Abstract: Objective To analyze the correlation between interventricular septum morphology and right heart catheterization indexes by cardiac magnetic resonance (CMR), and to evaluate the use of interventricular septum curvature(C_IVS) in diagnosis of patients with pulmonary artery hypertension(PAH). Methods Retrospective analysis was performed where RHC and CMR data were collected from 32 adult patients with atrial septal defect (ASD).According to their mean pulmonary artery pressure (mPAP), the patients were divided into two groups: a PAH group(≥25 mmHg) and a non-PAH (NPAH) group. Both groups were compared for CMR parameters,and the correlation between C_IVS and CMR parameters and RHC measurements was analyzed.The receiver operating characteristic (ROC) curve was used to analyze the use of C_IVS for detection of PAH.Results In the current study, there were 16 ASD patients with PAH.Compared with the NPAH group, end-diastolic C_IVS(dC_IVS) decreased in the PAH group (P<0.01); and no statistical difference was found in end systolic C_IVS between the two groups. There were significant correlations between dC_IVS and mPAP (r =-0.85, P<0.01),between dC_IVS and systolic pulmonary artery pressure(sPAP)( r =-0.75, P<0.01),between dC_IVS and diastolic pulmonary artery pressure(dPAP)(r=-0.84, P<0.01).The ROC showed that dC_IVS was effective for diagnosis of PAH. The AUC was 0.94, with a specificity of 94% and a sensitivity of 81%. Conclusions For adult ASD with PAH, dC_IVS can be used as an important index for noninvasive evaluation of PAH.