A 58-year-old man complains of the sudden onset of syncope. It occurs without warning and with no sweating, dizziness, or light-headedness. He believes episodes tend to occur when he turns his head too quickly or sometimes when he is shaving. Physical examination is unremarkable. He has no carotid bruits, and cardiac examination is normal.
Which of the following is the best way to make a definitive diagnosis in this patient?
A. ECGWhen syncope occurs in an older patient as a result of head turning, wearing a tight shirt collar, or shaving over the neck area, carotid sinus hypersensitivity should be considered. It usually occurs in men above the age of 50. Baroreceptors of the carotid sinus are activated and pass impulses throughthe glossopharyngeal nerve to the medulla. Some consider the process to be quite rare. Gentle massage of one carotid sinus at a time may show a period of asystole or hypotension. This should be performed in a controlled setting with monitoring and atropine available. Most cases of carotid sinus hypersensitivity are not associated with significant carotid stenosis; if a carotid bruit is heard on physical examination, however, a duplex study should precede carotid massage. More expensive studies, such as Holter monitoring or electrophysiologic study, would be unnecessary if carotid sinus massage demonstrates the diagnosis.