Septal Defects

(Atrial Septal Defect; Atrioventricular Canal Defect; Atrioventricular Septal Defect; Endocardial Cushion Defect; Ventricular Septal Defect)


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 atria. 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 right 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 left 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:
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:


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


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:
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:


American Heart Association

National Institute of Child Health and Human Development


Canadian Cardiovascular Society

The College of Family Physicians of Canada


Atrial septal defects and patent foramen ovale. EBSCO DynaMed website. Available at: Updated May 26, 2015. Accessed August 6, 2015.

Congenital heart defects. American Heart Association website. Available at: Accessed August 6, 2015.

Antibiotic prophylaxis for heart patients. American Dental Association's Mouth Healthy website. Available at: Accessed September 17, 2015.

Ventricular septal defect (VSD). EBSCO DynaMed website. Available at: Updated October 15, 2014. Accessed August 6, 2015.

6/18/2010 DynaMed's Systematic Literature Surveillance Jentink J, Loane M, Dolk H, et al. Valproic acid monotherapy in pregnancy and major congenital malformations. N Engl J Med. 2010;362(23):2185.

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