Pathology

  • Two types-
    • Defect in upper part (atrioventricular part) of membranous septum
    • Perimembranous VSD + STL cleft

Incidence

  • Equal in both sexes

Hemodynamics

  • Volume overload of all cardiac chambers

Clinical features

  • Wide split S2
  • PSM on both right and left sternal borders
  • PSM is present from birth (unlike VSD)

ECG

  • Biatrial enlargement
  • Biventricular enlargement
  • Right axis deviation

Chest X-ray

  • Ball shaped huge cardiomegaly due to RA & LV enlargement.

Cardiac catheterization

  • Catheter enters LV from RA without entering LA
  • Oxygen step up in RA
  • LV angio shows early RA opacification

Management

Surgery