Complete Atrioventricular Septal Defect: Impact of DownSyndrome on Atrioventricular Valve Morphology andHaemodynamics and Clinical Outcomes

Background Complete atrioventricular septal defect (CAVSD) is a common congenital heart disease among children with Donw syndrome Purpose Investigate the impact of Down syndrome on atrioventricular valve morphology and haemodynamics as well as on outcomes in children with CAVSD. Methods We performed a single-centre, retrospective, analytic study with a prospective follow-up in the Congenital Heart Disease Unit of cardiology department over a 9-year period (from December 2008 to September 2017).We compared 2 groups of patients with CAVSD: Down syndrome patients (group 1) and non-Down syndrome patients (group 2). Results Among the 2778 patients registered in our CHD Unit during the study period, 225 (8%) were diagnosed with CAVSD, 121 (54%) in group 1 and 104 (46%) in group 2. Median age at diagnosis was 5 months [0–17 years] in group 1 versus 5 months [1month–10 years] in group 2. The situs was solitus in all group 1 patients. However, in group 2, the situs was inversus in 4 patients (3.8%) and ambiguous in 17 (16.3%) (P  Conclusion Down syndrome patients have a better atrioventricular valve anatomy, fewer preoperative left atrioventricular valve regurgitation and a lower long-term mortality rate after surgery.