Evaluation of Suspected Cardiogenic Syncope
A 72-year-old man presents to the emergency department after having abrupt syncope while hiking in Sedona, Arizona. He states that he has never passed out before. He was walking through a shaded grove up a hill when he had 1-2 sec of his vision darkening followed by abrupt loss of consciousness. His spouse rushed to his side and he regained consciousness in a few seconds. He denies any other symptoms such as flushing, nausea, or sweats. He denies any new medications.
On physical examination, he is oriented to person, place, and time but notably worried about having passed out. His neurological examination shows unremarkable findings. His cardiac examination shows regular rhythm with a systolic murmur. His electrocardiogram (ECG) shows sinus rhythm at 65 bpm, P-R interval 225 msec, left bundle branch block (LBBB), and normal axis. He is admitted overnight and telemetry shows unremarkable findings.
Which one of the following would be an appropriate test to evaluate his syncope further?