Ebstein's malformation is a rare congenital cardiac anomaly characterized by rotational displacement of the septal and inferior leaflets of the tricuspid valve such that they are hinged within the right ventricle, rather than as expected at the atrioventricular junction. The disease is Ebstein anomaly (MONDO_0009144). Also known as: Ebstein anomaly (disease), Ebstein anomaly of the tricuspid valve, Ebstein's anomaly, Ebstein's anomaly (disorder) [ambiguous], Ebstein's anomaly of common atrioventricular valve, Ebstein's anomaly of right atrioventricular valve, Ebstein's anomaly of tricuspid valve.