Types of congenital heart defect
Holes in the heart can occur:
- In the upper chambers (atrial septal defects)
- In tower chambers (ventricular septal defects)
- Between all four chambers (atrioventricular septal defects)
- In the great artery, which is called patent ductal arteriosus
The holes are part of the circulation system in the foetus but should close up after birth.
More complex conditions include tetralogy of Fallot. The main symptom is cyanosis, and for this reason babies with this problem are commonly known as ‘blue babies’.
In tetralogy of Fallot, the baby has a large hole in the heart, allowing blood to pass from the right ventricle to the left without going through the lungs. There is a narrowing at or just below the pulmonary valve, the right ventricle is more muscular than normal and the aorta lies directly over the hole – the ventricular septal defect.
Babies may have rapid breathing or fall unconscious. Older children may become short of breath and faint.
An obstruction, or stenosis, can occur between the valves between the upper and lower chambers of the heart. More frequently, the obstruction is between the ventricles and trunks coming from them, either the valve to the lungs or the valve to the body.
Only severe aortic stenosis requires surgery, and some children may have the condition without showing any symptoms. The obstruction can also be within the vessels themselves. In this case, the narrowing is within the artery and effects supplies of blood to different parts of the body. This defect may not be picked up for many years.