Atrial septal defect (ASD) Type II

What is it?

A «hole» in the wall that separates the top two chambers of the heart.

This defect allows oxygen-rich blood to leak into the oxygen-poor blood chambers in the heart. ASD is a defect in the septum between the heart’s two upper chambers (atria). The septum is a wall that separates the heart’s left and right sides.

Normally, the left side of the heart only pumps blood to the body, and the right side of the heart only pumps blood to the lungs. In a child with ASD, blood can travel across the hole from the left upper heart chamber (left atrium) to the right upper chamber (right atrium) and out into the lung arteries.

If the ASD is large, the extra blood being pumped into the lung arteries makes the heart and lungs work harder and the lung arteries can become gradually damaged.

If the hole is small, it may not cause symptoms or problems. Many healthy adults still have a small leftover opening in the wall between the atria, sometimes called a Patent Foramen Ovale (PFO).

How does the ASD affect my child?

Children with an ASD often have no symptoms. If the opening is small, it won’t cause symptoms because the heart and lungs don’t have to work harder. If the opening is large, the only abnormal finding may be a murmur (noise heard with a stethoscope) and other abnormal heart sounds. In children with a large ASD, the main risk is to the blood vessels in the lungs because more blood than normal is being pumped there. Over time, usually many years, this may cause permanent damage to the lung blood vessels.

Can the ASD be repaired?

If the opening is small, it doesn’t make the heart and lungs work harder. Surgery and other treatments may not be needed. Small ASDs that are discovered in infants often close or narrow on their own. There isn’t any medicine that will make the ASD get smaller or close any faster than it might do naturally.

If the ASD is large, it can be closed with open-heart surgery, or by cardiac catheterization using a device inserted into the opening to plug it. Sometimes, if the ASD is an unusual position within the heart, or if there are other heart defects such as abnormal connections of the veins bringing blood from the lungs back to the heart (pulmonary veins), the ASD can’t be closed with the catheter technique. Then surgery is needed.

Closing a large ASD by open-heart surgery usually is done in early childhood, even in patients with few symptoms, to prevent complications later. Many defects can be sewn closed without using a patch.