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Taconné M, Le Rolle V, Galli E, Owashi KP, Al Wazzan A, Donal E, Hernández A. Characterization of cardiac resynchronization therapy response through machine learning and personalized models. Comput Biol Med 2024; 180:108986. [PMID: 39142225 DOI: 10.1016/j.compbiomed.2024.108986] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2024] [Revised: 07/25/2024] [Accepted: 08/02/2024] [Indexed: 08/16/2024]
Abstract
INTRODUCTION The characterization and selection of heart failure (HF) patients for cardiac resynchronization therapy (CRT) remain challenging, with around 30% non-responder rate despite following current guidelines. This study aims to propose a novel hybrid approach, integrating machine-learning and personalized models, to identify explainable phenogroups of HF patients and predict their CRT response. METHODS The paper proposes the creation of a complete personalized model population based on preoperative CRT patient strain curves. Based on the parameters and features extracted from these personalized models, phenotypes of patients are identified thanks to a clustering algorithm and a random forest classification is provided. RESULTS A close match was observed between the 162 experimental and simulated myocardial strain curves, with a mean RMSE of 4.48% (±1.08) for the 162 patients. Five phenogroups of personalized models were identified from the clustering, with response rates ranging from 52% to 94%. The classification results show a mean area under the curves (AUC) of 0.86 ± 0.06 and provided a feature importance analysis with 22 features selected. Results show both regional myocardial contractility (from 22.5% to 33.0%), tissue viability and electrical activation delays importance on CRT response for each HF patient (from 55.8 ms to 88.4 ms). DISCUSSION The patient-specific model parameters' analysis provides an explainable interpretation of HF patient phenogroups in relation to physiological mechanisms that seem predictive of the CRT response. These novel combined approaches appear as promising tools to improve understanding of LV mechanical dyssynchrony for HF patient characterization and CRT selection.
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Affiliation(s)
- Marion Taconné
- Univ Rennes, CHU Rennes, Inserm, LTSI - UMR 1099, Rennes, France.
| | | | - Elena Galli
- Univ Rennes, CHU Rennes, Inserm, LTSI - UMR 1099, Rennes, France
| | - Kimi P Owashi
- Univ Rennes, CHU Rennes, Inserm, LTSI - UMR 1099, Rennes, France
| | - Adrien Al Wazzan
- Univ Rennes, CHU Rennes, Inserm, LTSI - UMR 1099, Rennes, France
| | - Erwan Donal
- Univ Rennes, CHU Rennes, Inserm, LTSI - UMR 1099, Rennes, France
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Gherbesi E, Gianstefani S, Angeli F, Ryabenko K, Bergamaschi L, Armillotta M, Guerra E, Tuttolomondo D, Gaibazzi N, Squeri A, Spaziani C, Pizzi C, Carugo S. Myocardial strain of the left ventricle by speckle tracking echocardiography: From physics to clinical practice. Echocardiography 2024; 41:e15753. [PMID: 38284665 DOI: 10.1111/echo.15753] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 12/21/2023] [Accepted: 01/02/2024] [Indexed: 01/30/2024] Open
Abstract
Speckle tracking echocardiography (STE) is a reliable imaging technique of recognized clinical value in several settings. This method uses the motion of ultrasound backscatter speckles within echocardiographic images to derive myocardial velocities and deformation parameters, providing crucial insights on several cardiac pathological and physiological processes. Its feasibility, reproducibility, and accuracy have been widely demonstrated, being myocardial strain of the various chambers inserted in diagnostic algorithms and guidelines for various pathologies. The most important parameters are Global longitudinal strain (GLS), Left atrium (LA) reservoir strain, and Global Work Index (GWI): based on large studies the average of the lower limit of normality are -16%, 23%, and 1442 mmHg%, respectively. For GWI, it should be pointed out that myocardial work relies primarily on non-invasive measurements of blood pressure and segmental strain, both of which exhibit high variability, and thus, this variability constitutes a significant limitation of this parameter. In this review, we describe the principal aspects of the theory behind the use of myocardial strain, from cardiac mechanics to image acquisition techniques, outlining its limitation, and its principal clinical applications: in particular, GLS have a role in determine subclinical myocardial dysfunction (in cardiomyopathies, cardiotoxicity, target organ damage in ambulatory patients with arterial hypertension) and LA strain in determine the risk of AF, specifically in ambulatory patients with arterial hypertension.
