RELATED STORIES • Ebstein's anomaly • Tricuspid atresia • Patent foramen ovale • Truncus arteriosus • Atrioventricular canal defect • Hypoplastic left heart syndrome • Transposition of the great arteries • Pulmonary valve stenosis • Coronary angiography and other heart catheterization procedures HEART & BLOOD Cardiovascular System • Aortic aneurysm • High blood pressure (hypertension) • High blood cholesterol • Thrombophlebitis • Rheumatic fever • Varicose veins • Heart arrhythmias • Atrial fibrillation • Endocarditis • Aortic valve stenosis • Aortic valve regurgitation • Mitral valve stenosis • Mitral valve regurgitation • Pulmonary hypertension • Raynaud's disease • Long QT syndrome • Mitral valve prolapse • Pericarditis • Cardiomyopathy • Myocarditis • Arteriosclerosis / Atherosclerosis • Peripheral arterial disease (PAD) • Low blood pressure (hypotension) • Aortic dissection • Lymphedema • Pulmonary valve stenosis • Ventricular septal defect (VSD) • Tetralogy of Fallot • Coarctation of the aorta • Atrial septal defect (ASD) • Patent ductus arteriosus (PDA) • Left ventricular hypertrophy • Bundle branch block • Heart murmurs • Patent foramen ovale • Transposition of the great arteries • Hypoplastic left heart syndrome • Sudden cardiac arrest • Prehypertension • Tricuspid atresia • Ebstein's anomaly • Buerger's disease

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An atrial septal defect (ASD) is a hole in the wall between the two upper chambers of the heart. The condition is present from birth (congenital). Smaller atrial septal defects may close on their own during infancy or early childhood. The health effects of holes that remain open often don't show up until adulthood — usually by age 40. Many people don't realize they have an atrial septal defect until then. Sometimes a doctor detects an atrial septal defect during a newborn exam, or during a routine exam later in life.

Large and long-standing atrial septal defects can damage the heart and lungs. An adult who has had an undetected atrial septal defect for decades may have a shortened life span from heart failure or high blood pressure in the lungs.

Surgery is usually necessary to repair atrial septal defects to prevent complications. The procedure is relatively simple, compared with those needed for more complicated heart defects.

Many babies born with atrial septal defects don't have signs or symptoms. In adults, signs or symptoms typically develop between the ages of 30 and 40.

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 appetite 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

Doctors know that congenital heart defects 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.

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.

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.

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.

Your doctor may detect a heart defect when listening to your heart. Atrial septal defects often cause a heart murmur that your doctor can hear through a stethoscope. 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 these tests:

• 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 or EKG). This test records the electrical activity of the heart through patches on your skin and helps identify heart rhythm problems.
• Echocardiogram. 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.
• 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 can also 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 the fingertip measures the amount of oxygen in your blood.

A small atrial septal defect (less than 6 millimeters) may never cause any problems. Small holes often close during infancy, perhaps even undetected. Larger defects can cause mild to life-threatening problems. Treatment can prevent or help manage many of these complications. Potential complications of an atrial septal defect include:

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

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

Although small defects may close on there own, many atrial septal defects need surgery. In a child, doctors may observe the atrial septal defect for a period of time to see if it closes on its own. If a hole hasn't closed early in childhood, it usually will never close on its own and requires surgery to correct.

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

Medications
Medications won't cure an atrial septal defect but may be used to alleviate some of the signs and symptoms. 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. Anti-coagulants 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:

• 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.
• Cardiac catheterization. A thin tube (catheter) is inserted into a blood vessel in the groin and guided to the heart. Through the catheter, a small mesh patch or plug is put into place to close the hole. The heart tissue grows around the mesh, permanently sealing 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.

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.

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 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.
• Employment. Having an atrial septal defect generally won't limit your career options, unless you have developed complications.
• 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 (endocarditis). If you have an atrial septal defect, you may need to take antibiotics before certain dental or surgical procedures. Whether you need antibiotics depends on the location of the defect and whether you have other heart defects or valve problems.

• 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 or Eisenmenger's syndrome can increase your risk of complications during pregnancy. Doctors strongly advise women with Eisenmenger's syndrome not to become pregnant.

  Women born with a heart defect may also be concerned about the risk that the baby will be born with a heart defect as well. Only a small percentage (6 percent or less) of babies born to a woman with a congenital heart disease also have a heart defect. Doctors recommend that any woman with a congenital heart defect, repaired or not, who is considering pregnancy, carefully discuss it beforehand with her cardiologist. This is especially important if the woman is taking medications.