How is Atrial Septal Defect (ASD) Diagnosed?


Common types of atrial septal defects are difficult to detect during routine pre-natal ultrasounds. When an atrial septal defect is suspected, a specialist may be able to confirm the diagnosis and can provide additional assessment before, and immediately after the birth.

When ASD is not detected before birth, and in patients of all ages, a heart murmur (a whooshing sound) that the doctor hears through a stethoscope may be the first sign of the condition. The definitive test to confirm an atrial septal defect diagnosis is an echocardiogram, in which sound waves (ultrasound) are used to provide images of the heart in motion. The defect in the wall can be easily identified in children, and the blood flowing abnormally between the chambers of the heart may also be viewed using this technology.

Imaging is more difficult in adults with a standard echocardiogram test, so the ultrasound camera may also be passed down the esophagus to image the heart from behind. This view is much closer to the wall where the atrial septal defect occurs and is the best test for assessing an atrial septal defect in adults.

Secondary tests used to confirm an atrial septal defect diagnosis may include:

  • Computed tomography (CT) scan - which provides a more detailed series of x-rays of the heart and its connections
  • Cardiac magnetic resonance imaging (MRI) - a form of imaging that uses magnetic fields and radio waves to evaluate heart function and blood flow

How is Atrial Septal Defect Treated?


Treatment for an atrial septal defect is entirely based on the size and location of the defect and the patient’s overall health. The presence of other cardiac conditions can also play a role in the approach to treatment. Medications are not used to treat atrial septal defects, but they may be given to address certain symptoms or related complications.

Small atrial septal defects

In the case of small atrial septal defects in young children, a cardiologist may recommend a “wait and see” approach with regular evaluation since some of these defects close on their own in the first year or two.

Medium to large atrial septal defects

When a larger atrial septal defect is found, repair to close the hole is usually recommended. (Repairs are not usually recommended in patients with severe pulmonary hypertension, high blood pressure in lungs.) 

Cardiologists may recommend one of two approaches depending on the type of ASD diagnosed:

  • Cardiac catheterization - also called percutaneous repair, where a cardiologist implants an umbrella device in the heart wall to close the hole. The device is delivered through a catheter, a long thin tube that is inserted through a needle hole in the vein of the leg near the groin. Following placement, new tissue in the heart grows over the implant, securing it in place. This approach is used for most secundum ASDs. In teenagers and adults, some sinus venosus ASDs can be repaired using a catheter approach. This type of repair offers the advantage of less discomfort, a shorter hospitalization and more rapid recovery. It is usually done as an outpatient procedure in adults. A blood-thinning medication is prescribed for a short period of time, following the procedure, to guard against the formation of blood clots on the device.
  • Heart surgery - All primum ASDs, coronary sinus defects and the majority of sinus venosus ASDs require surgical treatment, in which the cardiac surgeon makes an incision in the chest and closes the atrial septal defect with stitches or with a patch of the patient’s own tissue (or a man-made material). Open-heart surgery is followed by a longer hospital stay and recovery period.



Based on data collected in 2019, experts estimate that one out of every 1,859 babies born in the United States had an atrial septal defect at birth. More female infants are affected than male.

A heart murmur is an abnormal sound that occurs from turbulent blood flow in the heart. In the case of atrial septal defects, some of the blood from the left heart is crossing to the right side, overloading that side of the heart. When all of that extra blood is pumped through the heart valve leading to the lungs, there is turbulence as it tries to squeeze through (like putting your finger over the end of a hose). 

Many atrial septal defects make no detectable abnormal sounds. That is why so many are missed in childhood when patients typically have no symptoms. When a heart murmur is present, it is an abnormal rumbling sound between the first and second heart sounds, heard best using a stethoscope under the collar bone on the left side of the breastbone.

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Trust NewYork-Presbyterian for atrial septal defect care

At NewYork-Presbyterian, our team of atrial septal defect care specialists provide comprehensive treatment using the latest approaches. Learn about for early diagnosis and treatment of the condition and to avoid potential complications. NewYork-Presbyterian provides advanced cardiovascular care services for all full range of cardiac conditions. Contact us to schedule an appointment.