Atrial Septal Defect, Pediatric

An atrial septal defect (ASD) is a hole in the heart. This hole is located in the septum, which is the thin tissue that separates the two upper chambers of the heart (right atrium and left atrium). The hole is present at birth (congenital). The two most common types of ASD are ostium primum and ostium secundum. A less common form of ASD is called sinus venosus.

1. Blood from the right side of the heart is pumped to the lungs, where oxygen is added to it (oxygenated) and carbon dioxide is removed.
2. The oxygenated blood from the lungs is pumped to the left side of the heart.
3. From the left side of the heart, blood is pumped out to the rest of the body.

1. The hole in the septum allows some blood from the left atrium to mix with blood in the right atrium.
2. The blood flows to the lungs and the left side of the heart. This means that some of the blood makes the trip twice.
3. From the left side of the heart, blood is pumped out to the rest of the body.

An ASD makes the heart work harder by increasing the amount of blood in the right side of the heart. This causes heart overload and eventually weakens the heart's ability to pump.

What are the causes?

• Changes in genes or chromosomes during fetal development.
• Factors that affect the mother, such as environment, medicines, or dietary choices.

What are the signs or symptoms?

• Mild to extreme tiredness (fatigue). For infants, this may be more evident during feeding.
• Trouble breathing or shortness of breath.
• Frequent respiratory infections.
• Sensations of fluttering in the chest due to irregular heartbeat (arrhythmias).
• An extra "swishing" or "whooshing" sound (heart murmur) heard when listening to the heart.

How is this diagnosed?

• Electrocardiogram (ECG). This test records the electrical activity of your child's heart and traces the patterns of his or her heartbeat onto paper.
• Chest X-ray.
• Echocardiogram. One of these two types may be done:
  • Transthoracic echocardiogram (TTE). This test uses sound waves to produce images of your child's heart and blood vessels by placing a wand-like tool on your child's chest.
  • Transesophageal echocardiogram (TEE). In this test, a flexible tube with a camera is passed down the part of the body that connects the mouth and the stomach (esophagus). This device uses sound waves to take more detailed images of your child's heart and blood vessels.
• MRI.
• CT Scan.
• Cardiac catheterization. In this test:
  • A small, thin tube (catheter) is passed through a large vein in your child's neck, groin, or arm.
  • Your child's heart specialist (cardiologist) looks at the heart defect, checks how well the heart is pumping, and checks the function of the heart valves.

How is this treated?

• Small ASD. Treatment may not be needed if your child has a small ASD. In this case, only a small amount of blood is moving back and forth (shunting) from the left to right atrium. Your child may not have symptoms.
• Large ASD. Larger ASDs cause symptoms. Treatment is required. Depending on the type and location of the defect, one of the following procedures will be used to close the ASD:
  • A cardiac catheterization procedure. The hole is repaired by placing an implantable closure device that is inserted using a catheter. In this procedure, the catheter is passed to the heart through a vein in the groin or wrist.
  • Surgery. The hole is repaired with a patch or stitches (sutures). This may be done with a minimally invasive approach that involves small incisions or through open heart surgery with one large incision.

Follow these instructions at home:

• Learn as much as you can about your child's condition.
• Keep all follow-up visits. This is important.

Where to find more information

• American Heart Association: www.heart.org
• Centers for Disease Control and Prevention: www.cdc.gov

Contact a health care provider if:

• Your infant is not feeding well or is not gaining weight.
• Your child is frequently short of breath.
• Your child appears unusually tired when playing, taking part in sports, or doing other high-energy activities.

Get help right away if:

• Your child has chest pain when resting or with activity.
• Your child's fingertips or lips appear pale or blue.

These symptoms may represent a serious problem that is an emergency. Do not wait to see if the symptoms will go away. Get medical help right away. Call your local emergency services (911 in the U.S.).

Summary

• An atrial septal defect (ASD) is a hole in the heart. This hole is located in the septum, which is the thin tissue that separates the upper chambers of the heart.
• The cause of this condition is usually not known. Symptoms include fatigue, trouble breathing, shortness of breath, and a heart murmur.
• Treatment for this condition depends on the size of the hole and the amount of blood that goes into the right atrium.
• Get help right away if your child has chest pain with activity or at rest or if you notice that his or her lips or fingertips have turned pale or blue.