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Willems E, Janssens KLPM, Dekker LRC, van de Vosse FN, Cluitmans MJM, Bovendeerd PHM. Strain-controlled electrophysiological wave propagation alters in silico scar-based substrate for ventricular tachycardia. Front Physiol 2024; 15:1330157. [PMID: 38655031 PMCID: PMC11036413 DOI: 10.3389/fphys.2024.1330157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Accepted: 03/21/2024] [Indexed: 04/26/2024] Open
Abstract
Introduction: Assessing a patient's risk of scar-based ventricular tachycardia (VT) after myocardial infarction is a challenging task. It can take months to years after infarction for VT to occur. Also, if selected for ablation therapy, success rates are low. Methods: Computational ventricular models have been presented previously to support VT risk assessment and to provide ablation guidance. In this study, an extension to such virtual-heart models is proposed to phenomenologically incorporate tissue remodeling driven by mechanical load. Strain amplitudes in the heart muscle are obtained from simulations of mechanics and are used to adjust the electrical conductivity. Results: The mechanics-driven adaptation of electrophysiology resulted in a more heterogeneous distribution of propagation velocities than that of standard models, which adapt electrophysiology in the structural substrate from medical images only. Moreover, conduction slowing was not only present in such a structural substrate, but extended in the adjacent functional border zone with impaired mechanics. This enlarged the volumes with high repolarization time gradients (≥10 ms/mm). However, maximum gradient values were not significantly affected. The enlarged volumes were localized along the structural substrate border, which lengthened the line of conduction block. The prolonged reentry pathways together with conduction slowing in functional regions increased VT cycle time, such that VT was easier to induce, and the number of recommended ablation sites increased from 3 to 5 locations. Discussion: Sensitivity testing showed an accurate model of strain-dependency to be critical for low ranges of conductivity. The model extension with mechanics-driven tissue remodeling is a potential approach to capture the evolution of the functional substrate and may offer insight into the progression of VT risk over time.
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Affiliation(s)
- Evianne Willems
- Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands
| | - Koen L. P. M. Janssens
- Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands
| | - Lukas R. C. Dekker
- Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands
- Department of Cardiology, Catharina Hospital, Eindhoven, Netherlands
| | - Frans N. van de Vosse
- Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands
| | - Matthijs J. M. Cluitmans
- Maastricht University Medical Center, Maastricht, Netherlands
- Philips Research Eindhoven, Eindhoven, Netherlands
| | - Peter H. M. Bovendeerd
- Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands
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Sengupta PP, Chandrashekhar Y. Understanding Myocardial Biomechanics Through the Lens of Cardiac Imaging: A Shear Privilege. JACC Cardiovasc Imaging 2022; 15:2158-2160. [PMID: 36481089 DOI: 10.1016/j.jcmg.2022.11.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Critical Evaluation of Current Hypotheses for the Pathogenesis of Hypertrophic Cardiomyopathy. Int J Mol Sci 2022; 23:ijms23042195. [PMID: 35216312 PMCID: PMC8880276 DOI: 10.3390/ijms23042195] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Revised: 02/07/2022] [Accepted: 02/14/2022] [Indexed: 02/04/2023] Open
Abstract
Hereditary hypertrophic cardiomyopathy (HCM), due to mutations in sarcomere proteins, occurs in more than 1/500 individuals and is the leading cause of sudden cardiac death in young people. The clinical course exhibits appreciable variability. However, typically, heart morphology and function are normal at birth, with pathological remodeling developing over years to decades, leading to a phenotype characterized by asymmetric ventricular hypertrophy, scattered fibrosis and myofibrillar/cellular disarray with ultimate mechanical heart failure and/or severe arrhythmias. The identity of the primary mutation-induced changes in sarcomere function and how they trigger debilitating remodeling are poorly understood. Support for the importance of mutation-induced hypercontractility, e.g., increased calcium sensitivity and/or increased power output, has been strengthened in recent years. However, other ideas that mutation-induced hypocontractility or non-uniformities with contractile instabilities, instead, constitute primary triggers cannot yet be discarded. Here, we review evidence for and criticism against the mentioned hypotheses. In this process, we find support for previous ideas that inefficient energy usage and a blunted Frank–Starling mechanism have central roles in pathogenesis, although presumably representing effects secondary to the primary mutation-induced changes. While first trying to reconcile apparently diverging evidence for the different hypotheses in one unified model, we also identify key remaining questions and suggest how experimental systems that are built around isolated primarily expressed proteins could be useful.
