ABSTRACT
An ASD is where there is a communication between the right and left atria. This is often the size of an old English penny, so large that it usually creates no murmur at all. A secundum ASD occurs at the top of the atrial septum and is the simplest type presenting on its own. A primum ASD is in the lower part of the atrial septum and may often involve problems of the mitral or tricuspid valves. An operation for this condition has a low mortality – less than 0.1% (see Figure 39).
