Congenital (kon-JEN-i-tal) heart defects are problems with the heart's structure that are present at birth. These defects can involve the interior walls of the heart, valves inside the heart, or the arteries and veins that carry blood to the heart or out to the body. Congenital heart defects change the normal flow of blood through the heart.
There are many different types of congenital heart defects. They range from simple defects with no symptoms to complex defects with severe, life-threatening symptoms.
Congenital heart defects are the most common type of birth defect, affecting 8 of every 1,000 newborns. Each year, more than 35,000 babies in the United States are born with congenital heart defects. Most of these defects are simple conditions that are easily fixed or need no treatment.
A small number of babies are born with complex congenital heart defects that need special medical attention soon after birth. Over the past few decades, the diagnosis and treatment of these complex defects has greatly improved.
As a result, almost all children with complex heart defects grow to adulthood and can live active, productive lives because their heart defects have been effectively treated.
Most people with complex heart defects continue to need special heart care throughout their lives. They may need to pay special attention to certain issues that their condition could affect, such as health insurance, employment, pregnancy and contraception, and preventing infection during routine health procedures. Today in the United States, about 1 million adults are living with congenital heart defects.
How the heart works
To understand congenital heart defects, it's helpful to know how the normal heart works.
Your child's heart is a muscle about the size of his or her fist. It works like a pump and beats 100,000 times a day.
The heart has two sides, separated by an inner wall called the septum. The right side of the heart pumps blood to the lungs to pick up oxygen. Then, oxygen-rich blood returns from the lungs to the left side of the heart, and the left side pumps it to the body.
The heart has four chambers and four valves and is connected to various blood vessels. Veins are the blood vessels that carry blood from the body to the heart. Arteries are the blood vessels that carry blood away from the heart to the body.
The illustration shows a cross-section of a healthy heart and its inside structures. The blue arrow shows the direction in which oxygen-poor blood flows from the body to the lungs. The red arrow shows the direction in which oxygen-rich blood flows from the lungs to the rest of the body.
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| Heart Diagram With Coordinates |
Heart Chambers
The heart has four chambers or "rooms."
- The atria (AY-tree-uh) are the two upper chambers that collect blood as it comes into the heart.
- The ventricles (VEN-trih-kuls) are the two lower chambers that pump blood out of the heart to the lungs or other parts of the body.
Heart Valves
Four valves control the flow of blood from the atria to the ventricles and from the ventricles into the two large arteries connected to the heart.
- The tricuspid (tri-CUSS-pid) valve is in the right side of the heart, between the right atrium and the right ventricle.
- The pulmonary (PULL-mun-ary) valve is in the right side of the heart, between the right ventricle and the entrance to the pulmonary artery, which carries blood to the lungs.
- The mitral (MI-trul) valve is in the left side of the heart, between the left atrium and the left ventricle.
- The aortic (ay-OR-tik) valve is in the left side of the heart, between the left ventricle and the entrance to the aorta, the artery that carries blood to the body.
Valves are like doors that open and close. They open to allow blood to flow through to the next chamber or to one of the arteries, and then they shut to keep blood from flowing backward.
When the heart's valves open and close, they make a "lub-DUB" sound that a doctor can hear using a stethoscope.
- The first sound - the "lub" - is made by the mitral and tricuspid valves closing at the beginning of systole (SIS-toe-lee). Systole is when the ventricles contract, or squeeze, and pump blood out of the heart.
- The second sound - the "DUB" - is made by the aortic and pulmonary valves closing at beginning of diastole (di-AS-toe-lee). Diastole is when the ventricles relax and fill with blood pumped into them by the atria.
Arteries
The arteries are major blood vessels connected to your heart.
- The pulmonary artery carries blood pumped from the right side of the heart to the lungs to pick up a fresh supply of oxygen.
- The aorta is the main artery that carries oxygen-rich blood pumped from the left side of the heart out to the body.
- The coronary arteries are the other important arteries attached to the heart. They carry oxygen-rich blood from the aorta to the heart muscle, which must have its own blood supply to function.
Veins
The veins are also major blood vessels connected to your heart.
- The pulmonary veins carry oxygen-rich blood from the lungs to the left side of the heart so it can be pumped out to the body.
