Normally, the aorta arises from the left ventricle (the chamber of the heart that usually pumps blood to the body). The pulmonary artery normally arises from the right ventricle.
In DORV, both arteries arise from the right ventricle. This is a problem because the right ventricle carries oxygen-poor blood, which the aorta then carries throughout the body. DORV always includes a ventricular septal defect (VSD). Pulmonary valve stenosis or transposition of the great arteries may also be part of the defect.
The presence of a VSD helps the infant with DORV, because oxygen-rich blood from the lungs flows from the left side of the heart, through the VSD opening and into the right chamber, mixing with the oxygen-poor blood. However, the body may still not get enough oxygen even with this mixture, and the heart has to work harder to try to bring more oxygen-rich blood to the body.
There are several types of DORV. The difference between these types is the location of the VSD compared to the location of the pulmonary artery and aorta. The type of DORV, and the presence or absence of pulmonary valve stenosis, affect the severity of signs and symptoms the baby may have.
Patients with DORV often have other heart abnormalities such as:
- Coarctation of the aorta
- Mitral valve problems
- Pulmonary atresia
- Pulmonary valve stenosis
- Right aortic arch
- Transposition of the great arteries