Ebstein's anomaly is a congenital heart defect in which the opening of the tricuspid valve is displaced towards the apex of the right ventricle of the heart. The valve leaflet themselves are to a varying degree atached to the walls and septum of the right ventricle. There is subsequent atrialization of a portion of the morphologic right ventricle (which is then contiguous with the right atrium). This causes the right atrium to be large and the anatomic right ventricle to be small in size. more...
While Ebstein's anomaly is defined as the congenital displacement of the tricuspid valve towards the apex of the right ventricle, it is often associated with other abnormalities.
Typically, there are anatomic abnormalities of the tricuspid valve, with enlargement of the anterior leaflet of the valve.
About 50% of individuals with Ebstein's anomaly have an associated shunt between the right and left atriums, either an atrial septal defect or a patent foramen ovale.
About 50% of individuals with Ebstein's anomaly have evidence of Wolff-Parkinson-White syndrome, secondary to the atrialized right ventricular tissue.
Read more at Wikipedia.org