The Electrocardiogram in Highly Trained Athletes.

Regular intensive exercise is associated with a constellation of several structural and functional adaptations within the heart that permit the generation of a large and sustained increase in cardiac output and/or increase in blood pressure. The magnitude with which these markers of physiological remodeling manifest on the surface electrocardiogram is governed by several factors and some athletes show electrical and structural changes that overlap with those observed in cardiomyopathy and in ion channel diseases, which are recognized causes of sudden cardiac death in young athletes. This article provides a critical appraisal of the athlete's ECG.