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Affiliation(s)
- Elisa Gherbesi
- Department of Cardio-Thoracic-Vascular Diseases, Foundation IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milano, Italy
| | - Silvia Gianstefani
- Cardiology Unit, IRCCS Azienda Ospedaliera-Universitaria di Bologna, Bologna, Italy
- Department of Medical and Surgical Sciences - DIMEC - Alma Mater Studiorum, University of Bologna, Bologna, Italy
| | - Francesco Angeli
- Cardiology Unit, IRCCS Azienda Ospedaliera-Universitaria di Bologna, Bologna, Italy
- Department of Medical and Surgical Sciences - DIMEC - Alma Mater Studiorum, University of Bologna, Bologna, Italy
| | - Khrystyna Ryabenko
- Cardiology Unit, IRCCS Azienda Ospedaliera-Universitaria di Bologna, Bologna, Italy
- Department of Medical and Surgical Sciences - DIMEC - Alma Mater Studiorum, University of Bologna, Bologna, Italy
| | - Luca Bergamaschi
- Cardiology Unit, IRCCS Azienda Ospedaliera-Universitaria di Bologna, Bologna, Italy
- Department of Medical and Surgical Sciences - DIMEC - Alma Mater Studiorum, University of Bologna, Bologna, Italy
| | - Matteo Armillotta
- Cardiology Unit, IRCCS Azienda Ospedaliera-Universitaria di Bologna, Bologna, Italy
- Department of Medical and Surgical Sciences - DIMEC - Alma Mater Studiorum, University of Bologna, Bologna, Italy
| | - Emiliano Guerra
- Cardiology Division, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Policlinico Di Modena, Modena, Italy
| | - Domenico Tuttolomondo
- Cardiology Division, Parma University Hospital, Azienda Ospedaliero-Universitaria di Parma, Parma, Italy
| | - Nicola Gaibazzi
- Cardiology Division, Parma University Hospital, Azienda Ospedaliero-Universitaria di Parma, Parma, Italy
| | - Angelo Squeri
- Maria Cecilia Hospital, GVM Care and Research, Cotignola, Ravenna, Italy
| | - Cristina Spaziani
- Department of Cardio-Thoracic-Vascular Diseases, Foundation IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milano, Italy
| | - Carmine Pizzi
- Cardiology Unit, IRCCS Azienda Ospedaliera-Universitaria di Bologna, Bologna, Italy
- Department of Medical and Surgical Sciences - DIMEC - Alma Mater Studiorum, University of Bologna, Bologna, Italy
| | - Stefano Carugo
- Department of Cardio-Thoracic-Vascular Diseases, Foundation IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milano, Italy
- Department of Clinical Sciences and Community Health, University of Milano, Milano, Italy
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Zhu M, Chen H, Fulati Z, Liu Y, Su Y, Shu X. The value of left ventricular strain-volume loops in predicting response to cardiac resynchronization therapy. Cardiovasc Ultrasound 2019; 17:3. [PMID: 30777069 PMCID: PMC6379938 DOI: 10.1186/s12947-019-0153-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2018] [Accepted: 02/12/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Three-dimensional (3D) speckle tracking imaging (STI) allows the simultaneous assessment of left ventricular (LV) strain and volume. We aim to explore the value of LV strain-volume loops in predicting response to cardiac resynchronization therapy (CRT). METHODS Forty heart failure (HF) patients scheduled for CRT and twenty healthy individuals were enrolled. All subjects received a 3D echocardiography and 3D STI analysis to acquire LV global and segmental principal strain (PS) and volume simultaneously. Values were plotted in a Cartesian system to construct PS-volume loop which was assessed using the two characteristics of the linear fitting curve: the slope and the coefficient of determination (R2-S/D coupling). RESULTS HF patients at baseline showed significantly lower slope and R2-S/D coupling of all PS-volume loops than healthy subjects. As for as comparing Segmental PS-Global volume loop at baseline, Midseptal R2-S/D coupling was lower and Midlateral slope was higher in CRT responders than in non-responders. For each individual, the abnormal segmental heterogeneity of Midseptal slope and R2-S/D coupling were lower than Midlateral was observed only in responders. At follow-up, significant improvements of the Midseptal slope and R2-S/D coupling were observed in responders. Midseptal R2-S/D coupling at baseline was an independent predictor of CRT response and the cut-off value of 0.55 was recommended with sensitivity of 89% and specificity of 77%. CONCLUSIONS Analysis of strain-volume loops could provide unique information for predicting response to CRT. Assessment of septal myocardial wasted work at baseline is helpful to improve patient selection for CRT.
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Affiliation(s)
- Mengruo Zhu
- Department of Echocardiography, Zhongshan Hospital, Fudan University, Shanghai Institute of Cardiovascular Diseases, Shanghai Institute of Medical Imaging, 180 Fenglin Road, Shanghai, 200032, China.,Department of Cardiology, Zhongshan Hospital, Fudan University; Shanghai Institute of Cardiovascular Diseases, 180 Fenglin Road, Shanghai, 200032, China
| | - Haiyan Chen
- Department of Echocardiography, Zhongshan Hospital, Fudan University, Shanghai Institute of Cardiovascular Diseases, Shanghai Institute of Medical Imaging, 180 Fenglin Road, Shanghai, 200032, China
| | - Zibire Fulati
- Department of Echocardiography, Zhongshan Hospital, Fudan University, Shanghai Institute of Cardiovascular Diseases, Shanghai Institute of Medical Imaging, 180 Fenglin Road, Shanghai, 200032, China
| | - Yang Liu
- Department of Echocardiography, Zhongshan Hospital, Fudan University, Shanghai Institute of Cardiovascular Diseases, Shanghai Institute of Medical Imaging, 180 Fenglin Road, Shanghai, 200032, China
| | - Yangang Su
- Department of Cardiology, Zhongshan Hospital, Fudan University; Shanghai Institute of Cardiovascular Diseases, 180 Fenglin Road, Shanghai, 200032, China
| | - Xianhong Shu
- Department of Echocardiography, Zhongshan Hospital, Fudan University, Shanghai Institute of Cardiovascular Diseases, Shanghai Institute of Medical Imaging, 180 Fenglin Road, Shanghai, 200032, China. .,Department of Cardiology, Zhongshan Hospital, Fudan University; Shanghai Institute of Cardiovascular Diseases, 180 Fenglin Road, Shanghai, 200032, China.
