Assessment Of Left Ventricular Dyssynchrony Research Articles

Assessment of left ventricular dyssynchrony by speckle tracking echocardiography in patients with Steinert's disease

Conduction system abnormalities and myocardial dysfunction are observed in patients with myotonic dystrophy type 1 (DM1) and may represent the initial manifestations of the disease. Some studies have shown improvements of outcomes with use of early cardiac resynchronization therapy (CRT) in DM1 patients. Two-dimensional speckle tracking echocardiography (2D-STE) has recently emerged as a non-invasive biomarker for early detection of dyssynchrony. The aim of this study is to assess a left ventricle (LV) dyssynchrony using 2D-STE analysis in this population. This is a prospective study, conducted from March 2020 to October 2022 which included DM1 with normal LV ejection fraction (LVEF) and control patients with comprehensive resting echocardiography. Three measures were performed to assess LV mechanical dyssynchrony: opposing-wall delays (longitudinal and radial analyses), modified Yu index, and time to-peak delays of each segment. Mean age was 23 ± 7 years. All three mechanical dyssynchrony criteria were significantly higher in the DM1 group than in healthy subjects: opposing-wall delays in basal inferoseptal to basal anterolateral segments (61.4 ± 45.3 msec vs. 18.3 ± 50.4 msec, P < 0.001, respectively) and in mid inferoseptal to mid anterolateral segments (58.6 ± 35.3 msec vs. 42.4 ± 36.4 msec, P < 0.05, respectively) (Fig. 1), modified Yu index (33.3 ± 10.1 msec vs. 28.5 ± 8.1 msec, P < 0.05, respectively), and most of time-to-peak values, especially in basal and mid anterolateral segments. The existence of an early LV mechanical dyssynchrony using 2D-STE analysis in DM1 patients before the onset of cardiomyopathy represents a perspective for early prediction of sudden heart death. However, are ICDs really beneficial in terms of improving overall survival, in patients with conduction system disease often presenting more severe forms of myotonic dystrophy itself. Mean corrected time-to-peak delays.

Acute echocardiographic and electrocardiographic effects of triggered left ventricular pacing.

Cardiac resynchronization therapy (CRT) is an essential pillar in the therapy of heart failure patients with reduced ejection fraction (HFrEF) presenting with broad left bundle branch block (LBBB) or pacemaker dependency. To achieve beneficial effects, CRT requires high bi-ventricular (BiV) pacing rates. Therefore, device-manufacturers designed pacing algorithms which maintain high BiV pacing rates by a left ventricular (LV) pacing stimulus immediately following a right ventricular sensed beat. However, data on clinical impact of these algorithms are sparse. We studied 17 patients implanted with a CRT device providing triggered left ventricular pacing (tLVp) in case of atrioventricular nodal conduction. Assessment of LV dyssynchrony was performed using echocardiographic and electrocardiographic examination while CRT-devices were set to three different settings: 1. Optimized bi-ventricular-stimulation (BiV); 2. Physiological AV nodal conduction (tLVp-off); 3. Physiological AV nodal conduction and tLVp-algorithm turned on (tLVp-on). QRS duration increased when the CRT-device was set to tLVp-off compared to BiV-Stim, while QRS duration was comparable to BiV-Stim with the tLVp-on setting. Echocardiographic analysis revealed higher dyssynchrony during tLVp-off compared to BiV-Stim. TLVp-on did not improve LV dyssynchrony compared to tLVp-off. QRS duration significantly decreased using tLVp-algorithms compared to physiological AV nodal conduction. However, echocardiographic examination could not show functional benefit from tLVp-algorithms, suggesting that these algorithms are inferior to regular biventricular pacing regarding cardiac resynchronization. Therefore, medical treatment and ablation procedures should be preferred, when biventricular pacing rates have to be increased. TLVp-algorithms can be used in addition to these treatment options.

