Septal defects are problems with the structure of the heart. They are present at birth. Septal defects are located on the inside of the heart. They are on a wall that separates the chambers of the heart. There are 2 upper chambers of the heart called atrium. 2 lower chambers of the heart are called ventricles.

In a healthy heart, the blood flows from the body to the right atrium. The blood then goes into the right ventricle. The ventricle pumps this blood to the lungs to pick up fresh oxygen. The blood then returns to the left side of the heart. It enters the left atrium first, then down to the left ventricle. The ventricle pushes the blood out to the rest of the body.

Septal defects allow the blood to move between the left and right chambers. The blood most often moves from the left side of the heart into the right side. This means that blood that has just returned from the lungs may end up being sent right back to the lungs. As a result, both the heart and lungs have to work harder than they need to work.

There are 3 main types of septal defects:

  • Atrial septal defect (ASD)—a hole in the wall between the 2 upper chambers (atrium) of the heart
  • Ventricular septal defect (VSD)—a hole in the wall between the 2 lower chambers (ventricles) of the heart
  • Atrioventricular septal defect (AVSD)—a combination of ASD, VSD, and problems with opening between chambers called valves

The stress of pushing extra blood to the lungs may lead to heart failure. The following information applies to all 3 of these defects except where noted.

Ventricular Septal Defect

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In most cases the cause is not known.

Risk Factors

Factors that may increase the risk of septal defects include:

  • Family history of congenital heart defects
  • Exposure to a viral infection, drugs, or alcohol during pregnancy
  • Certain medications, such as those used to treat seizure disorder

Many people with ASD or VSD do not have symptoms. Large defects and AVSD may cause:

  • Shortness of breath
  • Getting tired easily
  • Poor growth

A septal defect may be found during a regular exam. The doctor may hear a heart murmur.

The heart may be tested. This can be done with: .

Chest x-rays can evaluate the heart and surrounding structures.


Treatment may depend on the type and size of defect. There may be some treatment steps for any complications. Treatment options may include:

  • ASD treatment options include:
    • No treatment.
      • About 40% of all ASDs will close on their own during the first year of life.
      • This is more likely to occur with small defects.
    • Surgery may be recommended in children with ASDs past 2 years of age.
      • 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.
    • Some ASDs can be closed without surgery. A device is placed in the hole with cardiac catheterization. This is a process that send the device to the heart through a large blood vessel.
  • VSD treatment options include:
    • No treatment.
      • Many VSDs will close on their own during the first year of life. This is more likely to occur with small defects.
      • Small VSDs that do not close rarely cause problems.
    • Surgical repair
      • May be needed in children with defects that cause symptoms or do not close after 1 year
      • Medium and large VSDs may cause problems. They may need supportive treatment in the first few months of life until surgery can be done.
  • Most infants with AVSD will have symptoms and require treatment. AVSD treatment options include:
    • Medication, which can help the heart beat strongly, keep the heart rate regular, or decrease the amount of fluid in the blood flow
    • Limiting physical activity
    • Surgery to close the defect
  • Medication may be needed for infants with septal defects with congestive heart failure

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

Living With Septal Defects

Certain septal defects may increase the risk of infections in the heart. You may need to take antibiotics before certain medical and dental procedures to decrease the risk of this infection. Check with your doctor to see if you need to do this. If you do need to take antibiotics, ask your doctor to explain when they may be needed.


Follow these prevention guidelines:

  • Talk to your doctor before considering pregnancy.
  • Go to all prenatal screening tests.
  • Avoid alcohol and drugs during pregnancy.
  • Talk to your doctor about ways to reduce your risk of having a child with Down syndrome. One type of AVSD is associated with the syndrome.