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Gong IY, Al-Amro B, Prasad GVR, Connelly PW, Wald RM, Wald R, Deva DP, Leong-Poi H, Nash MM, Yuan W, Gunaratnam L, Kim SJ, Lok CE, Connelly KA, Yan AT. Cardiovascular magnetic resonance left ventricular strain in end-stage renal disease patients after kidney transplantation. J Cardiovasc Magn Reson 2018; 20:83. [PMID: 30554567 PMCID: PMC6296102 DOI: 10.1186/s12968-018-0504-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Accepted: 11/09/2018] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Cardiovascular disease is a significant cause of morbidity and mortality in patients with end-stage renal disease (ESRD) and kidney transplant (KT) patients. Compared with left ventricular (LV) ejection fraction (LVEF), LV strain has emerged as an important marker of LV function as it is less load dependent. We sought to evaluate changes in LV strain using cardiovascular magnetic resonance imaging (CMR) in ESRD patients who received KT, to determine whether KT may improve LV function. METHODS We conducted a prospective multi-centre longitudinal study of 79 ESRD patients (40 on dialysis, 39 underwent KT). CMR was performed at baseline and at 12 months after KT. RESULTS Among 79 participants (mean age 55 years; 30% women), KT patients had significant improvement in global circumferential strain (GCS) (p = 0.007) and global radial strain (GRS) (p = 0.003), but a decline in global longitudinal strain (GLS) over 12 months (p = 0.026), while no significant change in any LV strain was observed in the ongoing dialysis group. For KT patients, the improvement in LV strain paralleled improvement in LVEF (57.4 ± 6.4% at baseline, 60.6% ± 6.9% at 12 months; p = 0.001). For entire cohort, over 12 months, change in LVEF was significantly correlated with change in GCS (Spearman's r = - 0.42, p < 0.001), GRS (Spearman's r = 0.64, p < 0.001), and GLS (Spearman's r = - 0.34, p = 0.002). Improvements in GCS and GRS over 12 months were significantly correlated with reductions in LV end-diastolic volume index and LV end-systolic volume index (all p < 0.05), but not with change in blood pressure (all p > 0.10). CONCLUSIONS Compared with continuation of dialysis, KT was associated with significant improvements in LV strain metrics of GCS and GRS after 12 months, which did not correlate with blood pressure change. This supports the notion that KT has favorable effects on LV function beyond volume and blood pessure control. Larger studies with longer follow-up are needed to confirm these findings.
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Affiliation(s)
| | - Bandar Al-Amro
- Terrence Donnelly Heart Centre, St. Michael’s Hospital, Toronto, Canada
| | - G. V. Ramesh Prasad
- University of Toronto, Toronto, Canada
- Division of Nephrology, St Michael’s Hospital, Toronto, ON Canada
| | - Philip W. Connelly
- University of Toronto, Toronto, Canada
- Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael’s Hospital, Toronto, Canada
| | - Rachel M. Wald
- University of Toronto, Toronto, Canada
- Division of Cardiology, Toronto General Hospital, Toronto, Canada
| | - Ron Wald
- University of Toronto, Toronto, Canada
- Division of Nephrology, St Michael’s Hospital, Toronto, ON Canada
| | - Djeven P. Deva
- University of Toronto, Toronto, Canada
- Department of Medical Imaging, St Michael’s Hospital, Toronto, Canada
| | - Howard Leong-Poi
- University of Toronto, Toronto, Canada
- Terrence Donnelly Heart Centre, St. Michael’s Hospital, Toronto, Canada
| | - Michelle M. Nash
- Division of Nephrology, St Michael’s Hospital, Toronto, ON Canada
| | - Weiqiu Yuan
- Division of Nephrology, St Michael’s Hospital, Toronto, ON Canada
| | - Lakshman Gunaratnam
- Division of Nephrology, Department of Medicine, London Health Sciences Centre, Schulich School of Medicine and Dentistry, Western University, London, Canada
| | - S. Joseph Kim
- University of Toronto, Toronto, Canada
- Department of Medicine, Division of Nephrology, Toronto General Hospital, University Health Network, Toronto, Canada
| | - Charmaine E. Lok
- Department of Medicine, University Health Network-Toronto General Hospital, Toronto, Canada
| | - Kim A. Connelly
- University of Toronto, Toronto, Canada
- Terrence Donnelly Heart Centre, St. Michael’s Hospital, Toronto, Canada
| | - Andrew T. Yan
- University of Toronto, Toronto, Canada
- Terrence Donnelly Heart Centre, St. Michael’s Hospital, Toronto, Canada
- Division of Cardiology, St. Michael’s Hospital, 30 Bond Street, Rm 6-030 Donnelly, Toronto, M5B 1W8 Canada
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Kronborg MB, Sommer A, Fyenbo DB, Norgaard BL, Gerdes C, Jensen JM, Jensen HK, Kristensen J, Nielsen JC. Left ventricular regional remodeling and lead position during cardiac resynchronization therapy. Heart Rhythm 2018; 15:1542-1549. [PMID: 29678780 DOI: 10.1016/j.hrthm.2018.04.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Indexed: 11/25/2022]
Abstract
BACKGROUND Cardiac resynchronization therapy (CRT) induces segmental left ventricular (LV) remodeling. The LV lead position (LV-LP) affects response to CRT and remodeling. OBJECTIVE We aimed to assess segmental remodeling concordant, adjacent, and remote to LV-LP using cardiac computed tomography (CT). METHODS We included patients from the Empiric Versus Imaging-Guided Left Ventricular Lead Placement in Cardiac Resynchronization Therapy trial. Dynamic cardiac CT was performed at baseline and after 6 months. We assessed systolic wall thickening (WT) and exact LV-LP from the CT scans according to a 16-segment model. Response to CRT was defined as ≥15% reduction in LV end-systolic volume. RESULTS A total of 107 consecutive patients were included. The change in WT from baseline to follow-up was -19% (95% confidence interval [CI] -25% to -13%; P < .001) in concordant segments, -0.1% (95% CI -5% to 5%; P = .97) in adjacent segments, and 20% (95% CI -17% to 23%; P < .001) in remote segments. Diastolic wall thickness changed only marginally. Twenty patients (19%) were nonresponders at follow-up. In nonresponders with nonischemic cardiomyopathy, we observed a significant reduction in WT in concordant and adjacent segments with no increase in WT in remote segments. CONCLUSION During CRT, systolic WT increases in segments remote to LV-LP, decreases in concordant segments, and remains unchanged in adjacent segments. Only marginal changes occur in wall thickness. In nonresponders with nonischemic cardiomyopathy, deleterious changes in segmental myocardial function occur, and further studies on how to treat these patients best are warranted.
