What is ATRIOVENTRICULAR CANAL DEFECT?

This condition is also known as atrioventricular septal defect, which means that there is a large hole in the septum. The right and left side of the heart is separated by the septum (a muscular wall).

This defect may be classified as partial or complete. In partial atrioventricular canal defect, the upper (atrial) or lower (ventricular) part of the septum may be affected. In complete atrioventricular canal defect, the hole is located in the upper (atrial) and the lower (ventricular) parts of the septum (where both of these parts of the septum meet), which is the more common condition.

With complete canal defect, one large hole and one valve are present and the valve is not able to close all the way, causing the blood to flow in all directions inside the heart.

Under normal circumstances, the tricuspid valve directs blood from the right atrium (upper right heart chamber) to the right ventricle (lower right heart chamber) and the mitral valve allows blood to move from the left atrium (upper left heart chamber) to the left ventricle (lower left heart chamber)

What symptoms may the patient experience?

The main problem is that too much blood flows to the lungs. This causes the heart to work too hard and the heart muscle becomes enlarged.

Small infants with canal defect often present with difficulty in breathing and they experience-delayed growth. This condition is more often associated with Trisomy 21 (Down syndrome or Mongolism). About one-fourth of children who are born with Down syndrome (Mongolism) also have atrioventricular canal defect. Approximately 50% of babies born with atrioventricular canal defect also have Trisomy 21 (Down syndrome or Mongolism).

What is the treatment?

In cases of complete atrioventricular canal defect, the hole in the septum must be closed by means of surgery. This is usually done within the first few months after birth. One or two patches are used to close the hole. The single heart valve is split into two and a mitral valve and tricuspid valve are created.

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