Layer-speciffc Longitudinal Strain Analysis By Speckle Tracking Echocardiography In Women With Early And Late Onset Preeclampsia

Objective:Long axis strain(LS)of left ventricular subendocardium,middle layer and epicardium in patients with early onset preeclampsia(EO-PE)and late onset preeclampsia(LO-PE)were obtained by myocardial layered strain technique,and the characteristics of long axis strain of left ventricular subendocardium,middle layer and epicardium in patients with EO-PE and LO-PE were compared.Methods:A total of 98 preeclampsia pregnant women diagnosed in the Affiliated Hospital of Qingdao University from January 2016 to January 2019 were selected as the preeclampsia group.According to the onset time,preeclampsia was divided into EO-PE group(gestational age at clinical onset<34 weeks)or LO-PE group(gestational age at clinical onset ≥ 34 weeks).In the same period,86 healthy pregnant women with age,gestational week and preeclampsia group were selected as the control group.The control group was divided into N1 group and N2 group according to gestational week(gestational age of N1group<34 weeks ago;gestational age of N2 group ≥ 34 weeks).The age,gestational week,height,weight,heart rate,systolic blood pressure(SBP)and diastolic blood pressure(DBP)of the subjects were recorded,and their body surface area(BSA)and body mass index(BMI)were calculated.The interventricular septal thickness(IVSd),left ventricular posterior wall thickness(LVPWd),left ventricular end diastolic diameter(LVEDd),left ventricular end systolic diameter(LVEDs)and left atrial anterior posterior diameter(LAd)were measured by M-mode ultrasound.Left ventricular ejection fraction(LVEF),end diastolic volume(EDV)and end systolic volume(ESV)were measured by biplane Simpson method,and left ventricular end diastolic volume index(EDVi)was calculated.Calculate the left ventricular mass(LVM)according to the correction formula,and calculate the left ventricular mass index(LVMi)according to the body surface area.The early diastolic(E peak)and late diastolic(A peak)flow velocities were measured by pulsed Doppler;The early diastolic velocity(e ’)of mitral annular septal lateral site and lateral wall site was measured by tissue Doppler,and E/e’ value was calculated.On the basis of 18 segments of left ventricular wall,The left ventricular wall was modeled as an18 segment model;Evaluate the long axis longitudinal strain parameters of the inner,middle,and outer layers of myocardium in each segment of the model in three consecutive apical long axis sections obtained,and take the average of the three cardiac cycles;The long axis longitudinal strain parameters of the inner,middle,and outer layers of myocardium are the average of the strain parameters of the 18 segment model of each layer of myocardium;The overall long axis longitudinal strain parameters of the left ventricle are the average values of the strain parameters of the inner,middle,and outer layers of the myocardium.;At the same time,calculate the LS transmural gradient from subendocardial to epicardial myocardium: [(subendocardial LS-epicardial LS)/subendocardial LS] × 100% 。 Compare and analyze the difference of the above parameters among EO-PE group,LO-PE group and control group.Results:1.The age,heart rate,body mass index(BMI),diastolic blood pressure(DBP),mean blood pressure(MBP)and cardiac index(CI)of EO-PE group and LO-PE group were similar,with no statistically significant difference(P>0.05),but the stroke output index(SVI)and systolic blood pressure(SBP)of women in EO-PE group were higher than those in LO-PE group,with statistically significant difference(P<0.05).2.LVd,IVSd,PWd,RWT,EDVi and LVMi in EO-PE group and LO-PE group were higher than those in the control group,and the difference was statistically significant(P<0.05);Compared with LO-PE group,the LVd,IVSd,PWd and RWT of EO-PE group and LO-PE group had no significant difference(P>0.05);However,EDVi and LVMi in EO-PE group were significantly higher than those in LO-PE group(P<0.05).3.The EF value in EO-PE group was significantly lower than that in the control group(P<0.05),while the EF value between LO-PE group and the control group,EO-PE group and LO-PE group had no significant difference(P>0.05).The E/e ’values in EO-PE group and LO-PE group were higher than those in their respective control groups,and the values in EO-PE group were higher than those in LO-PE group,with statistical significance(P<0.05).4.Compared with the control group,the LS of three layers of myocardium in EO-PE group and LO-PE group decreased significantly,and the LS of each layer of myocardium in EO-PE group decreased more significantly than that in LO-PE group(P<0.05).5.In the segmental analysis of left ventricular wall,in EO-PE group,LO-PE group and control group,LS in myocardial subendocardium,middle layer and epicardium increased gradually from the basal segment to the apical segment,the apical segment was the largest,the middle segment was the second,and the basal segment was the lowest.The difference was statistically significant(P<0.05).Except the middle and lower epicardial layers of apical myocardium in LO-PE group,the LS of left ventricular segments in EO-PE group and LO-PE group were significantly lower than that in control group(P<0.05).Compared with LO-PE group,LS in each segment and muscle layer of left ventricle in EO-PE group decreased significantly,with significant difference(P<0.05).6.Compared with the control group,EO-PE group showed a higher LS transmural gradient from subendocardium to epicardium,no matter in the whole ventricle or in each segment,the difference was statistically significant(P<0.05);The LS transmural gradient in the middle and apical segments of LO-PE group was significantly lower than that in the control group(P<0.05).Compared with LO-PE patients,the LS transmural gradient in EO-PE patients was significantly higher in the middle and apical segments(P<0.05).Conclusion:1.The left ventricular morphology of PE patients changed correspondingly,and the left ventricular remodeling in EO-PE group was more significant than that in LO-PE group.2.Compared with LO-PE group,EO-PE group was more prone to decrease of left ventricular systolic function and diastolic function.3.The LS of three layers of myocardium in EO-PE group,LO-PE group and healthy control group had gradient characteristics,that is,the LS decreased layer by layer from endocardium to epicardium;At di\erent levels of left ventricular wall,the LS of myocardium also has gradient characteristics,that is,it decreases from apex to base.4.LS of left ventricular three-layer myocardium,LS of left ventricular segments and LS of left ventricle as a whole in EO-PE group were lower than those in LO-PE group.5.At the level of the middle segment and apex segment of left ventricle,the LS transmural gradient in EO-PE group was significantly higher than that in LO-PE group,indicating that there were specific muscle layer differences in myocardial dysfunction between EO-PE group and LO-PE group.It is considered that EO-PE group may experience more significant myocardial damage in the subendocardium than LO-PE group.