A 20-year-old man was admitted to an outside institution with chest pain, shortness of breath, and a syncopal episode. He had previously been in good health until 2.5 years earlier, when he developed presyncope associated with chest pain and shortness of breath during an army training exercise. An emergency room evaluation, which included a chest radiograph and an ECG, was normal. He continued to be bothered by fatigue and poor exercise capacity after this initial evaluation. On the day of admission, the patient developed dizziness, palpitations, central chest pressure, and shortness of breath after playing basketball for 30 minutes. After leaving the court, he lost consciousness for ≈2 minutes, with spontaneous recovery. The patient was transported to a nearby hospital with persistent chest pain. On initial examination, the patient was diaphoretic and anxious. He had a blood pressure of 70/30 mm Hg, a heart rate of 103 beats per minute, and respirations of 24 breaths per minute. Physical examination revealed a well-developed man in mild distress. The lungs were clear. The cardiovascular examination revealed tachycardia, with a regular rhythm. On cardiac auscultation, the S1 and S2 were normal, and an S4 gallop was present. There was no jugular venous distension, and the carotid upstrokes were normal. The remainder of his physical examination was unremarkable. The initial ECG showed normal sinus rhythm with marked and diffuse ST segment depression and widening of the QRS complex in the precordial leads (Fig 1⇓). Continuous rhythm monitoring showed occasional nonsustained ventricular ectopy. The patient’s hypotension rapidly resolved after resuscitation with intravenous fluids. A diagnosis of an acute coronary ischemic syndrome was made, and treatment with intravenous heparin, intravenous nitroglycerin, and lidocaine was begun. After gradual resolution of his chest pain over several hours, the ECG reverted to normal. On the …