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Affiliation(s)
- Mads Brix Kronborg
- Department of Cardiology, Aarhus University Hospital, Skejby, Aarhus N, Denmark.
| | - Anders Sommer
- Department of Cardiology, Aarhus University Hospital, Skejby, Aarhus N, Denmark
| | - Daniel B Fyenbo
- Department of Cardiology, Aarhus University Hospital, Skejby, Aarhus N, Denmark
| | - Bjarne L Norgaard
- Department of Cardiology, Aarhus University Hospital, Skejby, Aarhus N, Denmark
| | - Christian Gerdes
- Department of Cardiology, Aarhus University Hospital, Skejby, Aarhus N, Denmark
| | | | | | - Jens Kristensen
- Department of Cardiology, Aarhus University Hospital, Skejby, Aarhus N, Denmark
| | - Jens C Nielsen
- Department of Cardiology, Aarhus University Hospital, Skejby, Aarhus N, Denmark
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Bunting E, Lambrakos L, Kemper P, Whang W, Garan H, Konofagou E. Imaging the Propagation of the Electromechanical Wave in Heart Failure Patients with Cardiac Resynchronization Therapy. PACING AND CLINICAL ELECTROPHYSIOLOGY: PACE 2016; 40:35-45. [PMID: 27790723 DOI: 10.1111/pace.12964] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Revised: 09/12/2016] [Accepted: 10/11/2016] [Indexed: 01/06/2023]
Abstract
BACKGROUND Current electrocardiographic and echocardiographic measurements in heart failure (HF) do not take into account the complex interplay between electrical activation and local wall motion. The utilization of novel technologies to better characterize cardiac electromechanical behavior may lead to improved response rates with cardiac resynchronization therapy (CRT). Electromechanical wave imaging (EWI) is a noninvasive ultrasound-based technique that uses the transient deformations of the myocardium to track the intrinsic EW that precedes myocardial contraction. In this paper, we investigate the performance and reproducibility of EWI in the assessment of HF patients and CRT. METHODS EWI acquisitions were obtained in five healthy controls and 16 HF patients with and without CRT pacing. Responders (n = 8) and nonresponders (n = 8) to CRT were identified retrospectively on the basis of left ventricular (LV) reverse remodeling. Electromechanical activation maps were obtained in all patients and used to compute a quantitative parameter describing the mean LV lateral wall activation time (LWAT). RESULTS Mean LWAT was increased by 52.1 ms in HF patients in native rhythm compared to controls (P < 0.01). For all HF patients, CRT pacing initiated a different electromechanical activation sequence. Responders exhibited a 56.4-ms ± 28.9-ms reduction in LWAT with CRT pacing (P < 0.01), while nonresponders showed no significant change. CONCLUSION In this initial feasibility study, EWI was capable of characterizing local cardiac electromechanical behavior as it pertains to HF and CRT response. Activation sequences obtained with EWI allow for quantification of LV lateral wall electromechanical activation, thus providing a novel method for CRT assessment.
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Affiliation(s)
- Ethan Bunting
- Department of Biomedical Engineering, Columbia University, New York, New York
| | - Litsa Lambrakos
- Division of Cardiology, Columbia University, New York, New York
| | - Paul Kemper
- Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, the Netherlands
| | - William Whang
- Division of Cardiology, Columbia University, New York, New York
| | - Hasan Garan
- Division of Cardiology, Columbia University, New York, New York
| | - Elisa Konofagou
- Department of Biomedical Engineering, Department of Radiology, Columbia University, New York, New York
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Hasselberg NE, Haugaa KH, Bernard A, Ribe MP, Kongsgaard E, Donal E, Edvardsen T. Left ventricular markers of mortality and ventricular arrhythmias in heart failure patients with cardiac resynchronization therapy. Eur Heart J Cardiovasc Imaging 2015; 17:343-50. [PMID: 26164406 PMCID: PMC4750507 DOI: 10.1093/ehjci/jev173] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Accepted: 06/12/2015] [Indexed: 01/04/2023] Open
Abstract
Aims Cardiac resynchronization therapy (CRT) reduces morbidity and mortality in heart failure. However, prediction of the outcome remains difficult. We aimed to investigate for echocardiographic predictors of ventricular arrhythmias and fatal outcome and to explore how myocardial function is changed by biventricular pacing in heart failure. Methods and results We prospectively included 170 heart failure patients (66 ± 10 years, New York Heart Association class 2.8 ± 0.5, 48% ischaemic cardiomyopathy) and recorded ventricular arrhythmias and fatal end point defined as death, heart transplantation, or left ventricular assist device implantation during 2 years. Two-dimensional echocardiography was performed before and 6 months after CRT implantation. CRT response was defined as ≥15% reduction in end-systolic volume at 6 months. Speckle-tracking technique was performed to assess longitudinal and circumferential left ventricular function, defined as global longitudinal (GLS) and circumferential strain (GCS), and to assess mechanical dyssynchrony, defined as mechanical dispersion. GLS before CRT was a predictor of fatal end point independently of CRT response [hazard ratio, HR 1.14 (1.02–1.27), P = 0.02]. Patients with GLS better than −8.3% showed event-free survival benefit (log rank, P < 0.001). Mechanical dispersion at 6 months was an independent predictor of ventricular arrhythmias [HR 1.20 (1.06–1.35), P = 0.005]. CRT responders (59%) had improvement of both GLS and GCS. Conclusion In heart failure patients with CRT, worse longitudinal function before CRT was an important predictor of fatal outcome during 2 years, independently of CRT response. Mechanical dispersion at 6 months was a strong predictor of ventricular arrhythmias. CRT response by reverse remodelling was dependent on improvement of both longitudinal and circumferential function.