The feasibility of 18F-FDG gated positron emission tomography (PET) for left ventricular dyssynchrony assessment in comparison with 99mTc-MIBI gated single-photon emission computed tomography (SPECT) among patients with prior myocardial infarction

Phase analysis by 99mTc-MIBI gated single-photon emission computed tomography (GSPECT) has been considered to be an adequate method in the validation of left ventricular (LV) dyssynchrony. Compared with GSPECT, prior myocardial infarction patients with myocardial perfusion defects but myocardial viability usually show preserved uptake of 18F-FDG, and extensive myocardium is detected by 18F-FDG gated positron emission tomography (GPET). Thus, theoretically, it should be more accurate. The aim of this study was to investigate the feasibility of GPET for LV dyssynchrony assessment in comparison with GSPECT among infarction patients. A total of 146 patients with infarction underwent 2 consecutive days of GSPECT and GPET examinations. Quantitative gated SPECT-derived LV phase analysis was applied to GPET and GSPECT data to assess the presence of LV dyssynchrony via histogram bandwidth (BW) and phase standard deviation (SD). The correlation and agreement of BW and SD between GSPECT and GPET were examined. Factors (i.e., total perfusion defect, scar and mismatch) related to the discrepancies of LV dyssynchrony (i.e., BW and SD) in GPET and GSPECT were assessed by univariate and multivariate regression analysis. A moderate correlation between GPET and GSPECT was found in the measurements of BW (r=0.554) and SD (r=0.537). Bland-Altman analysis revealed that GPET overestimated both BW and SD (20.5° and 9.5°, respectively). In addition, the BW and SD measured by GPET were still overestimated after subgroup analysis. Between GPET and GSPECT, multivariate regression analysis revealed that total perfusion defects were related to the difference in BW measurement (P<0.001), and mismatch was associated with the difference in SD measurement (P<0.01). In patients with infarction, GPET moderately correlated with GSPECT in assessing LV dyssynchrony. GPET overestimated both BW and SD, so these analyses should not be interchangeable in individual patients.

Assessment of left ventricular dyssynchrony by speckle tracking echocardiography in children with Duchenne muscular dystrophy

Prognosis of Duchenne muscular dystrophy (DMD) is related to cardiac dysfunction. Two dimensional-speckle tracking echocardiography (2D-STE) has recently emerged as a non-invasive functional biomarker for early detection of DMD-related cardiomyopathy. This study aimed to determine, in DMD children, the existence of a left ventricle (LV) dyssynchrony using 2D-STE analysis. This prospective controlled study enrolled 25 boys with DMD (mean age 11.0 ± 3.5 years) with normal LV ejection fraction and 50 age-matched controls. Three measures were performed to assess LV mechanical dyssynchrony: the opposing-wall delays (longitudinal and radial analyses), the modified Yu index, and the time-to-peak delays of each segment. Feasibility and reproducibility of 2D-STE dyssynchrony were evaluated. All three mechanical dyssynchrony criteria were significantly higher in the DMD group than in healthy subjects: – opposing-wall delays in basal inferoseptal to basal anterolateral segments (61.4 ± 45.3 msec vs. 18.3 ± 50.4 msec, P < 0.001, respectively) and in mid inferoseptal to mid anterolateral segments (58.6 ± 35.3 msec vs. 42.4 ± 36.4 msec, P < 0.05, respectively); – modified Yu index (33.3 ± 10.1 msec vs. 28.5 ± 8.1 msec, P < 0.05, respectively); – most of time-to-peak values, especially in basal and mid anterolateral segments. Feasibility was excellent and reliability was moderate to excellent, with ICC values ranging from 0.49 to 0.97 ( Fig. 1 ). Detection of LV mechanical dyssynchrony using 2D-STE analysis is an easily and reproducible method in pediatrics. The existence of an early LV mechanical dyssynchrony visualized using 2D-STE analysis in children with DMD before the onset of cardiomyopathy represents a perspective for future pediatric drug trials in the DMD-related cardiomyopathy prevention.

