A newborn with Down syndrome is screened for cardiac defect. The most common congenital heart defect in Down syndrome is:
- A Ventricular septal defect (perimembranous)
- B Atrioventricular septal defect (AVSD/endocardial cushion defect) — complete AVSD is nearly pathognomonic for Down syndrome ✓
- C Patent ductus arteriosus
- D Tetralogy of Fallot
Correct answer: B. Atrioventricular septal defect (AVSD/endocardial cushion defect) — complete AVSD is nearly pathognomonic for Down syndrome
Explanation
Atrioventricular septal defect (AVSD, also called endocardial cushion defect or AV canal defect) is the most common cardiac malformation in Down syndrome (trisomy 21), occurring in approximately 40–45% of Down syndrome patients with CHD. Complete AVSD involves both an ostium primum ASD and an inlet VSD with a common AV valve. While VSD is the most common CHD overall in the general population, AVSD is specifically associated with Down syndrome.
Reference: Ghai Essential Pediatrics, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.