Ebstein's anomaly.

Ebstein's anomaly is a rare congenital heart disease, accounting for less than 1% of all congenital heart diseases, characterized by a wide clinical, electrocardiographic, echocardiographic, anatomic and prognostic polymorphism. The disease can be fatal since birth or may remain asymptomatic until adulthood, sometimes being associated with septal defects, transposition of great vessels, preexcitation syndromes, or left ventricular noncompaction. The genetic changes underlying this syndrome are not fully known, but in the cases associating left ventricular nonompaction a mutation in MYH7 gene encoding the beta-myosin heavy chain was recently detected.