What Is an Atrial Septal Defect?

Having a doctor listen to your heart is a routine part of every checkup, right? Here's the reason why: Listening to the thumping of your heart can give doctors the heads-up on certain problems, like an atrial septal defect.

An ASD is usually found during a checkup or routine physical exam. Because the murmur it causes can be difficult to hear, the condition may not be diagnosed right away. An ASD can be discovered in a person as an infant, child, teen, or even as an adult.

Atrial septal defect (pronounced: ay-tree-ul sep-tul dee-fekt), or ASD for short, is sometimes referred to as a hole in the heart. It's a type of congenital heart disease, which means a person is born with it. People with ASD have an abnormal opening in the dividing wall between the upper filling chambers of the heart, or the atria. In most cases, ASDs are diagnosed and treated successfully with few or no complications.

To understand ASD, it helps to learn about how a healthy heart works:

Heart Basics

The heart has four chambers. The two lower pumping chambers are the ventricles (the left ventricle and the right ventricle). The two upper filling chambers are the atria (the left atrium and the right atrium).

In a healthy heart, blood that returns from the body to the right-sided filling chamber (right atrium) is low in oxygen. This blood passes to the right-sided pumping chamber (right ventricle), and then to the lungs to receive oxygen. The blood that has been enriched with oxygen returns to the left atrium, and then to the left ventricle. It's then pumped out to the body through the aorta, a large blood vessel that carries the blood to the smaller blood vessels in the body. The right and left filling chambers are separated by a thin shared wall, called the atrial septum.

In a person with an atrial septal defect, there's an opening in the wall (septum) between the atria. As a result, some oxygenated blood from the left atrium flows through the hole in the septum into the right atrium, where 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, which is known as a heart murmur. A heart murmur, along with other specific heart sounds, is often the first tip-off to a doctor that a teen has an ASD.

What Causes an Atrial Septal Defect?

ASDs occur during a baby's development in the mother's womb and are present at birth. Before birth, the heart develops from a large tube, dividing into sections that will eventually become its walls and chambers. If a problem occurs during this process, a hole in the wall that divides the left atrium from the right may result.

In some cases, the tendency to develop an ASD may be inherited, or genetic. For most people with an ASD, no one knows exactly why it happens.

Signs and Symptoms

The size of an ASD and its location in the heart determines what kind of symptoms a person experiences. Most people with ASDs seem healthy and appear to have no symptoms. Usually, someone with an ASD grows normally and feels well.

People with larger, more severe ASDs might experience some of these signs or symptoms:

• poor appetite
• poor growth
• fatigue and tiredness during activity
• shortness of breath
• lung problems and infections, such as pneumonia

If an ASD isn't treated in childhood, health problems can develop later, including an abnormal heart rhythm (an atrial arrhythmia) and problems in how well the heart pumps blood. As kids with ASDs get older, they also might be at an increased risk for stroke, since a blood clot that develops can pass through the hole in the wall between the atria and travel to the brain. Pulmonary hypertension (high blood pressure in the lungs) may also develop over time in older patients with larger untreated ASDs.

Fortunately, most teens with ASD are treated long before the heart defect causes physical symptoms.

Diagnosis

After hearing the heart murmur that suggests a hole in the atrial septum, a doctor may refer a teen to a pediatric cardiologist, a doctor who specializes in diagnosing and treating heart disease in kids and teens.

In addition to doing a physical examination, the cardiologist will take a medical history, asking you about any concerns and symptoms you have, your past health, your family's health, any medications you're taking, and other issues relating to the heart.

The cardiologist might order one or more of these tests:

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

Treatment

Once a person is diagnosed with an ASD, treatment will depend on the patient's age, the size of the hole, and where it's located in the heart. For teens with very small ASDs, the cardiologist may not feel any treatment is needed. In other cases, the doctor may recommend follow-up visits for observation. In most teens with ASD, though, the cardiologist will recommend having the hole fixed.