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Affiliation(s)
- Nina E Hasselberg
- Department of Cardiology, Oslo University Hospital, Rikshospitalet, Oslo, Norway Center for Cardiological Innovation, Oslo, Norway University of Oslo, Oslo, Norway Institute for Surgical Research, Oslo University Hospital, Rikshospitalet, Oslo, Norway
| | - Kristina H Haugaa
- Department of Cardiology, Oslo University Hospital, Rikshospitalet, Oslo, Norway Center for Cardiological Innovation, Oslo, Norway University of Oslo, Oslo, Norway Institute for Surgical Research, Oslo University Hospital, Rikshospitalet, Oslo, Norway
| | - Anne Bernard
- LTSI, INSERM UMR 1099-Université Rennes-1, CIC-IT 804 CHU RENNES, Rennes, France
| | - Margareth P Ribe
- Department of Cardiology, Oslo University Hospital, Rikshospitalet, Oslo, Norway Center for Cardiological Innovation, Oslo, Norway Institute for Surgical Research, Oslo University Hospital, Rikshospitalet, Oslo, Norway
| | - Erik Kongsgaard
- Department of Cardiology, Oslo University Hospital, Rikshospitalet, Oslo, Norway Center for Cardiological Innovation, Oslo, Norway University of Oslo, Oslo, Norway Institute for Surgical Research, Oslo University Hospital, Rikshospitalet, Oslo, Norway
| | - Erwan Donal
- LTSI, INSERM UMR 1099-Université Rennes-1, CIC-IT 804 CHU RENNES, Rennes, France
| | - Thor Edvardsen
- Department of Cardiology, Oslo University Hospital, Rikshospitalet, Oslo, Norway Center for Cardiological Innovation, Oslo, Norway University of Oslo, Oslo, Norway Institute for Surgical Research, Oslo University Hospital, Rikshospitalet, Oslo, Norway
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Bernard A, Donal E, Leclercq C, Schnell F, Fournet M, Reynaud A, Thebault C, Mabo P, Daubert JC, Hernandez A. Impact of Cardiac Resynchronization Therapy on Left Ventricular Mechanics: Understanding the Response through a New Quantitative Approach Based on Longitudinal Strain Integrals. J Am Soc Echocardiogr 2015; 28:700-8. [DOI: 10.1016/j.echo.2015.02.017] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2014] [Indexed: 10/23/2022]
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Comparison of septal strain patterns in dyssynchronous heart failure between speckle tracking echocardiography vendor systems. J Electrocardiol 2014; 48:609-16. [PMID: 25620788 DOI: 10.1016/j.jelectrocard.2014.12.021] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Indexed: 11/23/2022]
Abstract
AIM To analyze inter-vendor differences of speckle tracking echocardiography (STE) in imaging cardiac deformation in patients with dyssynchronous heart failure. METHODS AND RESULTS Eleven patients (all with LBBB, median age 60.7 years, 9 males) with implanted cardiac resynchronization therapy devices were prospectively included. Ultrasound systems of two vendors (i.e. General Electric and Philips) were used to record images in the apical four chamber view. Regional longitudinal strain patterns were analyzed with vendor specific software in the basal, mid and apical septal segments. Systolic strain (SS), time to peak strain (TTP) and septal rebound stretch (SRS) were determined during four pacing settings, resulting in 44 unique strain patterns per segment (total 132 patterns). Cross correlation was used to analyze the comparability of the shape of 132 normalized strain patterns. Correlation of strain patterns of the two systems was high (R(2) median: 0.68, interquartile range: 0.53-0.82). Accordingly, strain patterns of intrinsic rhythm were recognized equally using both systems, when divided into three types. GE based SS (18.9 ± 4.7%) was significantly higher than SS determined by the Philips system (13.4 ± 4.3%). TTP was slightly but non-significantly lower in GE (384 ± 77 ms) compared to Philips (404 ± 83 ms) derived strain signals. Correlation of SRS between the systems was poor, due to minor differences in the strain signal and timing of aortic valve closure. CONCLUSIONS The two systems provide similar shape of strain patterns. However, important differences are found in the amplitude, timing of systole and SRS. Until STE is standardized, clinical decision making should be restricted to pattern analysis.
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Motonaga KS, Dubin AM. Cardiac resynchronization therapy for pediatric patients with heart failure and congenital heart disease: a reappraisal of results. Circulation 2014; 129:1879-91. [PMID: 24799504 DOI: 10.1161/circulationaha.113.001383] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Russell K, Eriksen M, Aaberge L, Wilhelmsen N, Skulstad H, Gjesdal O, Edvardsen T, Smiseth OA. Assessment of wasted myocardial work: a novel method to quantify energy loss due to uncoordinated left ventricular contractions. Am J Physiol Heart Circ Physiol 2013; 305:H996-1003. [PMID: 23893165 DOI: 10.1152/ajpheart.00191.2013] [Citation(s) in RCA: 218] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Left ventricular (LV) dyssynchrony reduces myocardial efficiency because work performed by one segment is wasted by stretching other segments. In the present study, we introduce a novel noninvasive clinical method that quantifies wasted energy as the ratio between work consumed during segmental lengthening (wasted work) divided by work during segmental shortening. The wasted work ratio (WWR) principle was studied in 6 anesthetized dogs with left bundle branch block (LBBB) and in 28 patients with cardiomyopathy, including 12 patients with LBBB and 10 patients with cardiac resynchronization therapy. Twenty healthy individuals served as controls. Myocardial strain was measured by speckle tracking echocardiography, and LV pressure (LVP) was measured by micromanometer and a previously validated noninvasive method. Segmental work was calculated by multiplying strain rate and LVP to get instantaneous power, which was integrated to give work as a function of time. A global WWR was also calculated. In dogs, WWR by estimated LVP and strain showed a strong correlation (r = 0.94) and good agreement with WWR by the LV micromanometer and myocardial segment length by sonomicrometry. In patients, noninvasive WWR showed a strong correlation (r = 0.96) and good agreement with WWR using the LV micromanometer. Global WWR was 0.09 ± 0.03 in healthy control subjects, 0.36 ± 0.16 in patients with LBBB, and 0.21 ± 0.09 in cardiomyopathy patients without LBBB. Cardiac resynchronization therapy reduced global WWR from 0.36 ± 0.16 to 0.17 ± 0.07 (P < 0.001). In conclusion, energy loss due to incoordinated contractions can be quantified noninvasively as the LV WWR. This method may be applied to evaluate the mechanical impact of dyssynchrony.
