Definition

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.

The heart is made up of two upper chambers and two lower chambers. Usually blood flows from the upper to lower chamber on the right side of the heart to the lungs. The blood picks up oxygen in the lungs and passes back into the upper chamber of the left side of the heart. It then passes to the lower chamber of the heart and out to the body.

The AV canal defect causes blood in the different chambers to mix. This means that some of the blood that is sent out to the body has not passed the lungs to pick up oxygen. The body does not get enough oxygen.

Heart Chambers and Valves

heart anatomy

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Blood Flow Through the Heart

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Causes

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

Factors that increase the risk of congenital heart defects include:

    
  • Family history of congenital heart defect
  • Certain chromosomal disorders such as Down syndrome
  • 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

    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.

    Diagnosis

    The doctor will ask about your child’s symptoms and medical history. A physical exam will be done. Imaging tests may be done to view your heart's structures:

        
  • Echocardiogram —to look at the size, shape, and motion of the heart
  • Cardiac catheterization —to assess the heart and its blood supply
  • Electrocardiogram —to test electrical activity of the heart
  • Treatment

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

    Surgery

    Surgery is usually recommended to correct the defect. The goal of surgery is to close the hole with a patch.

    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 medications to treat symptoms after surgery.
  • Takes antibiotics before medical or dental procedures to prevent infections.
  • Prevention

    Since the cause is not clear, AV canal defects usually cannot be prevented. Prenatal care can decrease the risk of some congenital defects.