Double-Outlet Right Ventricle With Intact Ventricular Septum and Left Atrioventricular Valve Regurgitation in a Patient With Right Atrial Isomerism

We present a very rare case of right atrial isomerism, double-outlet right ventricle, and incomplete atrioventricular septal defect (intact ventricular septum). In the neonatal period, the right ventricle was compressed by a "blind-ended" left ventricle with mild-to-moderate left atrioventricular valve regurgitation. The regurgitation gradually decreased from mild-to-moderate to mild with body weight gain. The patient underwent systemic-to-pulmonary shunt at three months of age and bilateral bidirectional Glenn at eight months of age. Although the echocardiogram demonstrated that the right ventricle was still compressed by the left ventricle, over time the size of the left ventricle reduced significantly and the left atrioventricular valve regurgitation became trivial.