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Sharifi Kia D, Fortunato R, Maiti S, Simon MA, Kim K. An exploratory assessment of stretch-induced transmural myocardial fiber kinematics in right ventricular pressure overload. Sci Rep 2021; 11:3587. [PMID: 33574400 PMCID: PMC7878470 DOI: 10.1038/s41598-021-83154-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Accepted: 01/22/2021] [Indexed: 01/30/2023] Open
Abstract
Right ventricular (RV) remodeling and longitudinal fiber reorientation in the setting of pulmonary hypertension (PH) affects ventricular structure and function, eventually leading to RV failure. Characterizing the kinematics of myocardial fibers helps better understanding the underlying mechanisms of fiber realignment in PH. In the current work, high-frequency ultrasound imaging and structurally-informed finite element (FE) models were employed for an exploratory evaluation of the stretch-induced kinematics of RV fibers. Image-based experimental evaluation of fiber kinematics in porcine myocardium revealed the capability of affine assumptions to effectively approximate myofiber realignment in the RV free wall. The developed imaging framework provides a noninvasive modality to quantify transmural RV myofiber kinematics in large animal models. FE modeling results demonstrated that chronic pressure overload, but not solely an acute rise in pressures, results in kinematic shift of RV fibers towards the longitudinal direction. Additionally, FE simulations suggest a potential protective role for concentric hypertrophy (increased wall thickness) against fiber reorientation, while eccentric hypertrophy (RV dilation) resulted in longitudinal fiber realignment. Our study improves the current understanding of the role of different remodeling events involved in transmural myofiber reorientation in PH. Future experimentations are warranted to test the model-generated hypotheses.
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Affiliation(s)
- Danial Sharifi Kia
- grid.21925.3d0000 0004 1936 9000Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA USA
| | - Ronald Fortunato
- grid.21925.3d0000 0004 1936 9000Department of Mechanical Engineering and Materials Science, University of Pittsburgh, Pittsburgh, PA USA
| | - Spandan Maiti
- grid.21925.3d0000 0004 1936 9000Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA USA ,grid.21925.3d0000 0004 1936 9000Department of Mechanical Engineering and Materials Science, University of Pittsburgh, Pittsburgh, PA USA
| | - Marc A. Simon
- grid.21925.3d0000 0004 1936 9000Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA USA ,grid.21925.3d0000 0004 1936 9000Division of Cardiology, Department of Medicine, University of Pittsburgh School of Medicine, 623A Scaife Hall, 3550 Terrace Street, Pittsburgh, PA 15213 USA ,grid.412689.00000 0001 0650 7433Heart and Vascular Institute, University of Pittsburgh Medical Center (UPMC), Pittsburgh, PA USA ,grid.412689.00000 0001 0650 7433Pittsburgh Heart, Lung, Blood and Vascular Medicine Institute, University of Pittsburgh and University of Pittsburgh Medical Center (UPMC), Pittsburgh, PA USA ,grid.21925.3d0000 0004 1936 9000McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA USA
| | - Kang Kim
- grid.21925.3d0000 0004 1936 9000Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA USA ,grid.21925.3d0000 0004 1936 9000Department of Mechanical Engineering and Materials Science, University of Pittsburgh, Pittsburgh, PA USA ,grid.21925.3d0000 0004 1936 9000Division of Cardiology, Department of Medicine, University of Pittsburgh School of Medicine, 623A Scaife Hall, 3550 Terrace Street, Pittsburgh, PA 15213 USA ,grid.412689.00000 0001 0650 7433Heart and Vascular Institute, University of Pittsburgh Medical Center (UPMC), Pittsburgh, PA USA ,grid.412689.00000 0001 0650 7433Pittsburgh Heart, Lung, Blood and Vascular Medicine Institute, University of Pittsburgh and University of Pittsburgh Medical Center (UPMC), Pittsburgh, PA USA ,grid.21925.3d0000 0004 1936 9000McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA USA ,grid.21925.3d0000 0004 1936 9000Center for Ultrasound Molecular Imaging and Therapeutics, University of Pittsburgh, Pittsburgh, PA USA
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Quinn TA, Kohl P. Cardiac Mechano-Electric Coupling: Acute Effects of Mechanical Stimulation on Heart Rate and Rhythm. Physiol Rev 2020; 101:37-92. [PMID: 32380895 DOI: 10.1152/physrev.00036.2019] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The heart is vital for biological function in almost all chordates, including humans. It beats continually throughout our life, supplying the body with oxygen and nutrients while removing waste products. If it stops, so does life. The heartbeat involves precise coordination of the activity of billions of individual cells, as well as their swift and well-coordinated adaption to changes in physiological demand. Much of the vital control of cardiac function occurs at the level of individual cardiac muscle cells, including acute beat-by-beat feedback from the local mechanical environment to electrical activity (as opposed to longer term changes in gene expression and functional or structural remodeling). This process is known as mechano-electric coupling (MEC). In the current review, we present evidence for, and implications of, MEC in health and disease in human; summarize our understanding of MEC effects gained from whole animal, organ, tissue, and cell studies; identify potential molecular mediators of MEC responses; and demonstrate the power of computational modeling in developing a more comprehensive understanding of ‟what makes the heart tick.ˮ.
