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Atrial Septal Defect

What's an Atrial Septal Defect?

Atrial septal defect (say: AY-tree-ul SEP-tul DEE-fekt), or ASD for short, is a heart condition that can affect kids.

What Happens in an Atrial Septal Defect?

In an atrial septal defect, there's an opening in the wall (septum) between the atria. This lets some oxygenated blood from the left atrium flow through the hole into the right atrium. There, it mixes with oxygen-poor blood and increases the total amount of blood that flows toward the lungs.

The increased blood flow to the lungs creates a swishing sound, known as heart murmur. These sounds may be the only clue that a kid has an ASD.

Many kids with an ASD don't have any problems or symptoms because of it. Occasionally, a kid with a very large ASD might have a poor appetite, get tired easily, grow slowly, be short of breath, or have lung problems, like pneumonia.

Who Gets Atrial Septal Defects?

About 1 in every 100 babies is born with some type of heart defect. Atrial septal defects are one of the more common types of these heart defects. A person could be diagnosed with an ASD in infancy, childhood, during the teen years, or even as an adult.

Weird Fact:

In some kids with small-sized atrial septal defects (small holes), the hole can close up on its own. Most kids with a medium-sized or large-sized ASD will need some kind of procedure to close the hole. If the hole is left open, later in life that person may develop other kinds of heart problems, such as an abnormal heartbeat.

The person also could develop serious damage to the lung blood vessels. The risk of having a stroke (a problem where a clot or air bubble clogs up a blood vessel in the brain) is also increased in someone with an ASD. To prevent these problems, doctors often recommend closing the hole while the kid is still young.

What Causes Atrial Septal Defects?

Atrial septal defects develop when a baby is still growing inside its mother. Before birth, the heart begins as a large tube that folds and divides into sections that will eventually become the walls and chambers of the baby's heart. If a problem happens during this process, a hole may open in the wall between the left atrium and right atrium.

In some cases, the risk for developing an ASD may be inherited, or genetic. In other cases, an ASD might happen if the pregnant woman was exposed to chemicals or drugs while the baby was growing inside her. For most kids with ASDs, no one knows why they developed this problem.

What Do Doctors Do?

Many kids who have ASDs have their heart murmur found by their regular doctor. Then they usually will see a pediatric cardiologist (say: pee-dee-AT-rik car-dee-OL-uh-jist), a doctor who specializes in diagnosing and treating heart problems in kids and teens.

Getting an EKG

The pediatric cardiologist will ask about the kid's medical history (the mother's health during pregnancy and illnesses the kid has had). The cardiologist also will do an exam and listen to the kid's heart.

If a doctor thinks a kid may have an ASD, these tests (which don't hurt) might be done:

  • chest X-ray, which produces a picture of the outline of the heart and surrounding organs in the chest
  • electrocardiogram, or EKG for short, which records the electrical activity of the heart
  • echocardiogram (echo), which uses sound waves to create a picture of the inside of the heart

In some kids, the doctor may recommend regular follow-up visits to see if a small defect will close on its own. A kid with a small ASD usually can play sports and do other regular activities without restrictions.

How Are Atrial Septal Defects Treated?

If the hole needs to be closed, the doctor will decide whether the kid needs surgery or a cardiac catheterization (say: KAR-dee-ak ka-thuh-tur-ih-ZAY-shun). With either one, the kid will get special medicine called anesthesia that causes sleepiness and prevents pain during the operation.

Heart Surgery

In ASD surgery, the doctor repairs the hole with stitches or a patch made out of either surgical material or the body's own tissue. A kid may have to spend a few days in the hospital after surgery. Within about 6 months, the tissue of the heart heals over the patch or stitches.

Cardiac Catheterization

Another way to fix the hole is cardiac catheterization. This method uses a thin, flexible tube called a catheter (say: KATH-uh-tur). The cardiologist inserts the catheter into a blood vessel in the leg that leads to the heart. The cardiologist then guides the tube into the heart and inserts a device that covers the hole in the heart. The device is made out of metal mesh and is springy and flexible.

The kid usually will spend a night at the hospital after the catheterization. As with surgery, over time the heart's natural tissue will grow to completely cover the device.

Kids who have had surgery or cardiac catheterization will need to follow their doctors' instructions about taking it easy for a while. But after just a few weeks, kids can return to their normal activities. Kids with ASDs rarely have any further heart problems. Then ASD can stand for something else: awesome, super, and dazzling!

Date reviewed: September 2016

Note: All information on KidsHealth® is for educational purposes only. For specific medical advice, diagnoses, and treatment, consult your doctor.

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