Single Ventricle Defects

To make an appointment with a Children's Heart Program physician, call 410-328-4348.

A single ventricle congenital heart defect is the general name for many types of heart defects that result in having one functional ventricle, or pump.

In some cases, one of the ventricles is hypoplastic, or small. In other situations, one of the valves that lets blood enter into the ventricles is missing (atresia) or does not let much blood go across it (stenosis).

Some of the specific types of single ventricle congenital heart defects include:

There are many other specific diagnoses that are classified as single ventricle congenital heart defects. The main thing that brings them together is that instead of two ventricles (one to pump to the lungs and one to pump to the body) there is only one usable pump.

There is no known cause of these types of heart defects. Some patients may have other birth defects, and some have genetic disorders. Certain types of single ventricle heart defects are more likely to be associated with additional defects.

How are these diagnosed?

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Single ventricle heart defects are often diagnosed by fetal ultrasound before the baby is born.

First trimester screening for chromosomal abnormalities is a good way to identify patients who might have an increased risk for cardiac defects.

Single ventricle heart defects can be diagnosed as early as 12 weeks gestation. In some cases, single ventricle heart defects develop during the pregnancy and cannot be diagnosed until the second trimester targeted scan. Other children may not be identified until after birth.

Babies with single ventricle heart defects may initially appear healthy, although their oxygen levels will be decreased. For this reason, they may fail their newborn pulse oximetry screening. Over time, they may develop difficulty breathing, poor feeding, cool and pale extremities, or appear blue.

Diagnosis of a single ventricle heart defect would be confirmed with an echocardiogram.