When lithium hurts: a look at Ebstein anomaly.

Ebstein anomaly (EA) is a congenital defect of the tricuspid valve (TV) and the right ventricle (RV) in which the attachments of the septal and posterior valve leaflets are apically displaced. The latter creates 3 morphologic components inside the right heart, namely the right atrium proper, the atrialized RV, and the functional RV. This rare anomaly accounts for <1.5% of all congenital heart diseases. The current opinion among authors is that it is a genetically heterogeneous condition caused by failure of delamination of the TV leaflets from the underlying myocardium and the interventricular septum. Its characteristic electrocardiographic findings include tall, broad, right atrial P waves, prolonged PR intervals, and deep Q waves in the right precordial leads. Echocardiography is currently the best technique for diagnosing this anomaly, although cardiac magnetic resonance imaging is also gaining traction as an alternative modality. The management strategies for EA correlate with the age of the patient, severity of the heart disease, and/or associated cardiac abnormalities. TV repair, rather than valve replacement, is preferred because of its favorable long-term prognosis. Nevertheless, a large, randomized study is still needed to compare the different valve repair techniques used in patients with EA.