Atrial septal defect

Atrial septal defect: Atrial septal defect is a defect in the wall between the two upper chambers of the heart – left atrium and right atrium. This results in blood from the left atrium mixing with that in the right atrium. As a consequence of this left to right shunt, blood flow to the lung increases as the extra blood coming to the right atrium enters the right ventricle and gets pumped to the lungs. In atrial septal defect, right atrium, right ventricle and pulmonary artery get enlarged.