In this section
The commonest form of this defect (so called Secundum ASD) is a
defect in the central part of the "Atrial Septum" (the partition
separating the Atriums). This allows red blood to pass through into
the right side of the heart, leading to enlargement of the right
ventricle and excessive flow in the lung circulation. Most affected
children are free of any major symptoms, but the risk of heart
failure developing later in life makes closure desirable, unless
the defect is very small. These defects may be repaired surgically
or by using an expanding plug ("Device"), which can be inserted
through a heart catheter without an operation (Device Closure)
Other types of ASD affect different parts of the atrial septum.
Defects in the lower part of the septum, close to th
Atrioventricular Valves (e.g. Tricuspid valve) are called 'Primum
ASD' (or Partial Atrioventricular Septal Defect).