Palpitations and fatigue in a football player.

An 18-year-old college football linebacker reported to the training room physician's office in early September complaining of an irregular heartbeat and lightheadedness while weightlifting. He also noted mild fever and chills and rapid fatigability during practice. He said that he had had a skin eruption several weeks earlier. He denied chest pain or pressure, near syncope or syncope, shortness of breath, or history of palpitations.