Prenatal diagnosis of pulmonary atresia with an intact ventricular septum and Ebstein malformation

Ebstein malformation is rare, accounting for approximately 0.3% to 0.5% of congenital cardiac malformations. Ebstein malformation of the tricuspid valve is a congenital malformation in which the septal and posterior mural leaflets of the tricuspid valve are displaced downward into the inlet portion of the right ventricle (RV). The salient anatomic feature for making the diagnosis is the finding of a hinge point of the septal and mural valve leaflets within the inlet component of the RV rather than at the atri-oventricular junction. Furthermore, the septal and mural leaflets show varying degrees of distal displacement from their annular attachment, and there is usually some dysplasia of the leaflets. Pulmonary atresia with an intact ventricular septum is also an uncommon malformation, with a reported incidence of between 2.5% and 4% of congenital heart disease cases, or 1 per 22,000 births. The location of pulmonary atresia is usually at the valve, but in some cases the infundibulum is also atretic. An interatrial communication provides the only outlet for systemic venous return. The morphologic characteristics of the pulmonary valve vary from being tricuspid with fusion of the commissures in cases with a better developed RV and infundibulum to being poorly formed and primitive in cases with an underdeveloped RV and infundibulum. In pulmonary atresia, the pulmonary artery size varies, and the pulmonary trunk can be normal, small, or even completely atretic. Thus, an intact pulmonary trunk does not guarantee that there is no pulmonary atresia. We prenatally diagnosed pulmonary atresia in a fetus with an intact interventricular septum and Ebstein malformation; on neonatal angiocardiography, the fetus had a normally developed main pulmonary artery (MPA) with an imperforate obstruction of the pulmonary valve.