(Atrial Septal Defect; Atrioventricular Canal Defect; Atrioventricular Septal Defect; Endocardial Cushion Defect; Ventricular Septal Defect)
by Laurie Rosenblum, MS
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.
In most cases the cause is not known.
Risk Factors TOP
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
Antibiotic prophylaxis for heart patients. American Dental Association's Mouth Healthy website. Available at:
...(Click grey area to select URL)
Accessed September 17, 2015.
Atrial septal defects and patent foramen ovale. EBSCO DynaMed Plus website. Available at: http://www.dynamed.... Updated December 29, 2015. Accessed September 23, 2016.
Congenital heart defects. American Heart Association website. Available at:
...(Click grey area to select URL)
Accessed August 6, 2015.
Congenital ventricular septal defect (VSD) in children and adults. EBSCO DynaMed Plus website. Available at: http://www.dynamed.... Updated January 25, 2016. Accessed September 23, 2016.
6/18/2010 DynaMed Plus Systematic Literature Surveillance http://www.dynamed...: 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.
Last reviewed August 2015 by Michael Woods, MD
Last Updated: 8/6/2015
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