A 45-year-old man is brought to the emergency department after fainting while walking his dog. He denies a history of chest pain or prior syncope. His past medical history is significant for a
cardiac murmur known since childhood. He does not smoke, and denies any recreational drug use. His temperature is 37 C (98.6 F), blood pressure is 128/78 mm Hg, pulse is 87 /min and regular, and ...