Relationship between left atrial pressure and atrial natriuretic peptide in children with cardiac disease.

To evaluate the relationship between atrial pressure and the concentrations of atrial natriuretic peptide (ANP) in plasma of children with cardiac disease combined with increased left atrial loading. We extracted plasma ANP through a Sep-Pak C18 cartridge and proceeded to radioimmunoassay. Of the nine children, aged from 20 days to 10 years, cardiac diseases included transposition of the great arteries (four cases), ventricular septal defect (three cases), patent ductus arteriosus (one case) and mitral regurgitation (one case). The concentrations of ANP in plasma in the left atrium were greater than in the inferior vena cava, and the concentrations of ANP in plasma in the inferior vena cava correlated significantly with the mean left atrial pressure (r = 0.89, p < 0.01), and the concentrations of ANP in plasma in the left atrium correlated significantly with the mean left atrial pressure (r = 0.85, p < 0.01). This study indicated that left atrial pressure may have an important influence on secretion of ANP in various cardiac conditions.