Technical aspects of gated SPECT MPI assessment of left ventricular dyssynchrony used in the VISION-CRT study

Technical aspects of gated SPECT MPI assessment of left ventricular dyssynchrony used in the VISION-CRT study

Time-modified OSEM algorithm for more robust assessment of left ventricular dyssynchrony with phase analysis in ECG-gated myocardial perfusion SPECT

BackgroundIn ordered subsets expectation maximization (OSEM) reconstruction of electrocardiography (ECG)-gated myocardial perfusion single-photon emission computed tomography (SPECT), it is often assumed that the image acquisition time is constant for each projection angle and ECG bin. Due to heart rate variability (HRV), this assumption may lead to errors in quantification of left ventricular mechanical dyssynchrony with phase analysis. We hypothesize that a time-modified OSEM (TOSEM) algorithm provides more robust results.MethodsList-mode data of 44 patients were acquired with a dual-detector SPECT/CT system and binned to eight ECG bins. First, activity ratio (AR)—the ratio of total activity in the last OSEM-reconstructed ECG bin and first five ECG bins—was computed, as well as standard deviation SDR-R of the accepted R–R intervals; their association was evaluated with Pearson correlation analysis. Subsequently, patients whose AR was higher than 90% were selected, and their list-mode data were rebinned by omitting a part of the acquired counts to yield AR values of 90%, 80%, 70%, 60% and 50%. These data sets were reconstructed with OSEM and TOSEM algorithms, and phase analysis was performed. Reliability of both algorithms was assessed by computing concordance correlation coefficients (CCCs) between the 90% data and data corresponding to lower AR values. Finally, phase analysis results assessed from OSEM- and TOSEM-reconstructed images were compared.ResultsA strong negative correlation (r = -0.749) was found between SDR-R and AR. As AR decreased, phase analysis parameters obtained from OSEM images decreased significantly. On the contrary, reduction of AR had no significant effect on phase analysis parameters obtained from TOSEM images (CCC > 0.88). The magnitude of difference between OSEM and TOSEM results increased as AR decreased.ConclusionsTOSEM algorithm minimizes the HRV-related error and can be used to provide more robust phase analysis results.

Assessment of Left Ventricular Asynchrony after Permanent Cardiac Pacing by Using Speckle Tracking Echocardiography

AbstractBackground: Echocardiography is important in assessing Left Ventricular (LV) Mechanical Dysynchrony (LVMD) and left ventricular function after permanent pacemaker. At present, Real-Time Three Dimensional Echocardiography (RT3DE) and tissue Doppler imaging (TDI) are the most sensitive and commonly used techniques for the quantification of LVMD. Global longitudinal strain (GLS) and LV dyssynchrony as-sessment enables us to detect early signs of LV dysfunction after cardiac pacing.Aim of Study: To evaluate LV mechanical dyssynchrony and LV function in different pacing modes after permanent cardiac pacing by using TDI and speckle tracking echocardi-ography and to correlate these changes with other clinical, electrocardiographic and echocardiographic data.Patients and Methods: Seventy patients were enrolled in this prospective cross sectional observational study, (mean age 60.99±13.77 years, 42 females), in Mansoura Specialized Medical Hospital over a period of 1 year from April 2018 to April 2019. All patients were assessed by thorough history taking, clinical examination, 12 lead surface ECG, echocar-diography, 2D speckle tracking echocardiography STE to assess GLS and tissue Doppler imaging TDI.Results: Regarding diastolic function by pulsed wave Doppler PWD: There was significant decrease in E/e¢ ratio (p<0.001 *), significant increase in myocardial performance index Tei index (p<0.001 *). Regarding internal dimensions and systolic function: There was significant increase in the following: Left Atrial Dimension (LAD) (p=0.001*), Left Ventricular End Systolic Dimension LVESD (p<0.001*) and Left Ventricular End Diastolic Dimension LVEDD (p<0.001 *) while there was significant decrease in ejection fraction EF (p<0.001 *) and fractional shortening FS (p<0.001 *). Regarding parameters of LV dysynchrony: There was significant increase in the following: Aortic preejection delay APED (p<0.001*), interventricular mechanical delay (p<0.001 *) and septal posterior wall motion delay SPWMD by M mode (p<0.001 *). Regarding parameters assessed by tissue synchronization imaging TSI: There was significant increase in the following: SD-Ts (p=0.001 *) and all segments Max delay (p=0.027*). Regarding parameters assessed by STE: There was significant decrease in global longitudinal strain GLS (p=0.034*) while there was significant increase in TP-SD by STE (p<0.001*).Also, there was significant decrease in global longitudinal strain GLS (p<0.001*) and significant increase in TP-SD by STE (p=0.001*) in DDD group. While there was significant decrease in global longitudinal strain GLS (p<0.001 *) and significant increase in TP-SD by STE (p<0.001*) in VVI group.Conclusion: GLS and 2D STE can help in the detection of subclinical left ventricular dysfunction after permanent pacemaker implantation before appearance of symptoms. Also, cardiac pacing leads to LVMD whatever the pacing mode is which may needs later on upgrading to cardiac resynchronization therapy CRT.

