Assessment Of The Left Ventricular Systolic Asynchrony And Partial Ventricular Function In Patients With Uremic Myocardiopathy Using Tissue Synchronization Imaging And Strain And Strain Rate Imaging

ObjectiveEchocardiography was an important means to diagnose uremic myocardiopathy(UM).The operator for echocardiogram had accumulated abundant experience in the diagnosis and differentiation of UM using echocardiography.Furthermore,the assesement of ventricular function was close to meeting clinical requirements,but it was based on global ventricular function,and accordingly was not always correspond to the clinical results.In recent years,new methods studying ventricular function for ventricular asynchrony and injured partial ventricular function were developed with the wide application of tissue Doppler imaging(TDI),especially tissue synchronization imaging(TSI),strain imaging(SI)and strain rate imaging(SRI).In this study,our aim is to evaluate the ventricular systolic asynchrony and partial ventricular function in patients with UM using TSI,SI and SRI. MethodsUltrasonic system equipped with TSI,SI,SRI and Q-analyze software was used.Fifty patients with UM were enrolled in this study, among which twenty-five renal transplant recipients were included in T group and others were in U group,meanwhile twenty-five normal subjects were used as controls.The mean peak systolic velocity of mitral annulus level was measured using tissue Doppler imaging in the cardiac apical four-chamber view,two-chamber view and long-axis view of left ventricular,and the strain and strain rate of inter-ventricular septum and left ventricular lateral walls were recorded at basal and mid-ventricular levels from the cardiac apical four-chamber view.Time-to-peak velocity (Tc)corrected by the heart rate and the peak systolic velocity(PSV)of 12 segments of left ventricular were recorded by real-time 3D echocardiography using TSI.Tel index was calculated based on routine measurement.All statistical analyses were performed by SPSS 14.0 for Windows. The results were expressed as mean±standard deviation,inter-group comparison was tested by t-test(P<0.05:significant;P<0.01:very significant). Results1.The total and mean T_C of all segments in UM group(UM group was U group and T group)were longer than those in the control group(P<0.05),and the T_C of most segments in UM group were longer as well(P<0.05).2.Delayed T_C was found in 101(101/300)segments in U group and left ventricular systolic asynchrony was detected in 92.00%(23/25),and delayed T_C was 48 segments in T group and the asynchrony rate was 84.00%(21/25).3.The mean PSV and the PSV of most segments in UM group were lower than those in the control group(P<0.05),whereas the PSV of basal segments was higher than that of the middle segments in UM group(P<0.001).4.The peak systolic strain(PS_S),the peak systolic strain rate(PSR_S) and the peak early diastolic strain rate(PSR_E)were lower than those in the control group(P<0.05),PS_S,PSR_S and PSR_E were negative correlated with Tei index,the coefficient were -0.574,-0.473 and -0.541 respectively(P<0.001),whereas PS_S,PSR_S and PSR_E were correlated well with peak systolic velocity of mitral annulus(Sa)and peak early diastolic velocity(Ea),the coefficient were 0.471,0.907,0.419 and 0.626,0.822, 0.617 respectively(P<0.001). 5.The accuracy(A_C),sensitivity(S_E)and specificity(S_P)of PSR_S for distinguishing left partial ventricular were 84.00%,80.00%,92.00% respectively when PSR_S was -1.2 l/s,the A_C S_E and S_P of PSR_E were 85.33%,82.00%,92.00%respectively when PSR_E was 1.3 l/s,the A_C,S_E and S_P of PS_S were 86.67%,90.00%,80.00%respectively when PS_S was -17.00%,the A_C,S_E and S_P of PS_S were 84.00%,80.00%,92.00% respectively when PS_S was -16.00%,and the A_C,S_E and S_P of PSV were 77.00%,77.50%,76.00%respectively when PSV was 6.5cm/s.6.Tei index,IRT,ICT in UM group were significantly longer than those in control group(P<0.05),whereas Sa was lower compared with the control group(P<0.05)7.The thickness of left ventricular wall and the mass of cardiac muscle increased compared with control group(P<0.05),However,no significant difference was found in ejection fraction(EF)and short-axis fractional shortening(FS)between the test groups and the control group (P>0.05).8.Compared with T group,Tc and Tei index were increased,PSV, PS_S,PSR_S,PSR_E and Sa were were decreased in U group. Conclusions1.It was firstly found in this paper that there were injured partial systolic function and asynchrony of left ventricular wall in patients with UM,and the synchronization and partial systolic function were improveded in patients with UM after renal transplant.To evaluate the synchronization and left ventricular partial systolic function in patients with UM using echocardiography,TSI for asynchrony was the best parameter and SRI for partial systolic function was the better way.2.Low-grade delayed T_C of partial segments more frequently was found as the asynchrony characteristic in patients with UM,but worse-grade and worst-grade deltyed T_C were rare.The segmental decrease in myocardial velocity in patients with UM was found to be involved massively.However,after renal transplantation,with the improvement of blood perfusion,the myocardial velocity increased and delayed T_C was ameliorated.3.It was important characteristic of the injured systolic function in patients with UM that PS_S,PSR_S,PSR_E,Sa and Ea were lower than control group,but Tei index was increased.4.Strain and strain rate were very important index for evaluating left ventricular function as well as Tei index,mitral annulus velocity. They had well pertinence,especially PSR_S was clear positive proportional to Sa and Ea,their proportional quotiety were 0.907 and 0.822.It was feasible and dependable for assessing ventricular function using strain imaging and strain rate imaging.5.The accuracy,sensitivity and specificity were higher by suitable liminal value for distinguishing the injured ventricular function.In this study,the liminal value of PSRs,PSR_E,PS_S PSR_S and PSV of different segment were -1.2 l/s,1.3 l/s,-17.00%,6.5cm/s respectively,and their accuracy,sensitivity and specificity were more than 80.00%,and some exceeded 90.00%.6.The indexes,such as PSR_S,PSR_E,PS_S,Sa,Ea,Tei index and delayed T_C were improved in the patients with UM after renal transplant.