Diagnosis, pathophysiology, and management of exercise-induced arrhythmias.

The cardiovascular benefits of physical activity are indisputable. Nevertheless, growing evidence suggests that both atrial fibrillation and right ventricular arrhythmia can be caused by intense exercise in some individuals. Exercise-induced atrial fibrillation is most commonly diagnosed in middle-aged, otherwise healthy men who have been engaged in endurance training for >10 years, and is mediated by atrial dilatation, parasympathetic enhancement, and possibly atrial fibrosis. Cardiac ablation is evolving as a first-line tool for athletes with exercise-induced arrhythmia who are eager to remain active. The relationship between physical activity and right ventricular arrhythmia is complex and involves genetic and physical factors that, in a few athletes, eventually lead to right ventricular dilatation, followed by subsequent myocardial fibrosis and lethal ventricular arrhythmias. Sinus bradycardia and atrioventricular conduction blocks are common in athletes, most of whom remain asymptomatic, although incomplete reversibility has been shown after exercise cessation. In this Review, we summarize the evidence supporting the existence of exercise-induced arrhythmias and discuss the specific considerations for the clinical management of these patients.