Are there normal values of phase analysis parameters for left ventricular dyssynchrony in patients with no structural cardiomyopathy?: a systematic review.

ECG-gated single photon emission computed tomography (SPECT) myocardial perfusion scintigraphy combined with phase analysis allows for the assessment of left ventricular dyssynchrony. However, there are several software programs available thereby introducing variability in outcome and normal values. The aim of this systematic review was to evaluate the variability between different programs as currently available in literature with a focus on normal values. A systematic review was performed using the Embase, LILACS and Medline databases looking for articles reporting on normal values of the most used phase analysis parameters. The search resulted in 110 articles from Medline, 349 from Embase and one from LILACS. After exclusion of duplicate articles, 370 documents remained. Of these only 13 were deemed eligible for the systematic review. Phase SD and bandwidth are the main parameters used in dyssynchrony analysis. Most articles reviewed here used the Emory Cardiac ToolBox (ECTb) to determine the phase analysis parameters values, which varied greatly among the four software tested. The bandwidth and phase SD calculated by the Quantitative Gated SPECT (QGS) tends to be smaller than that calculated by the ECTb. In relation to the bandwidth, ECTb and cardioREPO (cREPO) have higher values than the other software programs. The value of entropy obtained from 4DM is lower than those obtained from QGS and cREPO. We found that normal values of phase analysis can vary among software programs and can be different even when the same software is used.

Assessment of Left Ventricular Dyssynchrony and Cardiac Function in Patients with Different Pacing Modes Using Real-Time Three-Dimensional Echocardiography: Comparison with Tissue Doppler Imaging

Background: Previous studies revealed that right ventricle apex pacing with different modes may yield abnormal electrical activity and left ventricle dyssynchrony.Aim of the work: To evaluate systolic function of left ventricle and mechanical dyssynchrony with different modes of pacing using real time three dimensional echocardiography [the RT3DE] and tissue Doppler imaging [TDI].Patients and Methods: The study included thirty-five individuals with permanent dual chamber pacemaker with atrial leads placed in right atrial appendage and right ventricular leads placed in right ventricular apex, the pacemakers were programmed to different modes. Imaging parameters were obtained following pacing for 24 hours in each mode.Results: The results revealed that the RT3DE and TDI-derived dyssynchrony indices in the atrial demand pacing [AAI] mode were significantly lower than those in the dual chamber demand pacing [DDD] and ventricular demand pacing [VVI] modes; however, there was no significant difference between the DDD and VVI modes. Also, left ventricular ejection fraction [LVEF] during AAI and DDD modes was significantly higher than that during VVI mode; however, there was no significant difference between the DDD and AAI modes. There were negative correlations between LVEF and Ts-MD and Ts-SD, and there was positive strong correlation between RT3DE and TDI-derived dyssynchrony indices.Conclusions: Left ventricular systolic synchronicity in AAI mode was superior to that in DDD and VVI modes. Left ventricular ejection fraction in the AAI and DDD pacing modes are superior to that in the VVI mode.

Development of Novel Algorithm for Quantitative Assessment of Left Ventricular Dyssynchrony Evaluated by ECG-gated Myocardial Perfusion SPECT Imaging

Development of Novel Algorithm for Quantitative Assessment of Left Ventricular Dyssynchrony Evaluated by ECG-gated Myocardial Perfusion SPECT Imaging

Echocardiographic assessment of Left Ventricular Dyssynchrony in Hypertensive Patients with Normal Systolic Function

