Evaluation Of Longitudinal Systolic Function In Normal And Gestational Diabetic Fetus By Two-dimensional Speckle Tracking Imaging

Objective:The aim of this study is to detect the left ventricular systolic function in both normal fetuses and those under the effect of gestational diabetes mellitus（GDM）by using two dimensional speckle-tracking imaging（2D-STI）and explore clinical value of 2D-STI in examining cardiac motor function of fetuses under the effect of GDM.Methods:78 fetuses under the effect of GDM and 76 normal fetuses were included,and standard fetal four-chamber surface dynamic two-dimensional acoustic image was obtained.The common cardiac indicators were determined,including left atrial transverse diameter（LATD）,right atrial transverse diameter（RATD）,left ventricular transverse diameter（LVTD）;right ventricular transverse diameter（RVTD）,interventricular septal thickness（IVST）,left ventricular lateral wall thickness（LVLWT）,aortic valve ring internal diameter（AVRID）and pulmonary valve ring internal diameter（PVRID）.STI was applied offline to trace systolic velocity（Vs）,systolic displacement（Ds）and systolic strain of 9 segments in both left-ventricle side of the ventricular septum（LVSVS）and lateral wall of left ventricle（LWLV）（including both endocardium and epicardium）in those short video clips.Comparisons of parameter differences in different segments and their gradual changes with gestational weeks were made.Later,the differences in parameters between two groups were analyzed.Results:（1）When the gestational age was between 32⁺00 and 35⁺66 week,the IVST in fetuses under the effect of GDM was significantly thicker than that in normal ones（P<0.05）;and when over the gestational age of 36⁺00 weeks,the IVST and LVLWT in fetuses under the effect of GDM were also statistically thicker than those in normal ones（P<0.05）;（2）The Vs,Ds and Ss in the LVSVS and LWLV（including both endocardium and epicardium）grew as gestational weeks increased in both groups of fetuses,which was in a positive correlation（P<0.05）;（3）As for the Vs and Ds in the basal,middle and apical segments of LVSVS and LWLV（including both endocardium and epicardium）,they showed a successive decrease in all the fetuses regardless of gestational age（P<0.05）;but Ss in different segments was not obviously different between groups（P>0.05）.（4）The Vs and Ds in endocardium of the LWLV were greater than those in epicardium in all fetuses regardless of gestational week（P<0.05）and yet there was no evident differences of Ss in the LWLV（including both endocardium and epicardium）between groups（P>0.05）.（5）The overall Vs,Ds,and Ss in endocardium of the LWLV and lateral wall of left ventricle（LWLV）as well as strain of epicardium is significantly lower in fetuses under the effect of GDM than those of normal ones in both gestational weeks of32⁺⁰³5⁺66 and over 36⁺⁰（P<0.05）.（6）The intraclass correlation coefficient of Vs and Ds was above 0.8,that of Ss was above 0.6 in endocardium,epicardium and ventricular septum left ventricular surface（including the basal,middle and apical segment）determined at same time by different measurer or at different time by the same measures.Conclusion:（1）STI is able to obtain various myocardial motor parameters from different levels in normal fetuses and those under the effect of GDM with favorable repeatability.Thus it could be a novel method to evaluate left ventricular myocardial systolic function in fetuses.（2）The systolic velocity and displacement in the basal,middle and apical segment of the LVSVS and LWLV（including both endocardium and epicardium）decreases successively in both normal fetuses and those under the effect of GDM but the strain distribution of these three segments proves no significant difference.（3）The systolic velocity,displacement and strain of LVSVS and LWLV（including both endocardium and epicardium）grew as gestational weeks increased with a positive correlation.（4）The systolic velocity,displacement in endocardium of the LWLV were greater than those in epicardium in all fetuses and yet there was no evident differences of strain in endocardium and epicardium.（5）In their third trimester,fetuses under the effect of GDM appear decreased in the systolic velocity,displacement and strain of endocardium in left ventricle than those of normal ones and the parameters from,and strain of epicardium.STI could give an quite accurate direction to fetal left ventricular dysfunction.