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Atrioventricular Septal Defect
Cardiac
Atrioventricular Septal Defect KEY FACTS
TERMINOLOGY • Atrioventricular septal defect: Complete atrioventricular canal (AVC) defect, endocardial cushion defect • Broad spectrum of defects characterized by involvement of atrial septum, ventricular septum, & 1 or both atrioventricular valves • Ostium primum defect: Partial AVC defect or partial atrioventricular septal defect
IMAGING • Large right atrium, right ventricle, & pulmonary artery with ↑ pulmonary artery flow • Large defect in anterior inferior portion of atrial septum (ostium primum defect) • Large defect in ventricular septum (posterior type most common) • Anterior & superior aortic position with elongation + dysplastic common 5-leaflet AV valve narrowing subvalvular LVOT → "gooseneck" deformity on angiography
(Left) Graphic shows a defect in the atrioventricular (AV) septum connecting the right atrium & right ventricle to the left atrium & left ventricle. (Right) Axial image from a cardiac CTA in a newborn with Down syndrome shows a large ventricular septal defect (VSD) ſt, septum primum atrial septal defect (ASD) st, & a common AV valve , consistent with an atrioventricular septal defect (AVSD). Notice the large right atrium .
(Left) Frontal chest radiograph in a 2 month old with Down syndrome shows cardiomegaly, increased pulmonary vascularity, & venous congestion. Notice the massive enlargement of the right atrium ſt. (Right) Axial image from a cardiac CTA shows an AVSD. There is a common dysplastic AV valve with an inlet-type VSD ſt & a septum primum ASD st. Notice the enlargement of the right atrium & the small right ventricle in this unbalanced AV canal defect.
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• When AV valve opens toward 1 ventricle → unbalanced canal defect (right ventricular or left ventricular dominance can occur with single ventricle physiology) • Pulmonary hypertension patients have abnormal lung compliance: Lungs often hyperinflated • Mitral insufficiency may occur both pre- & postoperatively
CLINICAL ISSUES • Presentation ○ Large shunts → tachypnea, tachycardia, & failure to thrive ○ Small shunts may be asymptomatic & well tolerated through 1st decade ○ Mitral insufficiency adds complexity & earlier symptoms • Associations: Trisomy 21, heterotaxy, tetralogy of Fallot • Treatment: Medical management until surgery (depending on lesion & severity) ○ Partial AVC closed by pericardial patch ○ Single ventricle physiology may necessitate staged procedure (e.g., Glenn → Fontan for unbalanced AVC)
Atrioventricular Septal Defect KEY FACTS
TERMINOLOGY • Atrioventricular septal defect: Complete atrioventricular canal (AVC) defect, endocardial cushion defect • Broad spectrum of defects characterized by involvement of atrial septum, ventricular septum, & 1 or both atrioventricular valves • Ostium primum defect: Partial AVC defect or partial atrioventricular septal defect
IMAGING • Large right atrium, right ventricle, & pulmonary artery with ↑ pulmonary artery flow • Large defect in anterior inferior portion of atrial septum (ostium primum defect) • Large defect in ventricular septum (posterior type most common) • Anterior & superior aortic position with elongation + dysplastic common 5-leaflet AV valve narrowing subvalvular LVOT → "gooseneck" deformity on angiography
(Left) Graphic shows a defect in the atrioventricular (AV) septum connecting the right atrium & right ventricle to the left atrium & left ventricle. (Right) Axial image from a cardiac CTA in a newborn with Down syndrome shows a large ventricular septal defect (VSD) ſt, septum primum atrial septal defect (ASD) st, & a common AV valve , consistent with an atrioventricular septal defect (AVSD). Notice the large right atrium .
(Left) Frontal chest radiograph in a 2 month old with Down syndrome shows cardiomegaly, increased pulmonary vascularity, & venous congestion. Notice the massive enlargement of the right atrium ſt. (Right) Axial image from a cardiac CTA shows an AVSD. There is a common dysplastic AV valve with an inlet-type VSD ſt & a septum primum ASD st. Notice the enlargement of the right atrium & the small right ventricle in this unbalanced AV canal defect.
88
• When AV valve opens toward 1 ventricle → unbalanced canal defect (right ventricular or left ventricular dominance can occur with single ventricle physiology) • Pulmonary hypertension patients have abnormal lung compliance: Lungs often hyperinflated • Mitral insufficiency may occur both pre- & postoperatively
CLINICAL ISSUES • Presentation ○ Large shunts → tachypnea, tachycardia, & failure to thrive ○ Small shunts may be asymptomatic & well tolerated through 1st decade ○ Mitral insufficiency adds complexity & earlier symptoms • Associations: Trisomy 21, heterotaxy, tetralogy of Fallot • Treatment: Medical management until surgery (depending on lesion & severity) ○ Partial AVC closed by pericardial patch ○ Single ventricle physiology may necessitate staged procedure (e.g., Glenn → Fontan for unbalanced AVC)