An atrial septal defect (ASD) is a hole in the wall between the two upper chambers of your heart (atria). The condition is present from birth (congenital). Small atrial septal defects may close on their own during infancy or early childhood.

Large and long-standing atrial septal defects can damage your heart and lungs. Small defects may never cause a problem and may be found incidentally. 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 that affects the arteries in the lungs (pulmonary hypertension). Surgery may be necessary to repair atrial septal defects to prevent complications.

Many babies born with atrial septal defects don't have associated signs or symptoms. In adults, signs or symptoms usually begin by age 30, but in some cases signs and symptoms may not occur until decades later.

Atrial septal defect signs and symptoms may include:

  • Shortness of breath, especially when exercising
  • Fatigue
  • Swelling of legs, feet or abdomen
  • Heart palpitations or skipped beats
  • Frequent lung infections
  • Stroke
  • Heart murmur, a whooshing sound that can be heard through a stethoscope

When to see a doctor

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

  • Shortness of breath
  • Tiring easily, especially after activity
  • Swelling of legs, feet or abdomen
  • Heart palpitations or skipped beats

These could be signs or symptoms of heart failure or another complication of congenital heart disease.

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 (ASD) 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. If this process continues, the blood pressure in your lungs increases as well, leading to pulmonary hypertension.

Atrial septal defects can be several types, including:

  • Secundum. This is the most common type of ASD, and occurs in the middle of the wall between the atria (atrial septum).
  • Primum. This defect occurs in the lower part of the atrial septum, and may occur with other congenital heart problems.
  • Sinus venosus. This rare defect occurs in the upper part of the atrial septum.
  • Coronary sinus. In this rare defect, part of the wall between the coronary sinus — which is part of the vein system of the heart — and the left atrium is missing.

It's not known why atrial septal defects occur, but 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 estimate the odds that any future children will have one.

Some conditions that you have or that occur during pregnancy may increase your risk of having a baby with a heart defect, including:

  • Rubella infection. Becoming infected with rubella (German measles) during the first few months of your pregnancy can increase the risk of fetal heart defects.
  • Drug, tobacco or alcohol use, or exposure to certain substances. Use of certain medications, tobacco, alcohol or drugs, such as cocaine, during pregnancy can harm the developing fetus.
  • Diabetes or lupus. If you have diabetes or lupus, you may be more likely to have a baby with a heart defect.
  • Obesity. Being extremely overweight (obese) may play a role in increasing the risk of having a baby with a birth defect.
  • Phenylketonuria (PKU). If you have PKU and aren't following your PKU meal plan, you may be more likely to have a baby with a heart defect.

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

Larger defects can cause mild to life-threatening problems, including:

  • Right-sided heart failure
  • Heart rhythm abnormalities (arrhythmias)
  • Increased risk of a stroke

Less common serious complications may include:

  • 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 syndrome. In rare cases, pulmonary hypertension can cause permanent lung damage. This complication, called Eisenmenger syndrome, usually develops over many years and occurs only in a small percentage of people with large atrial septal defects.

Treatment can prevent or help manage many of these complications.

Atrial septal defect and pregnancy

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 syndrome not to become pregnant because it can endanger their lives.

The risk of congenital heart disease is higher for children of parents with congenital heart disease, whether in the father or the mother. Anyone with a congenital heart defect, repaired or not, who is considering starting a family should carefully discuss it beforehand with a doctor. Some medications may need to be stopped or adjusted before you become pregnant because they can cause serious problems for a developing fetus.

If your doctor suspects an atrial septal defect, you or your child will likely be referred to a doctor trained in heart disorders (cardiologist).

Because appointments can be brief, and there's often a lot to discuss, it's a good idea to arrive well-prepared. Here's some information to help you get ready for your appointment, and know what to expect from your doctor.

What you can do

  • Write down any symptoms you're experiencing, including any that may seem unrelated to the reason for which you scheduled the appointment.
  • Write down key personal information, including any major stresses or recent life changes.
  • Make a list of all medications, vitamins or supplements that you're taking.
  • Write down questions to ask your doctor.

Your time with your doctor is limited, so preparing a list of questions can help you make the most of your time together. List your questions from most important to least important in case time runs out. For atrial septal defect, some basic questions to ask your doctor include:

  • What's the most likely cause of my symptoms?
  • Are there other possible causes for my symptoms?
  • What kinds of tests do I need? Do these tests require any special preparation?
  • Is this condition temporary or long lasting?
  • What are my treatment options?
  • What are the risks of cardiac catheterization or surgery?
  • Are there any alternatives to the primary approach that you're suggesting?
  • I have other health conditions. How can I best manage them together?
  • Are there any activity restrictions that I need to follow?
  • Are there any brochures or other printed material that I can take home with me? What websites do you recommend visiting?

