What is a single ventricle heart defect?

The heart has four chambers. The upper chambers, called atria, receive blood flowing into the heart. The lower chambers, called ventricles, pump blood out of the heart.

A child with a single ventricle defect is born with a heart that has only one ventricle that is large enough or strong enough to pump effectively. Single ventricle heart defects include:

• Hypoplastic left heart syndrome (HLHS)
• Tricuspid atresia
• Double outlet left ventricle (DOLV)
• Some heterotaxy defects

• Other congenital heart defects

Single ventricle heart defects are also referred to as single ventricle lesions or anomalies.

Treatments for single ventricle heart defect

The various types of single ventricle heart defects are very different. For instance, in hypoplastic left heart syndrome (HLHS), the left side of the heart doesn’t work correctly. In tricuspid atresia, it's the right side. Even though the types of defects are different, the treatments are similar.

Single ventricle defects require a series of open-heart procedures, performed over several years. This is called “staged reconstruction.” Surgeons reconfigure the heart and circulatory system during the procedures.

Your Cardiac Center team will explain the procedures to you in detail, based on your child’s heart anatomy. Your child will also be monitored between surgeries by the Infant Single Ventricle Monitoring Program.

Many patients with single ventricle defects may also require cardiac catheterization during childhood. CHOP’s interventional cardiologists treat a high volume of single ventricle patients using catheterization. The Cardiac Center has also established a standard of approach to assessing these patients, which includes magnetic resonance imaging and catheterization.