NPPB and atrial septal defect: The pre-operative brain natriuretic peptide (BNP) level was normal; however, 6 months after ASD closure, the BNP level was elevated, and the continuous-wave Doppler waveform of pulmonary regurgitation at the time of transthoracic echocardiography changed, suggesting an increase in diastolic RV pressure.<h4>Discussion</h4>When ASD is complicated by hypoxaemia, the possibility of IRVH, although rare, should be considered.