Background: Normal Left Ventricular systolic function is present in nearly 50% of patients with congestive heart failure, the majority of such patients have systemic hypertension. Recent studies have demonstrated Left Ventricular dyssynchrony among patients with heart failure and normal systolic function. The co-existence between Left Ventricular dyssynchrony and hypertension with normal systolic function (with no clinical evidence of heart failure) is less well understood.&#x0D; Objective:&#x0D; To assess the Left Ventricular dyssynchrony among hypertensive patients with normal systolic function by using Tissue doppler imaging.To find out the associations between the LV dyssynchrony and other global echocardiographic findings like (LA volume index, LVmassindex , LV sephericity and LV filling pressure E/E`)&#x0D; Type of the study: Prospective case- control study&#x0D; Methods: The study conducted in Baghdad Teaching Hospital from 1st of June 2015 to 30th of May 2016 .Study included two groups of people, 40 patients, age_ matched healthy (control) group (group1) and 60 patients with established hypertension (group 2). A Complete 2-D and TDI echocardiography studies with simultaneous ECG were performed for all patients. Examination involved LV septal and posterior wall thicknesses, internal dimensions, left atrial size, ejection fraction and tissue doppler derived waves velocities E', E/E.' Dyssynchrony was determined by measuring T-P max ( the maximal time difference from the onset of QRS to peak systolic velocity on TDI between any opposing LV wall in 3 apical views) .&#x0D; Results: The study included 40 age –matched control people, 27males (67.5%) and 13 females (32.5%) with a male to female ratio was 1.8 :1, ranging from (42.4-58y) with mean age was (50.2 ±7.8y ) (group 1) and 60 hypertensive patients, 38 males (63.3%) and 22 females (36.7%) with a male to female ratio was 1.7 :1, ranging from (48.5- 66.5y) with mean age of (57.5± 9.0 y) (group 2) . Left Ventricular dyssynchrony was identified in 20 of 60 patients (33.3%) .Dyssynchrony had no significant association with age and BSA. But it was significantly associated with LA volume index (r = 0.61, p=0.001), LV mass index(r=0.52 ,p=0.001) , LV sphericity index (r= 0.5, p = 0.003) ) and LV filling pressure(r=0.6 , p value=0.001) . Dyssynchrony had significant negative correlation with ( E`) velocity (r= - 0.7 ,P =0.001) .&#x0D; Conclusion: Left Ventricular dyssynchrony is frequent among hypertensive patients with normal LV systolic function .The Left Ventricular dyssynchrony is significantly related to LA volume, LV mass, LV sphericity and LV filling pressure.

Assessment of left ventricular dyssynchrony by three-dimensional echocardiography: Prognostic value in patients undergoing cardiac resynchronization therapy.

Systolic dyssynchrony index (SDI) using three-dimensional echocardiography (3DE) was shown to be a reliable measure of left ventricular (LV) dyssynchrony. However, the prognostic value of SDI on long-term outcomes after cardiac resynchronization therapy (CRT) remains unknown. A total of 414 patients (mean age 67 ± 10 years, 60% ischemic etiology) with 3DE evaluation before CRT implantation were included. SDI was evaluated as continuous value and in quartiles. The study endpoint was combined all-cause mortality, heart transplantation, and LV assist device implantation. At baseline, median SDI was 8.0% (IQR 5.6-11.3%). During a median follow-up of 45 months (IQR 25-59 months), the endpoint was observed in 94 (23%) patients. SDI was independently associated with the endpoint together with ischemic etiology, diabetes, and renal function (HR 0.914, P=0.003) after adjustment for age, atrial fibrillation, hemoglobin level, NYHA functional class, and posterolateral LV lead position. Patients from the 1st, 2nd, and 3rd SDI quartiles showed similar survival and superior as compared to the 4th quartile with the lowest SDI values (≤5.5%; χ²: 30.4, log-rank P<0.001). From receiver operating characteristic curve analysis, the optimal SDI cut-off value associated with the endpoint was>6.8% (area under the curve 0.634). Finally, a subgroup analysis (293 patients) demonstrated that a more pronounced reduction in SDI immediately after CRT (resynchronization) was independently associated with superior survival (HR 0.461, P=0.011) after adjustment for prognostic relevant parameters. SDI is independently associated with long-term prognosis after CRT and might therefore be important to optimize risk-stratification in these patients.

