Assessment Of Left Ventricular Function In Patients With Chronic Kidney Disease By Two-dimensional Speckle Tracking Imaging

Objective:The purpose of this study is to evaluate the changes of left ventricular strain in chronic kidney disease(CKD)patients with left ventricular ejection fraction?55%by using two-dimensional speckle tracking imaging(2D-STI).The subclinical left ventricular myocardial dysfunction in patients with CKD were also discussed to provide reference for clinical diagnosis and treatment.Methods:Fifty patients with CKD who were treated in outpatient and inpatient departments of nephrology of the First Affiliated Hospital of Wannan Medical College from January 2019 to December 2019 were selected.According to 2012 guidelines from the Kidney Disease:Improving Global outcomes Organization(KDIGO),CKD patients were divided into 2 groups by the glomerular filtration rate(GFR)levels.There were 20patients with CKD stages 2/3(GFR was 30-89ml/min/1.73m~2)and 30 patients with CKD stages 4/5(GFR<30mL/min/1.73m~2).We recruited 30 healthy people who received physical examination in our hospital during the same period as the control.General clinical data of all subjects were recorded.Using conventional transthoracic echocardiography to measure conventional data,including left ventricular end-diastolic diameter(LVDd),left ventricular end-systolic diameter(LVSd),interventricular septal end-diastolic thickness(IVSd),left ventricular posterior wall end-diastolic thickness(LVPWd),left ventricular mass(MASS).Calculate the left ventricular mass index(LVMI)and relative wall thickness(RWT).Left ventricular average ejection fraction(BP-LVEF)were obtained through the Simpson's method.The trans-mitral pulsed-wave doppler measurements include early and late diastolic peak flow velocity(E,A).Early mitral annulus tissue velocity(e)and isovolumic relaxation time(IVRT)were measured by tissue doppler.The E/A ratio and E/e ratio was calculated.Apply 2D-STI to obtain the global peak longitudinal strain value(Endo-GLS,Mid-GLS,Epi-GLS)and the global peak circumferential strain value(Endo-GCS,Mid-GCS,Epi-GCS)of the left ventricular tri-layer myocardium.The peak longitudinal strain values of the endocardium,middle myocardium and epicardium in the two-chamber,three-chamber and four-chamber sections of the apex(AP2 Endo-LS,AP3 Endo-LS,AP4 Endo-LS,AP2 Mid-LS,AP3Mid-LS,AP4 Mid-LS,AP2 Epi-LS,AP3 Epi-LS,AP4 Epi-LS).Peak circumferential strain values of the endocardium,middle myocardium and epicardium in the base segment,middle segment and apex segment of the parasternal left ventricular short axis(SAXB Endo-CS,SAXM Endo-CS,SAXA Endo-CS,SAXB Mid-CS,SAXM Mid-CS,SAXA Mid-CS,SAXB Epi-CS,SAXM Epi-CS,SAXA Epi-CS).Comparisons of conventional and STI parameters were performed between controls and patients with different stages of CKD.Results:(1)LVDd,IVSd,LVPWd,RWT,IVRT,MASS,LVMI,A and E/e in CKD stages4/5 group increased significantly compared with CKD stages 2/3 group and the control group.LVDs in CKD stages 4/5 group were higher compared with the control group.E/A and e decreased significantly compared with CKD stages 2/3 group and the control group(P<0.05).IVSd,RWT,IVRT,MASS,LVMI and E/e in the CKD stages 2/3 group were higher compared with the control group.In CKD stages 2/3 group,e was lower than the control group(P<0.05).There were no significant differences in BP-LVEF and E among the three groups(P>0.05).(2)Endo-GLS,Mid-GLS,Epi-GLS and Endo-GCS in CKD stages 4/5 group were significantly lower than those in CKD stages 2/3 group and the control group.Mid-GCS in CKD stages 4/5 group was significantly less than that in control group(P<0.05).Endo-GLS in CKD stages 2/3 group decreased significantly compared with control group(P<0.05).(3)Compared with CKD stages 2/3 group and the control group,AP2 Endo-LS,AP3 Endo-LS,AP4 Endo-LS,AP2 Mid-LS,AP3 Mid-LS,AP4 Mid-LS,AP2 Epi-LS,AP3 Epi-LS and AP4 Epi-LS in CKD stages 4/5 group were reduced significantly(P<0.05).Compared with the control group,AP2 Endo-LS,AP3Endo-LS,AP4 Endo-LS,AP4 Mid-LS and AP4 Epi-LS were significantly declined in the CKD stages 2/3 group(P<0.05).(4)SAXB Endo-CS,SAXM Endo-CS and SAXB Mid-CS in CKD stages 4/5 group were lower when compared with CKD stages 2/3 group and the control group(P<0.05).SAXM Mid-CS in CKD stages 4/5 group was significantly less than that in control group(P<0.05).Although peak circumferential strain values in each layer and section were lower in the CKD 2/3 group when compared with the control group,the differences were not significant(P>0.05).Conclusion:(1)In patients with CKD,the changes in the heart cavity were not obvious at the early stage,but the left ventricular myocardium has begun to thicken.Diastolic function began to decline at the early stage of the disease and more obviously with the aggravation of the disease.Although the left ventricular ejection fraction of patients with early CKD was in the normal range,the left ventricular myocardial systolic function has been reduced.Early changes in left ventricular systolic function could be detected more sensitively by advanced stratified techniques in 2D-STI.In the early stage of the disease,the decline in the longitudinal myocardial strain of the endocardium was the earliest.Therefore,more attention should be paid to the longitudinal strain of the endocardium for the change of subclinical myocardial function.