• Atrioventricular Canal Defect—Child

    (AV Canal Defect—Child; Complete AV Canal—Child; Complete Common AV Canal—Child; Endocardial Cushion Defect—Child)


    The heart is made up of four different chambers, two atria and two ventricles. Usually blood flows from the right atrium to the right ventricle and then to the lungs. Here the blood receives oxygen. The oxygenated blood comes back to the left atrium and moves down to the left ventricle, where it is pumped out to the body.
    Heart Chambers and Valves
    heart anatomy
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    Blood Flow Through the Heart
    Copyright © Nucleus Medical Media, Inc.
    An atrioventricular (AV) canal defect is a rare heart defect. There is a large hole in the center of the heart that connects all four chambers. This allows blood to mix from all the chambers.
    Instead of valves that separate the atria from the ventricles, one large valve forms. Other abnormalities may also be present.


    AV canal defect is a congenital defect. This means that the baby is born with it. It is not known exactly why some babies’ hearts develop abnormally.

    Risk Factors

    Risk factors for congenital heart defects include:
    • Family history of congenital heart defect
    • The child has certain chromosomal disorders
    • Previous pregnancy with fetal heart abnormalities or miscarriage
    • Conditions during pregnancy, such as:
      • Being infected with a virus
      • Having poorly controlled diabetes
      • Drinking alcohol
      • Taking certain medicines


    Symptoms may include:
    • Fast breathing
    • Poor feeding
    • Slow growth
    • Bluish skin color
    • Fatigue
    • Irritability
    • Lowered alertness
    • Wheezing
    • Swelling of the legs, ankles, and feet
    • Sweating
    • Fast heart beat
    • Sudden weight gain from retained fluid
    This condition can lead to heart failure . If your child has any of these symptoms, get medical care right away.


    The doctor will ask about your child’s symptoms and medical history. A physical exam will be done. Tests may include:
    • Echocardiogram —an imaging test that uses sound waves to look at the size, shape, and motion of the heart
    • Cardiac catheterization —a test that uses a catheter (tube) and x-ray machine to assess the heart and its blood supply


    Talk with the doctor about the best treatment plan for your child. Treatment options include:


    Surgery is usually recommended to correct the defect. The goal of surgery is to close the hole with a patch. The large valve is separated into two valves. If the valve cannot be repaired, heart valve replacement surgery may need to be done.

    Lifelong Monitoring

    After surgery, your child will need to have regular visits with a heart doctor. The doctor may recommend that your child:
    • Makes lifestyle changes, including limiting certain activities
    • Takes medicines to treat symptoms after surgery
    • Takes antibiotics before medical or dental procedures


    Atrioventricular canal defects usually cannot be prevented. Getting proper prenatal care is always important.


    American Family Physician http://www.aafp.org/

    American Heart Association http://www.americanheart.org/


    Canadian Cardiovascular Society http://www.ccs.ca/

    Heart and Stroke Foundation of Canada http://ww2.heartandstroke.ca/splash/


    American Heart Association. Atrioventricular canal defect. American Heart Association website. Available at: http://www.americanheart.org/presenter.jhtml?identifier=132 . Accessed July 14, 2010.

    Mayo Clinic. Atrioventricular canal defect. Mayo Clinic website. Available at: http://www.mayoclinic.com/health/atrioventricular-canal-defect/DS00745/DSECTION=risk-factors . Accessed July 7, 2010.

    Revision Information

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