Eligibility and Disqualification Recommendations for Competitive Athletes With Cardiovascular Abnormalities: Task Force 3: Hypertrophic Cardiomyopathy, Arrhythmogenic Right Ventricular Cardiomyopathy and Other Cardiomyopathies, and Myocarditis: A Scientific Statement From the American Heart Associat

Hypertrophic cardiomyopathy (HCM)1,2 is a major focus of this document given that it is the single most common cause of sudden death in young competitive athletes in the United States, responsible for at least one-third of these events.3 HCM is the most frequent nontraumatic cause of sudden death in the young1,2 and a common genetic heart disease, occurring in at least 1 in 500 people in the general population.4 HCM is a clinically and genetically heterogenous disease, associated with >1500 mutations in ≥11 major genes (and a variety of other susceptibility genes with lesser evidence for pathogenicity), encoding proteins of the cardiac sarcomere, adjacent Z disk, and calcium handling.5 Although HCM is associated with substantial diversity in morphological expression,6 clinical diagnosis usually occurs with recognition of the characteristic disease phenotype, that is, left ventricular (LV) hypertrophy without chamber dilatation in the absence of another cardiac or systemic disease capable of producing the magnitude of hypertrophy evident.1,6 Neither systolic anterior motion of the mitral valve, hyperdynamic LV function, or identification of pathogenic sarcomere mutations is obligatory for the clinical diagnosis of HCM.2 Atrial fibrillation is a common cause of morbidity in HCM, occurring in ≈20% of patients, although usually after 30 years of age.1,2 Notably, the clinical presentation and course are diverse, with unexpected sudden death in the young the most visible disease complication. A major impetus in HCM has been the identification of those patients at increased risk for sudden death. Indeed, a risk-stratification algorithm has been largely effective in identifying those people at highest risk who are eligible for primary prevention of sudden death with an implantable cardioverter-defibrillator (ICD),7–10 thereby markedly reducing HCM-related mortality to 0.5% per year.7 …