Atrial Septal Defect

• Etiology: congenital
  — Ostium primum (30%) – at cushion, associated with AV canal
  — Ostium secundum (60%) – at fossa ovale
  — Sinus venosus (10%) – at below superior vena cava, associated with partially anomalous pulmonary venous return, see right atrial enlargement without right ventricle enlargement and collapsed aorta
• Complications: Long-term untreated ASD may lead to Eisenmenger physiology seen in 6% of patients with untreated ASD
• Clinical: usually present in adults

Cases of Atrial Septal Defect