Assessment Of Ventricular Synchrony And Prediction Of The Response To Cardiac Resynchronization Therapy By Three-Dimensional Echocardiography And Speckle Tracking Imaging

Part One:Usefulness of Real-Time Three Dimensional Echocardiography and Speckle Tracking Imaging to Quantify Left Ventricular Synchrony in Heart Failure PatientsObjective:The dyssynchrony in heart failure (HF) patients and the correlation between RT3DE and STI parameters were studied. The dyssynchrony in groups of different causes, heart functions and different types of conduction block were compared.Methods:A total of24controls and65HF patients were enrolled. The patients were divided into ICM group (n=11) and NICM group (n=17), EF≤35%group (n=47) and EF>35%group (n=18), LBBB group (n=34) and NLBBB group (n=31). Routine two dimensional echo, TDI, RT3DE and STI were performed. Offline analysis was carried out in Qlab8.1to measure the parameters below. Parameters of heart function:3D-EDV,3D-ESV,3D-EF; parameters of synchrony:IVMD, SPWMD, Ts-SD, Tmsv16-SD; parameters of strain:Global LS, Tlsl6-SD, Global RS, Trs12-SD, Global CS, Tcs12-SD; parameters of twist:Basal Rotation, Apical Rotation, LV twist, BARC.Results:Significant differences were found in all the TDI, RT3DE and STI parameters between controls and HF patients (P<0.05). There were no remarkable differences in heart function and synchrony parameters between ICM group and NICM group (P>0.05). Compared to EF>35%group, EDV and ESV in EF≤35%group were significantly larger (247±95ml vs164±40ml, P=0.000;177±71ml vs98±24ml, P=0.000). IVMD、Tls16-SD、Trs12-SD、Tcs12-SD were also larger in EF<35%group (37.06±37.67ms vs4.67±46.19ms, P=0.005;14.57±5.23%vs8.50±3.16%, P=0.000;15.17±6.52%vs10.49±5.41%, P=0.009;13.10±5.05%vs10.03±2.93%, P=0.004), together with the absolute value of Global LS and Global CS less than EF>35%group (-6.52±2.08%vs-8.39±2.28%, P=0.002;-7.03±2.29%vs-9.82±3.56%, P=0.003). Of the four parameters of twist, only BARC showed differences between the two groups (-1.28±2.10°vs0.56±2.78°, P=0.018). Tmsvl6-SD and BARC were higher (5.98±3.32%vs4.33±3.88%, P=0.009;0.58±0.37vs0.03±0.55, P=0.000), and LV twist was lower (0.79±2.44°vs2.37±2.66°, P=0.015) in LBBB group than NLBBB group, excluding the effects of EF and QRSd. No correlations were found between RT3DE and STI parameters (P>0.05). LV twist had a correlation with Tcs12-SD (r=-0.340, P=0.006). BARC had correlations with Tls16-SD, Trs12-SD and Tcs12-SD (r/P equaled0.375/0.002,0.338/0.006and0.389/0.001respectively).Conclusions:Remarkable mechanical dyssynchrony exists in HF patients. Systolic synchrony worsens as EF decreases. IVMD and parameters of strain are sensitive in finding the worsening. LBBB causes severer LV global dyssynchrony than NLBBB, and tends to result in the basal and apical rotation turning into the same direction. There are no significant differences in dyssynchrony between ICM and NICM patients. LV twist has a correlation with circumferential synchrony, while BARC has correlations with all the longitudinal, radial and circumferential synchrony. No correlations exist between RT3DE and STI parameters. Part Two:The Predictive Value of Real-Time Three-Dimensional Echocardiography and Speckle Tracking Imaging on Cardiac Resynchronization TherapyObjective:To assess the predictive value of real-time three-dimensional echocardiography and speckle tracking imaging on cardiac resynchronization therapy, expecting to find a forceful echo predictor.Methods:From October2010to February2012, a consecutive group of65CRT candidates were enrolled. The disease course, NT-proBNP, ECG and reports of coronary artery CTA or angiography were recorded. Routine two dimensional echo, TDI, RT3DE and STI were performed. Offline analysis was carried out in Qlab8.1to measure the parameters below:3D-EDV,3D-ESV,3D-EF, IVMD, SPWMD, Ts-SD, Tmsv16-SD, Global LS, Tls16-SD, Global RS, Trs12-SD, Global CS, Tcs12-SD, Basal Rotation, Apical Rotation, LV twist and BARC. An at least10%reduction in ESV at3-month follow up after CRT was defined as responders. Patients who reached clinical primary endpoint (death or rehospitalization for HF) or ESV reduced less than10%during follow up were defined as non-responders. According to this, patients were divided into responders and non-responders. The pre-CRT parameters of the two groups were compared. The parameters pre and post CRT in each group were compared. The predictive value of the parameters was studied. Results:Thirty-seven patients completed the3-month follow up, in which there were18(49%) responders. Baseline conditions were comparable in the two groups, except that the proportion of LBBB was larger in responders than in non-responders. In responders, IVMD, Tmsv16-SD and the absolute values of Global RS, Global CS were greater than in non-responders (37.39±30.36ms vs8.58±39.82ms, P=0.018;6.81±4.77%vs3.92±1.97%,P=0.048;16.35±5.49%vs11.35±5.93%, P=0.006;-8.67±1.99%vs-6.44±2.63%, P=0.005). No differences were found in others parameters (P>0.05). EDV and ESV reduced after CRT in responders (P<0.001), together with EF (P<0.001), IVMD, SPWMD and Tcsl2-SD (P<0.05) improved. ESV increased at the3-month follow up after CRT in non-responders, and no significant changes were found in parameters of synchrony. Global CS, Global RS, IVMD and Tmsv16-SD were parameters which had predictive value. Global CS≤-7.34%had a sensitivity of77.8%, specificity of78.9%to predict CRT response. The best combined parameters were IVMD+Global CS. IVMD≥25.5ms and Global CS≤-7.34%had a sensitivity of55.6%, specificity of100%to predict CRT response. Patients who met both the criteria had a response rate of100%(10/10), those who met one of them42%(8/19), and those who met none of the two criteria0%(0/8).Conclusions:Global CS, Global RS, IVMD and Tmsv16-SD can predict CRT response. The combination of IVMD and Global CS is promising, while LBBB has no addictive value upon this. Parameters of twist have no predictive value. Mechanical dyssynchrony and radial, circumferential contractility should be necessary for CRT response. STI does well in short axis view. In responders, CRT improves inter-ventricular, septal-posterior and circumferential synchrony, reserves LV remodeling, and increases heart function.