NPPA and atrial septal defect: In this study, we showed that (1) plasma ANP concentrations were elevated in patients with ASD regardless of the presence of PAH, (2) plasma ANP concentrations were correlated positively with PAP, RVEDV and RVESV; and correlated negatively with RVEF, and (3) after transcatheter closure of ASD, plasma ANP concentrations were markedly decreased, the RVEDV, RVESV decreased and the RVEF increased markedly.