Assessment Of Left Ventricular Diastolic Function Using Vector Flow Mapping In Patients With Chronic Kidney Disease

Objective: The purpose of this study was to evaluate the LV diastolic function in chronic kidney disease(CKD)with different degrees of LV diastolic dysfunction(LVDD)using flow energetic parameters by vector flow mapping(VFM).Methods: In this study,a total of 96 cases were recruited,including 58 CKD patients and 38 healthy controls.CKD patients were divided into 2 groups according to LVDD severity,named as DD1 and DD2.Vector flow mapping(VFM)analysis was executed to calculate left ventricle average energy loss(EL)during early filling phase(E-EL-ave),atrial filling phase(A-EL-ave),diastole phase(D-EL-ave),and ejection phase(S-EL-ave).In addition,the position,shape and motion of the vortex were observed using the Velocity vector + Stream line + Circulation generated by VFM,and the average vortex circulation during early filling phase(E-cir-ave)and atrial filling phase(A-cir-ave)were also assessed in the apical three-chamber view.The rate of average EL during early filling and atrial filling was expressed as E/A-EL.Results:1.Analysis of basic clinical and 2D and TDI measurement indicators of the study population:There was no significant difference in BSA and gender among the three groups(P>0.05).In DD1 group,age,EDV,SV,CO,LVMI,LAVImax,LAD,CI,Tei index,e '(septal),e'(lateral),E /e ',E /A and Peak a-wave velocity were all higher than those in control group(P<0.05).In DD2 group,LVDd,LVPW,EDV,ESV,SV,Peak e-wave velocity,LVMI,E/ e ',TE-e ' time interval and E/Vp were higher than those in the normal control group(P<0.05).Compared with DD1 group,LVPW,LVDI,LVMI,EDV,ESV,SV,Peak e-wave velocity,E/ e',TE-e were higher.2.Comparison of parameters of the left atrium among the three groups:Compared with the control group,LAD and LAVImax were higher in DD1 group(P<0.05),while left atrial total emptying fraction(LAtEF),left atrial passive emptying fraction(LApEF)and left atrial active emptying fraction(LAaEF)were decreased,but the difference was not statistically significant.The LAD and LAVImax values in DD2 group were significantly higher than those in the normal control group,while the values of LAtEF and LAaEF were significantly lower than those in the normal control group,indicating that the morphology of the left atrium had changed in DD1 group.Patients in DD2 group had not only affected the morphology of the left atrium,but also had impaired left atrium function.3.Comparison of blood flow energy parameters among the three groups:In the control group,energy loss(EL)showed three peaks in one cardiac cycle fluctuation chart,which appeared in E-peak filling period,A-peak filling period and systolic period respectively,and the average energy loss in E-peak filling period was significantly higher than that in A-peak filling period.In the DD1 group,there were also three peaks in one cardiac cycle,but the average energy loss in the E-peak filling period was significantly lower than that in the A-peak filling period.EL and vortex circulation parameters were compared found that A-EL-ave,S-EL-ave and A-cir-ave in DD1 group were significantly higher than those in control group(P<0.05).In the DD2 group,the fluctuation of energy loss in one cardiac cycle was similar to that in the normal control group,that is,the average energy loss in the E-peak filling period was significantly higher than that in the A-peak filling period.However,the E-peak filling,A-peak filling and average energy loss during the systolic period of DD2 group were all higher than those of the control group.In addition to the above indicators,D-EL-ave,E-cir-ave and A-cir-ave of DD2 group were also significantly higher than those of the control group(P<0.05).Compared with DD1 group,E-EL-ave and D-EL-ave increase gradually(P<0.05),although there is no statistical significance,A-EL-ave and S-EL-ave also have an upward trend.4.Correlation analysis between blood flow energy parameters and left ventricular function:There was a significant correlation between left ventricular diastolic function and blood flow energy parameters.Multiple stepwise regression analysis showed that parameters of left ventricular diastolic function could be used as independent predictors of mean energy loss in left ventricular diastolic period.Conclusions: For CKD patient with LVDD and LVEF>50%,effective LV filling and systolic ejection with optimized energy consumption have been impaired.As a new flow-derived index,EL can quantitatively evaluate LV diastolic function in terms of blood fluid dynamics in CKD with various LVDD.