Congenital Heart Disease

According to the American Heart Association, about nine of every 1,000 babies born in the United States have a congenital (present at birth) heart defect. This is a problem that occurs as the baby's heart is developing during pregnancy, before the baby is born. Congenital heart defects are the most common birth defects.

A baby's heart begins to develop at conception, but is completely formed by eight weeks into the pregnancy. Congenital heart defects happen during this crucial first eight weeks of the baby's development. Specific steps must take place in order for the heart to form correctly. Often, congenital heart defects are a result of one of these crucial steps not happening at the right time. For example, a hole is left where a dividing wall should have formed, or a single blood vessel is left, where two ought to be.

Prevention & Risk Treatment

Prevention & Risk Treatment

What causes congenital heart disease?

The vast majority of congenital heart defects have no known cause. Mothers will often wonder if something they did during the pregnancy caused the heart problem. In most cases, nothing can be attributed to the heart defect. Some heart problems do occur more often in families, so there may be a genetic link to some heart defects. Some heart problems are likely to occur if the mother had a disease while pregnant and was taking medications, such as antiseizure medicines or the acne medication isotretinoin. However, most of the time, there is no identifiable reason as to why the heart defect occurred.

Congenital heart problems range from simple to complex. Some heart problems can be watched by the baby's doctor and managed with medicines, while others will require surgery, sometimes as soon as in the first few hours after birth. A baby may even "grow out" of some of the simpler heart problems, such as patent ductus arteriosus or atrial septal defect. These defects may simply close up on their own with growth. Other babies will have a combination of defects and require several operations throughout their lives.

What are the different types of congenital heart defects?

We can classify congenital heart defects into several categories in order to better understand the problems the baby will experience. They include:

  • Problems that cause too much blood to pass through the lungs. These defects allow oxygen-rich blood that should be traveling to the body to recirculate through the lungs, causing increased pressure and stress in the lungs.
  • Problems that cause too little blood to pass through the lungs. These defects allow blood that has not been to the lungs to pick up oxygen (and, therefore, is oxygen-poor) to travel to the body. The body does not receive enough oxygen with these heart problems, and the baby will be cyanotic, or have a blue coloring.
  • Problems that cause too little blood to travel to the body. These defects are a result of underdeveloped chambers of the heart or blockages in blood vessels that prevent the proper amount of blood from traveling to the body to meet its needs.

Again, in some cases there will be a combination of several heart defects.
This creates a more complex problem that can fall into several of these categories.

Some of the problems that cause too much blood to pass through the lungs include the following:

  • Patent ductus arteriosus (PDA). This defect occurs when the normal closure of the patent ductus arteriosus, which is present in all fetuses, does not occur. Extra blood goes from the aorta into the lungs and may lead to "flooding" of the lungs, rapid breathing, and poor weight gain. PDA is often seen in premature infants.
  • Atrial septal defect (ASD). In this condition, there is an abnormal opening between the two upper chambers of the heart—the right and left atria. This causes an abnormal blood flow through the heart. Some children may have no symptoms and appear healthy. However, if the ASD is large, permitting a large amount of blood to pass through the right side, symptoms will be noted.
  • Ventricular septal defect (VSD). In this condition, a hole in the ventricular septum (a dividing wall between the two lower chambers of the heart— the right and left ventricles) occurs. Because of this opening, blood from the left ventricle flows back into the right ventricle, due to higher pressure in the left ventricle. This causes an extra volume of blood to be pumped into the lungs by the right ventricle, which can create congestion in the lungs.
  • Atrioventricular canal (AVC or AV canal). AVC is a heart problem that involves several abnormalities of structures inside the heart. These include atrial septal defect, ventricular septal defect, and improperly formed mitral and/or tricuspid valves.

Some of the problems that cause too little blood to pass through the lungs include the following:

