Double outlet right ventricle (DORV), as depicted in the image below, is a type of ventriculoarterial connection in which both the aorta (AO) and pulmonary artery (PA) arise entirely or predominantly from the right ventricle (RV). The only outlet from the left ventricle (LV) is a ventricular septal defect (VSD).
Double outlet right ventricle (DORV) with transposition of the great arteries accounts for 26% of cases of DORV. The aorta (AO) is anterior and to the right of the pulmonary artery (PA), and both arteries arise from the right ventricle (RV). The only outflow from the left ventricle (LV) is a ventricular septal defect (VSD), which diverts blood toward the RV. Pulmonary veins drain into the left atrium (LA) after blood has been oxygenated in the lungs (L). Systemic venous return is to the right atrium (RA).
DORV is usually associated with concordant atrioventricular (AV) connections (ie, the right atrium drains into the RV and the left atrium drains into the LV). Fibrous discontinuity is present between the mitral and semilunar valves. Conus is present beneath both the aortic and pulmonary valves (subpulmonic and subaortic conus).
DORV is virtually always associated with a VSD and, occasionally, with an atrial septal defect. Patients with DORV may also present with varying degrees of left ventricular hypoplasia and mitral valve anomalies such as stenosis or atresia. Straddling of the AV valves across the VSD may be present. The aortic valve may be stenosed, and the aortic arch may show coarctation or even interruption. Anomalies of the coronary arteries (CAs), such as those that occur in patients with dextro-transposition of the great arteries may be present. These include the left circumflex arising from the right main, a single right CA, a single left CA, and inverted origin of the CA.
The AV node and His-Purkinje fibers may be displaced in DORV because of the anatomic characteristics of these hearts.
In DORV, the great arteries may take different relationships as follows:
In 64% of cases of DORV, the great arteries lie side by side with the AO to the right of the PA and both semilunar valves lying in the same transverse and coronal plane (physiologically similar to tetralogy of Fallot [TOF]).
In 26% of cases of DORV, the AO is anterior and to the right of the PA, physiologically resembling transposition of the great arteries (ie, d-transposition of the great arteries), with a VSD.
In 7% of cases of DORV, the AO is anterior and to the left of the PA (levo-transposition of the great arteries).
Only 3% of cases of DORV have a normal great artery relationship with the AO arising posterior and to the right of the PA.