Description:
<jats:sec><jats:title>Aim</jats:title><jats:p>Atrioventricular septal defect (<jats:styled-content style="fixed-case">AVSD</jats:styled-content>) is widely accepted as the most common type of congenital heart defect in trisomy 21. Most of these studies, however, were conducted in <jats:styled-content style="fixed-case">C</jats:styled-content>aucasian communities. The few <jats:styled-content style="fixed-case">A</jats:styled-content>sian studies that had been conducted on this subject yielded different results. In the largest study of its kind in Asia, we described the distribution of types of congenital heart defects associated with trisomy 21 in <jats:styled-content style="fixed-case">S</jats:styled-content>ingapore.</jats:p></jats:sec><jats:sec><jats:title>Methods</jats:title><jats:p>Five hundred and eighty‐eight patients with trisomy 21 born in 1996–2010, and confirmed by karyotyping, were included in the study. The diagnosis of congenital heart defects were made on echocardiography. Variables extracted for analysis were demographics (race and gender) and the types of congenital heart defects. Except for complex cyanotic heart defects, haemodynamically significant lesions were accounted for separately in cases where more than one type of congenital heart defect coexisted in a patient.</jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p>Ventricular septal defect (<jats:styled-content style="fixed-case">VSD</jats:styled-content>) (39.2%) was the most common congenital heart defect associated with trisomy 21 in our study, followed by patent ductus arteriosus (34.3%), secundum atrial septal defect (23.4%) and <jats:styled-content style="fixed-case">AVSD</jats:styled-content> (15.6%). This study validates previous smaller <jats:styled-content style="fixed-case">A</jats:styled-content>sian studies identifying <jats:styled-content style="fixed-case">VSD</jats:styled-content> as the most common cardiac lesion associated with trisomy 21. A high proportion (25.0%) of trisomy 21 patients with tetralogy of <jats:styled-content style="fixed-case">F</jats:styled-content>allot also had <jats:styled-content style="fixed-case">AVSD</jats:styled-content>s. Coarctation of the aorta was uncommon.</jats:p></jats:sec><jats:sec><jats:title>Conclusion</jats:title><jats:p><jats:styled-content style="fixed-case">VSD</jats:styled-content> was the most common congenital heart defect seen in trisomy 21 in our study. A high proportion (25.0%) of trisomy 21 patients with tetralogy of Fallot also had <jats:styled-content style="fixed-case">AVSD</jats:styled-content>s.</jats:p></jats:sec>