  • Tricuspid atresia. In this condition, the tricuspid valve is completely blocked. Therefore, no blood flows from the right atrium to the right ventricle. Tricuspid atresia defect is characterized by the following:
    • A small right ventricle
    • Diminished pulmonary circulation
    • Cyanosis. A bluish color of the skin and mucous membranes caused from a lack of oxygen
  • A surgical shunting procedure is often necessary to increase the blood flow to the lungs.
  • Pulmonary atresia. A congenital defect in which there is underdevelopment of the pulmonary valve. Normally, the pulmonary valve is found between the right ventricle and the pulmonary artery. It has three leaflets that function like a one-way door, allowing blood to flow forward into the pulmonary artery, but not backward into the right ventricle.
  • With pulmonary atresia, problems with valve development prevent the leaflets from opening, therefore, blood cannot flow forward from the right ventricle to the lungs.
  • Transposition of the great arteries. With this congenital heart defect, the positions of the pulmonary artery and the aorta are reversed, thus:
    • The aorta originates from the right ventricle, so most of the blood returning to the heart from the body is pumped back out without first going to the lungs.
    • The pulmonary artery originates from the left ventricle, so that most of the blood returning from the lungs goes back to the lungs again
  • Tetralogy of Fallot. This condition is characterized by the following four defects:
    1. An abnormal opening, or ventricular septal defect, that allows blood to pass from the right ventricle to the left ventricle without going through the lungs
    2. A narrowing (stenosis) at, or just beneath, the pulmonary valve that partially blocks the flow of blood from the right side of the heart to the lungs
    3. The right ventricle is more muscular than normal and often enlarged
    4. The aorta lies directly over the ventricular septal defect
  • Tetralogy of Fallot can result in cyanosis (bluish color of the skin and mucous membranes due to lack of oxygen).
  • Double outlet right ventricle (DORV). A complex form of congenital heart defect, in which both the aorta and the pulmonary artery are connected to the right ventricle.
  • Truncus arteriosus. The aorta and pulmonary artery start as a single blood vessel, which eventually divides and becomes two separate arteries. Truncus arteriosus occurs when the single great vessel fails to separate completely. This leaves a large connection between the aorta and the pulmonary artery.

Some of the problems that cause too little blood to travel to the body include the following:

  • Coarctation of the aorta (CoA). In this condition, the aorta is narrowed or constricted. This obstructs blood flow to the lower part of the body and increases blood pressure above the constriction. Usually there are no symptoms at birth, but they can develop as early as the first week of life. If severe symptoms of high blood pressure and congestive heart failure develop, surgery may be considered.
  • Aortic stenosis (AS). In AS, the aortic valve between the left ventricle and the aorta did not form properly and is narrowed. This makes it difficult for the heart to pump blood to the body. A normal valve has three leaflets or cusps, but a stenotic valve may have only one cusp (unicuspid) or two cusps (bicuspid).
  • Although aortic stenosis may not cause symptoms, it may worsen over time. Surgery or a catheterization procedure may be needed to correct the blockage, or the valve may need to be replaced with an artificial one.

A complex combination of heart defects known as hypoplastic left heart syndrome can also occur.

  • Hypoplastic left heart syndrome (HLHS). A combination of several abnormalities of the heart and the great blood vessels. In HLHS, most of the structures on the left side of the heart (including the left ventricle, mitral valve, aorta, and aortic valve) are small and underdeveloped. The degree of underdevelopment differs from child to child. The left ventricle may not be able to pump an adequate blood volume to the body. HLHS is fatal without treatment.
Children's Team

Children's Team

Providers

David Wessel

Chief Medical Officer, Hospital and Specialty Services
Our Stories

Our Stories

Dylan C.'s Story

"The heart team at Children's National was excellent. We felt like we were in the right place and our son was in the right hands. There is no substitute for this . . . none."

Patient story

Matthew's Story

"The doctors and staff of Children's National mend the broken hearts of not only the children, but the family of those children as well. My son is alive and well today because of the miracle that happened at Children's National."

Gary's Story

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Sarah's Story

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Departments

Departments

Electrophysiology

Learn about our specialized pediatric electrophysiology department for diagnosing and treating arrhythmias in children.

Critical Care Medicine

With the only pediatric, cardiac, and neuro intensive care units in the immediate Washington, DC, area, Children’s National Health System is the region’s leading provider of critical care medicine for seriously ill and injured infants and children.

Washington Adult Congenital Heart Program (WACH)

The Washington Adult Congenital Heart Program meets the unique needs of adult patients with congenital heart disease by providing all the necessary resources and highly sophisticated care in a central location.

Genetics and Metabolism

With more than 4,000 visits annually and 12 physicians, Children’s National is now the largest clinical genetics program in the United States.

Cardiac Neurodevelopmental Outcome Program

Our Cardiac Neurodevelopmental Outcome Program treats patients impacted by congenital heart disease to try to maximize their potential.

Cardiology

Children’s National Heart Institute, an international leader in comprehensive cardiac care for infants, children, and adults.

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Matthew's Story

Patient story

"The doctors and staff of Children's National mend the broken hearts of not only the children, but the family of those children as well. My son is alive and well today because of the miracle that happened at Children's National."

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