Atrioventricular septal defect (“atrioventricular canal”)

Anatomy The definition of atrioventricular (AV) canal is both embryologic and anatomic: the AV canal is the zone of junction between the atria and the ventricles, including the vestibular septum (lowest part of the atrial septum), the AV valves, and the inlet septum (inferior part of the ventricular septum). Morphologically, the congenital heart defect named the “atrioventricular canal” or “atrioventricular septal defect” (AVSD) is defined as the persistence of a common AV junction guarded by a common AV valve and is associated with anomalies of varying degrees in these three components.1