- The vena cava is a large vein that carries oxygen-poor blood from the body back to the heart.
What are the types of congenital heart defects?
Congenital heart defects change the normal flow of blood through the heart because some part of the heart didn't develop properly before birth.
There are many types of congenital heart defects. They include simple ones such as a hole in the interior walls of the heart that allows blood from the left and right sides of the heart to mix, or a narrowed valve that blocks the flow of blood to the lungs or other parts of the body.
Other defects are more complex. These include combinations of simple defects, problems with where the blood vessels leading to and from the heart are located, and more serious abnormalities in how the heart develops.
Examples of Simple Congenital Heart Defects
Holes in the Heart (Septal Defects)
The septum is the wall that separates the chambers on the left side of the heart from those on the right. It prevents mixing of blood between the two sides of the heart. Sometimes, a baby is born with a hole in the septum. When that occurs, blood can mix between the two sides of the heart.
Atrial septal defect (ASD). An ASD is a hole in the part of the septum that separates the atria - the upper chambers of the heart. This heart defect allows oxygen-rich blood from the left atrium to flow into the right atrium instead of flowing to the left ventricle as it should. Many children who have ASDs have few, if any, symptoms.
Normal Heart and Heart With Atrial Septal Defect
Normal Heart and Heart With Atrial Septal Defect
Figure A shows the normal structure and blood flow in the interior of the heart. Figure B shows a heart with an atrial septal defect, which allows oxygen-rich blood from the left atrium to mix with oxygen-poor blood from the right atrium.
An ASD can be small or large. Small ASDs allow only a little blood to leak from one atrium to the other. Very small ASDs don't affect the way the heart works and therefore don't need any special treatment. Many small ASDs close on their own as the heart grows during childhood. Medium to large ASDs allow more blood to leak from one atrium to the other, and they're less likely to close on their own.
Half of all ASDs close on their own or are so small that no treatment is needed. Medium to large ASDs that need treatment can usually be repaired using a catheter procedure. (See "How Are Congenital Heart Defects Treated?")
Ventricular septal defect (VSD). A VSD is a hole in the part of the septum that separates the ventricles - the lower chambers of the heart. The hole allows oxygen rich blood to flow from the left ventricle into the right ventricle instead of flowing into the aorta and out to the body as it should.
Normal Heart and Heart With Ventricular Septal Defect
Normal Heart and Heart With Ventricular Septal Defect
Figure A shows the normal structure and blood flow in the interior of the heart. Figure B shows two common locations for a ventricular septal defect. The defect allows oxygen-rich blood from the left ventricle to mix with oxygen-poor blood in the right ventricle. A VSD can be small or large. A small VSD doesn't cause problems and may often close on its own. Large VSDs cause the left side of the heart to work too hard and increase blood pressure in the right side of the heart and the lungs because of the extra blood flow. The increased work of the heart can cause heart failure and poor growth. If the hole isn't closed, the high blood pressure in the lungs can cause the delicate arteries in the lungs to scar, a condition called pulmonary arterial hypertension. Open-heart surgery is used to repair VSDs.
- Narrowed Valves
Simple congenital heart defects also can involve the heart's valves, which control the flow of blood from the atria to the ventricles and from the ventricles into the two large arteries connected to the heart (the aorta and the pulmonary artery). Valves can have the following types of defects:
- Stenosis. This is when the valve doesn't open completely, and the heart has to work harder to pump the blood through the valve.
- Atresia. This is when the valve doesn't form correctly, so there is no opening for blood to pass through.
- Regurgitation (re-GUR-ji-TA-shun). This is when the valve doesn't close completely, so blood leaks back through the valve.
The most common valve defect is called pulmonary valve stenosis, which is a narrowing of the pulmonary valve. This valve allows blood to flow from the right ventricle into the pulmonary arteries and out to the lungs to pick up oxygen.
Pulmonary valve stenosis can range from mild to severe. Most children with this defect have no signs or symptoms other than a heart murmur. Treatment isn't needed if the stenosis is mild.
