Aorto–Right Ventricular Tunnel Causing Functional Tricuspid Atresia

A girl with symmetrical intrauterine growth retardation and a birth weight of 2240 g was delivered at term by primary cesarean section to a 27-year-old primiparous woman. Fetal echocardiography had shown a nearly atretic tricuspid valve. Postnatally, the child stabilized rapidly but showed signs of heart failure with tachypnea and general weakness, as well as cyanosis (transcutaneous oxygen saturation, 85%).The presence of an aorto–right ventricular (RV) tunnel (ARVT) was confirmed by transthoracic echocardiography, which showed a 5 to 6×15–mm structure extending from the proximal ascending aorta to the outflow tract of the RV, with the left coronary artery originating from the aortic end of the tunnel. The ARVT caused a strong left-to-right shunt during diastole (Figure 1 and Movies I and II in the online-only Data Supplement).Figure 1. Echocardiographic views. A , Apical 4-chamber view. Arrow indicates the minimal tricuspid valve opening during diastole. B , Aorto–right ventricular tunnel (ARVT). C , Diastolic left-to-right shunt through the ARVT (arrow). RA …