Review Question - QID 214990

A 38-year-old man is brought to the emergency room due to severe substernal pressure for the past 45 minutes. He states that the chest pain is accompanied by palpitations, although he is not having any shortness of breath. He has no history of hypertension or diabetes. He has a history of intravenous drug use and started a methadone program last month. He presented to the emergency room 6 weeks ago with agitation and pressured speech but left without being evaluated. His mother died of a myocardial infarction at age 58, and his father died of pancreatic cancer at age 72. The patient is agitated and sweating profusely during the examination, frequently yelling at staff and to himself. His temperature is 99.5°F (37.5°C), blood pressure is 165/90 mmHg, pulse is 115/min, and respirations are 20/min. The remainder of his exam is notable for dilated, reactive pupils. EKG reveals sinus tachycardia with ST elevations in leads II, III, and aVF. What is the most likely explanation for the patient’s symptoms?