Hypertrophic cardiomyopathy: practical steps for preventing sudden death.

Hypertrophic cardiomyopathy (HCM) is a rare cause of death among the many participants in sports and recreational athletics, but it attracts widespread attention because the deaths occur in young, apparently healthy people. Differentiating HCM from conditioning hypertrophy (athlete's heart) remains a challenge. Routine detection of HCM patients is most commonly done with family history, physical examination, electrocardiography, and echocardiography. Keys to the differential diagnosis include evidence of heterogenous left ventricle hypertrophy, left atrial enlargement, unusual ECG patterns, and family history or gene mutations. Molecular detection methods for known defective genes in HCM have not yet become routine clinical tools. Athletes with unequivocal HCM should not participate in competitive sports, except for perhaps some low-intensity ones.