Biventricular Function In The Transplanted Hearts By Three-dimensional Speckle-tracking Echocardiography

Part1 Assessment of biventricular function in heart transplant recipients using 3D-STE: A validation study comparison with cardiac magnetic resonance imaging [Objective] The aim of this study was to testify the feasibility and accuracy of three-dimensional speckle-tracking echocardiography(3D-STE)to evaluate the biventricular volumes and ejection fraction(EF)in transplanted hearts comparison with cardiac magnetic resonance(CMR).[Methods] A total of 38 patients after heart transplant(HT)at our hospital were prospectively enrolled in this study,and every patient l underwent both echocardiography and CMR examination within 24 h.The left ventricular(LV)and right ventricular(RV)3D full volume images were acquired and analyzed by the Tom Tec 4D Cardio-View work station,offline.3D LV end diastolic volume(EDV),LV end systolic volume(ESV),LVEF,RVEDV,RVESV and RVEF,LV global longitudinal strain(GLS)and global circumferential strain(GCS),RV free wall longitudinal strain(FWLS)were then acquired.In addition,a set of contiguous short-axis cine imaging of LV and RV were collected,and processed with a commercial CMR software to acquire the biventricular volumes and EF.Finally,the correlation and consistency of the two different imaging technology were analyzed.[Results](1)There were 27 males(71%)in these 38 HT patients,mean age(46±13y).The technical imagine analyzability rate was high,with 95% for 3D-STE.(2)The corresponding biventricular volumes derived from 3D-STE and CMR showed a good correlation and consistency:(LVEDV: r= 0.88,LOA =-11±19mL;LVESV: r= 0.92,LOA =-4±9mL;RVEDV: r= 0.86,LOA =-13±25mL;RVESV: r= 0.89,LOA =-8±15mL).(3)The corresponding biventricular EF derived from 3D-STE and CMR showed an excellent correlation and consistency:(LVEF: r= 0.96,LOA =-0.5±3.7%;RVEF: r= 0.95,LOA = 0.5%±4.5%).(4)LVGLS,LVGCS by 3D-STE correlated well with CMR-LVEF: LVGLS:(r = 0.85,P<0.01),LVGCS(r = 0.93,P<0.01).(5)3DSTE-RV FWLS correlated well with CMR-RVEF(r = 0.83,P<0.001).(6)The measurements of LVEDV,LVESV,LVEF,RVEDV,RVESV,RVEF,LVGLS,LVGCS,RV FWLS obtained by the 3D-STE showed an excellent reproducibility.[Conclusion] 3D-STE had a high feasibility,accuracy to evaluate biventricular function.And the LVGLS,LVGCS and RV FWLS may be an important additive and complementary in assessing ventricular function comparable with CMR-EF.Part 2 The biventricular mechanical function in heart transplant recipients by 3D-STE [Objective] The aims of this study were to explore LV and RV myocardial mechanical function,and to evaluate the radial displacement(RDisp)and systolic mechanical synchrony of LV in clinically stable patients at 1 year after HT.[Methods] This study enrolled 46 patients after HT and 46 healthy controls.The healthy controls were matched by gender and age with HT group.The conventional 2D images and 3D full volume images of LV and RV were acquired,and analyzed using the Tom Tec 4D Cardio-View work station offline.The 2D conventional echocardiography derived LVEF,RV fraction area change(FAC),biventricular myocardial performance index(MPI)and 3D-STE derived LVEF,RVEF,LVGLS,LVGCS,RVFWLS,LV RDisp,LV systolic dyssynchrony index(SDI),LV twist and LV global performance index(GPI)were then acquired.Finally,to analyze and compare the difference of 2D echocardiography and 3D-STE parameters between the HT group and the healthy controls.[Results](1)There were no significant differences between the two groups in sex,age,height,weight and body surface area.However,the HR in HT group were higher than healthy controls(P<0.05).(2)Compared with healthy controls,the measurements of 2D-LVEF and RV FAC were decreased in HT group(P<0.05),but these two values were still within normal range.(3)Compared with healthy controls,lower 3D-LVEF and RVEF were observed in HT group(P<0.05),but these two values were still within normal range.(4)Compared with healthy controls,LVGLS,LVGCS,and RV FWLS,respectively,was lower in HT group(P<0.05,all).The cutoff value of-19.3% for the LVGLS had 91% sensitivity,87% specificity,94% accuracy and the cutoff value of-20.8% for the RV FWLS had 85% sensitivity,85% specificity,and 90% accuracy in differentiating HT group from healthy controls.(5)In addition,LV twist was reduced,LVSDI was higher in HT group than healthy controls(P<0.05).And LVGPI was significantly reduced in HT group(P<0.05).(6)Furthermore,comparing with healthy group,LV lateral wall RDisp was higher,while septal wall RDisp was reduced in HT group;And LV lateral wall RDisp was higher than septal wall RDisp in HT group themselves,while lateral wall RDisp was lower than septal wall RDisp in healthy controls themselves(P<0.05,all).[Conclusion] Although,for clinically stable HT recipients with normal conventional echocardiography paraments of ventricular function,their 3D-STE derived parameters of ventricular mechanic showed significantly different from non-HT healthy subjects.Our study suggested that the 2D-LVEF,RVFAC were decreased in patients after HT,but these two values were still within normal range.And the LVGLS,LVGCS,RV FWLS,LV Twist were decreased,while the LVSDI was increased in in patients after HT.Therefore,exploring the specifically normal 3D biventricular mechanical function of HT recipients is essential during follow-up studies.