Septal defects are a type of congenital heart problem in which there is a hole in the wall that separates the chambers of the heart. The word “septal" refers to the wall between the chambers, and “congenital” describes a condition that has been present since before birth. Congenital heart disease occurs in just 4-12 out of 1,000 births.

In a normal heart, the blood flows in from the body to the right atrium, goes into the right ventricle, and then goes to the lungs to pick up fresh oxygen. Then, the blood returns to the left atrium, goes into the left ventricle, and goes out to the rest of the body.

When there is a hole in the wall between the two atria or the two ventricles, blood can flow directly between them. In this case, the blood usually moves from left to right. This causes blood that has already been refreshed with oxygen to flow back into the right side of the heart and then into the lungs again. As a result, both the heart and lungs have to work harder than necessary because blood has to make one or more unnecessary passages through the lungs.

There are three main types of septal defects:

  • Atrial septal defect (ASD)—a hole in the wall between the two upper chambers (right and left atria) of the heart
  • Ventricular septal defect (VSD)—a hole in the wall between the two lower chambers (right and left ventricles) of the heart
  • Atrioventricular septal defect (AVSD)—a combination of ASD, VSD, and abnormalities of the tricuspid and mitral heart valves

The following information applies to all three of these defects except where noted otherwise.

Ventricular Septal Defect

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In most cases the cause is not known. However, in a small number of cases, the cause may be one of the following:

  • Family history of congenital heart defects
  • Exposure to a viral infection, drugs, or alcohol during pregnancy

Risk Factors

A risk factor is something that increases your chance of getting a disease or condition. In most cases, there are no known risk factors for septal defects.


Many people with ASD or VSD do not have symptoms. However, if the hole is large, the symptoms listed below occur. Most people with AVSD have these symptoms starting in infancy.

  • Shortness of breath
  • Getting tired easily
  • Poor growth
  • High blood pressure in the lungs and possibly damage to the blood vessels in the lungs (in VSD and AVSD)
  • Congestive heart failure]]> (in AVSD, and large ASDs and VSDs)



An ASD is most often suspected when a doctor hears a heart murmur]]> during a physical exam. This sound is caused by the blood moving through the valve from the heart to the lungs. It occurs because the heart has to move an extra large amount of blood through the valve.

An ]]>echocardiogram]]> is the most common method for confirming a diagnosis of ASD and AVSD. It may also be used for VSD. An echocardiogram uses high-frequency sound waves (ultrasound) to examine the size and shape of the hole in the septum and any enlargement of the heart chambers.

Other tests may include:

  • ]]>Electrocardiogram (ECG, EKG)]]> —a test that records the heart's activity by measuring electrical currents through the heart muscle
  • ]]>Chest x-ray]]> —a test that uses radiation to take a picture of structures inside the chest. It may show enlargement of the heart and increased blood flow from the heart to the lungs.



About 40% of all ASDs and many VSDs close on their own during the first year of life. Small ones are more likely to close without treatment.

An ASD that still exists at age 2 is unlikely to ever close on its own. If it is not closed in childhood, it may cause problems in adulthood; therefore, surgery is often recommended.

Small VSDs that do not close rarely cause problems. Medium and large VSDs may cause problems and need treatment, often in the first few months of life.

Most infants with AVSD have symptoms and need treatment.

Infants with signs of congestive heart failure often need to take medicine. When septal defect symptoms cannot be controlled with medicine or the heart continues to have to do extra work, surgery is often recommended to close the hole(s). In AVSD, surgery is usually necessary.

The type of surgery used most often for septal defects is open-heart surgery. The hole is closed with stitches or a patch, depending on its size and shape. In AVSD, the abnormal valves are also repaired.

Some ASDs can be closed without surgery by placing a device in the septum hole during a cardiac catheterization]]> . The device is inserted into the heart through a large vein. Both procedures have a very high success rate. Most patients go on to live a normal life, although a small number of those with AVSD have problems with repaired valves.

Living With Septal Defects

Children and adults with unrepaired VSDs and those who have had recent surgery to repair any defect may need antibiotics before certain medical and dental procedures. Among these procedures are:

  • Dental cleaning
  • Tooth extraction
  • Orthodontic procedures (placing of braces on teeth)
  • Certain examinations of, or operations on, the mouth or bladder
People with unrepaired VSD or AVSD should ask their primary care doctor or cardiologist to clarify which examinations or procedures might require antibiotic pretreatment.



There are no general guidelines for preventing septal defects.

One type of AVSD is strongly associated with Down syndrome]]> , and programs have been developed to help some parents reduce their risk of having a baby with this condition.

Women who have a serious health condition or who need to take medication regularly should discuss potential risks with their doctor before considering pregnancy.