Which cardiac lesion is most commonly associated with patients who have Down syndrome?

Atrioventricular septal defect is the cardiac lesion most commonly associated with Down syndrome due to the genetic abnormalities that affect the development of the heart. In individuals with Down syndrome, there are specific patterns of congenital heart defects that occur, with atrioventricular septal defects being particularly prevalent.

This type of defect involves a combination of atrial and ventricular septal defects and results from improper formation of the heart structures during fetal development. It is characterized by a single common atrioventricular valve instead of separate mitral and tricuspid valves, leading to various hemodynamic consequences. The high association between Down syndrome and atrioventricular septal defects can be attributed to the chromosomal abnormalities inherent in the condition, primarily involving chromosome 21.

Understanding this relationship is crucial for identifying and managing congenital heart defects in patients with Down syndrome. Early diagnosis through echocardiography allows for timely interventions, which can significantly improve clinical outcomes for these patients.