Double outlet right ventricle (DORV) is a conotruncal congenital heart defect in which BOTH great arteries (aorta AND pulmonary artery) arise entirely or predominantly from the morphologic right ventricle (normally, the aorta arises from the left ventricle and the pulmonary artery from the right ventricle). This results in obligatory mixing of oxygenated and deoxygenated blood, with the clinical presentation determined by three critical anatomic variables: 1. VSD position relative to the great arteries: A ventricular septal defect (VSD) is almost always present and serves as the ONLY outlet for the left ventricle. The relationship of the VSD to the great arteries determines the hemodynamic physiology: - Subaortic VSD (~65% of DORV): oxygenated blood from the left ventricle preferentially streams through the VSD to the aorta → physiology resembles a LARGE VSD with LEFT-TO-RIGHT SHUNT → increased pulmonary blood flow → congestive heart failure (CHF) rather than cyanosis. Signs: tachypnea, poor feeding, failure to thrive, hepatomegaly, pulmonary overcirculation on CXR. - Subpulmonic VSD (Taussig-Bing anomaly, ~20%): oxygenated blood from the left ventricle streams through the VSD preferentially to the pulmonary artery...