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Congenital Heart Disease

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What Is Congenital Heart Disease?

The term "congenital heart disease" indicates that a structural problem (or defect) in a baby's heart is present at birth. A baby's heart begins to form shortly after conception. By the end of the 2nd month of pregnancy, the baby's heart is completely formed. It is during this time that a congenital heart defect can occur. In this case, a part of the heart, heart valves, and/or blood vessels near the heart do not develop properly. When this happens, blood flow can:

  • Slow down
  • Go in the wrong direction or to the wrong place
  • Be blocked completely.

Congenital heart disease is the most common type of major birth defect. More than 30,000 babies are born with a congenital heart defect in the United States each year.

Types of Congenital Heart Defects

There are many types of congenital heart defects. They are:

  • Abnormal passages in the heart or between blood vessels
  • Problems with the heart valves
  • Problems with the placement or development of blood vessels near the heart
  • Problems with development of the heart itself.

Some of these problems are described below.

Abnormal Passages in the Heart or Blood Vessels

  • Atrial septal defect (ASD) is a hole in the wall that separates the upper chambers (atria) of the heart. This causes blood to leak from one atrium to the other.

  • Ventricular septal defect (VSD) is a hole in the wall that separates the lower chambers (ventricles) of the heart. This causes blood to leak from one ventricle to the other.

  • Atrioventricular septal defect (AVSD) includes an ASD, VSD, and abnormal development of the atrioventricular valves (tricuspid and mitral). This causes blood to flow abnormally inside the heart. An AVSD is also known as an atrioventricular canal defect.

  • Patent ductus arteriosus (PDA) is a persistent connection between the aorta and the pulmonary artery. This connection is called the ductus arteriosus and is normally present before birth. In most babies, the vessel closes within a few hours to days after birth. In some children, this vessel fails to close.

Problems with the Heart Valves

Heart and valve abnormalities can affect any of the valves and include the following:

  • Stenosis: The valve opening is narrow and does not open completely.

  • Atresia: The valve is not formed so that there is not communication for blood to pass from one chamber to another.

  • Regurgitation: The valve does not close completely causing blood to leak back.

Examples of heart valve problems include:

  • Aortic valve stenosis is a defect of the aortic valve in the heart that often causes it to open incompletely. This reduces blood flow to the body.

  • Pulmonary valve atresia is a defect where a solid sheet of tissue forms instead of the pulmonary valve. This prevents oxygen-poor blood in the right side of the heart from traveling normally to the lungs to pick up oxygen.

  • Pulmonary valve stenosis is a narrowing of the pulmonary valve. This slows the flow of blood from the right side of the heart to the lungs. The heart must pump harder to push blood through the smaller opening to the lungs where the blood picks up oxygen.

  • Tricuspid atresia is a defect where a solid sheet of tissue forms instead of the tricuspid valve. The tricuspid valve is between the right atrium (the upper chamber) and right ventricle (the lower chamber) of the heart. Without the tricuspid valve, oxygen-poor or blue blood entering the right atrium cannot travel normally to the lungs to pick up oxygen.

  • Ebstein's anomaly is a defect where the tricuspid valve is both displaced and abnormally formed. The valve is leaky and allows blue blood to flow back into the right atrium instead of to the lungs to pick up oxygen.

Problems with Placement or Development of Blood Vessels near the Heart

  • Transposition of the great vessels is a defect where the location of the "great vessels" (the aorta and pulmonary artery) coming off the heart is switched. The aorta comes off the right ventricle instead of the left ventricle. The pulmonary artery arises from the left ventricle instead of the right ventricle. Therefore, blood without oxygen is continually pumped to the body, instead of blood with oxygen.

  • Tetralogy of Fallot is a combination of four defects:
    • Pulmonary valve stenosis is the narrowing of the pulmonary valve that slows the flow of blood from the right ventricle to the lungs.
    • VSD is a hole in the wall that separates the left and right ventricles.
    • Overriding aorta is a defect where the aorta is positioned between the left and right ventricles, over the VSD.
    • Right ventricular hypertrophy is the thickening of the right ventricle. It is caused by the heart having to work harder because of the other defects.

  • Truncus arteriosus is a defect of the great vessels (aorta and pulmonary artery). The aorta and pulmonary artery do not form as separate arteries. Instead, a large artery, called the truncus, comes from the heart. As the truncus leaves the heart, it may branch into arteries that carry blood to the body and to the lungs.

  • Coarctation of the aorta is a narrowing of the aorta. It slows or blocks the flow of blood from the heart to the body.

  • Anomalous pulmonary venous return is a defect where 1 or more of the 4 pulmonary veins that normally return oxygen-rich or red blood from the lungs to the heart, return to the wrong chamber in the heart.

Problems with Development of the Heart

  • Hypoplastic left heart syndrome* is a combination of defects where the left side of the heart does not develop properly. Usually there is mitral atresia, aortic atresia, and a tiny left ventricle.
    • Mitral atresia occurs when a solid sheet of tissue forms instead of the mitral valve, which separates the left atrium and the left ventricle.
    • Aortic atresia occurs when a solid sheet of tissue forms instead of the aortic valve, which separates the left ventricle from the aorta.

  • Single ventricle* describes a group of heart defects where only one ventricle is present instead of two. It can be a single right or a single left ventricle. The other ventricle is usually absent or very tiny. Hypoplastic left heart syndrome is an example of a single ventricle defect.

