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Atrial Septal Defect

  • Cynthia M. Johnson, MA
Publication Type:


Atrial Septal Defect

(ASD; “Hole” in the Heart)


An atrial septal defect (ASD) is a hole in the wall between the left and right upper chambers of the heart. Blood can flow through this hole. This makes it hard for the heart to work as it should. It can also lead to a backup of fluids in the lungs.

Heart Chambers and Valves.

heart anatomyhttp://services.epnet.com/getimage.aspx?imageiid=75857585si55551150.jpgsi55551150.jpgNULLjpgsi55551150.jpgNULL\\hgfiler01a\intellect\images\si55551150.jpgNULL82NULL2008-12-103004007585_223517Copyright © Nucleus Medical Media, Inc.


ASD happens as the baby grows in the uterus. It is not always known why the wall does not grow as it should. Some things that may play a role are:

  • Changes in certain genes—may happen on their own or may be passed down from a parent
  • Illness during the mother’s pregnancy

Risk Factors

The chances of ASD are higher if the mother:

  • Used tobacco or alcohol during pregnancy
  • Took antidepressants during pregnancy
  • Has diabetes
  • Has elevated blood glucose
  • Is 35 years of age or older


Small holes may only cause problems when the child becomes more active in later life. Problems may be:

For older children and adults:

  • Breathing problems
  • Fainting
  • Tiring easily
  • Problems doing physical activity
  • Irregular or fast heart beat
  • Swelling of the lower legs and ankles
  • Bluish tint to the skin, lips, or fingernails

For babies (rare):

  • Problems gaining weight
  • Fast heart beat


The doctor will ask about your symptoms and health history. A physical exam may be done. The doctor may hear a murmur while listening to the heart.

The doctor may suspect ASD based on symptoms. An echocardiogram to view the heart can confirm the diagnosis.

ASD can make the right side of the heart larger. This can lead to other health issues. These tests may be done to look for any changes to the heart:


Not all ASDs will make the heart and lungs work harder. ASD in infants may close on their own by 3 to 5 years of age. These may not need treatment. The heart will be monitored for any changes.

People with ASD who have heart changes may need to limit certain activities. Those with smaller holes can often do all activities.

Holes that are causing stress to the heart and lungs will need treatment. The hole will be sealed with surgery or a device. Options are:

  • Percutaneous procedure: A tube is inserted into a blood vessel in the thigh and passed up to the heart. A plug is used to seal the hole in the heart.
  • Open heart surgery: A large incision is made in the chest and patches are used to close the hole.


There are no known methods to prevent ASD.





  • Atrial septal defect (ASD). Kids Health—Nemours Foundation website. Available at: http://kidshealth.org/en/parents/asd.html.
  • Atrial septal defect (ASD). American Heart Association website. Available at: https://www.heart.org/en/health-topics/congenital-heart-defects/about-congenital-heart-defects/atrial-septal-defect-asd.
  • Atrial septal defects. EBSCO DynaMed website. Available at: https://www.dynamed.com/condition/atrial-septal-defects.


  • Kari Kuenn, MD
Last Updated:

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.