A 59-year-old man is brought to emergency by his wife for a 3-week history of dizziness and episodes of feeling like he is going to faint, especially when doing yard work or climbing stairs. He has hypertension managed with lisinopril. Vitals are normal. An ECG is performed. Which of the following is the most appropriate next step in management?
Ambulatory ECG monitoring
Dipyridamole-thallium stress test
Exercise-echocardiography stress test
External pacing
No treatment necessary
Propranolol