Several uncommon congenital abnormalities are compatible with survival into adulthood.
Ebstein’s anomaly is characterized by apical displacement of the tricuspid valve into the right ventricle. As a result, the basal portion of the right ventricle forms part of the right atrium and leaves a small functional right ventricle.
The tricuspid leaflets are often dysplastic, and the leaflets may partially adhere to the interventricular septum or right ventricular free wall, often with significant tricuspid regurgitation. The degree of right ventricular dysfunction depends on the size of the”functioning” right ventricle and the severity of the tricuspid regurgitation. A patent foramen ovale or ostium secundum ASD is present in >50% of patients and may result in right to left shunt flow as right atrial pressure increases. Supraventricular arrhythmias are common in Ebstein’s anomaly, as is ventricular preexcitation associated with Wolff -Parkinson-White syndrome. Inversion of the ventricles and abnormal positionin of the great arteries characterize congenitally correcte transposition of the great arteries(L- transposition). In this anomaly, the anatomic right ventricle lies on the left and receives oxygenated blood from the left atrium. Blood is ejected into an anteriorly displaced aorta. The anatomic left ventricle lies on the right and receives venous blood from the right atrium and ejects it into the posteriorly displayed pulmonary artery . The clinical course the of patients corrected transposition depends on the severity of other intracardiac the anomalies.
When the abnormality is an isolated lesion,many persons survive into adulthood without symptoms. In some persons the systemic ventricle may fail,and pulmonary congestion may result. Associated anomalies include atrioventricular nodal block, VSD, and Ebstein’s anomaly.