Evaluation of left atrial active systolic characteristics in healthy subjects by two-dimensional speckle tracking imaging

Objective To evaluate left atrial active systolic characteristics in healthy subjects by two-dimensional speckle tracking imaging(STI).Methods Twenty-eight healthy subjects were enrolled in this study.The peak velocity(Vmax),peak longitudinal strain(LS),time to peak longitudinal strain(TLS),peak radial contraction(RS) and time to peak radial strain(TRS) were measured in each left atrial wall(anterior,inferior,lateral and septal) at all levels(basal,middle and apical) during left atrial active contraction by STI.Results ①There were no significant differences in the Vmax,LS,RS,TLS and TRS among all left atrial walls at the same level(P 0.05),except the TRS at the middle level(P 0.05).②The Vmax,LS and RS were decreased gradually from basal to apical,and there were significant differences(P 0.05) except the RS in anterior and septal wall.③Compared all levels in each left atrial wall,there were no significant differences at the TLS and TRS(P 0.05),except the TRS in lateral wall.Conclusion STI technique may palys an important role in evaluation of left atrial active systolic characteristics.There is some regularity at the Vmax,peak strain and time to peak in left atrial walls.