Objective To evaluate the changes of right ventricular flow field and energy loss（EL）in secundum atrial septal defect（ASD）by vector flow mapping（VFM）

and to provide a reference for quantitative assessment of right ventricular structure and function in ASD.Methods A total of 97 patients with ASD were divided into non PAH group（30 patients

pulmonary artery systolic pressure≤30 mm Hg

1 mm Hg=0.133 kPa）

mild PAH group（25 patients

30 mm Hg<pulmonary artery systolic pressure≤50 mm Hg）

moderate PAH group（22 patients

50 mm Hg<pulmonary artery systolic pressure≤70 mm Hg）and severe PAH group（20 patients

pulmonary artery systolic pressure>70 mm Hg）. 29 healthy volunteers were enrolled as control group.Right ventricular vortex parameters and EL were measured by VFM

and the correlation between right ventricular global EL and right ventricular parameters were analyzed.Results There were more vortices near the tricuspid valve orifice during P1 and P2 among control group

non PAH group and mild PAH group. Between moderate PAH group and severe PAH group

there were different sizes

directions and numbers of vortices in right ventricle at different time phases of cardiac cycle.There were no significant differences in vortex area

circulation

vortex quantity and EL between control group and non PAH group at each phase

despite which increased with the increases of PAH pressures among mild group

moderate group and severe PAH group（P<0.05）

and EL peak appeared during P1. EL was positively correlated with Tei index

E and E/e

respectively（r=0.768

0.941

0.937

all P<0.05）and negatively correlated with TAPSE

RVFAC and e

respectively（r=-0.864

-0.734

-0.817

all P<0.05）.Conclusion VFM imaging technology can evaluate the characteristics of flow field and EL of right ventricular blood flow in ASD

which can provide a reference for quantitative assessment of right ventricular hemodynamics and PAH pressure

and application analysis of right ventricular EL in ASD.