Q) Most common type of Atrial Septal Defect (ASD) is:
A. Ostium Primum
B. Ostium Secundum
C. Sinus Venosus
D. All are equal
| ASDs ■ Common defects Ostium secundum: fossa ovalis defect (approximately 70 per cent of ASDs) Ostium primum: atrioventricular septal defect (approx imately 20 per cent of ASDs) Sinus venosus defect: often associated with anomalous pulmonary venous drainage (approximately 10 per cent of ASDs) Patent foramen ovale: common in isolation, usually no left-to-right shunt (not strictly an ASD) Rarer defects Inferior vena cava defects: a low sinus venosus defect and may allow shunting of blood into the left atrium Coronary sinus septal defect: also known as unroofed coronary sinus with the left superior vena cava draining to the left atrium as part of a more complex lesion |