What we know about Atrioventicular Septal Defect
An AVSD is the most common congenital heart defect found in children with Down’s Syndrome, accounting for 50% of the total. In its complete form there is a hole in the wall between the top chambers (atria) and a hole in the wall between the bottom chambers (ventricles), and one common valve between the two atria and the two ventricles. In the partial forms there may not be a hole between the bottom chambers (ventricles) or the mitral and tricuspid valves may not be joined together, but either or both may leak, known as valve incompetence.Because of the high pressure in the left ventricle (needed to pump the blood around the body), blood is forced through the holes in the septum (central heart wall) when the ventricle contracts, thus increasing the pressure in the right ventricle. This increased pressure (pulmonary hypertension) results in excess blood flow to the lungs.
Symptoms
Some of the early symptoms which may be exhibited are difficulty in feeding, poor weight gain, fast irregular breathing and a degree of cyanosis (blueness) particularly noticeable around the mouth, fingers and toes. Clinical examination may show an enlarged heart and liver, and a diagnosis of ‘heart failure’ may be given. This is not as frightening as it sounds - it is in fact the medical term used to indicate that the heart is working inefficiently due to the demands the body is placing on it. Because of the flow of blood from one side to the other, the heart has to work harder than normal.Not all children will exhibit symptoms early in life, and those that do will not necessarily show all of these.
