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Atrioventricular Canal Defect

There are many terms are used to describe this complex congenital (from birth) heart defect, which include atrioventricular (AV) canal, complete AV canal, complete common AV canal and endocardial cushion defect. All are defined as a a hole between the chambers of your heart and problems with the valves that regulate blood flow in your heart.

It develops as the heart is forming during the first eight weeks of fetal development. The heart begins as a hollow tube, then partitions within the tube develop that become the walls dividing the right side of the heart from the left. Atrioventricular canal defects happen the partitioning process is incomplete, leaving holes in the atrial and ventricular septum. The valves that separate the upper and lower heart chambers are being formed during this time, as well, and for some reason they do not develop properly, either.

Atrioventricular canal defect is often associated with Down syndrome. If left untreated, atrioventricular canal defect may cause congestive heart failure and high blood pressure in the lungs. To correct this defect, doctors often recommend surgery during the first year of life to close the hole and reconstruct the valves.

What are the symptoms of atrioventricular canal defect?

The size of the holes in the heart will affect the type of symptoms, the severity of symptoms, and the age at which they first occur. The larger the holes, the greater the amount of blood that passes through from the left side to the right side of the heart. The result is that the right heart and lungs become overloaded with blood.

Symptoms typically show themselves during infancy. While each child may experience symptoms of atrioventricular canal defect differently, they may include:

  • Fatigue
  • Sweating
  • Pale skin
  • Cool skin
  • Rapid breathing
  • Heavy breathing
  • Rapid heart rate
  • Congested breathing
  • Disinterest in feeding, or tiring while feeding
  • Poor weight gain