Syncope: Who Needs Imaging? Who Needs Admission?

A 60-year-old man presents to the emergency department (ED) by EMS with a report of sudden collapse while running a road race. It is a hot summer day, and he was at mile 5 of a 10 K race when he suddenly collapsed. He was helped up by bystanders after a report of roughly 1 min of unconsciousness. He has scrapes on his knees and elbows from the fall to pavement but is only complaining of fatigue. He is awake and alert, with mild tachycardia, a normal blood pressure, and a normal neurological exam. His respiratory rate is normal and he is afebrile. His skin is pale and warm, with some mild sweat. He reports that he has a history of hypertension and non-insulin-dependent diabetes. He takes metformin for the latter, but cannot recall his antihypertensive medication name. EMS has started a peripheral IV en route and given him 500 cm3 of normal saline. They report that a 12 lead ECG showed sinus tachycardia without any features concerning for arrhythmia or ischemia.