Competitive sports activity is associated with an increase in the risk of sudden cardiovascular death in adolescents and young adults with clinically silent cardiovascular disorders. Strategies for primary prevention include screening programs based on history and physical examination alone or including electrocardiogram (ECG). ECG screening is more sensitive and has a higher cost–benefit ratio than that based on history and physical examination alone. Modern criteria for athletes' ECG interpretation significantly improves the screening accuracy by reducing the false-positive rate (increased specificity), with the important requisite of maintaining the ability to detect life-threatening heart diseases (preserved sensitivity).