Suppression of ouabain-induced atrial arrhythmias by carotid sinus stimulation.

In dogs anaesthetized with chloralose ectopic atrial arrhythmias were produced by subepicardial injection of ouabain. Stimulation of the right carotid sinus abruptly suppressed the ectopic arrhythmias. They returned on cessation of stimulation and sometimes already during the period of stimulation. It is suggested that in view of its response to carotid sinus stimulation the ouabain-induced arrhythmia resembles paroxysmal atrial tachycardia and that it is distinct from the aconitine-induced arrhythmia which on account of its response to vagal stimulation has been classified as atrial flutter.