Today, the outlook for an infant born with a heart defect is much better than it was 30 years ago. Rapid advances in infant and childhood surgery, better tests, and new medicines help most children with congenital heart defects. Many children born with more complex or severe heart defects now reach adulthood. Today, there are more than 1 million adults living with congenital heart disease.

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What Causes Congenital Heart Disease?

Doctors do not know what causes most cases of congenital heart disease. Heredity may play a role. In rare cases, more than one child in a family is born with a heart defect. Also, parents who have a congenital heart defect may be more likely than other parents to have a child with the condition.

Babies who have certain other birth defects, such as Down syndrome, are also more likely to have congenital heart disease.

Other factors that raise the risk for congenital heart disease are:

  • Having viral infections such as German measles during pregnancy
  • Having diabetes
  • Taking some types of prescription or over-the-counter medications during pregnancy
  • Being repeatedly exposed to some chemicals or x-rays during pregnancy
  • Using alcohol or street drugs during pregnancy.

Research continues to find the causes of congenital heart defects.

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What Are the Signs and Symptoms of Congenital Heart Disease?

The most common signs and symptoms of congenital heart disease are:

  • A heart murmur
  • A bluish tint to skin, lips, and fingernails ("blue baby")
  • Fast breathing
  • Shortness of breath
  • Poor feeding, especially in infants because they tire easily while nursing
  • Poor weight gain in infants
  • Tiring easily during exercise or activity (older children).

The signs and symptoms that your child has depends on:

  • The number and types of defects
  • The severity of the defect.

Some infants and children have no signs or symptoms. Others have severe or life-threatening symptoms.

Many types of congenital heart defects cause the heart to work harder than it should. This stresses the heart and can lead to heart failure, causing the heart muscle to weaken and the heart to enlarge.

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How is Congenital Heart Disease Treated?

Doctors treat congenital heart disease with:

  • Medications
  • Special procedures using catheters
  • Surgery
  • Heart transplants.

The treatment your child receives depends on the type and severity of the defect. Other factors include your child's age, size, and general health. Treatment can be simple or very complex. Many children are treated with medications and are monitored by their doctor. Other children may need surgery.


Your child may take one or more of the following medications to help the heart work better and lessen symptoms:

  • Digoxin is thought to improve heart function and can keep the heartbeat regular.

  • Diuretics treat the buildup of fluid in the heart and body.

  • ACE inhibitors decrease the work the heart has to do and may help remodel the heart and blood vessels to work more efficiently.

  • Beta-blockers slow the heart rate and lower blood pressure to decrease the workload on the heart.

  • Inotropes strengthen the heart's pumping ability.

  • Prostaglandin E1 is used to keep the ductus arteriosus open in some defects until corrective surgery can be performed. This improves blood flow and oxygen levels until the defect is corrected. The ductus arteriosus normally closes within a few days after birth.

Special Procedures Using Catheters

Doctors can correct some congenital heart diseases during cardiac catheterization. These are called catheter-based procedures or interventions. They can be used instead of open-heart surgery, which is a major operation. A catheter is inserted through blood vessels in your child's groin. It is then threaded to the heart where some holes in the interior walls of the heart can be fixed, a patent ductus can be closed, and narrow valves and blood vessels can be opened up. Interventional catheterization:

  • Does not require your child's chest to be opened
  • Lets your child recover quickly
  • Has different risks than open heart surgery.


Your child may need open-heart surgery if the defect cannot be repaired using a catheter-based procedure. Some surgeries repair the defect completely. Other surgeries improve your child's health but do not completely repair the defect. Open-heart surgeries that may correct the defect include:

  • Closing holes with sutures or with a patch
  • Repairing valves
  • Widening arteries or openings to valves
  • Putting the great arteries (aorta and pulmonary artery) back to their normal position.

Sometimes, open-heart surgeries can improve a child's health but do not repair the problem. Examples include:

  • Decreasing blood flow to the lungs by placing a band around the pulmonary artery

  • Increasing blood flow to the lungs by connecting an artery from the aorta to the pulmonary artery

  • Connecting the veins that bring back blue blood directly to the pulmonary artery in a 3-stage surgery when the right ventricle is not developed, e.g., Hypoplastic left heart syndrome

Heart Transplantation

Babies born with multiple defects that are too complex to repair may need a heart transplant. In this procedure, the child's heart is replaced with a healthy heart that has been donated.

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How is Congenital Heart Disease Prevented?

There is no known way to prevent congenital heart disease, but there are things you can do to lower the chance that your baby will have a congenital heart defect. However, even by lowering the risks, your baby may still develop congenital heart disease.

If you are planning to become pregnant or are pregnant, talk to your doctor about any medications that you are taking, including:

  • Over-the-counter medications
  • Prescription medications
  • Vitamin and mineral supplements
  • Herbal supplements.

Your doctor will recommend that you take folate before you become pregnant. This is recommended mainly to prevent abnormalities in the baby's nervous system, but there is some evidence that it may also help prevent certain types of congenital heart defects.

You need to avoid:

  • Strong chemicals, including some cleaning products
  • Repeated x-rays
  • Any harmful or poisonous materials.

If you or anyone in your family has congenital heart disease, genetic testing may be available. This may show a genetic cause for congenital heart disease. Testing cannot prevent congenital heart disease, but may be able to make you aware of the risks.

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Congenital Heart Disease