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AVSD and Down Syndrome — EECC MCQ

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EasyCongenital Heart Disease (Adult)AVSD and Down SyndromeEECC

A 18-year-old man with surgically repaired complete AVSD (atrioventricular septal defect) as an infant presents with progressive breathlessness. Echocardiography shows moderate left AV valve regurgitation with a cleft in the anterior leaflet. What is the most common associated genetic condition?

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Correct answer: E — Down syndrome (trisomy 21) — AVSD occurs in approximately 40-50% of individuals with trisomy 21

Complete atrioventricular septal defect (AVSD) is the most common congenital heart defect in Down syndrome (trisomy 21), occurring in approximately 40-50% of affected individuals. The AVSD consists of a common AV valve, an ostium primum ASD, and an inlet VSD. Even after surgical repair, long-term complications include: left AV valve regurgitation (due to the cleft in the 'mitral' component of the common AV valve), subaortic stenosis, AV block, and residual shunting. The 2020 ESC ACHD Guidelines recommend lifelong follow-up for repaired AVSD. Left AV valve regurgitation is the most common reason for reoperation.

Reference: ESC (2020): Guidelines for the Management of Adult Congenital Heart Disease