From the Guidelines
The most common cardiac problem in Trisomy 21 (Down syndrome) is atrioventricular septal defect (AVSD), also known as endocardial cushion defect or atrioventricular canal defect. This congenital heart defect occurs in individuals with Down syndrome and involves abnormalities in the center of the heart, specifically holes between the chambers and problems with the valves that control blood flow. The defect allows oxygen-rich blood to mix with oxygen-poor blood, causing the heart to work harder and potentially leading to heart failure and pulmonary hypertension if left untreated. Other common cardiac defects in Down syndrome include ventricular septal defects, atrial septal defects, and tetralogy of Fallot, but AVSD remains the most prevalent, as noted in the 2019 guidelines for the management of adults with congenital heart disease 1. The high incidence of cardiac defects in Down syndrome is related to the genetic alterations from the extra chromosome 21, which affects normal heart development during early fetal life. Early detection through echocardiography is recommended for all infants with Down syndrome, even without symptoms, as surgical correction is typically needed within the first few months of life to prevent complications, with most adults with AVSD having had surgical repair as children, and long-term follow-up required to monitor for left atrioventricular valve regurgitation and stenosis, left ventricular outflow tract (LVOT) obstruction, and tachyarrhythmias and bradyarrhythmias 1. Key points to consider in the management of AVSD in Down syndrome include:
- The strong association between AVSD and Down syndrome, with most complete AVSDs occurring in Down patients 1
- The importance of early surgical repair to prevent complications such as Eisenmenger physiology 1
- The need for long-term follow-up to monitor for potential complications after surgical repair 1
From the Research
Cardiac Problems in Trisomy 21 (Down Syndrome)
The most common cardiac problems in Trisomy 21 (Down syndrome) vary according to different studies.
- Ventricular septal defect (VSD) is identified as the most common congenital heart defect associated with Trisomy 21 in some studies 2.
- Patent ductus arteriosus is found to be the most common cardiac defect in Trisomy 21 patients in other studies 3.
- Atrioventricular septal defect (AVSD) is also commonly associated with Trisomy 21, although its frequency may vary 2, 3, 4.
- The spectrum of congenital heart disease in Trisomy 21 is wide and includes various types of defects, such as atrial septal defects, tetralogy of Fallot, and coarctation of the aorta 2, 3, 4.
Comparison of Cardiac Defects
Comparing the frequencies of different cardiac defects in Trisomy 21 patients:
- VSD is reported to be the most common defect in one study, with a frequency of 39.2% 2.
- Patent ductus arteriosus is found to be the most common defect in another study, with a frequency of 39.7% 3.
- AVSD is reported to have a frequency of 15.6% in one study 2 and 12.7% in another study 3.
Geographical Variations
There may be geographical variations in the frequencies of cardiac defects in Trisomy 21 patients: