Many babies born with atrial septal defects don't have signs or symptoms. In adults, signs or symptoms may not develop until age 30 or later.

Your doctor may first uncover an atrial septal defect during a regular checkup while listening to your heart using a stethoscope. Hearing a heart murmur may signal a hole in your heart. Atrial septal defects are often found when an ultrasound exam of the heart (echocardiogram) is done for another reason.

Signs and symptoms of atrial septal defects develop once damage occurs to the heart and lungs. Infants with larger atrial septal defects may have poor appetites and not grow as they should. Adults and infants may have signs of heart failure or arrhythmias.

Signs and symptoms of large or long-standing atrial septal defects may include:

• Shortness of breath
• Fatigue
• Swelling of legs, feet or abdomen
• Heart palpitations or skipped beats

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Doctors know that heart defects present at birth (congenital) arise from errors early in the heart's development, but there's often no clear cause. Genetics and environmental factors may play a role.

An atrial septal defect allows freshly oxygenated blood to flow from the left upper chamber of the heart (left atrium) into the right upper chamber of the heart (right atrium). There it mixes with deoxygenated blood and is pumped to the lungs, even though it's already refreshed with oxygen. If the atrial septal defect is large, this extra blood volume can overfill the lungs and overwork the heart. If not treated, the right side of the heart eventually enlarges and weakens. In some cases, the blood pressure in your lungs increases as well, leading to pulmonary hypertension.

Comparing ASD with patent foramen ovale
The term "atrial septal defect" usually refers to holes in the atria resulting from a lack of atrial septal tissue, rather than those related to a condition called patent foramen ovale (PFO).

Patent foramen ovale occurs when part of the normal fetal heart circulation fails to close properly at birth. During fetal heart development, a channel (the foramen ovale) is present between the atria to allow blood to bypass the lungs. At birth, once the lungs take over breathing, the hole normally closes. In about one in three people, this opening doesn't close.

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Congenital heart defects appear to run in families and sometimes occur with other genetic problems, such as Down syndrome. If you have a heart defect, or you have a child with a heart defect, a genetic counselor can predict the approximate odds that any future children will have one.

Experiencing any the following conditions during pregnancy can increase your risk of having a baby with a heart defect:

• Rubella infection. Becoming infected with rubella (German measles) while pregnant can increase the risk of fetal heart defects. The rubella virus crosses the placenta and spreads through the fetus's circulatory system damaging blood vessels and organs, including the heart.
• Poorly controlled diabetes. Uncontrolled diabetes in the mother in turn affects the fetus's blood sugar causing various damaging effects to the developing fetus.
• Drug or alcohol use or exposure to certain substances. Use of certain medications, alcohol or drugs, or exposure to chemicals or radiation during pregnancy can harm the developing fetus.

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Contact your doctor if you or your child has any of these signs or symptoms:

• Poor appetite
• Failure to gain weight (infants)
• Bluish discoloration of the skin
• Shortness of breath
• Easy tiring
• Swelling of legs, feet or abdomen
• Heart palpitations or skipped beats

These could be indications of heart failure or another complication of an atrial septal defect.

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Many atrial septal defects are first detected when a suspicious heart murmur is heard during a routine examination of the heart. If your doctor hears a heart murmur or finds other signs or symptoms of a heart defect, he or she may request one or more of the following tests:

• Echocardiogram. This is the most common test used to diagnose an atrial septal defect. In fact, many atrial septal defects are found during an echocardiogram done for another reason. In echocardiography, sound waves produce a video image of the heart. It allows your doctor to see your heart's chambers and measure their pumping strength. This test also checks heart valves and looks for any signs of heart defects.
• Chest X-ray. An X-ray image helps your doctor see the condition of your heart and lungs. An X-ray may identify conditions other than a heart defect that may explain your signs or symptoms.
• Electrocardiogram (ECG). This test records the electrical activity of your heart and helps identify heart rhythm problems.
• Cardiac catheterization. In this test, a thin, flexible tube (catheter) is inserted into a blood vessel at the groin or arm and guided to your heart. Through catheterization, doctors can diagnose congenital heart defects, test how well your heart is pumping and check the function of your heart valves. Using catheterization, the blood pressure in your lungs also can be measured. Doctors are investigating catheterization techniques to repair heart defects as well.
• Pulse oximetry. This painless test measures how well oxygen is reaching your tissues. It helps detect whether oxygenated blood is mixing with deoxygenated blood, which can help diagnose the type of heart defect present. A small clip on your fingertip measures the amount of oxygen in your blood.

