Down syndrome (DS) is one of the most common chromosomal abnormalities. The incidence of DS at birth in developed countries has remained relatively stable over the last 20 years, at approximately 1 per 1000 live births. DS is associated with a number of congenital defects and is also at increased risk of conditions that may develop later in life, and thus requires multidisciplinary care and close surveillance. Congenital heart disease (CHD) is present in 35%–50% of patients and is haemodynamically significant in two-thirds.1 Early diagnosis and treatment in expert centres are essential for improving short-term and long-term outcomes and avoiding important complications, such as the development of pulmonary arterial hypertension (PAH).

Pulmonary arterial hypertension related to congenital heart disease in Down syndrome

The CHD most commonly encountered in DS is atrioventricular septal defects, ventricular septal defects and atrial septal defects.1 Large post-tricuspid defects allow significant left–right shunting after birth and produce significant pressure and volume overload to the pulmonary circulation, which over time can lead to the development of pulmonary vascular disease. Eisenmenger syndrome (ES) is at the extreme of the spectrum of PAH related to CHD (PAH–CHD), with severe pulmonary vascular disease, resulting in systemic levels of pulmonary vascular resistance and reversal of the shunt causing central cyanosis. ES is a systemic condition, significantly affecting effort tolerance and quality of life, and, over time, resulting in multiorgan failure.2 Major recent advances in management, including the use of PAH therapies, have led to an improvement …