Known as a hole in the heart, atrial septal defect is a congenital condition that causes babies to be born with an opening in the wall that divides the two upper chambers (atria) of the heart. The wall, or atrial septum, separates oxygen-rich blood headed to the body from oxygen-depleted blood returning to the heart. A hole in the atrial septum allows the blood to mix and affects how the heart and lungs work. If the hole doesn’t close on its own, a pediatric cardiologist can repair the atrial septum to avoid the long-term health issues untreated atrial septal defects can cause.

Wellness & Prevention

Your child’s heart forms in the first eight weeks of fetal development when the fetus is no bigger than a kidney bean. The heart starts as a hollow tube, then grows partitions that become the four chambers. A defect can happen in this phase if the atrial septum doesn’t completely close. Atrial septal defects can also happen if the hole that each baby has in its heart fails to close after birth.

Left untreated, an atrial septal defect can cause lung problems over time because blood passes through the defect from the left atrium to the right one where oxygenated blood mixes with the oxygen-poor blood in the right atrium headed for the lungs. The right atrium then pushes more blood than normal through the pulmonary artery into the lungs. The higher volume of blood eventually raises the blood pressure in the lungs and hardens blood vessels in the lungs, causing disease and permanent damage. Your child may be at higher risk of having a stroke as an adult.

The exact cause of ASD isn’t known but some defects may be genetic. Others may be affected by conditions during pregnancy. The risk of a fetus developing a heart defect may be higher in women who have rubella (German measles) early in the pregnancy, have diabetes or lupus, phenylketonuria and don’t follow a specific meal plan, are obese or use drugs, tobacco, alcohol or are exposed to certain substances. Girls are also more likely than boys to have an atrial septal defect.

Most children who have an atrial septal defect don’t have any symptoms, especially if the defect is small. A larger defect can overwork the right side of the heart and lungs, causing symptoms that include:

  • Tiring easily while playing or exercising
  • Difficult and rapid breathing or shortness of breath
  • Frequent respiratory infections
  • Slow growth
  • Migraines in older children
  • Stroke from a blood clot
  • Abnormal heart rhythm or beat
  • Fatigue
  • Sweating

Children who have atrial septal defects may experience different symptoms. ASD symptoms can resemble other conditions. Talk to your child’s doctor and see a pediatric cardiologist if any heart abnormalities are detected.


During physical examinations, your child’s doctor checks for a heart murmur, which are unusual sounds during the cycle of your heart beating. If your pediatrician hears extra noise caused by the larger flow of the blood in the right atrium, he may recommend that your child visit a pediatric heart center to see a specialist.

There are several different ways that pediatric cardiologists can diagnosis an atrial septal defect.

  • Chest X-ray: A chest X-ray produces an image of the tissue and bones in the child’s heart and lungs.
  • Electrocardiogram (ECG or EKG): Electrocardiograms are used to record the electrical activity in the heart. An ECG can show abnormal rhythms and stress on the heart.
  • Echocardiogram: Using an ultrasound, an echocardiogram creates an image of the heart and assesses the structure and function of the heart.
  • MRI or CT scan: Your child’s pediatric cardiologist may use an MRI or CT scan to take more detailed images of the heart if an echocardiogram hasn’t shown an atrial septal defect.


As a child develops, small atrial septal defects may close on their own without treatment during infancy or early childhood. Your pediatric cardiologist may recommend monitoring your child’s heart, then repairing the hole if it doesn’t close on its own. Medication may be prescribed to lessen symptoms and help reduce the affects of ASD.

To repair an atrial septal defect, a pediatric cardiologist patches or plugs the hole during cardiac catheterization or open heart surgery.

  • Cardiac catheterization: A tiny tube is inserted through a blood vessel in the groin and threaded into the heart where a mesh patch or plug is placed. Heart tissue grows around the mesh and seals the hole.
  • Open heart surgery: A pediatric cardiologist places the patch through small incisions or a larger incision in the chest.


After an initial recovery period and restricted activity, your child should be able to resume her daily routine. Follow-up appointments may be recommended to monitor your child’s health whether the defect was repaired or closed on its own.