HY USMLE Q #1377 – Cardio

A 62-year-old man is brought to emergency by his wife several hours after an episode of sudden-onset right arm weakness and difficulty speaking that resolved after 45 minutes. He has a history of hypertension and dyslipidemia but does not take medications consistently. He has a 40-pack-year smoking history. He drinks Scotch. Blood pressure is 160/90. Neurologic exam is unremarkable. A non-contrast CT of the head shows no acute abnormalities. ECG shows sinus rhythm. Which of the following is the most appropriate next diagnostic step to evaluate the cause of this patient’s symptoms?