pediatrics
Atrioventricular Septal Defect
Complete AV septal defect
A complete atrioventricular septal defect, also called a complete common AV canal defect (see figure), consists of a Large Classification (ASD) in the anteroinferior aspect of the septum Contiguous nonrestrictive inlet ventricular septal defect Common AV valve orifice A complete AV septal defect is a single large central defect in the septation of the heart. A left-to-right shunt occurs at the atrial and ventricular levels and is often large. AV valve regurgitation may be significant, sometimes causing a direct left ventricle-to-right atrial shunt. These abnormalities result in enlargement of all 4 cardiac chambers. Large defects result in direct transmission of the systemic left ventricular pressure to the right ventricle and pulmonary arteries. Hemodynamic findings are similar to those of a large Ventricular Septal Defect (VSD) (VSD). If a complete AV septal defect is unrepaired, over time the increase in pulmonary blood flow, pulmonary artery pressure, and pulmonary vascular resistance may lead to reversal of shunt direction with cyanosis and Eisenmenger Syndrome . Pulmonary blood flow, all chamber volumes, and often pulmonary vascular resistance are increased. Atrial pressures are mean pressures. AO=aorta; IVC=inferior vena cava; LA=left atrium; LV=left ventricle; PA=pulmonary artery; PV=pulmonary veins; RA=right atrium; RV=right ventricle; SVC=superior vena cava. 