Single Ventricle Defects, Pediatric

Body outline of a child, with two images of the heart. One heart is normal. The other shows hypoplastic left heart syndrome.

Single ventricle defects are heart problems that a child is born with (congenital heart defects). The heart is made up of four chambers. The upper chambers are called the right atrium and left atrium, and the lower chambers are called the right ventricle and left ventricle. The right ventricle pumps blood to the lungs to get oxygen. After blood returns from the lungs, the left ventricle pumps it out to the rest of the body.

There are many different forms of single ventricle defects. They can involve one or more valves in the heart and a ventricle that does not pump effectively. In almost all cases, a single ventricle defect means that blood flow to the child’s body or lungs is less than it should be. Children with single ventricle defects may also have abnormalities of the valves that control blood flow through the heart. Some common types of single ventricle defects include:

  • Hypoplastic left heart syndrome. This means that the left side of the heart has not developed enough.

  • Pulmonary atresia. This is when there is no pulmonary valve. This valve separates the right ventricle from a pathway that leads to the lungs.

  • Tricuspid atresia. This is when there is no tricuspid valve. This valve separates the right atrium from the right ventricle.

Single ventricle defects develop as a child’s heart is forming inside the womb. Most children with single ventricle defects require a series of operations starting in infancy. In some cases, a heart transplant may be needed.

What are the causes?

The cause of this condition is usually not known. Possible causes include:

  • Changes in genes or chromosomes during fetal development.

  • Factors that affect the mother, such as environment, medicines, or dietary choices.

What are the signs or symptoms?

Symptoms of single ventricle defects depend on the type of defect and how severe it is. Symptoms usually show up within a few days of birth. The most common symptoms are:

  • Shortness of breath or rapid breathing.

  • Bluish color of the skin and lips (cyanosis).

  • Getting tired easily while feeding.

  • Lack of weight gain.

  • Swelling of the feet, ankles, face, or abdomen.

  • Pale, sweaty skin.

How is this diagnosed?

A health care provider, usually a children’s heart specialist (cardiologist), can diagnose a single ventricle defect from your child’s symptoms and from a physical exam. During the exam, the health care provider will listen for an abnormal heart sound. Abnormal blood flow through the heart (heart murmur) causes this.

The child’s health care provider may also do tests to confirm the diagnosis. These tests may include:

  • Chest X-ray, which may show that your child’s heart is larger than normal. This can happen because the child’s heart has to work harder.

  • Electrocardiogram (ECG or EKG) to check for heart rhythm problems (arrhythmias).

  • An echocardiogram. This may show an abnormal heart structure.

  • MRI of the heart.

  • Checking the blood flow through your child’s heart and coronary arteries. This is done using cardiac catheterization, which involves:

    • Inserting a long thin tube (catheter) through a vein in your child’s arm or groin.

    • Injecting dye into the blood entering your child’s heart. This dye passes through your child’s heart and coronary arteries, and your child’s cardiologist observes the dye on an X-ray machine.

How is this treated?

Treatment depends on the type of single ventricle defect your child has. There are many options. It is important to discuss them with your child’s cardiologist.

  • Surgery. Your child may need:

    • A cavopulmonary shunt. This procedure creates a connection to restore blood flow to the lungs. This may be the first surgery. It is often done before an infant leaves the hospital.

    • Fontan operations. These are a series of surgeries that try to restore blood flow through the heart and lungs. Your child may have these procedures anytime from age 4 months to 3 years.

    • A heart transplant.

  • A pacemaker to regulate your child’s heart rate.

  • Medicines:

    • To control your child’s heart rate.

    • To control the heart’s ability to pump blood throughout the body.

    • To control your child’s blood pressure.

    • To prevent blood clots from forming in your child’s heart.

Follow these instructions at home:

  • Keep a record of your child’s medical information to share with his or her health care providers. These records may include:

    • What type of single ventricle defect your child was born with.

    • What surgeries your child has had.

    • What medicines your child is taking.

  • Your child should exercise or be active as told by the health care provider. Your child may need to limit exercise that takes a lot of effort, such as competitive sports.

  • Your child should eat a heart-healthy diet and maintain a healthy weight. Work with a diet specialist (dietitian), if necessary.

  • Ask your child’s health care provider if your child needs to take antibiotic medicines before certain procedures.

  • Give over-the-counter and prescription medicines only as told by your child’s health care provider.

  • Keep all follow-up visits. This is important.

Where to find more information

  • American Heart Association: www.heart.org

  • Centers for Disease Control and Prevention: www.cdc.gov

Contact a health care provider if:

  • Your child has a fever.

  • Your child is not feeding well or not gaining weight.

  • Your child is breathing faster than usual.

  • Your child seems lethargic, or lacking in strength and energy.

Get help right away if:

  • Your child’s symptoms get worse.

  • Your child has trouble breathing.

  • Your child’s skin turns pale or blue.

  • Your child who is younger than 3 months has a temperature of 100.4°F (38°C) or higher.

  • Your child who is 3 months to 3 years old has a temperature of 102.2°F (39°C) or higher.

These symptoms may represent a serious problem that is an emergency. Do not wait to see if the symptoms will go away. Get medical help right away. Call your local emergency services (911 in the U.S.)

Summary

  • Single ventricle defects are heart problems that a child is born with (congenital heart defects).

  • Single ventricle defects develop as your child’s heart is still forming inside the womb.

  • A health care provider, usually a children’s heart specialist (cardiologist), can diagnose a single ventricle defect from your child’s symptoms and from a physical exam.

  • Treatment depends on the type of single ventricle defect your child has and often includes surgery.

  • Get help right away if your child has trouble breathing or your child’s skin turns pale or blue.

This information is not intended to replace advice given to you by your health care provider. Make sure you discuss any questions you have with your health care provider.