[Abnormal ECG findings in athletes].

Athlete's heart, as a consequence of exercise training, is characterized by hypervagotonia and enlargement of cardiac chambers. Such modifications influence the electrocardiogram. In fact, athletes frequently present with common cardiac alterations, including sinus bradycardia, first and second degree atrioventricular block, increased QRS voltage, and early repolarization. In addition, uncommon alterations (borderline or abnormal) may be discovered incidentally during screening, which may underline cardiac disease in a preclinical phase. The challenge of sports cardiology, which daily engages sports medicine physicians, is to differentiate in athletes benign alterations from those that may be due to dangerous heart diseases.