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Affiliation(s)
- Kristoffer Russell
- Institute for Surgical Research and Department of Cardiology, Rikshospitalet, Oslo University Hospital, Oslo, Norway, and Medical Faculty, University of Oslo, Oslo, Norway; and
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Piella G, De Craene M, Butakoff C, Grau V, Yao C, Nedjati-Gilani S, Penney GP, Frangi AF. Multiview diffeomorphic registration: application to motion and strain estimation from 3D echocardiography. Med Image Anal 2013; 17:348-64. [PMID: 23410512 DOI: 10.1016/j.media.2013.01.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2012] [Revised: 12/07/2012] [Accepted: 01/12/2013] [Indexed: 11/16/2022]
Abstract
This paper presents a new registration framework for quantifying myocardial motion and strain from the combination of multiple 3D ultrasound (US) sequences. The originality of our approach lies in the estimation of the transformation directly from the input multiple views rather than from a single view or a reconstructed compounded sequence. This allows us to exploit all spatiotemporal information available in the input views avoiding occlusions and image fusion errors that could lead to some inconsistencies in the motion quantification result. We propose a multiview diffeomorphic registration strategy that enforces smoothness and consistency in the spatiotemporal domain by modeling the 4D velocity field continuously in space and time. This 4D continuous representation considers 3D US sequences as a whole, therefore allowing to robustly cope with variations in heart rate resulting in different number of images acquired per cardiac cycle for different views. This contributes to the robustness gained by solving for a single transformation from all input sequences. The similarity metric takes into account the physics of US images and uses a weighting scheme to balance the contribution of the different views. It includes a comparison both between consecutive images and between a reference and each of the following images. The strain tensor is computed locally using the spatial derivatives of the reconstructed displacement fields. Registration and strain accuracy were evaluated on synthetic 3D US sequences with known ground truth. Experiments were also conducted on multiview 3D datasets of 8 volunteers and 1 patient treated by cardiac resynchronization therapy. Strain curves obtained from our multiview approach were compared to the single-view case, as well as with other multiview approaches. For healthy cases, the inclusion of several views improved the consistency of the strain curves and reduced the number of segments where a non-physiological strain pattern was observed. For the patient, the improvement (pacing ON vs. OFF) in synchrony of regional strain correlated with clinician blind assessment and could be seen more clearly when using the multiview approach.
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Affiliation(s)
- Gemma Piella
- Center for Computational Imaging & Simulation Technologies in Biomedicine, Information & Communication Technologies Department, Universitat Pompeu Fabra, Barcelona, Spain.
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Iwano H, Yamada S, Watanabe M, Mitsuyama H, Mizukami K, Nishino H, Yokoyama S, Kaga S, Okada K, Nishida M, Yokoshiki H, Mikami T, Tsutsui H. Strain Rate Dispersion Index Can Predict Changes in Left Ventricular Volume and Adverse Cardiac Events Following Cardiac Resynchronization Therapy. Circ J 2013; 77:2757-65. [DOI: 10.1253/circj.cj-13-0483] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Hiroyuki Iwano
- Department of Cardiovascular Medicine, Hokkaido University Graduate School of Medicine
| | - Satoshi Yamada
- Department of Cardiovascular Medicine, Hokkaido University Graduate School of Medicine
| | - Masaya Watanabe
- Department of Cardiovascular Medicine, Hokkaido University Graduate School of Medicine
| | - Hirofumi Mitsuyama
- Department of Cardiovascular Medicine, Hokkaido University Graduate School of Medicine
| | - Kazuya Mizukami
- Department of Cardiovascular Medicine, Hokkaido University Graduate School of Medicine
| | - Hisao Nishino
- Division of Clinical Laboratory and Transfusion Medicine, Hokkaido University Hospital
| | - Shinobu Yokoyama
- Division of Clinical Laboratory and Transfusion Medicine, Hokkaido University Hospital
| | - Sanae Kaga
- Faculty of Health Sciences, Hokkaido University
| | - Kazunori Okada
- Division of Health Sciences, Hokkaido University Graduate School of Health Sciences
| | - Mutsumi Nishida
- Division of Clinical Laboratory and Transfusion Medicine, Hokkaido University Hospital
| | - Hisashi Yokoshiki
- Department of Cardiovascular Medicine, Hokkaido University Graduate School of Medicine
| | | | - Hiroyuki Tsutsui
- Department of Cardiovascular Medicine, Hokkaido University Graduate School of Medicine
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Strik M, Regoli F, Auricchio A, Prinzen F. Electrical and mechanical ventricular activation during left bundle branch block and resynchronization. J Cardiovasc Transl Res 2012; 5:117-26. [PMID: 22311563 PMCID: PMC3294208 DOI: 10.1007/s12265-012-9351-1] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2011] [Accepted: 01/21/2012] [Indexed: 11/27/2022]
Abstract
Cardiac resynchronization therapy (CRT) aims to treat selected heart failure patients suffering from conduction abnormalities with left bundle branch block (LBBB) as the culprit disease. LBBB remained largely underinvestigated until it became apparent that the amount of response to CRT was heterogeneous and that the therapy and underlying pathology were thus incompletely understood. In this review, current knowledge concerning activation in LBBB and during biventricular pacing will be explored and applied to current CRT practice, highlighting novel ways to better measure and treat the electrical substrate.