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A small atrial septal defect may never cause any problems. Small holes often close during infancy.

Larger defects can cause mild to life-threatening problems:

• Pulmonary hypertension. If a large atrial septal defect goes untreated, increased blood flow to your lungs increases the blood pressure in the lung arteries (pulmonary hypertension).
• Eisenmenger's syndrome. In rare cases, pulmonary hypertension can cause permanent lung damage, and it becomes irreversible. This complication, called Eisenmenger's syndrome, usually develops over many years and occurs only in a small percentage of people with large atrial septal defects.

Other complications
Other potential complications of an untreated atrial septal defect include:

• Right-sided heart failure
• Heart rhythm abnormalities
• Shortened life expectancy
• Increased risk of a stroke

Treatment can prevent or help manage many of these complications.

Atrial septal defect and pregnancy
Pregnancy is often a concern for women born with a heart defect. Most women with an atrial septal defect can tolerate pregnancy without any problems. However, having a larger defect or having complications such as heart failure, arrhythmias or pulmonary hypertension can increase your risk of complications during pregnancy. Doctors strongly advise women with Eisenmenger's syndrome not to become pregnant because it can endanger the woman's life.

The risk of congenital heart disease in the general population is less than 1 percent. For children of parents with congenital heart disease, whether father or mother, this risk increases to between 2 percent and 20 percent, according to the American Heart Association. Experts recommend that anyone with a congenital heart defect, repaired or not, who is considering starting a family, carefully discuss it beforehand with his or her doctor.

In some cases, preconception consultations with doctors who specialize in cardiology, genetics and high-risk obstetric care are needed. Some heart medications can cause serious problems for a fetus and may need to be stopped or adjusted before you become pregnant.

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If your child has an atrial septal defect, your doctor may recommend monitoring it for a period of time to see if it closes on its own, while treating any symptoms with medications.

According to the National Institutes of Health, about half of all atrial septal defects eventually close on their own. About 20 percent close within the first year of life. If a hole hasn't closed early in childhood, it usually won't close on its own. Some small atrial septal defects don't cause any problems and may not need closure, but many require surgery to be corrected.

If your child needs treatment, the timing of it depends on your child's condition and whether your child has any other congenital heart defects.

Medications
Medications won't repair the hole, but they may be used to alleviate some of the signs and symptoms that can accompany an atrial septal defect. Medications may include those to:

• Keep the heartbeat regular. Examples include beta blockers (Lopressor, Inderal) and digoxin (Lanoxin).
• Increase the strength of the heart's contractions. Examples include digoxin (Lanoxin).
• Decrease the amount of fluid in circulation. Doing so reduces the volume of blood that must be pumped. These medications, called diuretics, include furosemide (Lasix).
• Reduce the risk of blood clots. Anticoagulants, often called blood thinners, can help reduce the chances of developing a blood clot and having a stroke. Anticoagulants include warfarin (Coumadin) and anti-platelet agents such as aspirin.

Surgery
Many doctors recommend repairing an atrial septal defect diagnosed during childhood to prevent complications as an adult. For adults and children, surgery involves plugging or patching the abnormal opening between the atria. Doctors can do this through two methods:

• Cardiac catheterization. A thin tube (catheter) is inserted into a blood vessel in the groin and guided to the heart. Through the catheter, a mesh patch or plug is put into place to close the hole. The heart tissue grows around the mesh, permanently sealing the hole.
• Open-heart surgery. This type of surgery is done under general anesthesia and requires the use of a heart-lung machine. Through an incision in the chest, surgeons use patches or stitches to close the hole.

Follow-up care depends on the type of defect and whether other defects are present. For simple atrial septal defects closed during childhood, only occasional follow-up care is needed. For adults, follow-up care may depend on any resulting complications.

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In most cases, atrial septal defects can't be prevented. If you have a family history of heart defects or other genetic disorders, consider talking with a genetic counselor before getting pregnant.

©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.

If you find out you have a congenital heart defect, or you've had surgery to correct one, you may wonder about limitations on activities and other issues.

• Exercise. Having an atrial septal defect usually doesn't restrict you from activities or exercise. If you have complications such as heart failure or pulmonary hypertension, you may not be able to do some activities or exercises. Your cardiologist can help you learn what is safe.
• Preventing infection. Some heart defects, and the repair of defects, create changes to the surface of the heart in which bacteria can become stuck and grow into an infection (infective endocarditis). Atrial septal defects generally aren't associated with infective endocarditis. But if you have other heart defects in addition to an atrial septal defect, you may need to take antibiotics before certain dental or surgical procedures.

©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.