Relationship between hemodynamics and plasma atrial natriuretic peptide in children with ventricular septal defect or patent ductus arteriosus.

To evaluate the relationship between concentrations of ANP in plasma of the right-sided central circulation and hemodynamic parameters in congenital heart disease with left-to-right shunt. We enrolled 20 children aged from 1 month to 4.8 years with ventricular septal defect (VSD) or patent ductus arteriosus (PDA). The concentrations of ANP in plasma were extracted through a cartridge (Sep-Pak C18) before being measured by radioimmunoassay. Significant increased concentrations of ANP in plasma from inferior vena cava (117.6 +/- 18.1 pg/mL), right atrium (160.6 +/- 21.6 pg/mL) to pulmonary artery (PA) (253.4 +/- 38.8 pg/mL) were recognized. In VSD (n = 10) and PDA (n = 10), the concentrations of ANP in plasma from the inferior vena cava correlated significantly with the ratio of pulmonary to systemic blood flow (Qp/Qs) (r = 0.69, p < 0.05; r = 0.94, p < 0.01 respectively), the systolic pulmonary artery pressure (r = 0.90, p < 0.01; r = 0.93, p < 0.01 respectively), the diastolic pulmonary artery pressure (r = 0.76, p < 0.02; r = 0.68, p < 0.05 respectively), and the mean pulmonary artery pressure (r = 0.88, p < 0.01; r = 0.87, p < 0.01 respectively). The concentrations of ANP in plasma from the pulmonary artery also correlated significantly with the Qp/Qs (r = 0.81, p < 0.01; r = 0.87, p < 0.01 respectively). The results indicated that left atrial volume loading may have an important influence on secretion of ANP in some congenital heart disease with left to right shunt.