How does a healthy heart work?
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 four 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 two 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).
The inside of 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 four valves in the heart, which open and close to allow blood to move through the chambers:
- The aortic valve, located on the left side of the heart, between the aorta and the left ventricle
- The mitral valve, located between the left ventricle and the left atrium
- The pulmonary valve, located on the right side of the heart between the right ventricle and the pulmonary artery (the blood vessel that carries blood to the lungs)
- The tricuspid valve, located on the right side of the heart between the right ventricle and the right atrium
The exterior of the heart.
Blood vessels—arteries, veins, and capillaries--are also involved in helping blood flow:
- The pulmonary artery moves blood from the heart to the lungs, where it picks up oxygen.
- Pulmonary veins move blood from the lungs to the heart’s left side, where it can be transported to the rest of the body.
- The aorta sends newly oxygenated blood from the left side of the heart to the rest of the body.
- The inferior vena cava and superior vena cava bring blood back to the heart to get new oxygen.
- The coronary arteries take blood and oxygen from the aorta to the heart muscle itself.
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 one million adults and children in the United States who have congenital heart defects.
What are the common types of pediatric congenital heart defects?
A septal defect is a hole in the septum, the wall that divides the heart. There are two 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:
- Stenosis (narrowing) — the valve is not able to open completely. As a result, the heart has to work harder to pump blood through it.
- Regurgitation — The valve does not close correctly and allows blood to leak backward.
- Atresia — the valve is missing a hole for the blood to pass through. This is considered a more complex defect.
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
- Coarctation of the aorta — This defect happens when the aorta narrows and prevents blood from flowing freely to the lower part of the body. Coarctation of the aorta can cause hypertension (high blood pressure) and heart damage. Surgery or balloon catheterization in selected cases can be used to correct this problem.
- Complete atrioventricular canal defect (CAVC) — The heart has a hole in all four chambers in the spot where the chambers would normally be divided. Symptoms may not appear until the baby is several weeks old; infants may have trouble breathing, eating, and growing. This defect can be corrected with surgery.
- D-transposition of the great arteries — The positions of the pulmonary artery and the aorta are reversed. The blood flow to either the body or the lungs is interrupted. Surgery is needed to fix this problem.
- Ebstein’s anomaly — The tricuspid valve does not work as it should and allows blood to leak back into the upper chambers of the heart from the lower pumping chambers. This defect often occurs along with an ASD. Ebstein’s anomaly may be mild enough to never require surgery. In some cases, however, it may cause cyanosis (the skin turns blue because of a lack of oxygen) or heart failure.
- Single ventricle defects — These include hypoplastic left heart syndrome, pulmonary atresia/intact ventricular septum, and tricuspid atresia:
- In hypoplastic left heart syndrome, the left side of the heart is underdeveloped. Without treatment, the baby will usually die. Treatment might include a series of heart operations or a heart transplant.
- In pulmonary atresia, the pulmonary valve has become narrowed or blocked. Blood can only get to the lungs through openings that usually close as the baby gets older.
- In tricuspid atresia, there is no tricuspid valve. Blood has to circulate through an ASD. Surgery is necessary to repair these defects.
- Tetralogy of Fallot — This defect combines four problems: a ventricular septal defect; pulmonary stenosis (a blockage between the heart and the lungs); right ventricular hypertrophy (the muscle around the lower right chamber of the heart is enlarged); and the aorta is in the wrong position (over both ventricles, instead of just the left ventricle). Surgery is needed to correct this defect.
- Total anomalous pulmonary venous connection — The veins from the lungs connect to the heart in the wrong place and let oxygenated blood into the wrong heart chamber. This defect requires open heart surgery early in infancy.
- Truncus arteriosis — This defect occurs when there is one large artery instead of the usual two separate ones to carry blood to the body and the lungs. Surgery is needed to close the VSD and to add another tube to act as the second artery.
What are the symptoms of pediatric congenital heart disease?
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:
- Trouble breathing
- Bluish tones to the skin (cyanosis)
- Poor eating habits
- Fatigue (tiredness)
- Swelling in the abdomen or around the eyes
- Rapid heartbeat
How are pediatric congenital heart defects diagnosed?
Tests to diagnose heart defects might include:
- Physical examination, including listening to the heart with a stethoscope
- Chest X-ray
- Electrocardiogram to test heart rate patterns
- Echocardiogram (takes pictures of the heart using sound waves)
- Cardiac catheterization (a thin tube is inserted through a vein into the heart to obtain details on heart function)
Some defects can be diagnosed while the baby is still developing in the womb.
What causes pediatric congenital heart defects?
In most cases, the reasons defects happen are not known, but some connections have been identified:
- Women who get German measles (rubella) during their first trimester of pregnancy have a higher risk of having a baby with a congenital heart defect.
- The risk may also be higher if the woman has some types of viral infections, is exposed to industrial solvents, takes certain kinds of medications, drinks alcohol, or uses cocaine while pregnant.
- Women who have given birth to a child with a congenital heart defect are at higher risk of giving birth to another child with a heart defect.
Heart defects can also occur along with other types of birth defects.
What can be done to prevent pediatric congenital heart defects?
In most cases, there is no way to prevent heart defects. However, certain precautions can be taken:
- A pregnant woman should not drink alcohol or take drugs that have not been prescribed to her.
- Women with certain chronic conditions (like diabetes, a seizure disorder, or phenylketonuria) should ask their doctors for advice on medications or special diets before they become pregnant.
- A woman who is able to become pregnant should get 400 micrograms of folate or folic acid per day to prevent birth defects.
How are pediatric congenital heart defects treated?
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 two 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.
What is the prognosis (outlook) for children with congenital heart defects?
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.
National Heart, Lung, and Blood Institute. Congenital heart defects. www.nhlbi.nih.gov. Updated August 2009. Accessed January 26, 2011.
National Heart, Lung, and Blood Institute. Heart valve disease. www.nhlbi.nih.gov Updated January 2010. Accessed January 26, 2011.
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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 health care provider. Please consult your health care provider for advice about a specific medical condition. This document was last reviewed on: 1/14/2011…#14735