Phenotyping the Many Faces of Hypertrophic Cardiomyopathy.

Hypertrophic cardiomyopathy is the most common inherited cardiomyopathy and is defined by the presence of left ventricular hypertrophy 15 mm or greater in the absence of any other identifiable cause. Beyond this definition, clinical phenotype is heterogeneous, and associated clinical manifestations occur in varying proportions of patients, including left ventricular outflow tract obstruction, systolic anterior motion of the mitral valve with associated mitral regurgitation, ventricular arrhythmias, and sudden cardiac death. Accurate clinical phenotyping allows the identification of groups with distinct natural history and prognosis, with risk stratification being crucial for prevention of sudden cardiac death.