Dr Muiris Houston, Medical Correspondent, describes advances in infant cardiac surgery
Congenital heart defects occur in about eight infants per 1,000 live births and vary enormously in severity and complexity.
Less than a quarter of affected children will die in the first year of life, with the majority of these occurring in the first month. The number of children with severe defects who now survive is increasing all the time as surgical and post-operative management techniques improve. However, the presence of an experienced paediatric intensive care nurse is essential for the safe management of a child after cardiac surgery.
Nine common congenital heart lesions make up 90 per cent of all cases. They can be divided into two groups depending on whether the infant has cyanosis or not. Young cyanosed children are commonly referred to as "blue babies" because of their skin colour, which reflects the poorly oxygenated blood circulating around the body.
The type of structural defect and its severity will determine how early in life a child is operated on. Children with a "hole in the heart" - a gap in the central wall of the heart - will be operated on between three and nine months of age if the defect is in the ventricles (the lower and larger chambers of the heart). For those with holes in the upper part of the wall between chambers called the atria, it is usual to carry out surgical repair at two-four years.
Some infants are born with more than one defect in the heart. In a condition called Tetralogy of Fallot, blood is shunted from the right to the left side of the heart, bypassing the lungs and so making it difficult to transport oxygen in the blood.
The structural defects include a large hole in the dividing wall of the heart and a narrowing in one of the outlet valves.
A palliative operation designed to create better blood flow to the lungs is carried out early in the child's life. Then, sometime after the age of six months, a total surgical correction of the defect is carried out, usually with excellent long-term results.
Death in children either pre- or post-cardiac surgery is a small but definite risk. It is caused by a sudden rhythm disturbance or other acute cardiac event.