Atrial Septal Defect

Also known as: ASD, coronary sinus atrial septal defect

What is Atrial Septal Defect (ASD)?

An Atrial Septal Defect is a heart condition that is present at birth due to abnormal development of the fetal heart during pregnancy. An ASD is a hole in the wall between the two upper chambers of the heart called the right and left atria.

There are four types of Atrial Septal Defects

  • Ostium secundum atrial septal defect: The most common ASD, caused when a part of the atrial septum does not close completely when the heart is developing.
  • Ostium primum atrial septal defect: This defect is associated with a split in one of the leaflets of the mitral valve.
  • Sinus venosus atrial septal defect: This defect causes the drainage of one or more of the pulmonary veins to be abnormal resulting in the pulmonary veins draining to the right atrium instead of the left atrium.
  • Coronary sinus atrial septal defect: The rarest of all ASDs, this defect is characterized by the absence of a portion of the common wall that separates the coronary sinus and left atrium

What are the signs/symptoms of ASD?

  • Fatigue
  • Difficulty breathing (rapid breathing or shortness of breath)
  • Recurring respiratory infections

What causes an ASD?

Most of the time this heart defect occurs by chance, with no clear reason for their development.

How is an ASD diagnosed?

An ASD may be discovered during your child's physical exam, while a pediatrician is listening to his/her heart. If a murmur (an abnormal heart sound) is detected, your child will be referred to a pediatric cardiologist for a diagnosis. Tests that a pediatric cardiologist may recommend include:

  • Chest X-ray
  • Echocardiogram (ECHO): A fetal echo is an ultrasound of your baby's heart. A fetal echo checks your baby's heart structure, rhythm, and function as well as the growth and development of your baby.
  • Electrocardiogram (ECG): An electrocardiogram checks for problems with the electrical activity of the heart
  • Cardiac catheterization: A minimally invasive procedure that provides comprehensive information about the structures inside the heart.

Treatment for Atrial Septal Defect

If the ASD is small, it may not cause problems and close up on its own as your child grows. In this case, your doctor may recommend monitoring your child's condition. Some ASDs are treated with cardiac catheterization, while other children need surgical repair. This condition is also treated with a Transcatheter Atrial Septal Defect Device Closure.


Reviewed by: Anthony F. Rossi, MD

This page was last updated on: July 15, 2021 03:31 PM