Atrioventricular Septal Defects

Atrioventricular septal defect is a lesion affecting the atrioventricular junction. Even though all lesions within this group have the same phenotypic anatomy in terms of the common atrioventricular junction, clinical manifestation and surgical approach vary according to the presence or absence of shunting at the ventricular level and presence and extent of atrioventricular valve regurgitation. This chapter reviews the morphological features, clinical presentation, and management of the most commonly encountered clinical scenarios of this lesion, as well as those associated with other congenital heart defects.