The heart is part of the circulatory system, which carries blood throughout the body. The heart is made of muscle and works like a pump to keep the blood moving through the blood vessels (arteries, veins, and capillaries).
The heart has 4 chambers — the right atrium and the left atrium (plural: atria) on top and the right and left ventricles on the bottom. The heart is divided by a solid wall called the septum into 2 sides: the right side sends blood to the lungs to get oxygen, while the left side of the heart moves oxygen-rich blood to the rest of the body through the aorta (the main artery in the heart).
Blood enters the heart through the right atrium and moves to the right ventricle, where it then moves through the pulmonary artery to the lungs to pick up oxygen. The newly oxygenated blood then enters the heart through the left atrium and moves to the left ventricle, where it is sent through the aorta to the rest of the body.
There are also 4 valves in the heart, which open and close to allow blood to move through the chambers:
The exterior of the heart.
Blood vessels—arteries, veins, and capillaries--are also involved in helping blood flow:
The word congenital means that a condition is present when a baby is born. If a baby is born with a heart defect, the heart is not working properly, usually because there is something wrong (defective) with the valves or the blood vessels around the heart. The defect can keep blood from flowing normally and can affect heart development. Congenital heart defects can be simple or complex. There are 1 million adults and children in the United States who have congenital heart defects.
A septal defect is a hole in the septum, the wall that divides the heart. There are 2 types of septal defects: atrial septal defects (ASDs) are holes in the septum between the left and the right atria; ventricular septal defects (VSDs) are holes in the septum between the left and right ventricles. Because of this hole, oxygenated blood mixes with non-oxygenated blood.
A septal defect means that blood flows from one chamber of the heart to the other, instead of taking its normal path. For instance, with an atrial septal defect, blood flows from one atrium to the other, instead of going to the ventricle.
Similarly, with a VSD, the blood flows from the left ventricle to the right ventricle, rather than through its normal path to the aorta and the rest of the body. As a result, blood that has picked up oxygen from the lungs mixes with oxygen-poor blood. This can mean that parts of the body aren’t getting enough oxygenated blood.
ASDs and VSDs can be small or large. Some ASDs close up on their own as the child grows older. Others may be repaired using catheters or with open heart surgery.
Although some small VSDs may close on their own, some are so large that the left side of the heart is forced to work much harder. If it is not treated, a VSD can lead to heart failure. These defects have to be repaired with open heart surgery.
Another type of defect involves the heart valves. Defective valves may be caused by:
Pulmonary valve stenosis is the most common valve defect. In this defect, the flaps of the pulmonary valve don’t work properly — they are too thick, or they become stiff, or even fuse together, making it difficult for the blood to move to the lung via the pulmonary artery.
Children who have a pulmonary valve stenosis may have a heart murmur, an irregular sound heard during a heartbeat. Children who are born with a severe pulmonary valve stenosis may have such symptoms as fatigue, breathing problems, and trouble eating.
Pulmonary valve stenosis may also be accompanied by other defects, such as an ASD or patent ductus arteriosis (PDA). The ductus arteriosis is a blood vessel in the fetus that connects the aorta and the pulmonary artery. The ductus arteriosis usually closes within minutes or days of birth; if it does not close, it is called a patent (open) ductus arteriosis (PDA).
A PDA lets oxygenated blood and deoxygenated blood mix and puts pressure on lung arteries. In the event of certain heart defects, doctors might choose to keep the PDA open until surgery to correct other blood flow defects can be done.
Stenosis can also affect the aortic valve. If this valve cannot open or close properly, blood may leak or pool. This can increase pressure on the heart and cause heart damage. A balloon catheter procedure might be performed in order to widen the valve and increase the blood flow.
Other types of congenital heart defects
In most cases, the reasons defects happen are not known, but some connections have been identified:
Heart defects can also occur along with other types of birth defects.
Often, there are no symptoms associated with these defects. The defects are usually found during routine physical examinations. In cases where there are symptoms, they may include:
Tests to diagnose heart defects might include:
Some defects can be diagnosed while the baby is still developing in the womb.
Many children who are born with heart defects do not need treatment. In these cases, the defects are mild or they simply correct on their own (for instance, an atrial septal defect may close on its own).
For children who have a heart defect that must be treated, there are 2 main options: treatment with a catheter, or open heart surgery.
Treatment with a catheter is much easier for the child to go through than surgery. Instead of opening the body with an incision as in surgery, the doctor makes a small cut in the skin and inserts a catheter (a thin tube) into the body through an artery or vein.
Catheters are used to treat simple heart defects, such as an atrial septal defect. In this procedure, the catheter is moved through a vein until it reaches the septum (the wall on the inside of the heart). There, the catheter places a small device into the septal defect to close it up. The catheter is then removed.
To treat pulmonary valve stenosis, the catheter is equipped with a small balloon that is inflated at the pulmonary valve in order to separate the fused leaflets.
Open heart surgery
In cases where the heart defect cannot be treated with a catheter, the child may need open heart surgery. In these situations, the pediatric heart surgeon opens the chest and operates directly on the heart to repair the defect. This type of treatment is usually done for more serious heart defects.
In most cases, there is no way to prevent heart defects. However, certain precautions can be taken:
The prognosis depends on the defect. In many cases, children with congenital heart defects go on to live normal lives. In most cases, people with heart defects are at greater risk for developing infection of the heart and valves. They may need to take antibiotics when having certain dental or surgical procedures in order to prevent endocarditis, an infection of the heart’s lining.
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This information is provided by the Cleveland Clinic and is not intended to replace the medical advice of your doctor or healthcare provider. Please consult your healthcare provider for advice about a specific medical condition. This document was last reviewed on: 01/14/2011