Sudden death among athletes is fortunately rare. It occurs with a frequency of 0.5 to 3 cases per 100,000 athletes per year with differences regarding region, age and gender. Male athletes are affected in 90% of cases. In more than half of the cases, structural heart disease or congenital anomalies of the coronary arteries are responsible for sudden death. In some cases, sudden death is due to trauma. A non-penetrating blow to the chest may trigger ventricular fibrillation (Commotio cordis). Rarely heat stroke, drug abuse or lung disease may be causal. Athletes with Marfan syndrome may suffer aortic dilatation and rupture. In the absence of a structural heart disease, abnormalities of the conduction system (e.g. Wolff-Parkinson-White syndrome) or the ion channels (e.g. Long QT syndrome or Catecholaminergic Polymorphic VT) may lead to exercise induced ventricular arrhythmias.
Hypertrophic Cardiomyopathy Picture
The disease is characterized by an asymmetric thickening (hypertrophy) of the heart muscle. In some cases, narrowing (obstruction) of the left-sided outflow tract may occur. Many patients are asymptomatic. Shortness of breath, chest pain, palpitations and fainting (syncope) may occur. Exercise related arrhythmias may lead to sudden death. The disease is inherited as an autosomal dominant trait and relatively common in the general population (1:500). Men and women are equally affected. More than 200 genetic defects have been documented. Children under the age of 13 are often silent gene carriers. The ECG is abnormal in more than 90% of the cases. The diagnosis is confirmed by echocardiography. Athletes with hypertrophic cardiomyopathy may not participate in competitive sports.
Arrhythmogenic Rightventricular Cardiomyopathy
The disease is characterized by a replacement of cardiac muscle tissue by connective tissue and fat, particularly in the right ventricle. This may lead to dilatation of the right ventricle and the occurrence of malignant arrhythmias. Patients present with syncope or sudden death. The disease is inherited as an autosomal dominant trait but may occur sporadically. The incidence vary from 1:10,000 in the U.S. to 40:10,000 in Italy. Athletes with arrhythmogenic right ventricular cardiomyopathy may not participate in competitive sports.
Congenital Long QT Syndromes Picture
Group of diseases characterized by ion channel abnormalities of the heart, leading to alterations in impulse propagation and facilitating ventricular arrhythmias. The ECG shows a prolongation of the repolarization of the heart. Patients may be asymptomatic or present with syncope or sudden death. In Long QT syndromes type I and II, arrhythmias are associated with exertion. Athletes with Long QT syndromes may not participate in competitive sports.
Congenital Anomalies of the Coronary Arteries Picture
Rare congenital heart disease with an atypical origin of the right or left coronary artery. In case of a false origin of the left coronary artery, the vessel may run between the aorta and the pulmonary artery. This may lead to kinking or dynamic compression of the left vessel wall. Myocardial ischemia may occur and trigger malignant ventricular arrhythmias. Patients may be asymptomatic or present with chest pain on exertion. If detected, competitive sports may be continued after surgical repair.
Coronary artery disease Picture
Vigorous exertion may lead to plaque rupture in individuals at risk, followed by myocardial infarction and letal arrhythmias.