Ebstein's Anomaly

Ebstein's anomaly is a congenital heart defect in which the tricuspid valve (TV) leaflets are abnormally displaced towards the cardiac apex.  This lesion results secondary to a failure of delamination of the tricuspid valve 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 tricuspid valve. The malformed tricuspid valve is usually regurgitant, but may rarely be stenotic. The clinical manifestations of this lesion 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 and in may presence in infancy should it be a more severe variant and be life threatening when a circular shunt develops.