Atrial Septal Defect

What is an atrial septal defect?

An atrial septal defect (ASD) is a hole in the wall that separates the upper right and left heart collecting chambers (atria). “Atrial” is the name we give to the upper chambers of the heart, “septal” is a medical term for wall, and “defect” is a gap. Taken together, it means that there is a gap in the wall of the upper portion of the heart.

ASD is a congenital condition. The wall that divides the two upper chambers has multiple building blocks and a deficiency in any of them can lead to a gap in a different portion of the upper wall.

An ASD allows oxygen-rich (red) blood to pass from the left heart chamber and mix with oxygen-poor (blue) blood in the right chamber. Over time, this can cause the heart and lungs to work harder and put the child at risk for other conditions including:

The size of the hole can vary from small to large. Some ASDs close on their own over time, typically during the first three years of life. However, if the hole remains significant, closure is necessary with options including non-surgical (trans-catheter) and minimally-invasive surgical techniques.

How we care for atrial septal defects

The Cardiovascular Program at Boston Children’s Hospital is experienced in diagnosing and treating all types of congenital heart problems, including atrial septal defects. Depending on the size of the ASD, non-surgical catheter-based techniques may be able to close the defect, thereby avoiding surgery. Our clinical experience with ASD is among the highest in the country.