Pediatric Atrial Septal Defect

  • Etiology: Congenital
    — Ostium primum (30%) – At level of endocardial cushion, associated with atrioventricular canal defect
    — Ostium secundum (60%) – At level of fossa ovale
    — Sinus venosus (10%) – At level of superior vena cava, associated with partially anomalous pulmonary venous return, see right atrial enlargement without right ventricle enlargement and collapsed aorta
  • Imaging: Intracardiac left to right shunt leads to acyanosis and increased pulmonary blood flow
  • Imaging CXR:
  • DDX:
  • Complications: Long-term untreated atrial septal defect may lead to Eisenmenger physiology which is seen in 6% of patients with untreated atrial septal defect
  • Treatment:
  • Clinical: Usually present in adults

Radiology Cases of Atrial Septal Defect

CXR of pediatric atrial septal defect
CXR AP (left) and CXR lateral (right) show the heart to be enlarged and the pulmonary vascularity to be increased. The lungs are clear.
CXR of atrial septal defect / ASD
CXR AP shows mildly increased pulmonary vascularity and a normal heart size.