In a baby with severe pulmonary valve stenosis, the right ventricle can get very overworked trying to pump blood to the pulmonary arteries. Oxygen-poor blood can back up from the right side of the heart into the left side, causing cyanosis. Cyanosis is a bluish tint to the skin, lips, and fingernails. It occurs because the oxygen level in the blood leaving the heart is below normal.
Older children with severe pulmonary valve stenosis may have symptoms such as fatigue (tiredness) when exercising. Severe pulmonary valve stenosis is treated with a catheter procedure.
Example of a Complex Congenital Heart Defect
Complex congenital heart defects need to be repaired with surgery. Because of advances in diagnosis and treatment, doctors can now successfully repair even very complex congenital heart defects.
The most common complex heart defect is tetralogy of Fallot (teh-TRALL-o-gee of fall-O), a combination of four defects:
- Pulmonary valve stenosis.
- A large VSD.
- An overriding aorta. The aorta sits above both the left and right ventricles over the VSD, rather than just over the left ventricle. As a result, oxygen poor blood from the right ventricle can flow directly into the aorta instead of into the pulmonary artery to the lungs.
- Right ventricular hypertrophy. The muscle of the right ventricle is thicker than usual because of having to work harder than normal.
These defects prevent enough blood from flowing to the lungs to get oxygen, while oxygen-poor blood flows directly out to the body.
Normal Heart and Heart With Tetralogy of Fallot
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| Normal Heart and Heart With Tetralogy of Fallot |
Figure A shows the normal structure and blood flow in the interior of the heart. Figure B shows a heart with the four defects of tetralogy of Fallot.
Babies and children with tetralogy of Fallot have episodes of cyanosis, which can sometimes be severe. In the past, when this condition wasn't treated in infancy, older children would get very tired during exercise and could have fainting spells. Tetralogy of Fallot is now repaired in infancy to prevent these types of symptoms.
Tetralogy of Fallot must be repaired with open heart surgery, either soon after birth or later in infancy, depending on how severely the pulmonary artery is narrowed. Children who have had this heart defect repaired need lifelong medical care from a specialist to make sure they stay as healthy as possible.
What are other names for congenital heart defects?
- Congenital heart disease
- Cyanotic heart disease
- Heart defects
- Congenital cardiovascular malformations
What causes congenital heart defects?
If you have a child with a congenital heart defect, you may think you did something wrong during your pregnancy to cause the problem. However, most of the time doctors don't know why congenital heart defects develop.
Heredity may play a role in some heart defects. For example, a parent who has a congenital heart defect may be more likely than other people to have a child with the condition. In rare cases, more than one child in a family is born with a heart defect. Children with genetic defects often have congenital heart defects. An example of this is Down syndrome - half of all babies with Down syndrome have congenital heart defects.
Scientists continue to search for the causes of congenital heart defects.
What are the signs and symptoms and signs of congenital heart defects?
Many congenital heart defects have few or no symptoms. A doctor may not even detect signs of a heart defect during a physical exam.
Some heart defects do have symptoms. These depend on the number and type of defects and how severe the defects are. Severe defects can cause symptoms, usually in newborn babies. These symptoms can include:
- Rapid breathing
- Cyanosis (a bluish tint to the skin, lips, and fingernails)
- Fatigue (tiredness)
- Poor blood circulation
Congenital heart defects don't cause chest pain or other painful symptoms.
Abnormal blood flow through the heart caused by a heart defect will make a certain sound. Your doctor can hear this sound, called a heart murmur, with a stethoscope. However, not all murmurs are a sign of a congenital heart defect. Many healthy children have heart murmurs.
Normal growth and development depend on a normal workload for the heart and normal flow of oxygen-rich blood to all parts of the body. Babies with congenital heart defects may have cyanosis or tire easily when feeding. Sometimes they have both problems. As a result, they may not gain weight or grow as they should.
Older children may get tired easily or short of breath during exercise or activity. Many types of congenital heart defects cause the heart to work harder than it should. In severe defects, this can lead to heart failure, a condition in which the heart can't pump blood strongly throughout the body. Symptoms of heart failure include:
- Fatigue with exercise
- Shortness of breath
- A buildup of blood and fluid in the lungs
- A buildup of fluid in the feet, ankles, and legs
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