In addition to the questions that you've prepared to ask your doctor, don't hesitate to ask questions during your appointment.

What to expect from your doctor

Your doctor is likely to ask you a number of questions. Being ready to answer them may reserve time to go over any points you want to spend more time on. Your doctor may ask:

  • When did the symptoms first begin?
  • Have the symptoms been continuous or occasional?
  • Do symptoms get worse with exercise?
  • Does anything else seem to make the symptoms worse?
  • Is there anything that seems to improve the symptoms?
  • Is there a family history of heart problems?
  • Is there a family history of birth defects?

Your child's doctor may first suspect an atrial septal defect or other heart defect during a regular checkup if he or she hears a heart murmur while listening to your child's heart using a stethoscope. Or an atrial septal defect may be found when an ultrasound exam of the heart (echocardiogram) is done for another reason.

If your doctor suspects you have a heart defect, your doctor may request one or more of the following tests:

  • Echocardiogram.This is the most commonly used test to diagnose an atrial septal defect. Some atrial septal defects are found during an echocardiogram done for another reason.

    In echocardiography, sound waves are used to 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. Doctors may use this test to evaluate your condition and determine your treatment plan.

  • Chest X-ray. An X-ray image helps your doctor to 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.

    However, this test usually isn't needed to diagnose atrial septal defect. Doctors may also use catheterization techniques to repair heart defects.

  • Magnetic resonance imaging (MRI). MRI is a technique that uses a magnetic field and radio waves to create 3-D images of your heart and other organs and tissues within your body. Your doctor may request an MRI if echocardiography can't definitively diagnose an atrial septal defect.
  • Computerized tomography (CT) scan. A CT scan uses a series of X-rays to create detailed images of your heart. A CT scan may be used to diagnose an atrial septal defect if echocardiography hasn't definitely diagnosed an atrial septal defect.

Many atrial septal defects close on their own during childhood. For those that don't close, some small atrial septal defects don't cause any problems and may not require any treatment. But many persistent atrial septal defects eventually require surgery to be corrected.

Medical monitoring

If your child has an atrial septal defect, your child's cardiologist may recommend monitoring it for a period of time to see if it closes on its own. Your child's doctor will decide when your child needs treatment, depending 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 reduce some of the signs and symptoms that can accompany an atrial septal defect. Drugs may also be used to reduce the risk of complications after surgery. Medications may include those to keep the heartbeat regular (beta blockers) or to reduce the risk of blood clots (anticoagulants).

Surgery

Many doctors recommend repairing an atrial septal defect diagnosed during childhood to prevent complications as an adult. Doctors may recommend surgery to repair medium- to large-sized atrial septal defects. However, surgery isn't recommended if you have severe pulmonary hypertension.

For adults and children, surgery involves plugging or patching the abnormal opening between the atria. Doctors will evaluate your condition and determine which procedure is most appropriate. Atrial septal defects can be repaired using two methods:

  • Cardiac catheterization. In this procedure, doctors insert a thin tube (catheter) into a blood vessel in the groin and guide it to the heart using imaging techniques. Through the catheter, doctors set a mesh patch or plug into place to close the hole. The heart tissue grows around the mesh, permanently sealing the hole.

    This type of procedure may be performed to repair secundum atrial septal defects. Some large secundum atrial septal defects may not be able to be repaired through cardiac catheterization, and may require open-heart surgery.

  • 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 to close the hole. This procedure is the preferred treatment for certain types of atrial septal defects (primum, sinus venosus and coronary sinus), and these types of atrial defects can only be repaired through open-heart surgery.

    This procedure may also be conducted using small incisions (minimally invasive surgery) for some types of atrial septal defects.

    Doctors use imaging techniques after the defect has been repaired to check the repaired area.

Follow-up care

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.Adults who've had atrial septal defect repair need to have regular follow-up appointments to check for complications, such as pulmonary hypertension, arrhythmias, heart failure or valve problems.

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 arrhythmias, 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.
  • Diet. A heart-healthy diet based on fruits, vegetables and whole grains, and low in saturated fat, cholesterol and sodium, can help you keep your heart healthy. Eating one or two servings of fish a week also is beneficial.
  • 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, or if you've had atrial septal defect repair within the last six months, you may need to take antibiotics before certain dental or surgical procedures.

In most cases, atrial septal defects can't be prevented. If you're planning to become pregnant, schedule a preconception visit with your health care provider. This visit should include:

  • Getting tested for immunity to rubella. If you're not immune, ask your doctor about getting vaccinated.
  • Going over your current health conditions and medications. You'll need to carefully monitor certain health problems during pregnancy. Your doctor also may recommend adjusting or stopping certain medications before you become pregnant.
  • Reviewing your family medical history. If you have a family history of heart defects or other genetic disorders, consider talking with a genetic counselor to determine what the risk might be before getting pregnant.
Dec. 11, 2014