Congenital 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.
Examples of simple defects include:
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. 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.
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. 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: Occurs when the valve doesn’t open completely, and the heart has to work harder to pump the blood through the valve.
Atresia: Occurs when the valve doesn’t form correctly, so there is no opening for blood to pass through.
Regurgitation: Occurs when the valve doesn’t close completely, so blood leaks back through the valve.
Signs & Symptoms
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:
Cyanosis (a bluish tint to the skin, lips, and fingernails)
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.
Source: "Heart and Vascular Diseases." Disease and Conditions Index. The National Heart, Lung, and Blood Institute. The National Institutes of Health.