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Affiliation(s)
- T Alexander Quinn
- Department of Physiology and Biophysics and School of Biomedical Engineering, Dalhousie University, Halifax, Nova Scotia, Canada; Institute for Experimental Cardiovascular Medicine, University Heart Centre Freiburg/Bad Krozingen, Medical Faculty of the University of Freiburg, Freiburg, Germany; and CIBSS-Centre for Integrative Biological Signalling Studies, University of Freiburg, Freiburg, Germany
| | - Peter Kohl
- Department of Physiology and Biophysics and School of Biomedical Engineering, Dalhousie University, Halifax, Nova Scotia, Canada; Institute for Experimental Cardiovascular Medicine, University Heart Centre Freiburg/Bad Krozingen, Medical Faculty of the University of Freiburg, Freiburg, Germany; and CIBSS-Centre for Integrative Biological Signalling Studies, University of Freiburg, Freiburg, Germany
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Cadeddu Dessalvi C, Deidda M, Farci S, Longu G, Mercuro G. Early ischemia identification employing 2D speckle tracking selective layers analysis during dobutamine stress echocardiography. Echocardiography 2019; 36:2202-2208. [PMID: 31742770 DOI: 10.1111/echo.14535] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 08/30/2019] [Accepted: 10/04/2019] [Indexed: 12/21/2022] Open
Abstract
PURPOSE Two-dimensional (2D) strain derived from speckle tracking proved to be feasible and accurate in the quantitative evaluation of myocardial ischemia during stress echocardiography. We compared the accuracy in detecting myocardial ischemia of the transmural segmental analysis with an endocardial specific evaluation in 20 patients undergoing dobutamine stress echocardiography (DSE) and coronary angiography. METHODS Peak systolic global strain (G-ε) and at the subendocardial level (Endo-ε) were measured off-line at rest, a low dose, and peak stress; then, we compared the results with wall-motion analysis and significant coronary artery disease (CAD > 70% diameter stenosis). Endocardial strain variation from basal to low and peak dose was computed both for global or subendocardial analysis. The utilization of the ROC curve allowed us to derive optimal cutoffs, sensibility and specificity for ischemic segments. RESULTS The subendocardial analysis at high dose showed to be able to increase significantly the accuracy of the test to detect the ischemic segments (sens 90.2% vs 85.4%; spec 93.1% vs 92.2%). Moreover, at the low dose, the subendocardial analysis showed to be able to increase significantly, mostly the specificity of the test (sens 69.6% vs 68.3%; spec 92.2% vs 86.2%). Notably, the strain subendocardial analysis at low dose showed to reach a high specificity, similar to the peak dose transmural analysis. CONCLUSIONS Measurement of subendocardial strain during DSE is feasible and can increase the accuracy of the test. Moreover, the subendocardial strain during DSE can reach a high specificity, even limiting the test at a low dose infusion.
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Affiliation(s)
| | - Martino Deidda
- Department of Medical Sciences and Public Health, University of Cagliari, Cagliari, Italy
| | - Salvatore Farci
- Azienda Ospedaliero-Universitaria di Cagliari - Clinica Cardiologica, Monserrato-Cagliari, Italy
| | - Giorgio Longu
- Department of Medical Sciences and Public Health, University of Cagliari, Cagliari, Italy
| | - Giuseppe Mercuro
- Department of Medical Sciences and Public Health, University of Cagliari, Cagliari, Italy
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Gsell MAF, Augustin CM, Prassl AJ, Karabelas E, Fernandes JF, Kelm M, Goubergrits L, Kuehne T, Plank G. Assessment of wall stresses and mechanical heart power in the left ventricle: Finite element modeling versus Laplace analysis. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2018; 34:e3147. [PMID: 30151998 PMCID: PMC6492182 DOI: 10.1002/cnm.3147] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 07/19/2018] [Accepted: 08/14/2018] [Indexed: 05/30/2023]
Abstract
INTRODUCTION Stenotic aortic valve disease (AS) causes pressure overload of the left ventricle (LV) that may trigger adverse remodeling and precipitate progression towards heart failure (HF). As myocardial energetics can be impaired during AS, LV wall stresses and biomechanical power provide a complementary view of LV performance that may aide in better assessing the state of disease. OBJECTIVES Using a high-resolution electro-mechanical (EM) in silico model of the LV as a reference, we evaluated clinically feasible Laplace-based methods for assessing global LV wall stresses and biomechanical power. METHODS We used N = 4 in silico finite element (FE) EM models of LV and aorta of patients suffering from AS. All models were personalized with clinical data under pretreatment conditions. Left ventricle wall stresses and biomechanical power were computed accurately from FE kinematic data and compared with Laplace-based estimation methods, which were applied to the same FE model data. RESULTS AND CONCLUSION Laplace estimates of LV wall stress are able to provide a rough approximation of global mean stress in the circumferential-longitudinal plane of the LV. However, according to FE results, spatial heterogeneity of stresses in the LV wall is significant, leading to major discrepancies between local stresses and global mean stress. Assessment of mechanical power with Laplace methods is feasible, but these are inferior in accuracy compared with FE models. The accurate assessment of stress and power density distribution in the LV wall is only feasible based on patient-specific FE modeling.
