Atrioventricular canal defect, also called atrioventricular septal defect, is a combination of heart problems affecting the center of the heart. The heart condition is present at birth (congenital heart defect). Children born with this condition have a hole between the heart's chambers and problems with the valves that control blood flow in the heart.
Atrioventricular canal defect allows extra blood to flow to the lungs. The extra blood forces the heart to work too hard, causing the heart muscle to enlarge.
Untreated, atrioventricular canal defect can cause heart failure and high blood pressure in the lungs. Doctors generally recommend surgery during the first year of life to close the hole in the heart and to reconstruct the valves.
Atrioventricular canal defect (atrioventricular septal defect) may also be called endocardial cushion defect. The condition is often associated with Down syndrome.
Atrioventricular canal defect can involve only the two upper chambers of the heart (partial defect) or all four chambers (complete defect). In both types, extra blood flows into the lungs. Signs and symptoms depend on whether the defect is partial or complete.
Signs and symptoms of a complete atrioventricular canal defect usually develop in the first several weeks of life. These signs and symptoms are generally similar to those associated with heart failure and might include:
Signs and symptoms of a partial atrioventricular canal defect might not appear until early adulthood and might be related to complications that develop as a result of the defect. These signs and symptoms can include:
Atrioventricular canal defect occurs before birth when a baby's heart is developing. Doctors aren't exactly sure what causes atrioventricular canal defect. Down syndrome might increase a person's risk of this congenital heart defect.
The heart is divided into four chambers, two on the right and two on the left.
The right side of the heart moves blood into vessels that lead to the lungs, where the blood receives oxygen. The oxygen-rich blood flows back to your heart's left side and into the body's main artery (aorta). From there, the blood flows to the rest of your body.
Valves control the flow of blood into and out of the chambers of your heart. These heart valves open to let blood in and close to keep blood from flowing backward.
Partial atrioventricular canal defect:
Complete atrioventricular canal defect:
Things that might increase a baby's risk of developing atrioventricular canal defect include:
Possible complications of atrioventricular canal defect include:
Treatment greatly improves the outlook for children with atrioventricular canal defect. However, some children who have surgery to treat atrioventricular canal defect may have heart problems when they are adults, including:
Women who had an atrioventricular canal defect that was surgically corrected before any permanent lung damage occurred can generally expect to have normal pregnancies. However, pregnancy isn't recommended in women who had serious heart or lung damage before atrioventricular canal defect surgery.
Evaluation by a cardiologist trained in congenital heart disease (adult congenital cardiologist) is recommended for women with repaired or unrepaired atrioventricular canal defect before they attempt pregnancy.
Atrioventricular canal defect might be detected in a baby before birth using ultrasound and special heart imaging.
After birth, signs and symptoms of complete atrioventricular canal defect are usually noticeable within the first few weeks. When listening to your baby's heart, your doctor might hear an abnormal whooshing sound (heart murmur).
If your baby is having signs and symptoms of atrioventricular canal defect, your doctor might recommend the following tests:
Surgery is needed to repair a complete or partial atrioventricular canal defect. More than one surgery may be needed. Surgery to correct atrioventricular canal defect involves using one or two patches to close the hole in the heart wall. The patches stay in the heart permanently, becoming part of the heart's wall as the heart's lining grows over them.
Other surgeries depend on whether you have a partial or complete defect and what other heart problems you may have. 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 abnormal large single valve between the upper and lower heart chambers into two valves. If separating the single valve isn't possible, heart valve replacement of both the tricuspid valve and the mitral valve might be needed.
If the heart defect is repaired successfully, you or your child will likely have no activity restrictions.
You or your child will need lifelong follow-up care with a cardiologist trained in congenital heart disease. Your cardiologist will likely recommend a follow-up exam once a year or more frequently if problems, such as a leaky heart valve, remain.
Adults whose congenital heart defects were treated in childhood may need care from a cardiologist trained in adult congenital heart disease (adult congenital cardiologist) throughout life. Special attention and care may be needed around the time of any future surgical procedures, even those that do not involve the heart.
You or your child might also need to take preventive antibiotics before certain dental and other surgical procedures if either of you:
The antibiotics are used to prevent inflammation and infection of the lining of the heart (endocarditis).
Many people who have corrective surgery for atrioventricular canal defect don't need additional surgery. However, some complications, such as heart valve leaks, may require treatment.
Having a congenital heart defect or caring for a child with a congenital heart defect can be challenging. To help make it easier:
Although every circumstance is different, remember that many children with congenital heart defects grow up to lead healthy lives.
Atrioventricular canal defect generally can't be prevented.
Some heart defects are passed down in families (inherited). If you have a family history of heart defects or if you already have a child with a congenital heart defect, talk with a genetic counselor and a cardiologist before getting pregnant again.
You or your child might be referred to a doctor trained in heart conditions (cardiologist).
Your doctor is likely to ask you a number of questions. Being ready to answer them may leave time to go over points you want to spend more time on. You may be asked questions such as:
Preparing a list of questions can help you make the most of your time with your doctor. For atrioventricular canal defect, some basic questions to ask your doctor include:
In addition to the questions that you've prepared to ask your doctor, don't hesitate to ask other questions during your appointment.
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