Are there different types of atrial septal defects?
There are many types of atrial septal defects. The point of difference is whether they involve other structures of the heart and how they are formed during the developmental process of the baby in the uterus. The commonest type is a Patent Foramen Ovale (PFO). This is actually present in upto 20 per cent of the adult population, but it rarely causes problems as it is usually only a few millimeters in diameter. The commonest type that causes problems is a secundum defect, which can be a few centimeters in diameter. Other, rarer septal defects that cause problems are ostium primum defects and complete atrioventricular canal defects. These are usually associated with other congenital problems.