Assessment of Left Ventricular Dyssynchrony using Gated Myocardial Perfusion SPECT in Cardiac Resynchronization Therapy

In cardiac resynchronization therapy (CRT), even if patient selection is made according to Japanese adaptive criteria, there are non-responders. Its main factor is considered to be the lack of adequate preoperative assessment against mechanical left ventricular dyssynchrony. Recently, phase analysis was enabled on gated myocardial perfusion SPECT (GMPS). The purpose of this study was to examine the relationship between the index of phase analysis using the two software (cardioREPO® and QGS) and the left ventricular reverse remodeling index (ΔLVESV) for the evaluation of left ventricular dyssynchrony in CRT patients is there. It also evaluated whether it could be an index of adaptation decision and effect determination. Methods: For 15 patients with severe heart failure who underwent CRT, GMPS was performed before (baseline) and after CRT. In cardioREPO®, standard deviation of the time to end systolic phase of 17 segments of the left ventricle (SDTES) and Bandwidth and Phase SD, Entropy of phase histogram were used as left ventricular dyssynchrony index. In QGS, standard deviation of the time to maximum displacement of each segment (SDTTMD) was used as an index. An example in which ΔLVESV (%Reduction) after 6 months of CRT decreased by 15% or more was defined as a CRT responder. Results: 10 of 15 patients were responders. Bandwidth at baseline of the responder group was significantly higher. SDTES, Phase SD, Entropy and SDTTMD of the responder group tended to be higher. All indexes decreased significantly in the responder group after 6 months of CRT but not in the non-responder group. Excluding SDTES, positive correlation was shown between baseline and ΔLVESV, and the optimal cutoff value of responder prediction was SDTES 7.637%, Bandwidth 218°, Phase SD 50.0°, Entropy 0.785, SDTTMD 19.85 ms. Conclusion: Phase analysis by GMPS showed that quantitative assessment of left ventricular dyssynchrony of CRT was possible and that the index was related to response prediction to CRT. In particular, SDTTMD showed good correlation between baseline and ΔLVESV, suggesting that it may be a more sensitive index of reaction prediction.

Phase analysis for the assessment of left ventricular dyssynchrony by Gated Myocardial Perfusion SPECT. Importance of clinical and technical parameters

Introducción. El análisis de fase (AF) del ventrículo izquierdo es una herramienta de reciente introducción en los estudios de cardiología nuclear, que permite valorar el sincronismo mecánico de la contracción del ventrículo izquierdo con diferentes aplicaciones clínicas, si bien es poco conocida.Objetivo. Mostrar la factibilidad de la nueva herramienta AF por perfusión miocárdica (Gated-SPECT) para valorar el sincronismo mecánico del ventrículo izquierdo y verificar diferencias entre sus valores, según situaciones clínicas y condiciones técnicas.Materiales y métodos. En el estudio participaron pacientes consecutivos con Gated-SPECT. Las variables principales fueron diferentes condiciones clínicas y técnicas. La valoración del AF se realizó mediante la herramienta FASE del programa cardiodedicado (QPS-QGS, Cedars-Sinai Medical Center, Los Angeles, USA). Se obtuvieron los siguientes parámetros: ancho del histograma (AH), desviación estandar de la fase (DE) y entropía (E). Se realizó análisis descriptivo y analítico de medias o medianas a través de test paramétricos o no paramétircos. El límite de significancia estadísitca fue p&lt;0.05. Se utilizó IBM-SPSS V21®.Resultados. Con un total de 300 pacientes y una media de edad de 65±12.7, en el análisis del AF no existieron diferencias según la fase del estudio (estrés-reposo) [AH (p=0.4), DE (p=0.6), E (p=0.7)], tipo de estrés [AH (p=0.38), DE (p=0.8), E (p=0.84)], dosis utilizada [AH(p=0.19), DE (p=0.05), E (p=0.06)], gammacámara [AH (p=0.02), DE (p=0.06), E (p=0.08)] ni entre antecedente de enfermedad coronaria [AH (p=0.44), DE (p=0.18), E (p=0.17)].Hubo diferencias según trastornos de conducción [AH (p=0.001), DE (p=0.02), E (p=0.001)], fracción de eyección &lt; o &gt;35% [AH (p=0.001), DE (p=0.001), E (p=0.001)], estudio normal o con necrosis [AH (p=0.001), DE (p=0.001), E (p=0.001)] y género [AH (p=0.002), DE (p=0.006), E (p=0.005)].Conclusiones. El uso de la nueva herramienta del AF de medicina nuclear es factible. Sus parámetros no se afectaron por el tipo de estrés producido, dosis administrada o fase del estudio por la gammacámara empleada. Por su parte, sí fueron afectados por género, trastornos de conducción interventricular, necrosis y disfunción sistólica.

