Arrhythmogenic right ventricular cardiomyopathy
The disease is characterised by a replacement of cardiac muscle tissue by connective tissue and fat, particularly in the right ventricle. This may lead to dilatation (widening) of the right ventricle, dysfunction and aneurysm formation. As a result, malignant arrhythmias can occur. The disease often occurs in men between 20 and 40 years of age and is inherited as an autosomal dominant trait. The estimated prevalence in the general population is 1 in 1000. Often, the first symptoms are seen during physical exercise in the form of syncope, arrhythmias and even SCD. If affected, patients should not participate in competitive sport.
Coronary artery disease
In athletes older than 35 years (also rarely in younger ones) coronary artery disease is the predominant cause of sudden death. Intensive exercise may lead to plaque rupture in athletes at risk, followed by myocardial infarction and malignant arrhythmias.
Coronary Artery Anomalies
Coronary anomalies are rare congenital malformations and characterised by an atypical origin of the right or left coronary artery. Most coronary anomalies are asymptomatic and represent incidental findings. The most common type of coronary anomaly associated with SCD is the false origin of the left coronary artery with subsequent run between the aorta and the pulmonary artery. This may lead to a dynamic compression of the left vessel wall during increased heart activity – myocardial ischemia may occur and trigger ventricular arrhythmias. Competitive sport may be continued after successful surgical repair and normal results in medical follow-ups.
Hypertrophic cardiomyopathy is a primary myocardial disorder with an autosomal dominant pattern of inheritance, characterised by an asymmetric thickening (hypertrophy) of the muscle of the left ventricle. In approximately 25% of patients there is a narrowing (obstruction) of the left ventricular outflow tract. The estimated prevalence of HCM in the general population is 1 in 500. Men and women are equally affected. Most patients are asymptomatic. Shortness of breath, chest pain, palpitations or syncope may occur. Exercise-dependent cardiac arrhythmias can lead to sudden death. Athletes with HCM are generally discouraged from competitive sport.
Congenital ion channel diseases (long QT or short QT syndromes, Brugada syndrome, catecholaminergic polymorphic ventricular tachycardia) are a group of rare cardiac arrhythmia syndromes caused by genetic changes in certain ion channels in the heart muscle. This affects the electrical functioning of the heart and may lead to malignant arrhythmias, syncope and cardiac arrest. Athletes with a congenital ion channel disease should not participate in competitive sport.
Myocarditis is an inflammatory disease of the heart muscle which is usually caused by a viral infection, rarely by bacteria. The disease represents a side effect of a general infection or occurs as a complication of an infectious disease. The clinical course is highly variable, ranging from asymptomatic or mild (majority of cases) to fulminant cases (rare). Symptoms such as fatigue, weakness or palpitations are usually associated with an infection. Athletes with a proven myocarditis should refrain from sports activity for three to six months.