AimsTo develop a novel myocardial deformation index that is highly sensitive to the effect of cardiac resynchronization therapy (CRT) and that can be used to predict response to CRT. Methods and resultsBefore and 6.5 + 2.3 months after implantation of a CRT device, longitudinal shortening and stretch were timed and quantified by speckle tracking echocardiography in a cohort of 62 patients. Distinction was made between systolic total stretch (STS; all systolic stretch) and systolic rebound stretch (SRS; only systolic stretch following initial shortening). Systolic total stretch and SRS could be measured in all wall segments in 41 of 62 patients. Septal SRS quantification was possible in all 62 patients and was performed by a blinded observer. Cardiac resynchronization therapy reduced STS (255 + 30%) but reduced SRS (277 + 21%) significantly more (P , 0.01). The largest amount of baseline SRS and the largest reductions in SRS (290 + 22%) were found in the septum. Reductions in local SRS were paralleled by increases in local systolic shortening that were twice as large (r ¼ 0.79), thereby strongly improving septal function. Baseline values of septal SRS correlated with reductions in left ventricular end-systolic volume index (DLVESVi; r ¼ 0.62) and brain-type natriuretic peptide (BNP) (Dlog 10 BNP; r ¼ 0.57). Septal SRS was an independent predictor of CRT response in linear regression analysis and predicted DLVESVi of 15% with a sensitivity and specificity of 81% at ROC analysis (areas under the curve 0.89 + 0.04). ConclusionSeptal rebound stretch appears to be a sensitive and practical diagnostic criterion to quantify the functional substrate amenable to CRT and to predict response.--

Background-Response to cardiac resynchronization therapy depends both on dyssynchrony and (regional) contractility.We hypothesized that septal deformation can be used to infer integrated information on dyssynchrony and regional contractility, and thereby predict cardiac resynchronization therapy response. Methods and Results-In 132 cardiac resynchronization therapy candidates with left bundle branch block (LBBB)-like electrocardiogram morphology (left ventricular ejection fraction 19Ϯ6%; QRS width 170Ϯ23 ms), longitudinal septal strain was assessed by speckle tracking echocardiography. To investigate the effects of dyssynchronous activation and differences in septal and left ventricular free wall contractility on septal deformation pattern, we used the CircAdapt computer model of the human heart and circulation. In the patients, 3 characteristic septal deformation patterns were identified: LBBB-1ϭdouble-peaked systolic shortening (nϭ28); LBBB-2ϭearly systolic shortening followed by prominent systolic stretching (nϭ34); and LBBB-3ϭpseudonormal shortening with less pronounced late systolic stretch (nϭ70). LBBB-3 revealed more scar (

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Background: Recent, conflicting results about the use of tissue Doppler imaging derived (TDI-) asynchrony indices to predict reverse remodelling after cardiac resynchronisation therapy (CRT) have raised questions about their physiological meaning and methodological limitations. Methods: In 41 patients, baseline TDI-derived septal to lateral delays of peak velocities (TDI-SL), standard deviation of peak velocities over 12 segments (Ts-SD), and peak 2D longitudinal strain (strain-SL) were compared with volumetric response (reduction in end-systolic volume of ≥ 15%) after at least 6 months of CRT. Timing of peak TDI velocities was compared to timing of 2DS velocities and strain-SL. Influence of sample position, transverse motion, and interobserver inconsistency of the chosen peak velocities was assessed. Diagnostic accuracy of TDI-based delays was compared to accuracy of visual and 2D strain-based assessment. Results: After 7.0 ± 3.2 months of CRT, 24 patients were classified as responders. TDI-SL and Ts-SD were similar between responders and nonresponders at baseline, did not predict response, and were unaffected by CRT. Visual asynchrony scoring and strain-SL were better predictors of response than TDI-SL and Ts-SD. TDI measurements were highly susceptible to sample location and transverse motion components and poorly correlated with the timing of longitudinal contraction. There was a considerably poor agreement between observers with regard to scoring of TDI-SL and Ts-SD. Conclusion: TDI-based measurements of asynchrony do not appear robust predictors of volume response to CRT.