Atrioventricular canal defect might be diagnosed in a baby before birth during a pregnancy ultrasound or special heart imaging.

After birth, symptoms of complete atrioventricular canal defect are usually noticeable within the first weeks. When listening to a baby's heart, a health care provider might hear a whooshing sound. The sound is called a heart murmur.

Tests to diagnose atrioventricular canal defect may include:

  • Pulse oximetry. A sensor placed on the fingertip records the amount of oxygen in the blood. Too little oxygen may be a sign of a heart or lung problem.
  • Electrocardiogram. Also called an ECG or EKG, this noninvasive test records the electrical activity of the heart. Sticky patches with sensors are placed on the chest. Wires connect the patches to a computer, which displays results.
  • Echocardiogram. Sound waves are used to create pictures of the heart in motion. An echocardiogram can reveal a hole in the heart or heart valve issues. It also shows how blood flows through the heart.
  • Chest X-ray. A chest X-ray shows the condition of the heart and lungs. It can show if the heart is enlarged, or if the lungs contain extra blood or other fluid. These could be signs of heart failure.
  • Cardiac catheterization. A thin, flexible tube called a catheter is inserted into a blood vessel in the groin and up to the heart. A dye injected through the catheter makes the heart structures show up more clearly on X-rays. During the procedure, a health care provider can measure pressure in different parts of the heart.


Surgery is needed to treat a complete or partial atrioventricular canal defect. More than one surgery may be needed. Surgery involves using one or two patches to close the hole in the heart wall. The patches stay in the heart. They become part of the heart's wall as the heart's lining grows over them.

Other surgeries depend on whether the defect is partial or complete and what other heart problems exist.

For a partial atrioventricular canal defect, surgery to repair the mitral valve is needed so that the valve will close tightly. If repair isn't possible, the valve might need to be replaced.

For a complete atrioventricular canal defect, surgeons separate the large single valve between the upper and lower heart chambers into two valves. If this isn't possible, the mitral and tricuspid valves might need to be replaced.

Many people who have corrective surgery for atrioventricular canal defect don't need more surgery. However, some complications, such as heart valve leaks, may require treatment.

Follow-up care

After congenital heart defect surgery, regular checkups are needed for life by a doctor trained in heart diseases. This type of care provider is called a cardiologist. Your provider will tell you how often you need an appointment or imaging tests.

Adults with a congenital heart defect treated in childhood may need care from an adult congenital cardiologist. Special attention and care may be needed around the time of future surgical procedures, even those that do not involve the heart.

Preventive antibiotics

Sometimes, a congenital heart defect can increase the risk of infection in the lining of the heart or heart valves. This infection is called infective endocarditis. You or your child might need to take preventive antibiotics before certain dental and other surgical procedures if either of you:

  • Has remaining heart problems after surgery
  • Received an artificial heart valve
  • Received artificial — or prosthetic — material during heart repair

Ask your or your child's health care provider if preventive antibiotics are necessary.

Coping and support

Many children with heart problems present at birth grow up to lead healthy lives.

But having a congenital heart defect or caring for a child with one can be challenging. These tips may be helpful.

  • Seek support. You may find that talking with other people who've experienced the same situation brings you comfort and encouragement. Ask your health care provider if there are any support groups in your area.
  • Record your or your child's health history. Write down medications, surgery and other procedures, and the dates they were performed. Include the medical report from the surgeon, and other important information about your or your child's care. This information will be useful for health care providers who are unfamiliar with you or your child. It will also help your child transition from pediatric to adult providers.
  • Ask about sports and other activities. Many people with successful repair of a congenital heart defect usually have no activity restrictions. But some people with a congenital heart defect may need to limit exercise or sports activities. Your health care provider can tell you which sports and types of exercise are safe for you or your child.

Preparing for your appointment

You or your child might be referred to a doctor trained in heart conditions, called a cardiologist.

What you can do

  • Write down all symptoms, including any that may seem unrelated to the reason why you scheduled the appointment.
  • Make a list of all your medications, vitamins and supplements, including doses.
  • Write down important medical information, including other health conditions you have or your child has.
  • Write down questions to ask your health care provider.
  • Find out if your family has a history of heart disease.

What to expect from your doctor

Your health care provider is likely to ask many questions, such as:

  • When did you notice symptoms? Are they continuous or occasional?
  • What, if anything, makes the symptoms worse or better?
  • Did you have diabetes or a viral infection, such as measles, during pregnancy?
  • Did you take medications during pregnancy?
  • Did you use tobacco or alcohol during pregnancy?

Questions to ask your doctor

For atrioventricular canal defect, some questions might include:

  • What's the most likely cause of these symptoms?
  • What tests are needed? Is there any special preparation for them?
  • What treatment do you recommend?
  • How can we manage other health problems together with atrioventricular canal defect?

Don't hesitate to ask other questions you have.

Sep 13, 2022

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  8. Atrioventricular septal defect. Merck Manual Professional Version. https://www.merckmanuals.com/professional/pediatrics/congenital-cardiovascular-anomalies/atrioventricular-septal-defect. Accessed Aug. 12, 2022.
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