Ebstein’s anomaly is a congenital heart defect in which the tricuspid valve leaflets are abnormally displaced toward the cardiac apex resulting in a small right ventricle and massive enlargement of the right atrium.
Ebstein's anomaly is frequently associated with Wolff-Parkinson-White syndrome which can manifest as atrioventricular reentrant tachycardia (AVRT) or atrial fibrillation with pre-excitation. Treatment is emergent cardioversion, procainamide and eventually ablation.
Ebstein's anomaly is associated with atrial septal defects in about 50% of cases.
Tricuspid valve regurgitation can ensue and frequently requires surgical repair. Indications for repair of the Ebstein’s anomaly and associated atrial septal defect (if present) include New York Heart Association Functional Class III or IV symptoms, marked right heart enlargement, cyanosis, and transient ischemic attack (TIA) or stroke.
Note: If a pregnant mother is taking lithium, the risk of Ebstein's anamaly in the newborn is markedly higher.