Partial Atrioventricular Septal Defect

PartialAtrioventricular septal defect (AVSD) atrioventricular septal defectsAtrioventricular septal defect (AVSD) (AVSDAtrioventricular septal defect (AVSD)) are variants of AVSDsAtrioventricular septal defect (AVSD) with no ventricular shunt. They occur when there is incomplete fusion of the primumPrimum septum and endocardial cushions in embryogenesis. The result is a single atrioventricular (AV) junction with two separate valve orifices and an interatrial shunt (primum defectPrimum Defect). Partial AVSDsPartial AVSD and secundumSecundum atrial septal defects (ASDAtrial septal defect (ASD)) have similar hemodynamics with right-sided volume overload. However, partial AVSDsPartial AVSD also have a high incidence of AV valve dysfunction and other associated lesions, which can dominate their clinical presentation. Patients are often asymptomatic at presentation and referred for a heart murmur. The diagnosis of an interatrial shunt is made clinically, with the diagnosis of a partial AVSDPartial AVSD confirmed by echocardiography. Echocardiography demonstrates the defining features of an AVSDAtrioventricular septal defect (AVSD) with a primum defectPrimum Defect but no interventricular shunting. Echocardiography is used to determine the size of the defect, the degree of AV valve dysfunction and the presence of associated lesions. The great majority of patients diagnosed with partial AVSDsPartial AVSD are recommended for surgical repair in childhood. Partial AVSDsPartial AVSD have a high rate of reoperation, usually for AV valve dysfunction and (less commonly) left ventricular outflow tract obstructionLeft ventricular outflow tract obstruction. Morbidity and mortality are higher than secundumSecundum ASDAtrial septal defect (ASD) repair, especially if reoperation is required.