Atrial Septal Defect (ASD)

What is an Atrial Septal Defect?

An Atrial Septal Defect (ASD) is a hole in the wall (called the septum) that separates the right and left atria. This allows a portion of the blood coming back from the lungs to pass from the left atrium to the right atrium, and then back to the lungs, without passing to the body. The proportion of the blood coming back from the lungs that passes through the hole depends on the size of the hole. If the hole is large enough, then the blood passing through the hole will cause the right atrium and right ventricle to be enlarged, and the excess blood flow to the lungs could cause damage to the small arteries in the lungs.

What are the warning signs and symptoms of Atrial Septal Defect?

There usually are no obvious signs or symptoms of an Atrial Septal Defect in a newborn or a child. Occasionally, growth will be slow or there may be more frequent pulmonary infections. A referral to a pediatric cardiologist is usually requested because of the presence of an abnormal heart murmur. Long-standing enlargement of the right heart may cause abnormal heart rhythms in adults.

How is Atrial Septal Defect detected?

An abnormal heart murmur is usually the first clue to the presence of congenital heart disease. Often an echocardiogram will be obtained which documents the presence of the Atrial Septal Defect. It is important to precisely determine the location and size of the hole using echocardiography.

What are the treatment options for Atrial Septal Defect?

A small Atrial Septal Defect generally does not cause complications in childhood and no treatment is required. If found in infancy, many of these small Atrial Septal Defects will close on their own with time.

If the Atrial Septal Defect is large enough to cause cardiac enlargement, and has not gotten any smaller after several years of age, then closure of the Atrial Septal Defect is warranted. For many years, the mainstay of treatment was open-heart surgery, either by simply stitching the hole closed or by sewing a patch over the hole to close it. The patch is generally obtained from the wall of the sac surrounding the heart.

A newer, non-surgical approach to Atrial Septal Defect closure has been developed and is becoming widely used. A catheter is threaded from a vein in the groin, up through the venous system to the right atrium, and then across the hole. An umbrella-like device is then threaded through the catheter and placed in a position that straddles the hole to seal it. The catheter itself is then removed.