pediatrics
Atrioventricular Septal Defect
Transitional AV septal defect
A transitional atrioventricular septal defect, also called a transitional AV canal defect, consists of An ostium primum atrial septal defect A restrictive inlet Ventricular Septal Defect (VSD) , which may be small or moderate in size A common AV valve, which may or may not be partitioned into a left and right orifice In a transitional AV septal defect, the shunt at the atrial level is usually large. The shunt at the ventricular level is smaller than in complete AV septal defect, and right ventricular pressure is lower than left ventricular pressure. The hemodynamics depend largely on the size of the VSD and whether there is significant AV valve regurgitation. 