An atrioventricular (AV) canal defect is a congenital heart defect. This means that your child is born with it. This condition includes the following heart problems:
There are several types of this heart defect depending on how broad the defect is. These conditions cause oxygen-rich (red) blood and oxygen-poor (blue) blood to mix. This sends extra blood to your child's lungs.
Genes and family history may play a part in AV canal defects. They may be caused by Down syndrome or other chromosome problems.
The symptoms of AV canal defect may be similar to symptoms caused by other heart problems.
Infants with AV canal defects often have symptoms. They can include:
Your child’s symptoms depend on the size of his or her septal openings. The larger the openings, the more blood is able to pass through them. This can overload your heart and lungs. This means that your child’s symptoms may be more severe.
Over time, the pressure in your child’s lungs will force blood back to his or her heart. This blood has low oxygen levels, and it’s sent to the rest body. This causes your child’s lips, nailbeds, and skin to turn blue (cyanosis).
Your child's healthcare provider may first suspect a heart defect when he or she hears an abnormal sound (heart murmur) when listening to your child's heart with a stethoscope. Your child may also have symptoms of a heart problem. Your child’s healthcare provider may refer your child to a heart doctor for children (pediatric cardiologist).
The heart doctor will check your child and listen to his or her heart and lungs. The location and loudness of the murmur will help the doctor make the diagnosis.
Your child’s doctor may then do tests to confirm the diagnosis. The tests your child has depends on his or her age and condition, and the doctor’s preferences.
A chest X-ray may show changes in the heart and lungs caused by an AV canal defect.
This test records the electrical activity of the heart. It also shows abnormal rhythms (arrhythmias) and spots heart muscle stress. These issues may be caused by caused by an AV canal defect.
This test uses sound waves to make a moving picture of the heart and heart valves. An echo can show the pattern of blood flow through the septal openings. It can also show how large the openings are and how much blood is passing through them. Most AV canal defects are diagnosed with an echo.
A cardiac catheterization gives very detailed information about the structures inside the heart. In this test, a small, thin, flexible tube (catheter) is put into a blood vessel in your child’s groin. Then the healthcare provider guides it to your child’s heart. Your child’s healthcare provider will inject your child with contrast dye to see his or her heart more clearly. Your child’s healthcare provider will give him or her medicine to help relax and prevent pain (sedation). Your child’s blood pressure and oxygen levels will be checked during the procedure.
Treatment will depend on your child’s symptoms, age, and general health. It will also depend on how severe the condition is.
All children with an AV canal defect will need to have surgery to fix it. They may also need other treatments.
Many children will need medicine to help their heart and lungs work better, such as:
Infants may become tired when feeding. This may stop them from eating enough to gain weight. Your child may need the following:
Children with heart problems are at risk for infections of the lining of the heart and heart valves (bacterial endocarditis). Make sure that you tell all of your child’s healthcare providers that your child has an AV canal defect. Your child may need to take antibiotics before medical tests or procedures to prevent infections.
Your child will need surgery to repair the septal openings and heart valves. This is done to stop his or her lungs from becoming damaged. Your child's heart doctor will decide when the best time for surgery is. After the surgery, your child's heart doctor may give him or her antibiotics. This is to prevent infections after he or she leaves the hospital.
Most children have surgery by the age of 6 months. Children with Down syndrome may develop lung problems earlier, and may need to have surgery at a younger age.
If left untreated, an AV canal defect can cause several problems.
This is because of higher than normal pressure in the blood vessels and lungs. This lung damage doesn’t happen right away. The lungs are able to cope with extra volume of blood for a while.
As the arteries in the lungs get thicker, less blood will flow from the left to the right side of the heart and to the lungs. It will be easier for oxygen-poor (blue) blood to flow from the right side into the left side of the heart, and on to the rest of the body. This stops the body from getting enough oxygen. This causes a blue coloring to your child’s skin, lips, and nailbeds.
Bacteria in the bloodstream can cause infections of the lining of the heart and heart valves.
All children with an AV canal defect will need to have surgery to repair it. Before their operation, it’s important to follow the recommended medicine and feeding schedules.
Many children who have had an AV canal defect will live active, healthy lives after their surgery. Their activity levels, appetite, and growth will return to normal over time. Some children will still have heart valve problems after surgery. They may eventually need another operation to repair or replace the leaky or blocked valve or valves. Ask your child's healthcare provider about your child’s outlook.
Tips to help you get the most from a visit to your child’s healthcare provider:
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