Atrioventricular canal is a serious congenital heart defect, usually requiring corrective surgery in the first few months of a child’s life. Like other heart defects, atrioventricular canal is relatively rare. However, once atrioventricular canal is discovered, surgery is necessary to help the child grow and develop properly.
Atrioventricular canal has several distinct defects that cause problems for the newborn. The septum, which divides the left and right chambers of the heart, fails to form properly. As a result, the child with atrioventricular canal has both a ventricular septal defect and an atrial septal defect. There may also be malformation of the valves dividing the atria and the ventricles, the tricuspid and mitral valves, respectively.
The septal defects result in blood mixing between the ventricles and atria, causing some deoxygenated blood to be sent back to the body, while oxygen rich blood is incorrectly sent back to the lungs. The bloodflow from the left atria and ventricles to the right side of the heart in atrioventricular canal results in the lungs receiving too much pressure. Untreated, high pressure to the lungs causes permanent lung damage, which can only be repaired via lung transplant.
Most parents and pediatricians notice when a newborn or young infant has several symptoms associated with atrioventricular canal and other heart defects. The pediatrician will probably hear a discernable murmur. The child may also exhibit inability to feed due to exhaustion, sweating, rapid or congested breathing, and pale or cyanotic skin.
When these symptoms and a heart murmur present, the parents and child are referred to a pediatric cardiologist who will examine the child closely to determine the correct diagnosis. Along with blood tests, the child will probably receive an X-ray and most likely an echocardiogram, a sonogram of the heart, to evaluate what defects might be present. The doctor may also elect to do a cardiac catheterization to evaluate the pressure in the lungs, and also to more closely examine any defects in the mitral and tricuspid valves.
Once diagnosed, the child with atrioventricular canal requires surgery. The type of surgery will depend on the degree of pressure in the lungs, as well as the degree to which the mitral and tricuspid valves are malformed. In some cases, the malformations are minor and can be easily repaired. Other cases may require replacement of either one or both valves.
During surgery, the surgeon will also address the ventricular and atrial defects, which will be closed with a patch so blood can no longer mix between the left and right side of the heart. Recovery depends upon early and successful treatment, and also upon the severity of valve deformity.
Even with severe valve malformation, atrioventricular canal has a high success rate of repair and later survival. Most children need to see a pediatric cardiologist once yearly after recovery from surgery. In the months directly after a surgery, the child may be monitored more closely. Generally, though, a child with a successful repair of atrioventricular canal can live a healthy, normal life, and will only require antibiotics before dental procedures to prevent bacterial endocarditis.