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Affiliation(s)
- Marc Strik
- Department of Physiology, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht 6200 MD, The Netherlands.
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Simple regional strain pattern analysis to predict response to cardiac resynchronization therapy: rationale, initial results, and advantages. Am Heart J 2012; 163:697-704. [PMID: 22520537 DOI: 10.1016/j.ahj.2012.01.025] [Citation(s) in RCA: 106] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2011] [Accepted: 01/26/2012] [Indexed: 02/03/2023]
Abstract
BACKGROUND A classical strain pattern of early contraction in one wall and prestretching of the opposing wall followed by late contraction has previously been associated with left bundle branch block (LBBB) activation and short-term response to cardiac resynchronization therapy (CRT). Aims of this study were to establish the long-term predictive value of an LBBB-related strain pattern and to identify changes in contraction patterns during short-term and long-term CRT. METHODS AND RESULTS Sixty-seven patients with standard CRT criteria were prospectively enrolled between early 2009 and late 2010. Echocardiography including regional strain analysis by 2-dimensional speckle tracking was performed 1 week before implantation, at day 1, and 6 months after. Response was defined as a decrease in left ventricular end-systolic volume ≥ 15%. The predictive ability of a classical pattern was compared with time-to-peak measurements from velocity and deformation analysis. Forty-three patients (65%) were classified as responders. The presence of a classical pattern showed 91% specificity and 95% sensitivity for response and performed significantly better than time-to-peak parameters in prediction of response to CRT (P < .001, all). In responders, CRT acutely increased septal longitudinal peak systolic strain (-8.7% ± 3.6% to -11.1% ± 3%, P < .001) but not in nonresponders. CONCLUSIONS The classical pattern is highly predictive of response to CRT and superior to time-to-peak methods. Patients who obtain long-term reverse remodeling are characterized by short-term reversal of the classical strain pattern. These findings emphasize the value of recognizing potentially reversible strain patterns in selection of CRT candidates.
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Valzania C, Gadler F, Boriani G, Eriksson MJ. Changes in global longitudinal strain during rest and exercise in patients treated with cardiac resynchronization therapy. Clin Physiol Funct Imaging 2012; 32:310-6. [DOI: 10.1111/j.1475-097x.2012.01128.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2011] [Accepted: 02/20/2012] [Indexed: 11/29/2022]
Affiliation(s)
- Cinzia Valzania
- Cardiovascular Department, S. Orsola-Malpighi Hospital; University of Bologna; Bologna; Italy
| | | | - Giuseppe Boriani
- Cardiovascular Department, S. Orsola-Malpighi Hospital; University of Bologna; Bologna; Italy
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Sakamaki F, Seo Y, Ishizu T, Yanaka S, Atsumi A, Yamamoto M, Machino-Ohtsuka T, Kawamura R, Yamasaki H, Igarashi M, Yoshida K, Sekiguchi Y, Tada H, Aonuma K. Tissue Doppler Imaging Dyssynchrony Parameter Derived From the Myocardial Active Wall Motion Improves Prediction of Responders for Cardiac Resynchronization Therapy. Circ J 2012; 76:689-97. [DOI: 10.1253/circj.cj-11-0774] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Fumiko Sakamaki
- Department of Clinical Laboratory, Tsukuba University Hospital
| | - Yoshihiro Seo
- Cardiovascular Division, Institute of Clinical Medicine, Graduate School of Comprehensive Human Sciences, University of Tsukuba
| | - Tomoko Ishizu
- Cardiovascular Division, Institute of Clinical Medicine, Graduate School of Comprehensive Human Sciences, University of Tsukuba
| | - Satomi Yanaka
- Department of Clinical Laboratory, Tsukuba University Hospital
| | - Akiko Atsumi
- Cardiovascular Division, Institute of Clinical Medicine, Graduate School of Comprehensive Human Sciences, University of Tsukuba
| | - Masayoshi Yamamoto
- Cardiovascular Division, Institute of Clinical Medicine, Graduate School of Comprehensive Human Sciences, University of Tsukuba
| | - Tomoko Machino-Ohtsuka
- Cardiovascular Division, Institute of Clinical Medicine, Graduate School of Comprehensive Human Sciences, University of Tsukuba
| | - Ryo Kawamura
- Cardiovascular Division, Institute of Clinical Medicine, Graduate School of Comprehensive Human Sciences, University of Tsukuba
| | - Hiro Yamasaki
- Cardiovascular Division, Institute of Clinical Medicine, Graduate School of Comprehensive Human Sciences, University of Tsukuba
| | - Miyako Igarashi
- Cardiovascular Division, Institute of Clinical Medicine, Graduate School of Comprehensive Human Sciences, University of Tsukuba
| | - Kentaro Yoshida
- Cardiovascular Division, Institute of Clinical Medicine, Graduate School of Comprehensive Human Sciences, University of Tsukuba
| | - Yukio Sekiguchi
- Cardiovascular Division, Institute of Clinical Medicine, Graduate School of Comprehensive Human Sciences, University of Tsukuba
| | - Hiroshi Tada
- Cardiovascular Division, Institute of Clinical Medicine, Graduate School of Comprehensive Human Sciences, University of Tsukuba
| | - Kazutaka Aonuma
- Cardiovascular Division, Institute of Clinical Medicine, Graduate School of Comprehensive Human Sciences, University of Tsukuba
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Abstract
Abnormal electrical activation of the ventricles creates major abnormalities in cardiac mechanics. Local contraction patterns, as reflected by measurements of local strain, are not only out of phase, but often also show opposing length changes in early and late activated regions. As a consequence, the efficiency of cardiac pump function (the amount of stroke work generated by a unit of oxygen consumed) is approximately 30% lower in asynchronous than in synchronous hearts. Moreover, the amount of work performed in myocardial segments becomes considerably larger in late than in early activated regions. Cardiac Resynchronization Therapy (CRT) improves mechano-energetics of the previously asynchronous heart in various ways: it alleviates impediment of the abnormal contraction on blood flow, it increases myocardial efficiency, it recruits contraction in the previously early activated septum and it creates a more uniform distribution of myocardial blood flow. These factors act together to increase the range of cardiac work that can be delivered by the patients’ heart, an effect that can explain the increased exercise tolerance and quality of life reported in several CRT trials.
