Single Ventricle Defects

A single ventricle defect is a congenital (present at birth) heart condition, and one of the most complex heart defects. It means that only one of the heart’s two ventricles is large enough or strong enough to effectively pump blood. Single ventricle defects occur in five out of every 100,000 live births. This type of defect develops as the heart grows during the first eight weeks of pregnancy. It might be caused by a combination of genes and factors in the baby’s and mother’s environment during this early stage of development.

Single ventricle defects may include:

As the leading providers of pediatric heart care in Louisville and Southern Indiana, the cardiothoracic surgeons at Norton Children’s Heart Institute, affiliated with the UofL School of Medicine, are experienced with successfully repairing single ventricle defects.

The board-certified and fellowship-trained specialists at Norton Children’s Heart Institute have the skills and experience to provide a pinpoint diagnosis and develop a customized treatment plan for you and your child.

Single Ventricle Defect Symptoms

A single ventricle defect causes mixing of oxygen-rich blood with oxygen-poor blood in the heart. A newborn with this condition can have:

These signs can start a few hours to a day or so after the birth. Without treatment, the baby’s blood pressure will fall too low to meet the body’s needs.

Single Ventricle Defect Diagnosis

Specialists at Norton Children’s Heart Institute diagnose single ventricle defects either during pregnancy with a fetal echocardiogram or shortly after birth with an echocardiogram, a test that uses ultrasound to build pictures of the heart. However, it is possible that some children with single ventricles will be diagnosed at a later time.

The following tests may be used to find more details about a child’s specific condition:

  • Pulse oximetry, a test done with a small medical device that measures oxygen in the body; it can show low oxygen levels caused by a heart that isn’t working properly
  • Chest X-rays, which show pictures of the heart and lungs, making major flaws visible
  • A cardiac echocardiogram, which uses sound waves (ultrasound) to produce images of the heart and blood vessels on a screen; this test shows whether the heart is pumping properly and how much blood is going to the lungs and to the rest of the body
  • Occasionally, a single ventricle defect can be seen on a prenatal ultrasound; the doctor will then order a more detailed cardiac echocardiogram.

In some cases, a doctor may order the following additional tests to confirm the diagnosis:

  • Electrocardiogram (EKG or ECG), a test that checks the heart’s electrical action to show damage or irregular rhythms
  • Cardiac magnetic resonance imaging (MRI), a test that uses radio waves, magnets and a computer to form three-dimensional pictures of the heart; these pictures can show structural issues, such as an enlarged ventricle
  • Cardiac catheterization, a procedure where a thin, long tube is inserted into a blood vessel at the belly button or groin and guided into the heart. With this procedure, the doctor can see more details of a single ventricle defect and determine blood pressure and oxygen levels in the heart’s chambers. The doctor also can widen narrowed blood vessels to boost blood oxygen levels short-term during this procedure.

Single Ventricle Defect Treatments

The cardiothoracic surgeons at Norton Children’s Heart Institute will repair single ventricle defects with a combination of procedures and surgeries based on short-term and long-term needs.

Short-term solutions

Balancing the amount of blood flow between the body and the lungs is the first short-term solution. It requires one of these procedures:

  • Pulmonary artery banding if too much blood is going to the lungs; blood flow is reduced by constricting the artery to the lungs
  • Blalock-Taussig shunt if not enough blood is going to the lungs; an artificial tube is inserted to increase the blood flow to the lungs

Sometimes, a newborn with a single ventricle defect won’t need a repair right away. Surgery will be necessary, but can wait until the child is older.

In complex cases, surgery such as a Norwood procedure, used in hypoplastic left heart syndrome, is necessary to reconstruct the way blood flows to or from the heart. All newborns need unobstructed blood flow to the body with a proper amount of blood flow going to the lungs.

Long-term solutions

In order to prepare for a long-term solution, a cardiac catheterization will help evaluate the structures of the heart and measure blood pressures within the heart and lungs. The catheterization will help determine if the child is able to have the next-stage surgery, called the bidirectional Glenn procedure.

Two large veins bring unoxygenated blood back from the body, one from the upper body and one from the lower body. In the bidirectional Glenn procedure, usually done when the child is 6 to 8 months old, the superior vena cava vein from the upper body is connected directly to the lungs which decreases the work load on the single ventricle while also increasing oxygen saturations. The Fontan procedure, usually done between ages 2 to 4 years, is the third modification in single ventricle treatment. In this procedure, blood from the inferior vena cava from the lower body is rerouted from the heart to the pulmonary artery. This further decreases the volume load on the single ventricle and again increases oxygen saturations. After completion of the Fontan procedure, the patient may have normal saturations, or lower saturations if a fenestration or hole was left connecting the Fontan tunnel with the heart. Your pediatric cardiologist will decide if the fenestration, if present, may be closed at a later time.

Single Ventricle Defect Complications and After Care

After completing the staged repairs for a single ventricle, children may lead a productive life. However, complications can occur, including heart rhythm issues that require medication or pacemaker placement. Lung issues also can occur, including a decrease in blood oxygen levels. Digestive issues can occur due to protein loss in the stool, which results in swelling and water retention. Some patients, despite doing well after surgeries, may need a heart or lung transplant later in life

The hope for children with single ventricle defects is that they will live into adulthood with as few long-term complications as possible. They will need lifelong follow-up care with a pediatric cardiologist. Monthly visits will be needed during their first few years. After having the Fontan procedure, visits may go down to once or twice a year. Most children who have had a single ventricle defect repaired will take medicines for the rest of their lives. Children who need the Fontan procedure can exercise normally, but many will have limits on how active they can be.

Why Choose Norton Children’s Heart Institute

The Adult Congenital Heart Association has recognized Norton Children's Heart Institute for its expertise treating adult congenital heart disease.

  • Norton Children’s Hospital has been a pioneer in pediatric cardiothoracic surgery, performing Kentucky’s first pediatric heart transplant in 1986 and becoming the second site in the United States to perform an infant heart transplant.
  • The American Board of Thoracic Surgery has certified our cardiothoracic surgeons in congenital heart surgery.
  • The Adult Congenital Heart Association has accredited Norton Children’s Heart Institute’s Adult Congenital Heart Program as the only comprehensive care center in Kentucky and Indiana treating adults born with a heart defect.
  • More than 5,000 children a year visit Norton Children’s Heart Institute for advanced heart care.
  • Norton Children’s Heart Institute has offices across Kentucky and Southern Indiana to bring quality pediatric heart care closer to home.
  • The Jennifer Lawrence Cardiac Intensive Care Unit (CICU) at Norton Children’s Hospital is the largest dedicated CICU in Kentucky, equipped with 17 private rooms and the newest technology available for heart care.
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