Evaluation Of Left Ventricular Function In Young And Middle-aged Peritoneal Dialysis Patients With Normal Left Ventricular Ejection Fraction By Two-dimensional Speckle-tracking Imaging And Myocardium Layer-specific Strain Analysis

Objective:This study was aimed to evaluate the role of two-dimensional speckle-tracking imaging(2D-STI)and myocardium layer-specific strain analysis in evaluating early left ventricular(LV)myocardial function in young and middle-aged peritoneal dialysis patients(PD)with normal left ventricular ejection fraction(LVEF).Methods:We enrolled 30 PD patients aged≤60 with LVEF≥54%and classified as normal LV diastolic function by conventional echocardiography as PD group,and 30 age-and sex-matched healthy people as the control group.The LVEF,LV mass index(LVMI),interventricular septal thickness(IVST),LV posterior wall thickness(LVPWT),left atrial maximum volume index(LAVI)and peak velocity of tricuspid regurgitation(TR)of two groups were recorded and calculated by conventional echocardiography,then we recorded peak early diastolic velocity(E),late diastolic velocity(A)of the mitral orifice(by Pulsed Doppler)and peak velocity of the early diastolic wave of the mitral orifice(e’)in the lateral wall(by Pulsed-wave tissue Doppler),and calculate E/A and E/e’.Using 2D-STI,We obtained longitudinal strains(LS)of the endocardium(LSendo),the myocardium(LSmyo),the epicardium(LSepi),and the global myocardium(GLS).Next,the LV global longitudinal diastolic strain rate(DSr)during early diastole(DSrE),late diastole(DSrA)and isovolumic relaxation period(DSrIVR)of three different views were obtained from 2D-STI.We calculate the average of them,and Combined with E,the new noninvasive indexes(E/DSrE avg,E/DSrA avg and E/DSrIVR avg)were derived.Lastly,the system automatically measured the post systolic index(PSI),time to peak longitudinal strain(TTP)and peak strain dispersion(PSD)from 17 consecutive segments of LV.Results:1.The PD group’s LVEF,E/e’,TR and LAVI were in the normal range compared with the controls,and only e’ was significantly decreased.LVMI,LVPWT,IVST increased,while E and E/A decreased.2.The GLS of the apical 2-chamber view(the inferior and anterior wall)and 3-chamber view(the posterior and anterior septum wall)were significantly decreased in PD patients,including the LSendo,LSmyo,and LSepi in 2-chamber view were also significantly decreased compared with the controls.And PSI was markedly delayed in the anterior septum,anterior,posterior and septum wall from basal segments,in the anterior and posterior wall from middle segments,and in the anterior and inferior wall from apical segments.3.PSD was significantly increased in PD group,and TTP was significantly delayed in the basal segments,including the anterior septum,anterior,lateral and posterior wall,and the posterior wall from middle segments.4.The DSrIVR avg,DSrE avg,E/DSrE avg,DSrA avg and E/DSrA avg had the significant difference between two groups while E/DSrIVR avg had none.5.DSrE related significantly with LVPWT and E/A.Conclusions:1.The LS decreased gradually from the endocardium to epicardium,showing the gradient characteristics.2.Despite being classified as normal systolic and diastolic function by conventional echocardiography,parameters based on 2D-STI in young and middle-aged PD patients already decreased,indicating that PD patients already developed left ventricular systolic and diastolic dysfunction and myocardial dyssynchrony compared with the age-matched controls.3.LV regional systolic function was significantly decreased especially in the anterior septum,anterior,posterior and inferior wall,and myocardial impairment in the endocardium layer and the basal segments was the most serious.4.Parameters based on 2D-STI such as LS,DSrE,E/DSrE,DSrA,E/DSrA,and DSrIVR were valuable parameters to evaluate LV systolic and diastolic function,providing a new non-invasive method for evaluating the degree of myocardial impairment.5.LVPWT and E/A significantly influenced DSrE,such parameters should be taken into account for predicting the LV diastolic dysfunction in patients with preserved LVEF.If some of them indicated abnormality,the STI should be taken for further inspection,and preventative measures should be implemented to provide primary or secondary preventive therapy for PD patients.Such measures included controlling hypertension and volume overload more stably,further adjusting serum calcium and phosphorus levels,using RAAS inhibition earlier to improve ventricular remodeling,and better correcting anemia.