The European Society of Cardiology (ESC) has proposed guidelines for pre-participation screening for young athletes planning to begin competitive sports, which includes a standard 12-lead electrocardiogram (ECG), based upon a national screening program that has been in effect in Italy since 1982.

The following recommendations were made:

The potential advantage of the ECG is most commonly attributed to its ability to detect hypertrophic cardiomyopathy, in which the ECG is abnormal in up 95% of patients.

The routine use of ECG screening is the risk of false-positive results. The prevalence of such findings was addressed in a series of 32,652 Italian subjects who underwent routine pre-participation screening that included an ECG. The prevalence of markedly abnormal ECG patterns suggestive of significant structural heart disease was <5%. However, these results cannot be generalized to other countries. In addition to the potential impact of genetic differences, the nature of pre-participation screening is unique in Italy, where it is performed by trained and licensed sports medicine specialists who practice in dedicated sports clinics.

Over 8 years, four athletes were found to have borderline left ventricular hypertrophy (LVH) (13 mm). One was later confirmed to have hypertrophic cardiomyopathy (HCM) by genetic analysis and a second was considered to have possible HCM. In addition, 12 athletes were diagnosed with other cardiac structural abnormalities including mitral valve prolapse, myocarditis, Marfan syndrome, arrhythmogenic right ventricular cardiomyopathy, and bicuspid aortic valves. The screening ECG also can detect arrhythmogenic right ventricular cardiomyopathy, long QT syndrome, and Brugada syndrome.

The majority of SCD events in athletes are due to malignant arrhythmias, usually sustained ventricular tachycardia (VT) degenerating into ventricular fibrillation (VF), or primary VF itself. Although definitions vary, “young” often refers to high school and college athletes, but applies in general to individuals under age 35 in whom SCD is usually due to congenital heart disease. Older, or “masters,” athletes include individuals over age 35, in whom SCD is most commonly due to coronary heart disease (CHD).

In general, patients with known genetic disorders that predispose to SCD (e.g., hypertrophic cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy, Marfan syndrome, long QT syndrome) should avoid recreational activities with the following characteristics:

Patients with unusual or high-risk clinical features may require greater restriction. These features include a history of syncope or pre-syncope, prior cardiac surgery, prior arrhythmic episodes, or an implantable cardioverter-defibrillator (ICD). It is widely acknowledged that SCD is the leading medical cause of death in athletes, although its exact incidence remains unclear.

An overall incidence of 1:50,000 per year in young athletes is a reasonable estimate based on existing information from retrospective cohort studies and prospective observational and cross-sectional studies. Male athletes are consistently found to be at greater risk, and there appears to be a disproportionately higher risk among male African-American athletes.

Structural heart disease can increase the risk for SCD by one or more of the following mechanisms:

Hypertrophic cardiomyopathy (HCM) is a relatively common disease, occurring in 0.16–0.29% of individuals in the general population (one in 350–625). Congenital coronary artery abnormalities were found in 12–33% of young athletes with SCD. The most common anomalies associated with SCD are the origin of the left main coronary artery from the right sinus of Valsalva and the origin of the right coronary artery from the left coronary sinus. Athletes with Marfan syndrome, familial aortic aneurysm or dissection, or congenital bicuspid aortic valve with any degree of ascending aortic enlargement should not participate in sports that involve the potential for bodily collision.

The incidence of SCD among competitive athletes is actually quite low, estimated to be between 1 per 50,000 athletes and 1 per 300,000 athletes.

Sudden cardiac death associated with athletic activity is a rare but devastating event. Victims are usually young and apparently healthy, but many have underlying cardiovascular disease that is not diagnosed until after the event. As a result, there is great interest in detecting such abnormalities early and then defining appropriate activity restrictions for affected individuals to minimize the risk of SCD.