Tags: Disease.
Atrial septal defect (ASD) is a form of a congenital heart defect that enables blood flow between two compartments of the heart called the left and right atria. Normally the right and left atria are separated by a septum called the interatrial septum. If this septum is defective or absent then oxygen-rich blood can flow directly from the left side of the heart to mix with the oxygen-poor blood in the right side of the heart or vice versa.
