An ASD is a communication between the two atria (top chambers) of the heart. During pregnancy, a baby normally has an opening between the two atria (the opening is called the foramen ovale). This opening exists because blood doesn’t need to be pumped to the lungs to pick up oxygen, so it can be shunted from the right side of the heart to the left and then pumped out to the body. Remember, oxygen comes from the placenta.
The foramen ovale has a flap of tissue, allowing blood to flow from the right to the left side, but not the other way. After birth, this flap seals shut. It is doesn’t, the condition is called patent foramen ovale. A patent foramen ovale is a concern if it allows blood to flow backwards (from the left side of the heart to the right). This basically pushes too much blood through the lungs, potentially damaging both the heart muscle and the lungs.
An atrial septal defect is very similar to a patent foramen ovale, except instead of failure of the flap to close, an ASD is a hole in the flap or even complete absence of the flap. An ASD may also be a hole in another place in the wall between the atria. Basically, a patent foramen ovale is a loose door that doesn’t shut properly and an ASD is a hole in the door or a hole in the wall near by.
An ASD can also affect the flow of blood through the heart potentially causing heart and lung problems as well as other health concerns.
Atrial septal defects are the second most common cause of congenital heart defects (about 10% of babies with CHD have an ASD – Oliver is one).
How an ASD is managed depends on the amount of blood flowing between the atria, the size of the hole, the location of the hole (in the door or the wall), and if the defect is causing any health problems. If everything is stable, observation will most likely be the course of action as many ASDs close on their own. For a patients with no symptoms and no abnormal blood flow, an ASD should be repaired before the age of 25 (unless it is very small, and then some doctors may advise against closing).
Oliver had a massive ASD. It was putting some strain on his heart and lungs and so by the age of 2 it was closed. He had to weigh at least 20 lbs to have the procedure, and gaining every ounce was a fight. We were fortunate that he could have it closed with a special device threaded through his groin into his heart. If he had been born a few years earlier he would have needed open heart surgery.
Now we just have the bad pulmonary valve, and if medicine keep progressing, I am hoping he will be able to have that closed with a catheter procedure as well.