Neonatal Ebstein’s Anomaly

Abstract

Ebstein’s anomaly is a rare congenital heart defect that results from varying degrees of failure of delamination of the tricuspid valve leaflets from the endocardium of the right ventricle. This results in apical displacement, particularly of the septal and posterior leaflets of the tricuspid valve. The anterior leaflet is typically broad and sail-like and is based at the true annulus. The right ventricle is also myopathic, with a reduced functional portion as a result of atrialization. Age at presentation can vary from neonate to adulthood. Symptoms in the neonate result from a combination of tricuspid valve regurgitation, right ventricle dysfunction, inadequate left ventricular filling owing to ventricular septal bowing, inadequate pulmonary blood flow, and arrhythmias. Mortality rates for symptomatic neonates with Ebstein’s anomaly are extraordinarily high. Neonates with Great Ormond Street Echocardiogram (GOSE) scores greater than 1.5, or greater than 1.1 with associated cyanosis, have a mortality approaching 100%. In addition, neonates with severe cardiomegaly with a cardiothoracic ratio greater than 0.8, those with severe tricuspid valve regurgitation, and acyanotic neonates with a GOSE score greater than 1.0 associated with functional pulmonary atresia and a large atrial septal defect also have a dismal prognosis. Surgical approaches for the management of these critically ill neonates have varied across institutions and include the Starnes right ventricle exclusion procedure, systemic-pulmonary shunts, hybrid-type procedures, biventricular repair and heart transplantation. This chapter covers the anatomy, pathophysiology, associated malformations of neonatal Ebstein’s anomaly and provides an overview of management options for this serious congenital heart disease.