Review Question - QID 214487

A 65-year-old man presents to the emergency department with a sensation of palpitations. The patient was engaging in intercourse with his wife when he felt a sensation of chest discomfort that lasted for 2 seconds. The patient had a myocardial infarction 1 month ago which was treated with stenting. He has a history of diabetes, hypertension, obesity, and peripheral vascular disease. His temperature is 99.3°F (37.4°C), blood pressure is 152/98 mmHg, pulse is 77/min, respirations are 14/min, and oxygen saturation is 99% on room air. Physical exam reveals an obese man in no acute distress with a normal S1 and S2 and clear breath sounds. An ECG is performed as seen in Figure A, and an initial cardiac troponin is 0.05 mg/dL (normal < 0.01 mg/dL) with a recent troponin 1 week ago of 0.05 mg/dL. Which of the following is the most likely diagnosis?