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Affiliation(s)
| | - Christoph M. Augustin
- Institute of BiophysicsMedical University of GrazGrazAustria
- Department of Mechanical EngineeringUniversity of CaliforniaBerkleyCalifornia
| | - Anton J. Prassl
- Institute of BiophysicsMedical University of GrazGrazAustria
| | - Elias Karabelas
- Institute of BiophysicsMedical University of GrazGrazAustria
| | - Joao F. Fernandes
- Institute for Cardiovascular Computer‐assisted MedicineCharité ‐ Universitätsmedizin BerlinBerlinGermany
| | - Marcus Kelm
- Institute for Cardiovascular Computer‐assisted MedicineCharité ‐ Universitätsmedizin BerlinBerlinGermany
- Department of Congenital Heart Disease/Pediatric CardiologyGerman Heart Institute BerlinBerlinGermany
| | - Leonid Goubergrits
- Institute for Cardiovascular Computer‐assisted MedicineCharité ‐ Universitätsmedizin BerlinBerlinGermany
| | - Titus Kuehne
- Institute for Cardiovascular Computer‐assisted MedicineCharité ‐ Universitätsmedizin BerlinBerlinGermany
- Department of Congenital Heart Disease/Pediatric CardiologyGerman Heart Institute BerlinBerlinGermany
| | - Gernot Plank
- Institute of BiophysicsMedical University of GrazGrazAustria
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Khokhlova A, Balakina-Vikulova N, Katsnelson L, Iribe G, Solovyova O. Transmural cellular heterogeneity in myocardial electromechanics. J Physiol Sci 2018; 68:387-413. [PMID: 28573594 PMCID: PMC10717105 DOI: 10.1007/s12576-017-0541-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Accepted: 04/24/2017] [Indexed: 12/22/2022]
Abstract
Myocardial heterogeneity is an attribute of the normal heart. We have developed integrative models of cardiomyocytes from the subendocardial (ENDO) and subepicardial (EPI) ventricular regions that take into account experimental data on specific regional features of intracellular electromechanical coupling in the guinea pig heart. The models adequately simulate experimental data on the differences in the action potential and contraction between the ENDO and EPI cells. The modeling results predict that heterogeneity in the parameters of calcium handling and myofilament mechanics in isolated ENDO and EPI cardiomyocytes are essential to produce the differences in Ca2+ transients and contraction profiles via cooperative mechanisms of mechano-calcium-electric feedback and may further slightly modulate transmural differences in the electrical properties between the cells. Simulation results predict that ENDO cells have greater sensitivity to changes in the mechanical load than EPI cells. These data are important for understanding the behavior of cardiomyocytes in the intact heart.
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Affiliation(s)
- Anastasia Khokhlova
- Ural Federal University, Ekaterinburg, Russia.
- Institute of Immunology and Physiology, Russian Academy of Sciences, 106 Pervomayskaya, Ekaterinburg, 620049, Russia.
| | - Nathalie Balakina-Vikulova
- Ural Federal University, Ekaterinburg, Russia
- Institute of Immunology and Physiology, Russian Academy of Sciences, 106 Pervomayskaya, Ekaterinburg, 620049, Russia
| | - Leonid Katsnelson
- Ural Federal University, Ekaterinburg, Russia
- Institute of Immunology and Physiology, Russian Academy of Sciences, 106 Pervomayskaya, Ekaterinburg, 620049, Russia
| | - Gentaro Iribe
- Okayama University, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama, 700-8558, Japan
| | - Olga Solovyova
- Ural Federal University, Ekaterinburg, Russia
- Institute of Immunology and Physiology, Russian Academy of Sciences, 106 Pervomayskaya, Ekaterinburg, 620049, Russia
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Khokhlova A, Iribe G, Katsnelson L, Naruse K, Solovyova O. The effects of load on transmural differences in contraction of isolated mouse ventricular cardiomyocytes. J Mol Cell Cardiol 2017; 114:276-287. [PMID: 29217431 DOI: 10.1016/j.yjmcc.2017.12.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 12/01/2017] [Indexed: 12/31/2022]
Abstract
Mechanical properties of cardiomyocytes from different transmural regions are heterogeneous in the left ventricular wall. The cardiomyocyte mechanical environment affects this heterogeneity because of mechano-electric feedback mechanisms. In the present study, we investigated the effects of the mechanical load (preload and afterload) on transmural differences in contraction of subendocardial (ENDO) and subepicardial (EPI) single cells isolated from the murine left ventricle. Various preloads imposed via axial stretch and afterloads (unloaded and heavy loaded conditions) were applied to the cells using carbon fiber techniques for single myocytes. To simulate experimentally obtained results and to predict mechanisms underlying the cellular response to change in load, our mathematical models of the ENDO and EPI cells were used. Our major findings are the following. Our results show that ENDO and EPI cardiomyocytes have different mechanical responses to changes in preload to the cells. Under auxotonic contractions at low preload (unstretched cells), time to peak contraction (Tmax) and the time constant of [Ca2+]i transient decay were significantly longer in ENDO cells than in EPI cells. An increase in preload (stretched cells) prolonged Tmax in both cell types; however, the prolongation was greater in EPI cells, resulting in a decrease in the transmural gradient in Tmax at high preload. Comparing unloaded and heavy loaded (isometric) contractions of the cells we found that transmural gradient in the time course of contraction is independent of the loading conditions. Our mathematical cell models were able to reproduce the experimental results on the distinct cellular responses to changes in the mechanical load when we accounted for an ENDO/EPI difference in the parameters of cooperativity of calcium activation of myofilaments.
