Diagnosis and management of Ebstein anomaly of the tricuspid valve

Ebstein anomaly (EA) is a rare congenital heart defect that may not be detected until late in adolescence or adulthood. Since the original description in a 19-year-old laborer with severe tricuspid valve (TV) regurgitation in 1866, our understanding of this rare condition has increased to the recognition that it is an abnormality not only of the TV, but also of the right ventricle (RV). EA is the result of failure of delamination of the TV leaflets from the interventricular septum, resulting in adherence of the leaflets to the underlying myocardium. This results in a wide variety of abnormalities, including apical and posterior displacement of the dilated TV annulus; dilation of the "atrialized" portion of the RV; and fenestrations, redundancy, and tethering of the anterior leaflet of the TV. The malformed TV is usually regurgitant, but may rarely be stenotic. The clinical manifestations of EA in the adult depend on several factors, including the extent of TV leaflet distortion, degree of tricuspid regurgitation (TR), right atrial pressure, and presence of a right-to-left atrial level shunt. Over the past several decades, advances in diagnostic imaging and surgical techniques have contributed to our current management of this challenging congenital heart defect.