Single Ventricle Defects

What is a single ventricle defect?

A single ventricle defect is a type of heart defect that a child is born with. It occurs when one of the two pumping chambers in the heart, called ventricles, isn’t large enough or strong enough to work correctly. In some cases, the chamber might be missing a valve.

Single ventricle heart defects can cause children to become cyanotic (turn a blue color), since a mixture of oxygen-poor (blue) and oxygen-rich (red) blood vessels leaves the heart and goes to the body. Just how much oxygen or how little oxygen depends on the type, location, and severity of the defect. Some children will only be mildly cyanotic, while others won’t have enough oxygen in the blood to meet the body's needs and will need early treatment.

Single ventricle defects are rare, affecting only about five out of 100,000 newborns. They are also one of the most complex heart problems, usually requiring at least one surgery.

There are several types of single ventricle defects. These include:

• tricuspid atresia
• hypoplastic left heart syndrome (HLHS)
• mitral valve atresia (usually associated with HLHS)
• single left ventricle
• double inlet left ventricle (DILV)
• double outlet right ventricle (DORV)
• pulmonary atresia with intact ventricular septum (PA/IVS)
• Ebstein’s anomaly
• atrioventricular canal defect (AV Canal)

The uniquely complex anatomy of the heart and its chambers make each ventricle defect different.

How we care for single ventricle defects

At Boston Children’s Hospital, our experienced surgeons in the Department of Cardiac Surgery treat some of the most complex pediatric heart conditions in the world, with overall success rates approaching 98 percent — among the highest in the nation among large pediatric cardiac centers.

Boston Children’s Congenital Heart Valve Program cares for children with congenital heart defects that involve absent or malfunctioning heart valves. Our surgeons have a strong record of excellence in heart valve repair and replacement, including minimally invasive techniques.

Babies with single ventricle defects usually need emergency treatment. Our cardiac intensive care unit (CICU), cardiac catheterization (cath) labs, and operating rooms deal with the urgent needs of our smallest patients 24/7. The Benderson Family Heart Center’s CICU was one of the first such units created anywhere, and professionals from many countries visit our CICU year-round to learn the advanced techniques of post-operative care.