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Affiliation(s)
- Anastasia Khokhlova
- Ural Federal University, Mira 19, 620002 Ekaterinburg, Russia; Institute of Immunology and Physiology, Russian Academy of Sciences, Pervomajskaya 106, 620049 Ekaterinburg, Russia.
| | - Gentaro Iribe
- Okayama University, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Shikata cho 2-5-1, 1700-8558 Okayama, Japan
| | - Leonid Katsnelson
- Ural Federal University, Mira 19, 620002 Ekaterinburg, Russia; Institute of Immunology and Physiology, Russian Academy of Sciences, Pervomajskaya 106, 620049 Ekaterinburg, Russia
| | - Keiji Naruse
- Okayama University, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Shikata cho 2-5-1, 1700-8558 Okayama, Japan
| | - Olga Solovyova
- Ural Federal University, Mira 19, 620002 Ekaterinburg, Russia; Institute of Immunology and Physiology, Russian Academy of Sciences, Pervomajskaya 106, 620049 Ekaterinburg, Russia; Institute of Mathematics and Mechanics, Russian Academy of Sciences, Kovalevskaya 16, 620990 Ekaterinburg, Russia
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10
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Khokhlova A, Balakina-Vikulova N, Katsnelson L, Solovyova O. Effects of cellular electromechanical coupling on functional heterogeneity in a one-dimensional tissue model of the myocardium. Comput Biol Med 2017; 84:147-155. [PMID: 28364644 DOI: 10.1016/j.compbiomed.2017.03.021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Revised: 02/28/2017] [Accepted: 03/21/2017] [Indexed: 11/25/2022]
Abstract
Based on the experimental evidence, we developed a one-dimensional (1D) model of heterogeneous myocardial tissue consisting of in-series connected cardiomyocytes from distant transmural regions using mathematical models of subendocardial and subepicardial cells. The regional deformation patterns produced by our 1D model are consistent with the transmural regional strain patterns obtained experimentally in the normal heart in vivo. The modelling results suggest that the mechanical load may essentially affect the transmural gradients in the electrical and mechanical properties of interacting myocytes within a tissue, thereby regulating global myocardial output.
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Affiliation(s)
- Anastasia Khokhlova
- Ural Federal University, Ekaterinburg, Russia; Institute of Immunology and Physiology, Russian Academy of Sciences, Ekaterinburg, Russia.