Many teens with ASDs who need treatment can be treated with cardiac catheterization (pronounced: car-dee-ack cath-uh-turr-eye-zay-shun), in which a thin, flexible tube (a catheter) is inserted into a blood vessel in the leg that leads to the heart. A cardiologist guides the tube into the heart to make measurements of blood flow, pressure, and oxygen levels in the heart chambers. A special implant is positioned into the hole and is designed to flatten against the septum on both sides to close and permanently seal the ASD.

In the beginning, the natural pressure in the heart holds the device in place. Over time, the normal tissue of the heart grows over the implant and covers it entirely. This non-surgical technique for closing an ASD eliminates the scar on the chest needed for a surgical approach, and has a shorter recovery time (usually just an overnight stay in the hospital).

If you have a cardiac catheterization, your doctor will probably recommend that you take it easy for a few days afterward and perhaps stay out of gym class for a few weeks. Your doctor may also ask you to take one aspirin each day for about 6 months to prevent small clots from forming on the device and being sent into the arteries of the body. Over time, the normal tissue of the heart grows over the device and the aspirin is no longer necessary.

In some cases, when the ASD is very large or close to the wall of the heart, a device cannot be safely used and surgery is needed to close the defect. If surgery is necessary, general anesthesia will be administered so the patient doesn't feel pain or move around during the surgery.

ASD surgery involves making a cut in the chest so a surgeon can stitch the hole in the atrial septum closed or sew a patch of manmade surgical material (such as Gore-Tex) over the defect. Eventually, the tissue of the heart heals over the patch or stitches, making the area smooth and nearly normal in appearance. Teens who have surgery for ASDs usually leave the hospital within 3 to 4 days after surgery, if there are no problems.

Open-heart surgery does leave a permanent scar on the chest. It will be sore at first and your doctor will likely prescribe a pain reliever, such as acetaminophen or ibuprofen. You may feel numbness, itchiness, tightness, and burning around the cut, although these feelings shouldn't be severe.

Once a scar is healed, there's no need to keep it covered. If you want to minimize its appearance, you can use an over-the-counter cosmetic concealer (after your doctor gives the OK — you'll need to wait for a while after surgery to do this).

For 6 months following surgery or catheterization closure, ASD patients will need to take antibiotics before a visit to the dentist or if they need certain other kinds of surgery, such as tonsil removal. This is to prevent bacteria from getting into the bloodstream and causing bacterial endocarditis (pronounced: en-doe-kar-dye-tus), an infection of the inner surface of the heart. Six months after surgery, though, most people who have had their ASDs corrected no longer need to worry about bacterial endocarditis.

After an ASD is closed with a device or surgery, and it's had plenty of time to heal, most teens have no further symptoms or problems.

Taking Care of Yourself

The first few days at home after ASD surgery, you'll be advised to hang out in bed or on the couch doing quiet activities such as reading, sleeping, and watching TV. Within a week or two, you'll probably feel better. Your doctor will advise you on when to go back to school, and during the 6-week healing period you may need to sit out gym class or sports. It takes about 6 weeks for a chest incision to heal.

About 6 weeks after surgery (if you don't have other problems and your doctor gives the go-ahead), you should be fully recovered and able to return to your normal activities.

In the weeks following the catheterization or surgery, your doctor will check on your progress and may repeat an echocardiogram at these visits.

In most cases, teens who have had ASD surgery or cardiac catheterization recover quickly without problems. But some signs and symptoms may indicate a problem. If you have trouble breathing or feel your heart racing, tell a parent or another adult so you can get medical treatment right away.

Other signs that might indicate a problem include:

• a bluish color to the skin around the mouth or on the lips and tongue
• loss of appetite
• weight loss
• decreased activity level
• prolonged or unexplained fever
• increasing pain, tenderness, or pus oozing from your incision

Tell an adult and seek medical help if you notice any of these signs.

Most people who have an ASD corrected during their teenage years have a normal life expectancy and go on to live otherwise healthy lives. After the recovery period, people who have had an ASD will be able to exercise, play sports, and do the other things they love — and perhaps do them even better than before!

Reviewed by: Steven B. Ritz, MD
Date reviewed: August 2010