A healthy 55-year-old man without known medical problems presented for a routine physical examination and was found to have an abnormal ECG. He denied chest pain, dyspnea, palpitations, dizziness, or syncopal episodes. He also denied orthopnea, paroxysmal nocturnal dyspnea, and lower-extremity edema. His exercise capacity had been excellent. He was a lifelong nonsmoker and never had lung problems.