Atrial Septal Defect (ASD) in Children

What is an atrial septal defect in children?

The
atrial septum is the wall between the 2 upper chambers of the heart (right and left
atria). An atrial septal defect (ASD) is an abnormal hole in this wall. ASD is a heart
problem that is present at birth (congenital).

ASDs can happen on their own. Or they can happen in children born with other congenital heart defects. Girls have ASDs twice as often as boys. Doctors don’t know why this is.

ASDs are classified by their different location and development:

  • Secundum ASD occurs in the middle part of the atrial septum.
  • Primum ASD occurs in the lower part of the atrial septum close to the tricuspid and mitral valves.
  • Sinus
    venosis occurs in the upper part of the atrial septum near the veins that drain into
    the right and left atrium.
  • Coronary sinus ASD occurs when there is a defect in the wall between the coronary sinus and the left atrium.

Patent foramen ovale (PFO) is an
opening between the right and left atria that is normally present. It typically closes
shortly after birth. But a PFO is not considered an ASD because no septal tissue is
missing.

What causes an atrial septal defect in a child?

The heart forms during the first 8 weeks of pregnancy. It starts as a hollow tube and divides into 4 chambers. These chambers are separated by walls (septa). It’s normal for the walls to have openings as the fetus grows. The openings usually close shortly before or just after birth. If they don’t all close, the atrial septum will have a hole in it. This is called an ASD.

Some
congenital heart defects may be passed down in certain families. Most atrial septal
defects occur by chance. Doctors can’t find a clear reason why they happen.

What are the symptoms of an atrial septal defect in a child?

Many
children have no symptoms and seem healthy. If the ASD is large, your child may have
symptoms. Your child may:

  • Tire
    easily
  • Have
    fast breathing
  • Have
    shortness of breath
  • Grow
    slowly
  • Have
    respiratory infections often
  • Have
    abnormal heart rhythm (arrhythmias)

Older children and adults with ASDs may have migraine headaches. But it’s not clear if
the ASD is the cause. A small blood clot that forms in the bloodstream that may cause a
stroke can be linked to ASD in older children and adults. But it does not appear that
closing the defect or taking blood thinners (anticoagulants) decreases risk.

The symptoms of ASD can seem like
other health conditions. Have your child see his or her healthcare provider for a
diagnosis.

How is an atrial septal defect diagnosed in a child?

Your
child’s healthcare provider may have heard a heart murmur when listening to your child’s
heart with a stethoscope. The heart murmur is from the abnormal flow of blood through
the heart.

Your
child may need to see a pediatric cardiologist for a diagnosis. This is a doctor with
special training in treating heart problems in children. The doctor will examine your
child and listen to your child’s heart and lungs. The doctor will find out where the
murmur is best heard and how loud it is. Your child may have some tests, such as:

  • Chest X-ray. This test may show an enlarged heart. Or it may show changes in your child’s lungs because of the blood flow changes caused by an ASD. 
  • Electrocardiogram (ECG). This test records the electrical activity of the heart. It shows abnormal rhythms (arrhythmias) that may be caused by an ASD. It can also find heart muscle stress caused by an ASD.
  • Echocardiogram (echo). This test uses sound waves to make a moving picture of the heart and heart valves. An echo can show the blood flow through the atrial septal opening and find out how big the opening is.
  • Cardiac
    catheterization.
    This test uses a thin, flexible tube (catheter) put near the
    heart. Contrast dye is used to get even clearer pictures. In some children, this
    procedure may be used to close the ASD.