What are congenital heart defects?
Congenital (kon-JEN-ih-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
- The valves inside the heart
- The arteries and veins that carry blood to the heart or the body
Congenital heart defects change the normal flow of blood through the heart.
There are many 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. They affect 8 out of every 1,000 newborns. Each year, more than 35,000 babies in the United States are born with congenital heart defects.
Many of these defects are simple conditions. They need no treatment or are easily fixed. Some babies are born with complex congenital heart defects. These defects require special medical care soon after birth.
The diagnosis and treatment of complex heart defects has greatly improved over the past few decades. As a result, almost all children who have complex heart defects survive to adulthood and can live active, productive lives.
Most people who have complex heart defects continue to need special heart care throughout their lives. They may need to pay special attention to how their condition affects issues such as health insurance, employment, birth control and pregnancy, and other health issues.
In the United States, more than 1 million adults are living with congenital heart defects.
How the heart works
To understand congenital heart defects, it's helpful to know how a healthy heart works. Your child's heart is a muscle about the size of his or her fist. The heart 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. The left side of the heart receives the oxygen-rich blood from the lungs and pumps it to the body.
The heart has four chambers and four valves and is connected to various blood vessels. Veins are blood vessels that carry blood from the body to the heart. Arteries are blood vessels that carry blood away from the heart to the body.
Picture of a healthy heart cross-section.
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.
The heart has four chambers or "rooms."
- The atria (AY-tree-uh) are the two upper chambers that collect blood as it flows into the heart.
- The ventricles (VEN-trih-kuhls) are the two lower chambers that pump blood out of the heart to the lungs or other parts of the body.
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. This artery carries blood from the heart 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. This artery carries blood from the heart 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. 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 the beginning of diastole (di-AS-toe-lee). Diastole is when the ventricles relax and fill with blood pumped into them by the atria.
The arteries are major blood vessels connected to your heart.
- The pulmonary artery carries blood 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 from the left side of the heart 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.
The veins also are 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 to the body.
- The superior and inferior vena cavae are large veins that carry oxygen-poor blood from the body back to the heart.
What are the types of congenital heart defects?
With congenital heart defects, some part of the heart doesn't form properly before birth. This changes the normal flow of blood through the heart.
There are many types of congenital heart defects. Some are simple, such as a hole in the septum. The hole allows blood from the left and right sides of the heart to mix. Another example of a simple defect is a narrowed valve that blocks blood flow to the lungs or other parts of the body.
Other heart defects are more complex. They include combinations of simple defects, problems with the location of blood vessels leading to and from the heart, and more serious problems with 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 left and right sides of the heart. The wall prevents blood from mixing between the two sides of the heart. Some babies are born with holes in the septum. These holes allow blood to 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. The hole allows oxygen-rich blood from the left atrium to flow into the right atrium, instead of flowing into the left ventricle as it should. Many children who have ASDs have few, if any, symptoms.
ASDs can be small, medium, or large. Small ASDs allow only a little blood to leak from one atrium to the other. They don't affect how the heart works and don't need any special treatment. Many small ASDs close on their own as the heart grows during childhood.
Medium and large ASDs allow more blood to leak from one atrium to the other. They're less likely to close on their own.
About half of all ASDs close on their own over time. Medium and large ASDs that need treatment can be repaired using a catheter procedure or open-heart surgery.
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.