An atrial septal defect is an opening in the wall that separates the upper chambers of the heart. It is one of the most common congenital heart defects, which are structural problems that develop ...

An atrial septal defect of the secundum type is relatively common and occurs from failure of the septum secundum to develop. This results in a communication between the left and right atrium ...

If you clench your hand into a fist, this is approximately the same size as your heart. It is located in the middle of the chest and slightly towards the left. The heart is a large muscular pump ...