| | - Nathalie Balakina-Vikulova
- Ural Federal University, Ekaterinburg, Russia; Institute of Immunology and Physiology, Russian Academy of Sciences, Ekaterinburg, Russia
| | - Leonid Katsnelson
- Ural Federal University, Ekaterinburg, Russia; Institute of Immunology and Physiology, Russian Academy of Sciences, Ekaterinburg, Russia
| | - Olga Solovyova
- Ural Federal University, Ekaterinburg, Russia; Institute of Immunology and Physiology, Russian Academy of Sciences, Ekaterinburg, Russia
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11
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Richardson RV, Batchen EJ, Thomson AJW, Darroch R, Pan X, Rog-Zielinska EA, Wyrzykowska W, Scullion K, Al-Dujaili EAS, Diaz ME, Moran CM, Kenyon CJ, Gray GA, Chapman KE. Glucocorticoid receptor alters isovolumetric contraction and restrains cardiac fibrosis. J Endocrinol 2017; 232:437-450. [PMID: 28057868 PMCID: PMC5292999 DOI: 10.1530/joe-16-0458] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Accepted: 01/05/2017] [Indexed: 01/17/2023]
Abstract
Corticosteroids directly affect the heart and vasculature and are implicated in the pathogenesis of heart failure. Attention is focussed upon the role of the mineralocorticoid receptor (MR) in mediating pro-fibrotic and other adverse effects of corticosteroids upon the heart. In contrast, the role of the glucocorticoid receptor (GR) in the heart and vasculature is less well understood. We addressed this in mice with cardiomyocyte and vascular smooth muscle deletion of GR (SMGRKO mice). Survival of SMGRKO mice to weaning was reduced compared with that of littermate controls. Doppler measurements of blood flow across the mitral valve showed an elongated isovolumetric contraction time in surviving adult SMGRKO mice, indicating impairment of the initial left ventricular contractile phase. Although heart weight was elevated in both genders, only male SMGRKO mice showed evidence of pathological cardiomyocyte hypertrophy, associated with increased myosin heavy chain-β expression. Left ventricular fibrosis, evident in both genders, was associated with elevated levels of mRNA encoding MR as well as proteins involved in cardiac remodelling and fibrosis. However, MR antagonism with spironolactone from birth only modestly attenuated the increase in pro-fibrotic gene expression in SMGRKO mice, suggesting that elevated MR signalling is not the primary driver of cardiac fibrosis in SMGRKO mice, and cardiac fibrosis can be dissociated from MR activation. Thus, GR contributes to systolic function and restrains normal cardiac growth, the latter through gender-specific mechanisms. Our findings suggest the GR:MR balance is critical in corticosteroid signalling in specific cardiac cell types.
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MESH Headings
- Animals
- Corticosterone/blood
- Female
- Fibrosis/metabolism
- Fibrosis/pathology
- Male
- Mice
- Mice, Knockout
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- Muscle, Smooth, Vascular/pathology
- Myocardial Contraction/genetics
- Myocardium/metabolism
- Myocardium/pathology
- Myocytes, Cardiac/drug effects
- Myocytes, Cardiac/metabolism
- Myocytes, Cardiac/pathology
- Myosin Heavy Chains/genetics
- Myosin Heavy Chains/metabolism
- Nonmuscle Myosin Type IIB/genetics
- Nonmuscle Myosin Type IIB/metabolism
- Receptors, Glucocorticoid/genetics
- Receptors, Glucocorticoid/metabolism
- Sex Factors
- Spironolactone/pharmacology
- Ventricular Function, Left/genetics
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Affiliation(s)
- Rachel V Richardson
- University/BHF Centre for Cardiovascular ScienceUniversity of Edinburgh, The Queen's Medical Research Institute, Edinburgh, UK
| | - Emma J Batchen
- University/BHF Centre for Cardiovascular ScienceUniversity of Edinburgh, The Queen's Medical Research Institute, Edinburgh, UK
| | | | - Rowan Darroch
- University/BHF Centre for Cardiovascular ScienceUniversity of Edinburgh, The Queen's Medical Research Institute, Edinburgh, UK
| | - Xinlu Pan
- University/BHF Centre for Cardiovascular ScienceUniversity of Edinburgh, The Queen's Medical Research Institute, Edinburgh, UK
| | - Eva A Rog-Zielinska
- University/BHF Centre for Cardiovascular ScienceUniversity of Edinburgh, The Queen's Medical Research Institute, Edinburgh, UK
| | - Wiktoria Wyrzykowska
- University/BHF Centre for Cardiovascular ScienceUniversity of Edinburgh, The Queen's Medical Research Institute, Edinburgh, UK
| | - Kathleen Scullion
- University/BHF Centre for Cardiovascular ScienceUniversity of Edinburgh, The Queen's Medical Research Institute, Edinburgh, UK
| | - Emad A S Al-Dujaili
- DieteticsNutrition, and Biological Sciences Department, Queen Margaret University, Musselburgh, UK
| | - Mary E Diaz
- University/BHF Centre for Cardiovascular ScienceUniversity of Edinburgh, The Queen's Medical Research Institute, Edinburgh, UK
| | - Carmel M Moran
- University/BHF Centre for Cardiovascular ScienceUniversity of Edinburgh, The Queen's Medical Research Institute, Edinburgh, UK
- Edinburgh Preclinical ImagingUniversity of Edinburgh, Edinburgh, UK
| | - Christopher J Kenyon
- University/BHF Centre for Cardiovascular ScienceUniversity of Edinburgh, The Queen's Medical Research Institute, Edinburgh, UK
| | - Gillian A Gray
- University/BHF Centre for Cardiovascular ScienceUniversity of Edinburgh, The Queen's Medical Research Institute, Edinburgh, UK
| | - Karen E Chapman
- University/BHF Centre for Cardiovascular ScienceUniversity of Edinburgh, The Queen's Medical Research Institute, Edinburgh, UK
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12
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Mądry W, Karolczak MA. Physiological basis in the assessment of myocardial mechanics using speckle-tracking echocardiography 2D. Part I. J Ultrason 2016; 16:135-44. [PMID: 27446598 PMCID: PMC4954859 DOI: 10.15557/jou.2016.0015] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Revised: 09/22/2015] [Accepted: 10/05/2015] [Indexed: 11/22/2022] Open
Abstract
