Effect of Carotid Sinus Stimulation on the Electrocardiograms of Clinically Normal Individuals

The cardioinhibitory effects of carotid sinus stimulation were studied by electrocardiographic means in 40 clinically normal, adult males. Although the carotid sinus reflex is of clinical importance, the measure of its effects in normal individuals is little known. Electrocardiographic changes were varied and occurred in nearly all. Almost one fourth of the patients developed ventricularasystole, and symptoms were induced in another fourth. The wide range of effects emphasizes the importance of this reflex even in normal persons and underscores the need for rigid criteria in the diagnosis of the hypersensitive carotid sinus syndrome.