Double Outlet Right Ventricle

In a normal heart, the aorta arises from the left ventricle and the pulmonary artery arises from the right ventricle. In double outlet right ventricle (DORV), both great arteries arise entirely or largely from the right ventricle. Blood from the left ventricle can leave it only through a hole in the wall between the ventricles. This defect is rare, about 1 to 2 of every 100 congenital heart defects, and forms in the early weeks of pregnancy. An overview of other congenital defects is covered on the Congenital Heart Disease page.

One Name, Several Forms

Symptoms and treatment depend greatly on the location of the hole and whether the pathway to the lungs is narrowed. If the hole lies below the aorta without narrowing, the condition resembles a large hole in the ventricular septum with too much blood flow to the lungs, covered on the Ventricular Septal Defect page. If the pathway to the lungs is narrowed, it resembles tetralogy of Fallot and the baby looks blue. If the hole lies below the pulmonary artery (Taussig-Bing anomaly), it resembles transposition of the great arteries and often comes with narrowing of the aorta. There are also holes located far from both vessels, which make repair more complex.

Surgery Is Planned Individually

The goal of surgery is to channel blood from the left ventricle to the aorta and blood from the right ventricle to the pulmonary artery. This can be done with a tunnel inside the ventricle from the hole to the aorta, combined with an arterial switch operation, widening of the pathway to the lungs, or placement of a conduit. If the anatomy does not allow the two ventricles to work separately, the doctor may choose a single-ventricle pathway with the Glenn and then the Fontan operation. Some babies need a temporary procedure first, for example to reduce excessive blood flow to the lungs or to increase blood flow in a baby who is very blue.

Lifelong Monitoring

After surgery, the outflow pathway to the aorta or to the lungs can narrow again, the septum can leak, and rhythm disorders can develop. The 2020 ESC and 2018 AHA/ACC guidelines recommend regular lifelong checkups at a service with expertise in congenital heart disease, including when teenagers move on to adult doctors.

This defect can be seen on a pregnancy ultrasound and confirmed with fetal echocardiography. After birth, doctors suspect it from a heart murmur, a bluish color, low oxygen saturation on screening, or signs of heart failure in the first few weeks.

Echocardiography is the main test. It assesses, among other things, the position of the septal hole relative to the aorta and pulmonary artery, the distance between them, whether there is narrowing of the pathway to the lungs or to the aorta, the position of the valves, and the shape of the aortic arch. Because these relationships determine the type of surgery, a cardiac CT scan or MRI is often used to create a three-dimensional image. Cardiac catheterization is done if the lung pressure needs to be measured or the blood vessels need to be mapped. Genetic testing may be recommended if there are other abnormalities outside the heart.

Take your baby to the emergency room right away if they look increasingly blue, are very limp, are hard to wake, are breathing very fast, or refuse to feed. Make an appointment with a pediatric cardiologist if:

• A pregnancy ultrasound shows an abnormality of the great arteries or the septum of the fetal heart.
• Your baby's oxygen saturation screening result is abnormal.
• Your baby breathes fast, sweats during feeding, or is not gaining weight.
• The doctor finds a heart murmur in your baby or child.
• Your child tires more quickly after surgery, becomes short of breath while playing, has palpitations, or has fainted.
• A teenager or adult who has had surgery has not had a checkup for a long time.