In this paper, the authors attempt to concisely present the anatomical and pathophysiological bases as well as the principles for echocardiographic evaluation of mechanical aspects of cardiac function based on speckle tracking method. This technique uses a phenomenon involving the formation of characteristic image units, referred to as speckles or acoustic markers, which are stable during cardiac cycle, on a two-dimensional echocardiographic picture. Changes in the position of these speckles throughout the cardiac cycle, which are monitored and analyzed semi-automatically by a computer system, reflect deformation of both, cardiac ventricle as a whole as well as its individual anatomical segments. The values of strain and the strain rate, as well as the range and velocity of the movement of these markers, which are in close relationship with multiple hemodynamic parameters, can be visualized as various types of charts – linear, two- and three-dimensional – as well as numerical values, enabling deeper insight into the mechanical and hemodynamic aspects of cardiac function in health and disease. The use of information obtained based on speckle tracking echocardiography allows to understand previously unclear mechanisms of physiological and pathophysiological processes. The first part of the study discusses the formation of a two-dimensional ultrasound image and the speckles, as well as the technical aspects of tracking their movement. The second part presents in more detail the methodology of speckle-tracking echocardiography, the characteristic abnormalities of cardiac mechanics presenting in different clinical entities, and the limitations related to given clinical and technical issues.
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Affiliation(s)
- Wojciech Mądry
- Department of Cardiac and General Pediatric Surgery, Warsaw Medical University Independent Public Paediatric Clinical Hospital in Warsaw, Poland
| | - Maciej Aleksander Karolczak
- Department of Cardiac and General Pediatric Surgery, Warsaw Medical University Independent Public Paediatric Clinical Hospital in Warsaw, Poland
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13
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Sun JP, Xu T, Yang Y, Yang XS, Shang Q, Li Y, Wang J, Yan BP. Layer-specific quantification of myocardial deformation may disclose the subclinical systolic dysfunction and the mechanism of preserved ejection fraction in patients with hypertension. Int J Cardiol 2016; 219:172-6. [PMID: 27327503 DOI: 10.1016/j.ijcard.2016.06.035] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Accepted: 06/12/2016] [Indexed: 11/29/2022]
Affiliation(s)
- Jing Ping Sun
- Department of Medicine and Therapeutics, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, NT., Hong Kong
| | - Tingyan Xu
- The Shanghai Institute of Hypertension, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Yan Yang
- The Shanghai Institute of Hypertension, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Xing Sheng Yang
- Department of Medicine and Therapeutics, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, NT., Hong Kong
| | - Qing Shang
- Department of Medicine and Therapeutics, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, NT., Hong Kong
| | - Yan Li
- The Shanghai Institute of Hypertension, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Jiguang Wang
- The Shanghai Institute of Hypertension, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Bryan P Yan
- Department of Medicine and Therapeutics, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, NT., Hong Kong.
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14
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Colquitt JL, Pignatelli RH. Strain Imaging: The Emergence of Speckle Tracking Echocardiography into Clinical Pediatric Cardiology. CONGENIT HEART DIS 2016; 11:199-207. [DOI: 10.1111/chd.12334] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 12/23/2015] [Indexed: 01/04/2023]
Affiliation(s)
- John L. Colquitt
- Section of Cardiology, Department of Pediatrics, Texas Children's Hospital; Baylor College of Medicine; Houston Tex USA
| | - Ricardo H. Pignatelli
- Section of Cardiology, Department of Pediatrics, Texas Children's Hospital; Baylor College of Medicine; Houston Tex USA
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15
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Rai ABS, Lima E, Munir F, Faisal Khan A, Waqas A, Bughio S, ul Haq E, Attique HB, Rahman ZU. Speckle Tracking Echocardiography of the Right Atrium: The Neglected Chamber. Clin Cardiol 2015; 38:692-7. [PMID: 26418622 DOI: 10.1002/clc.22438] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Revised: 06/25/2015] [Accepted: 06/29/2015] [Indexed: 12/15/2022] Open
Abstract
The right atrium (RA) plays a pivotal role in electromechanical and endocrine regulation of the heart. Its peculiar anatomical features and phasic mechanical function make it distinct from ventricles. Various invasive and noninvasive techniques have been used to elucidate RA structure and function. Of these modalities, echocardiography has distinct advantages over others. Several conventional measures of RA function through echocardiography have been described in the literature, but they are load dependent. A relatively new technique is speckle tracking-derived strain, which is relatively less dependent on loading conditions. Speckle tracking echocardiography tracks acoustic scatters (speckles) of myocardium frame-by-frame to calculate strain or deformation of the myocardium. Speckle tracking echocardiography has been used extensively for strain assessment of the right and left ventricle to detect subtle disease pathology, to gain mechanistic insight, as a marker of ischemic metabolic memory, as an endpoint in clinical trials, and as a functional assessment tool. The RA is a relatively neglected chamber, as it is mostly studied for assessment of atrial mass lesions, for electrophysiological studies, and in animal models for physiological assessment. However, its role in the systolic and diastolic function of the right heart, pulmonary vascular pathology, congenital heart diseases, and combined electromechanical activation phenomena has been less explored or unexplored. Speckle tracking echocardiography is an ideal tool for the assessment of the RA because of its regional and global functional characterization, angle independence, and high temporal resolution.
