Atrial septal defect


A congenital heart defect known as an atrial septal defect (ASD) causes a hole between the upper chambers of the heart (atria) and causes blood from the left atrium to flow into right atrium in the wrong direction, causing an increase of blood flow to the lungs as a result of the hole. It may have presented as an incidental finding without causing any problem. Some small atrial septal defect close on their own over time, usually during infancy or early childhood. The likelihood of experiencing symptoms and need of treatment increases with the size of an ASD. The heart and lungs can be harmed by a large, long-lasting atrial septal defect. To repair an atrial septal defect and avoid consequences, surgery may be required.

Different types of atrial septal defects include:

  • Secundum: It appears at the middle of the wall separating the upper heart chambers (atrial septum). The most common type of ASD.
  • Primum: Other congenital heart disorders may coexist with this kind of ASD, which affects the lower portion of the atrial septum.
  • Sinus venosus: The upper portion of the atrial septum is where this rare type of ASD typically manifests. It is linked to other birth-related changes in the heart’s structure.
  • Coronary sinus: The wall separating the coronary sinus, a venous system component of the heart, and the left atrium is partially absent in this rare form of ASD.


Many infants with atrial septal defects are born without any symptoms. The signs and symptoms may be present in the adulthood.

Signs and symptoms of an atrial septal defect can include:

  • Shortness of breath or difficulty in breathing with exercise
  • Fatigue
  • Swelling of legs, feet or abdomen
  • Arrhythmias
  • Rapid heartbeat (heart palpitations) or skipped beats
  • Heart murmur

Before or shortly after a child is born, serious congenital heart problems, such as large atrial septal defects, are frequently identified. If the child exhibits any symptoms, get medical attention right away.


There is no known what cause atrial septal defects, but they usually come from an abnormal development of the heart that occurs while the infant is in the womb. However, there may be a connection between genetics, specific medical disorders, the usage of specific drugs, and environmental or lifestyle variables like smoking or excessive alcohol consumption.

The large atrial septal defect causes the right side of the heart may pump too hard and the lungs may become overfilled with blood. The right side of the heart ultimately enlarges and weakens if untreated. Pulmonary hypertension can also develop as a result of elevated blood pressure in the arteries that supply the lungs.

Risk factors

As the baby’s heart develops throughout pregnancy, an atrial septal defect (ASD) can develop. The likelihood of an atrial septal defect or another congenital heart defect in a fetus may be increased by specific medical conditions or drug use during pregnancy. These include the following:

  • German measles (rubella) during early stages of pregnancy
  • Diabetes
  • Lupus
  • Alcohol consumption
  • Tobacco use
  • Usage of drugs such as cocaine
  • Taking some pharmaceuticals, such as some anti-seizure meds and those for treating mood problems

A genetic counselor’s screening can assist in the prediction of the likelihood of heart problems will occur in future children if you or a family member has congenital heart disease, including ASD.