Which cardiac defect is most commonly associated with Down syndrome?

Which cardiac defect is most commonly associated with Down syndrome?

• A. Coarctation of the aorta
• B. Endocardial cushion defect
• C. Tetralogy of Fallot
• D. Transposition of the great arteries

Answer: (B)

Down syndrome carries a high risk of congenital heart disease, and the most common lesion is an endocardial cushion defect, also known as an atrioventricular septal defect. This arises when the endocardial cushions fail to fuse properly during heart development, creating a common AV canal with defects in both the atrial and ventricular septa (ostium primum ASD and inlet VSD) and often a single, shared AV valve. The genetic and developmental factors linked to Down syndrome preferentially affect cushion formation, making this defect the classic association. Other defects such as coarctation of the aorta, Tetralogy of Fallot, or transposition of the great arteries can occur but are far less commonly linked to Down syndrome.

Down syndrome carries a high risk of congenital heart disease, and the most common lesion is an endocardial cushion defect, also known as an atrioventricular septal defect. This arises when the endocardial cushions fail to fuse properly during heart development, creating a common AV canal with defects in both the atrial and ventricular septa (ostium primum ASD and inlet VSD) and often a single, shared AV valve. The genetic and developmental factors linked to Down syndrome preferentially affect cushion formation, making this defect the classic association. Other defects such as coarctation of the aorta, Tetralogy of Fallot, or transposition of the great arteries can occur but are far less commonly linked to Down syndrome.