atrioventricular defect

Last edited 12/2022 and last reviewed 02/2023

This condition was previously known as the atrioventricular canal defect or endocardial cushion defect.

This condition consists of different combinations of:

  • primum atrial septal defect
    • in ostium primum atrial septal defect (ASD) there are separate atrioventricular valvar orifices despite a common junction
      • this contasts with complete atrioventricular septal defect (AVSD) where the valve itself is also shared
  • abnormalities of the atrioventricular valve, varying from a cleft mitral valve to a common atrioventricular valve
  • inlet ventricular septal defect

If there is a complete atrioventricular defect then there is an atrial component, a ventricular component and a common atrioventricular valve.

Click here for example ECG and further information

An AVSD with unequal position of the common AV valve above the ventricles is accompanied by a variable degree of ventricular hypoplasia (unbalanced AVSD)