Atrioventricular Septal Defect

(Atrioventricular Canal Defect; Endocardial Cushion Defect)


The heart is divided into 4 chambers that help circulate blood through the body. The top 2 chambers are called atria. The bottom 2 chambers are called ventricles. 2 valves are between the upper and lower chambers. Tissue called the septum divides the chambers. The tissue grows as the fetus develops.
An atrioventricular septal defect is present at birth. It occurs when any of the tissues that divide the septum do not grow completely. This leaves 1 or more holes. It may also leave 1 leaky valve instead of 2 separate valves.


This condition is caused when the septal tissue fails to grow correctly as the fetus develops in the womb.
Ventricular Septal Defect
Ventral septal defect
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Risk Factors

Risk factors that increase the chance that a baby will be born with a ventricular septal defect include:


Symptoms include:


You will be asked about your baby's symptoms and medical history. A physical exam will be done. Most types of congenital heart disease can be identified by listening for a heart murmur.
Images may be needed of your baby's heart. This can be done with a chest x-ray .
Information may be needed about how your baby's heart functions. This can be done with:


Any of the following treatments may be advised:


It may not be possible to prevent the condition because the exact cause is unknown. A septal defect can be identified, watched, and treated early in pregnancy and childhood:
12 Week Fetus
12 week fetus
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American Heart Association

Family Doctor—American Association of Family Physicians


Canadian Adult Congenital Heart Network

Canadian Heart and Stroke Foundation


Atrioventricular septal defect, complete. Cove Point Foundation website. Available at: Updated May 16, 2011. Accessed June 30, 2015.

Atrial septal defects and patent foramen ovale. EBSCO DynaMed website. Available at: Updated May 26, 2015. Accessed June 30, 2015.

Saenz R, Beebe D, Triplett L. Caring for infants with congenital heart disease and their families. Am Fam Physician. 1999;59. Available at: Accessed June 30, 2015.

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