Atrial Septal Defect (ASD)
An atrial septal defect (ASD) is an opening in the wall between the right and left atrium. If the defect is not repaired, oxygen-rich blood from the left atrium flows through the opening and mixes with oxygen-poor blood in the right atrium.
Concerns and Symptoms
ASD causes the heart and lungs to handle more blood than normal. This can increase the pressure in the lung's blood vessels, a condition called pulmonary hypertension. Because of the extra blood flowing through the heart, the right side of the heart may enlarge, become damaged, and be less able to pump blood effectively. The child may then develop congestive heart failure.
Many children with ASD exhibit few symptoms. During routine physical examinations, the defect is often detected by a heart murmur or a noticeable delay in the closure of the pulmonary valve. If an ASD is detected, it is usually repaired when the child is three to four years old.
Most ASDs can be repaired by guiding a catheter through a blood vessel up into the heart. An umbrella-shaped device is then passed through the catheter into the defect. This prevents blood from flowing through the opening. This type of procedure is performed by interventional cardiologists.
If the defect is particularly large, surgery is required. The operation to repair an ASD is performed under general anesthesia, which means the child will be asleep during surgery.
First, the surgeon makes a vertical incision in the front of the chest, opens the breastbone, and exposes the heart. Blood from the heart is redirected to a bypass machine. The bypass machine does the job of the heart and lungs during the operation.
The surgeon then opens the heart and identifies the defect. If the defect is small, he stitches it closed. If it is large, he cuts a small piece of the pericardium (the sac that surrounds the heart) in the size and shape of the defect and uses this tissue as a patch.
After the defect is repaired and the heart and pericardium closed, the surgeon shuts down the heart-lung bypass machine, and the heart starts beating again. The surgeon then closes the breastbone and chest incision and applies bandages to the incision site.