THE CARDIOVASCULAR ASPECTS OF CAROTID SINUS HYPERSENSITIVITY WITH SPECIAL REFERENCE TO SOME CARDIAC ARRHYTHMIAS

Abstract

Four cases of carotid sinus hypersensitivity were presented, each occurring in a different basic cardiac rhythm, namely: regular sinus rhythm, paroxysmal auricular tachycardia, auricular fibrilla-tion and auricular flutter. The results evoked following carotid sinus stimulation in each of these cases are presented electrocardiographically. The 3 cases of arrhythmia re-sponded to carotid sinus stimulation by ventricular asystole, whereas the case of regular sinus rhythm responded by complete cardiac standstill. It is impossible to predict the differential effects of right and left carotid sinus stimulation on the sino-auricular and auriculo-ventricular nodes. Digitalis exerts a sensitizing effect on the carotid sinus reflex, confirming previous observations. The differential diagnosis between auricular flutter and paroxysmal tachycardia may occasionally be made by studying the electrocardiographic effects of carotid sinus stimulation.