Myocarditis: when to suspect and how to diagnose it in athletes.

Myocarditis should be suspected in athletes with unexplained cardiac arrhythmias and dysfunction, especially if preceded by a flu-like syndrome. An early diagnosis is desirable in order to avoid the risk of fatal consequences, since physical activity can enhance the inflammatory process. Although several diagnostic tools can be useful for the diagnosis of myocarditis, endomyocardial biopsy is still the gold standard. Athletes with myocarditis should be withdrawn from all competitive sports for at least 6 months and resume training when ventricular function and cardiac dimensions return to normal and the clinically relevant arrhythmias disappear. In the presence of life-threatening arrhythmias or rapidly progressive cardiac dysfunction an antiviral or an immunosuppressive treatment should be considered depending on whether a viral agent is present or absent, respectively, in the myocardium.