What is an atrial septal defect?

An atrial septal defect is a type of congenital heart disease. Congenital heart disease refers to heart problems a baby is born with.

The heart is a muscular pump with four chambers. The two bottom chambers are the left and right ventricles. The two top chambers—the left atrium and right atrium—are separated by a wall of tissue called a septum. An atrial septal defect is a hole in this wall.

A very small hole may not cause problems. It may close on its own.

When the hole is larger, some of the blood may flow through it from the left atrium to the right atrium. So the right side of the heart may pump too much blood. Over time, this can cause the right ventricle to enlarge. And it can damage the lungs and weaken the heart.

How is an atrial septal defect diagnosed?

Your doctor may hear abnormal heart sounds, such as a heart murmur, when examining your baby.

Your doctor will order tests to find the cause of abnormal sounds or of symptoms. The most common test used to diagnose this problem is called an echocardiogram, or "echo" for short. It uses sound waves to make an image of your baby's heart.

Your baby may have other tests to find the problem, such as an EKG (electrocardiogram) or a chest X-ray. Another test may look at the amount of oxygen in the blood.

What are the symptoms?

If the hole is large and the heart has to work too hard, a baby may have symptoms, such as:

• Fast breathing.
• Sweating while feeding.
• Not eating well.
• Trouble gaining weight.

How is it treated?

If the hole is large or causing symptoms, your doctor may advise treatment to close the hole. Some children may have a treatment called catheterization.

If your baby has this treatment, your baby will be asleep while it is done. The doctor puts a thin tube into a blood vessel in your child's groin. This tube is called a catheter. The doctor will move the catheter through the blood vessel to the heart. A dye can be put into the catheter. The doctor can take X-ray pictures of the dye as it moves through your child's heart and blood vessels.

The pictures can show exactly where the hole is. Then the doctor moves special tools through the catheter to the heart. The doctor uses these tools to close the hole. Then the tools and the catheter are removed.

Some babies have surgery to close the hole.

What can you expect?

• It may seem that your baby is getting lots of tests. All of these tests help your doctor keep track of your baby's condition and give the best treatment possible.
• After treatment, your baby will need routine checkups to check the heart.
• It's hard to be apart from your baby, especially when you worry about your baby's condition. Know that the hospital staff is well prepared to care for babies with this condition. They will do everything they can to help. If you need it, ask for support from friends and family. You can also ask the hospital staff about counselling and support.