Atrial Septal Defect


An atrial septal defect is a birth defect in the upper chambers (atria) of the heart. Every child is born with an opening (septum) between the atria that closes with time. Sometimes the opening does not close, resulting in a hole that increases blood flow to the lungs. If the hole is small, a person with this defect may not experience any symptoms or problems. A larger opening may cause damage to blood vessels and other problems in adulthood. These defects are rare, and only 10% of babies in the United States born with a congenital heart defect have an atrial septal defect.


There are three types of atrial septal defects, which are characterized by where the defect is located:

  • Sinus venosus defects affect the upper part of the septum.
  • Ostium secundum defects, the most common type, affect the middle part of septum.
  • Ostium primum defects affect the lower part of septum.


A child may not show signs of an atrial septal defect right away. Instead, symptoms often occur in adults. These symptoms may include:

  • Difficulty breathing
  • Frequent respiratory infections
  • Heart failure
  • Heart murmur
  • Irregular heartbeats
  • Shortness of breath during activity
  • Stroke
  • Swelling in the abdomen, legs and feet


Research is unclear of the exact cause of an atrial septal defect. Most cases occur for no apparent reason, however some cases appear to be genetic and cannot be prevented.

Risk Factors

  • You’re at risk if you have a family member with the defect.
  • Some other disorders, such as Down syndrome or Ellis van-Creveld syndrome, are more commonly associated with atrial septal defects.


  • Clinical evaluation. Your healthcare provider will conduct a physical exam to look for signs of heart failure. The physician may use a stethoscope to detect a heart murmur, a common symptom of the condition.
  • Echocardiogram. This is a common test used to diagnose an atrial septal defect. An echocardiogram uses sound waves to generate pictures of the heart. This test will help your physician look at the motion and function of your heart for any abnormalities.
  • Other tests. Your healthcare provider may order additional tests to confirm the presence of a defect, including an electrocardiogram, heart MRI and cardiac catheterization.


Surgical Treatment

There are two main procedures to treat a defect:

  • Cardiac catheterization. This is a less-invasive procedure than open-heart surgery and works best for defects in the middle of the septum. During this procedure, a thin tube called a catheter is inserted into the groin and maneuvered to the heart, where it’s able to patch the hole.
  • Open-heart surgery. This procedure requires a surgeon to open the chest to reach the heart. Your surgeon will sew both edges of the defect closed or patch the hole with a graft.

Follow-up Care

If you require surgery to treat atrial septal defect, follow your healthcare provider's instructions for care, which may include:

  • Specific instructions for returning to normal activity levels
  • Scheduling periodic visits with a cardiologist
  • Taking any prescribed medications to prevent blood clots and infection after surgery