system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
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. He has anxiety and takes alprazolam as needed. He smokes half a pack of cigarettes daily and drinks two glasses of wine with dinner each night. 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. Cardiopulmonary examination shows no abnormalities. Neurologic examination shows no focal findings. A complete blood count shows no abnormalities. Bedside cardiac monitoring shows infrequent premature ventricular contractions and QRS voltage below 5 mm in leads II and III. Which of the following is the most likely diagnosis?
assistant
Carotid sinus hypersensitivity