Atrial septal defect (ASD)

What is an atrial septal defect?

An atrial septal defect (ASD) is a condition where there is a hole in the wall between the heart’s two upper chambers. This causes blood to flow between the chambers, making the heart and lungs work harder than usual. An ASD is a congenital heart defect, meaning it’s present from birth. It can vary in size, and in some cases, small holes can close on their own, but larger ones may need surgery to prevent problems like heart failure or stroke.

Penn Medicine Heart and Vascular care offers an experienced, qualified, and committed network of heart specialists in the greater Philadelphia, Lancaster, and Princeton regions. These experts help repair and manage atrial septal defects using minimally invasive treatments whenever possible.

Types of atrial septal defect

The types of atrial septal defect include:

  • Secundum: A hole in the center of the atrial wall. This is the most common type of ASD. 
  • Primum: An opening near the lower portion of the atrial wall that may be associated with other heart defects. 
  • Sinus venosus: A rare type of atrial septal defect where the hole is near the veins that brings blood back to the heart, often affecting blood flow between the right atrium and pulmonary veins. 
  • Coronary sinus: A large vein that collects deoxygenated blood from the heart muscle and drains it into the right atrium.

Atrial septal defect symptoms

Sometimes people with ASD don’t experience symptoms at all. A person with no other heart defect, or a small defect, may not have any symptoms, or symptoms may not occur until middle age or later. In more severe cases of ASD, however, some symptoms may include:

  • A rapid, pounding, or fluttering heartbeat 
  • Difficulty breathing 
  • Frequent respiratory infections or a slow growth rate in children 
  • Shortness of breath when physically active 
  • Swollen legs and feet

What causes atrial septal defect?

During fetal development, a hole forms in the upper right and left chambers of the heart. This opening allows blood to flow away from the lungs before birth. It usually closes by the time the child is born. However, sometimes the hole stays open, and blood continues to flow between the chambers, resulting in ASD.

While the exact cause of ASD in most children is unknown, genetics has been identified as a possible factor. In addition, ASD can occur alongside other congenital heart defects.

Diagnosing atrial septal defect

If ASD is suspected, certain tests are recommended to determine the presence and location of the hole in the heart. Tests might be used to assess heart rhythm, visualize the heart’s structures and function, and examine the lungs and heart.

Atrial septal defect treatment

Treatment typically depends on the size and type of atrial septal defect, its impact on your heart, and any other medical conditions you may have. For smaller, less severe atrial septal defects, a less invasive procedure called cardiac catheterization might be used. For larger ASDs or in cases with other heart problems, open-heart surgery may be necessary. The best treatment option will be determined by a cardiologist after a thorough evaluation.

Can ASD be prevented?

Atrial septal defects can’t be prevented since they develop before birth. However, getting regular checkups and avoiding harmful substances during pregnancy may help lower the chances of heart defects in general.

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