A pregnant woman with Ebstein's anomaly. A case report.

Ebstein's anomaly is characterised by downward displacement of the tricuspid valve into the right ventricle. The most deformed leaflets are the septal and mural ones. The abnormally situated tricuspid orifice produces a portion of the right ventricle lying between the atrioventricular ring and the origin of the valve. This proximal segment is atrialized. Commonly associated anatomical defects include a atrial septal second defect, a ventricular septal defect, pulmonary stenosis or atresia, and mitral valve prolapse. An accessory conduction pathway (Wolf-Parkinson White syndrome) was found in this malformation. It is thought that this malformation is due to a direct teratogenic effect of lithium on the atrioventricular junction. Ebstein's anomaly can be accurately identified by echocardiography and angiography.