Evaluation the changes of strain rate and strain of right ventricular using speckle tracking imaging after transcatheter closure of atrtial septal defect

Objective:To investigate the changes of right ventricular velocities,strain and strain rate in patients with atrial septal defect(ASD)after transcatheter closure. Methods:Using speckle tracking imaging(STI),the 6 segments of longitudinal peak systolic velocities,peak systolic strain rate (SR),and end systolic strain of the RV free wall and the septum were calculated repeatedly in 25 patients with ASD before surgery and the 3rd day after surgery,and 25 healthy subjects as controls. LVESV,LVEDV,LVSV,RVESV, RVEDV and RVSV were calculated. LV and RV ejection fraction(EF)was measured by Biplane Simpson method. Results:Compared with before closure of ASD,a significant reduction in RV long-axis dimension was noted in 72 hours after ASD closure. In patients with ASD,significantly higher peak systolic velocities were recorded from the RV free wall,compared with that in healthy control subjects. After transcatheter closure of the defect,we observed a significant reduction of peak systolic velocities,which returned to normal physiologic value. Before ASD closure,end systolic strain values were significantly higher,while peak systolic SR values showed a trend to increase,however,no significance compared with control. After transcatheter ASD closure,peak systolic SR and end systolic strain showed a diminishing tendency. However,the difference was not significant. In the patients with ASD,significant higher end systolic strain values and peak systolic velocities were found at the interventricular septum,followed by a significant reduction after ASD closure. Peak systolic SR did not differ significantly from normal values and remained unchanged after closure of the defect. Conclusion:RV longitudinal systolic deformation were not significantly influenced by chronic ventricular volume overload and sudden abolishment of this volume overload. These findings suggest that SR/S are relatively load-stable measures of contractile function in clinic. In contrast,myocardial velocities are load-dependent obviously.