Most common type of ASD?

Types of ASD: Name Remarks Ostium secundum Located in the central poion of atrial septum; Most common type of ASD Ostium primum Located at lower pa of the atrial septum Sinus venosus defect Located at junction of superior vena cava and right atrium Coronary sinus defect Refers to unroofed coronary sinus which is a rare communication between the coronary sinus and the left atrium