Rational and design of EuroCRT: an international observational study on multi-modality imaging and cardiac resynchronization therapy.

Assessment of left ventricular (LV) volumes and ejection fraction (LVEF) with cardiac imaging is important in the selection of patients for cardiac resynchronization therapy (CRT). Several observational studies have explored the role of imaging-derived LV dyssynchrony parameters to predict the response to CRT, but have yielded inconsistent results, precluding the inclusion of imaging-derived LV dyssynchrony parameters in current guidelines for selection of patients for CRT. The EuroCRT is a large European multicentre prospective observational study led by the European Association of Cardiovascular Imaging. We aim to explore if combing the value of cardiac magnetic resonance (CMR) and echocardiography could be beneficial for selecting heart failure patients for CRT in terms of improvement in long-term survival, clinical symptoms, LV function, and volumes. Speckle tracking echocardiography will be used to assess LV dyssynchrony and wasted cardiac work whereas myocardial scar will be assessed with late gadolinium contrast enhanced CMR. All data will be measured in core laboratories. The study will be conducted in European centres with known expertise in both CRT and multimodality cardiac imaging.

Assessment of left ventricular mechanical dyssynchrony in left bundle branch block canine model: Comparison between cine and tagged MRI.

To compare cine and tagged magnetic resonance imaging (MRI) for left ventricular dyssynchrony assessment in left bundle branch block (LBBB), using the time-to-peak contraction timing, and a novel approach based on cross-correlation. We evaluated a canine model dataset (n = 10) before (pre-LBBB) and after induction of isolated LBBB (post-LBBB). Multislice short-axis tagged and cine MRI images were acquired using a 1.5 T scanner. We computed contraction time maps by cross-correlation, based on the timing of radial wall motion and of circumferential strain. Finally, we estimated dyssynchrony as the standard deviation of the contraction time over the different regions of the myocardium. Induction of LBBB resulted in a significant increase in dyssynchrony (cine: 13.0 ± 3.9 msec for pre-LBBB, and 26.4 ± 5.0 msec for post-LBBB, P = 0.005; tagged: 17.1 ± 5.0 msec at for pre-LBBB, and 27.9 ± 9.8 msec for post-LBBB, P = 0.007). Dyssynchrony assessed by cine and tagged MRI were in agreement (r = 0.73, P = 0.0003); differences were in the order of time difference between successive frames of 20 msec (bias: -2.9 msec; limit of agreement: 10.1 msec). Contraction time maps were derived; agreement was found in the contraction patterns derived from cine and tagged MRI (mean difference in contraction time per segment: 3.6 ± 13.7 msec). This study shows that the proposed method is able to quantify dyssynchrony after induced LBBB in an animal model. Cine-assessed dyssynchrony agreed with tagged-derived dyssynchrony, in terms of magnitude and spatial direction. J. MAGN. RESON. IMAGING 2016;44:956-963.

Clinical utility of speckle-tracking echocardiography in cardiac resynchronisation therapy.

Cardiac resynchronisation therapy (CRT) can profoundly improve outcome in selected patients with heart failure; however, response is difficult to predict and can be absent in up to one in three patients. There has been a substantial amount of interest in the echocardiographic assessment of left ventricular dyssynchrony, with the ultimate aim of reliably identifying patients who will respond to CRT. The measurement of myocardial deformation (strain) has conventionally been assessed using tissue Doppler imaging (TDI), which is limited by its angle dependence and ability to measure in a single plane. Two-dimensional speckle-tracking echocardiography is a technique that provides measurements of strain in three planes, by tracking patterns of ultrasound interference (‘speckles’) in the myocardial wall throughout the cardiac cycle. Since its initial use over 15 years ago, it has emerged as a tool that provides more robust, reproducible and sensitive markers of dyssynchrony than TDI. This article reviews the use of two-dimensional and three-dimensional speckle-tracking echocardiography in the assessment of dyssynchrony, including the identification of echocardiographic parameters that may hold predictive potential for the response to CRT. It also reviews the application of these techniques in guiding optimal LV lead placement pre-implant, with promising results in clinical improvement post-CRT.

