Abstract:
Children with Down’s syndrome (DS)-associated
complete atrioventricular septal defect (AVSD) have rapid and
aggressive development of pulmonary vascular disease when
compared with non-Down’s syndrome (ND) children. We
aimed to evaluate the role of plasma endothelin-1 (ET-1) and
nitrate levels in DS children with complete AVSD-associated
pulmonary hypertension (PH) and compare this to ND patients.
The study included 20 patients (11 males, nine females) who
had complete AVSD associated with PH. Comparisons were
made between DS patients (n=12) aged 4 to 8 months
(median 5 months) and ND patients (n=8) aged 4 to 12
months (median 7 months). Blood samples were drawn from
the inferior vena cava, pulmonary artery, pulmonary vein, and
aorta. The plasma ET-1 concentrations of the two groups were
compared to the peripheral venous and arterial ET-1 levels,
and pulmonary vein nitrate was compared to the peripheral
arterial nitrate levels of ten healthy infants. The mean
pulmonary artery (PA) pressure and pulmonary vascular
resistance (Rp) were significantly higher in the DS group
than ND patients, and the pulmonary blood flow (Qp) in ND
patients was higher than DS patients. There were no differences
between the two study groups in regard to plasma ET-1
and nitrate levels obtained from matched sampling sites. The
plasma ET-1 and nitrate levels were significantly higher in
both study groups compared to the control subjects. The
plasma ET-1 and nitrate levels in DS patients with PH were
not different when compared to those of ND patients.
