Hypertrophic cardiomyopathy in children.

Hypertrophic cardiomyopathy (HCM) is the second commonest form of heart muscle disease affecting children and adolescents and is a leading cause of sudden death in young athletes. The aetiology of HCM is heterogeneous in the paediatric population, and includes inborn errors of metabolism, neuromuscular disorders and malformation syndromes. However, most cases of apparently idiopathic HCM in childhood are caused by mutations in cardiac sarcomere protein genes. Patients with metabolic or syndromic HCM usually present in infancy or early childhood, whereas those with neuromuscular disorders are more frequently diagnosed in adolescence. The diagnosis of HCM in infants is often made during evaluation for a heart murmur or congestive heart failure. Older children are usually referred for evaluation of symptoms, electrocardiographic abnormalities or heart murmur, or for family screening following the diagnosis of HCM in a relative. Risk stratification in the paediatric population remains a challenge. As most cases of HCM are familial, evaluation of first-degree relatives and other family members at risk of inheriting the disease should be a routine component of clinical management.