Strain-time curve analysis by speckle tracking echocardiography in cardiac resynchronization therapy: Insight into the pathophysiology of responders vs. non-responders.

BackgroundPatients with non-ischemic heart failure etiology and left bundle branch block (LBBB) show better response to cardiac resynchronization therapy (CRT). While these patients have the most pronounced left ventricular (LV) dyssynchrony, LV dyssynchrony assessment often fails to predict outcome. We hypothesized that patients with favorable outcome from CRT can be identified by a characteristic strain distribution pattern.MethodsFrom 313 patients who underwent CRT between 2003 and 2006, we identified 10 patients who were CRT non-responders (no LV end-systolic volume [LVESV] reduction) with non-ischemic cardiomyopathy and LBBB and compared with randomly selected CRT responders (n = 10; LVESV reduction ≥15 %). Longitudinal strain (εlong) data were obtained by speckle tracking echocardiography before and after (9 ± 5 months) CRT implantation and standardized segmental εlong-time curves were obtained by averaging individual patients.ResultsIn responders, ejection fraction (EF) increased from 25 ± 9 to 40 ± 11 % (p = 0.002), while in non-responders, EF was unchanged (20 ± 8 to 21 ± 5 %, p = 0.57). Global εlong was significantly lower in non-responders at pre CRT (p = 0.02) and only improved in responders (p = 0.04) after CRT. Pre CRT septal εlong -time curves in both groups showed early septal contraction with mid-systolic decrease, while lateral εlong showed early stretch followed by vigorous mid to late contraction. Restoration of contraction synchrony was observed in both groups, though non-responder remained low amplitude of εlong.ConclusionsCRT non-responders with LBBB and non-ischemic etiology showed a similar improvement of εlong pattern with responders after CRT implantation, while amplitude of εlong remained unchanged. Lower εlong in the non-responders may account for their poor response to CRT.

Left Ventricular Dyssynchrony Predicts Left Main Coronary Artery Disease in Patients with Non-ST-Segment Elevation Myocardial Infarction.

The purpose of our study was to examine whether left ventricular dyssynchrony predicts left main coronary artery stenosis in patients with non-ST-segment elevation myocardial infarction. A total of 100 consecutive patients with non-ST-segment elevation myocardial infarction underwent echocardiography and coronary artery angiography. The 3-dimensional echocardiography-derived left ventricular dyssynchrony parameter was determined by using the standard deviation of the time to the minimal systolic volume for the 16 segments. A stenosis ≥ 50% of the diameter of the left main coronary artery or a stenosis ≥ 70% in 1 or more of the major epicardial vessels or their main branches was considered significant. The logistic regression analysis revealed that this parameter (odds ratio 1.2; 95% confidence interval, 1.01-1.42; p = 0.04) was the independent predictor of left main coronary artery stenosis. The receiver operating characteristic curve analysis revealed 8.86 as the optimal cutoff value to predict left main coronary artery stenosis (sensitivity, 71.4%; specificity, 89.2%). The assessment of left ventricular dyssynchrony by 3-dimensional echocardiography is useful for a noninvasive diagnosis of the left main coronary artery stenosis in patients with non-ST-segment elevation myocardial infarction. Dyssynchrony; Left main coronary artery stenosis; Non-ST-segment elevation myocardial infarction.

45 Assessment of left ventricular dyssynchrony and prediction of response to cardiac resynchronization therapy: a new three-dimensionnal echocardiography integral-based indicator of longitudinal strain

45 Assessment of left ventricular dyssynchrony and prediction of response to cardiac resynchronization therapy: a new three-dimensionnal echocardiography integral-based indicator of longitudinal strain