15. Complete Atrio- Ventricular Septal Defect
There is a large hole in the wall between all four chambers of the heart – and only the single valve between them in the middle of the heart.
The hole allows excess blood to pass from the left to the right side of the heart. If the valve leaks, this further increases the work of the heart by allowing blood to be pumped backwards into the receiving chambers as well as forwards into the arteries.
Repair is usually planned early in life before damage to the lung arteries occurs. The holes between the filling chambers and the pump chambers are closed with patches and the single valve is divided into halves, the middle portions of the valve being attached to the patch. In some babies, narrowing of the lung artery (a banding) may be performed in the first instance to protect the lungs and allow very small children to grow. The majority of children are significantly improved as a result of their surgery. Residual leaking of repaired valves can be a problem and if severe, further surgery may be necessary. Long-term follow-up and antibiotic prophylaxis is required.
This is one of the commonest heart problems occurring in Down’s syndrome.