A 53-year-old man is brought to the emergency department following an episode of loss of consciousness 1 hour ago. He had just finished shaving when he fell down. His wife heard the noise and found him unconscious on the floor. He regained consciousness after 30 seconds and was able to talk normally with his wife immediately. There was no urinary incontinence. On arrival, he is alert and oriented. Cardiopulmonary examination shows no abnormalities. Neurologic examination shows no focal findings. Serum concentrations of glucose, creatinine, and electrolytes are within the reference range. An electrocardiogram shows no abnormalities. Which of the following factors is most likely contributing to this patient's symptomatic episodes?

Question

Quizplus · Accepted Answer

Eductional Objective: Carotid sinus hypersensitivity is a common cause of syncope associated with tactile stimulation of the carotid sinus (eg, shaving).  The syncope results from an exaggerated vagal response stimulated by the carotid baroreceptors, which leads to slowed heart rate and marked peripheral vasodilation with a resulting transient loss of cerebral perfusion.

A 53-Year-Old Man Is Brought to the Emergency Department Following