A 65-year-old man comes to the emergency department 1 hour after a loss of consciousness. His wife said he suddenly fainted while she was adjusting his necktie. He regained consciousness within 30 seconds and was fully alert and oriented. He has had two similar episodes in the last year. His temperature is 37.2°C (98.9°F), pulse is 70/min and regular, respirations are 13/min, blood pressure is 130/82 mm Hg when supine and 122/80 mm Hg while standing. Physical examination reveals no heart murmurs or carotid bruits. ECG shows normal sinus rhythm. The patient is given an ambulatory ECG monitoring device. During symptomatic episodes, the device is most likely to show which of the following?

Question

A 65-year-old man comes to the emergency department 1 hour after a loss of consciousness. His wife said he suddenly fainted while she was adjusting his necktie. He regained consciousness within 30 seconds and was fully alert and oriented. He has had two similar episodes in the last year. His temperature is 37.2°C (98.9°F), pulse is 70/min and regular, respirations are 13/min, blood pressure is 130/82 mm Hg when supine and 122/80 mm Hg while standing.  Physical examination reveals no heart murmurs or carotid bruits.  ECG shows normal sinus rhythm.  The patient is given an ambulatory ECG monitoring device.  During symptomatic episodes, the device is most likely to show which of the following?

Quizplus · Accepted Answer

Eductional Objective: Carotid sinus hypersensitivity is most commonly seen in elderly men and involves an exaggerated vasovagal response to tactile stimulation of carotid sinus baroreceptors (eg, adjusting a shirt collar or necktie).  The resulting increase in parasympathetic output leads to a prolonged sinus pause that contributes to the excessive drop in blood pressure, leading to transient loss of cerebral perfusion that manifests as presyncope (eg, lightheadedness) or syncope.

A 65-Year-Old Man Comes to the Emergency Department 1 Hour