What is double outlet right ventricle?
Double outlet right ventricle (DORV) is a rare congenital heart defect (the
baby is born with it) involving the "great arteries" (the aorta and the
pulmonary artery). In a normal heart, the aorta exits from the left ventricle
and pumps blood to the body, while the pulmonary artery exits from the right
ventricle and pumps blood to the lungs (where it picks up oxygen). In DORV, the
aorta and the pulmonary artery both come out of the right ventricle.
The causes of DORV are not completely understood. DORV appears in many forms,
with most including a ventricular septal defect . A ventricular septal defect is
a hole in the wall of the septum, the muscular wall that separates the right
ventricle from the left ventricle. Cases of DORV can vary due to the size of the
ventricular septal defect, where the ventricular septal defect is located, and
the existence of pulmonary valve stenosis (a blockage in the flow of blood from
the right ventricle to the pulmonary artery).
Having the hole in the septum is actually helpful in DORV because blood that
has oxygen is able to pass through the hole from the left ventricle into the
right for circulation in the body. If there were no hole, the blood could not be
distributed. However, because the right ventricle normally collects oxygen-poor
blood to pump to the lungs, the two types of blood mix and the baby does not get
the proper levels of oxygenated blood.
What are some common types of double outlet right ventricle defects?
One of the ways that DORV is diagnosed is by the location of the ventricular septal defect:
- When the ventricular septal defect is just under the aorta, the
condition is called DORV with subaortic ventricular septal defect.
- When the ventricular septal defect is just under the pulmonary artery,
the condition is called DORV with subpulmonary ventricular septal defect, or
Taussig-Bing anomaly.
- When the ventricular septal defect is under both of the great arteries,
the condition is called DORV with doubly committed ventricular septal defect.
- When the ventricular septal defect is not near the aorta or the
pulmonary artery, the condition is called DORV with non-committed
ventricular septal defect or DORV with remote ventricular septal defect.
Another factor in determining the type of DORV is whether or not the
condition includes pulmonary valve stenosis and how extensive the stenosis is.
In addition, an infant can have DORV along with other types of congenital heart defects.