The cardioinhibitory carotid sinus syndrome

O F interest for years as a readily demonstrable etiologic factor in certain cases of syncopal or convulsive attacks, the cardioinhibitory carotid sinus syndrome has itself fallen under suspicion as a manifestation of myocardial disease. This report concerns 11 unselected patients seen by the author within the past year and a half whose presenting complaint was fainting or giddiness and whose symptoms were reproduced by mechanical stimulation of the carotid sinus. A review of the literature, pertinent if not exhaustive, will be attempted before presentation of the cases. SYMPTOMS Clinical differentiation of carotid sinus hypersensitivity as a cause of syncope was popularized by the observations of Weiss and his coworkerslf 2 two of whose later papers will be discussed here; though a full description of the anatomy and physiologic activity of the carotid sinuses had been written earlier by Hering.3 Dizziness, weakness, ringing in the ears, even epigastric distress may precede periods of unconsciousness lasting one t