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Atrial Septal Defect


An atrial septal defect (ASD) is an abnormal hole in the atrial septum, the wall that separates the heart's two upper chambers. A small opening in the atrial septum is normal during gestation and may still be present at birth but will usually close up on its own. If the hole doesn't close after birth, excess blood flows into the right side of the heart, then through the pulmonary artery and into the lungs. The extra blood flow forces the heart and lungs to work harder than they should, which can cause damage over time.

About 2,000 infants in the United States are born with ASD each year, with girls about twice as likely as boys to be affected.

Small ASDs may close on their own by the time a child is 2 years old. Larger ASDs are more problematic and can increase a person's risk for congestive heart failure and stroke later in life. In some people, the defect doesn't cause symptoms until middle age.

Our approach to atrial septal defect

UCSF provides comprehensive, highly specialized care for adults living with atrial septal defect or other heart defects. Our dedicated team of experts offers a wide array of services, including thorough medical evaluations; advanced treatments; long-term monitoring; and personalized recommendations on diet, exercise, psychosocial support and family planning.

For surgical repair of the defect, we can often take a minimally invasive approach. This means that surgeons perform the repair via a small "keyhole" incision on the side of the chest or through a catheter (a thin, flexible tube), which they insert into a blood vessel through a small incision in the groin and gently guide up to the heart. These techniques offer patients many benefits, including less postoperative pain, a faster recovery and less scarring.

Learn more about the UCSF Adult Congenital Heart Disease Clinic.

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Signs & symptoms

Symptoms vary in severity, depending on the ASD's size. They may arise in childhood or as late as middle age. Common symptoms include:

  • Shortness of breath
  • Fatigue
  • Heart palpitations
  • Decreased capacity to exercise
  • Heart murmur (a heartbeat sound caused by extra blood flow, detectable with a stethoscope)
  • Arrhythmia (an irregular heartbeat)

If untreated, ASDs can have serious complications, including congestive heart failure, stroke and Eisenmenger syndrome, a life-threatening issue that develops over time from high blood pressure in the arteries that go from the heart to the lungs.


Most ASDs are discovered during a childhood physical exam, when a health care provider detects a heart murmur.

To help diagnose ASD in adulthood, your doctor may suggest one or more of the following tests:

  • Electrocardiogram (EKG or ECG). This involves placing electrodes on the skin to record the heart's electrical activity.
  • Chest X-rays. These provide images of the heart, lungs and major blood vessels.
  • Echocardiogram. This study uses sound waves (ultrasound) to create images of the heart.
  • Coronary angiography. This involves passing a catheter into the heart and injecting a dye to see moving images of its structure and function.


Because ASDs can cause irreversible damage to the heart and lungs over time, all ASDs larger than a few millimeters across should be treated, regardless of your age at the time of diagnosis.

In the past, ASD closure required open-heart surgery through an incision in the center of the chest. These days, we can close ASDs with less invasive procedures, which can speed up your recovery and reduce post-op pain and scarring. Your surgeon will use stiches or a small patch to repair the defect.

Closing an ASD usually leads to significant improvement in symptoms, and most patients can enjoy good health after surgery. A small percentage of patients develop pulmonary hypertension (high blood pressure in the arteries connecting the heart and lungs) or an irregular heartbeat. After surgery, it's a good idea to periodically see a cardiologist who specializes in heart birth defects, especially if you may become pregnant.

Minimally invasive ASD closure surgery

Most patients are eligible for the minimally invasive approach, in which the surgeon makes a small incision between two ribs on the right side of the chest, inserts specialized surgical instruments, and closes the ASD using stiches or a patch. The operation usually takes five to six hours and involves several days of recovery in the hospital. Most patients return to their normal routines within eight weeks.

ASD closure via cardiac catheterization

Alternatively, some small ASDs can be closed using a procedure known as cardiac catheterization. Rather than making an incision in your chest, your provider inserts a catheter into a blood vessel in your groin and gently guides it through blood vessels until it's inside your heart. The catheter is used to measure the ASD, then a small patch or plug is fed through the tube and used to close the hole.

Cardiac catheterization takes about three hours, and complications are rare. Most patients leave the hospital the day after having the procedure.

UCSF Health medical specialists have reviewed this information. It is for educational purposes only and is not intended to replace the advice of your doctor or other health care provider. We encourage you to discuss any questions or concerns you may have with your provider.

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