillation was never observed in vagotomized dogs.