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Affiliation(s)
- Frits W Prinzen
- Department of Physiology, Cardiovascular Research Institute Maastricht, Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands.
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Lilli A, Baratto MT, Del Meglio J, Chioccioli M, Magnacca M, Svetlich C, Ghidini Ottonelli A, Poddighe R, Comella A, Casolo G. Three-dimensional simultaneous strain-volume analysis describes left ventricular remodelling and its progression: a pilot study. EUROPEAN JOURNAL OF ECHOCARDIOGRAPHY 2011; 12:520-7. [PMID: 21676962 PMCID: PMC3135213 DOI: 10.1093/ejechocard/jer073] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
AIMS Three-dimensional (3D)-echocardiography speckle imaging allows the evaluation of frame-by-frame strain and volume changes simultaneously. The aim of the present investigation was to describe the strain-volume combined assessment in different patterns of cardiac remodelling. METHODS AND RESULTS Fifty patients received a 3D acquisition. Patients were classified as follows: healthy subjects (CNT), previous AMI, and normal ejection fraction (EF; group A); ischaemic cardiomyopathy with reduced EF (group B); hypertrophic/infiltrative cardiomyopathy (group C). Values of 3D strain were plotted vs. volume for each frame to build a strain-volume curve for each case. Peak of radial, longitudinal, and circumferential systolic strain (Rεp, Lεp, and Cεp, respectively), slopes of the curves (RεSl, LεSl, CεSl), and strain to end-diastolic volume (EDV) ratio (Rε/V, Lε/V, Cε/V) were computed for the analysis. Strain-volume curves of the CNT group were steep and clustered, whereas, due to progressive dilatation and reduction of strains, progressive flattening could be demonstrated in groups A and B. Quantitative data supported visual assessment with progressive lower slopes (P< 0.05 for RεSl, CεSl, P= 0.06 for LεSl) and significantly lower ratios (P< 0.01 for Rε/V, Lε/V, and Cε/V). Group C showed an opposite behaviour with slopes and ratios close to those of normal subjects. Correlation coefficients between EDV and slopes of the curves were significant for all the directions of strain (CεSl: r = 0.891; RєSl: r = 0.704; LєSl: r = 0.833; P< 0.0001 for all). CONCLUSION We measured left ventricular volumes and strain by 3D-echo and obtained strain-volume curve to evaluate their behaviour in remodelling. A distinctive and progressive pattern consistent with pathophysiology was observed. The analysis here shown could represent a new non-invasive method to assess myocardial mechanics and its relationship with volumes.
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Affiliation(s)
- Alessio Lilli
- UO Cardiology, Versilia Hospital, Via Aurelia 335, Lido Di Camaiore, Italy.
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Donal E, Leclercq C, Daubert JC. Prediction of the Response to Cardiac Resynchronization Therapy: Is it Worthwhile Doing an Echocardiography and Looking for Mechanical Dyssynchrony? J Card Fail 2011; 17:403-4. [DOI: 10.1016/j.cardfail.2011.01.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2011] [Indexed: 10/18/2022]
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Iwano H, Yamada S, Watanabe M, Mitsuyama H, Nishino H, Yokoyama S, Kaga S, Nishida M, Yokoshiki H, Onozuka H, Mikami T, Tsutsui H. Novel Strain Rate Index of Contractility Loss Caused by Mechanical Dyssynchrony - A Predictor of Response to Cardiac Resynchronization Therapy -. Circ J 2011; 75:2167-75. [DOI: 10.1253/circj.cj-10-1099] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Hiroyuki Iwano
- Department of Cardiovascular Medicine, Hokkaido University Graduate School of Medicine
| | - Satoshi Yamada
- Department of Cardiovascular Medicine, Hokkaido University Graduate School of Medicine
| | - Masaya Watanabe
- Department of Cardiovascular Medicine, Hokkaido University Graduate School of Medicine
| | - Hirofumi Mitsuyama
- Department of Cardiovascular Medicine, Hokkaido University Graduate School of Medicine
| | - Hisao Nishino
- Division of Clinical Laboratory and Transfusion Medicine, Hokkaido University Hospital
| | - Shinobu Yokoyama
- Division of Clinical Laboratory and Transfusion Medicine, Hokkaido University Hospital
| | - Sanae Kaga
- Division of Clinical Laboratory and Transfusion Medicine, Hokkaido University Hospital
| | - Mutsumi Nishida
- Division of Clinical Laboratory and Transfusion Medicine, Hokkaido University Hospital
| | - Hisashi Yokoshiki
- Department of Cardiovascular Medicine, Hokkaido University Graduate School of Medicine
| | | | | | - Hiroyuki Tsutsui
- Department of Cardiovascular Medicine, Hokkaido University Graduate School of Medicine
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Auricchio A, Prinzen FW. Non-Responders to Cardiac Resynchronization Therapy - The Magnitude of the Problem and the Issues -. Circ J 2011; 75:521-7. [DOI: 10.1253/circj.cj-10-1268] [Citation(s) in RCA: 170] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
| | - Frits W. Prinzen
- Department of Physiology, Cardiovascular Research Institute Maastricht
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