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Affiliation(s)
| | - Eduardo Lima
- Department of cardiovascular medicine, University of Oxford, Oxford, United Kingdom
| | - Farrukh Munir
- Department of Internal Medicine, King Edward Medical University, Lahore, Pakistan
| | - Anum Faisal Khan
- Department of Internal Medicine, King Edward Medical University, Lahore, Pakistan
| | - Ahmed Waqas
- Medical Student, CMH Lahore Medical College & Institue of Dentistry, Lahore, Pakistan
| | - Sara Bughio
- Department of Internal Medicine, Bronx-Lebanon Hospital Center, Bronx, New York
| | - Ehtesham ul Haq
- Department of Cardiology, University of South Alabama, Mobile, Alabama
| | - Hassan Bin Attique
- Department of Internal Medicine, Hammad Medical Corporation, Doha, Qatar
| | - Zia Ur Rahman
- Department of Internal Medicine, East Tennessee State University, Johnson City, Tennessee
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16
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Ntelios D, Tzimagiorgis G, Efthimiadis GK, Karvounis H. Mechanical aberrations in hypetrophic cardiomyopathy: emerging concepts. Front Physiol 2015; 6:232. [PMID: 26347658 PMCID: PMC4541419 DOI: 10.3389/fphys.2015.00232] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Accepted: 08/03/2015] [Indexed: 11/13/2022] Open
Abstract
Hypertrophic cardiomyopathy is the most common monogenic disorder in cardiology. Despite important advances in understanding disease pathogenesis, it is not clear how flaws in individual sarcomere components are responsible for the observed phenotype. The aim of this article is to provide a brief interpretative analysis of some currently proposed pathophysiological mechanisms of hypertrophic cardiomyopathy, with a special emphasis on alterations in the cardiac mechanical properties.
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Affiliation(s)
- Dimitrios Ntelios
- Laboratory of Biological Chemistry, Medical School, Aristotle University of Thessaloniki Thessaloniki, Greece ; Department of Cardiology, AHEPA University Hospital Thessaloniki, Greece
| | - Georgios Tzimagiorgis
- Laboratory of Biological Chemistry, Medical School, Aristotle University of Thessaloniki Thessaloniki, Greece
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17
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Omar AMS, Abdel-Rahman MA, Khorshid H, Helmy M, Raslan H, Rifaie O. Tissue Doppler-Derived Myocardial Acceleration during Isovolumetric Contraction Predicts Pulmonary Capillary Wedge Pressure in Patients with Significant Mitral Regurgitation. ULTRASOUND IN MEDICINE & BIOLOGY 2015; 41:2108-2118. [PMID: 25944284 DOI: 10.1016/j.ultrasmedbio.2015.03.031] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2014] [Revised: 03/28/2015] [Accepted: 03/31/2015] [Indexed: 06/04/2023]
Abstract
The aim of this study was to determine whether isovolumic contraction velocity (IVV) and acceleration (IVA) predict pulmonary capillary wedge pressure (PCWP) in mitral regurgitation. Forty-four patients with mitral regurgitation were studied. PCWP was invasively measured. IVV, IVA and the ratio IVRT/Te'-E (where IVRT = isovolumic relaxation time, and Te'-E = time difference between the onset of mitral annular e' and mitral flow E waves) were measured. Mean age was 59.2 ± 13.3 y. Twenty-six patients had an ejection fraction ≥55%, and 18 patients had an ejection fraction <55%. IVRT/Te'-E was impossible in 11 patients because Te'-E = zero. PCWP correlated with IVV, IVA and IVRT/Te'-E; overall (r = -0.714, -0.892 and, -0.752, all p < 0.001), ejection fraction ≥55 (r = -0.467, -0.749, -0.639, p = 0.016, <0.001, 0.003) and ejection fraction <55% (r = -0.761, -0.911 and -0.833, all p < 0.001). Similar correlations were found for sinus and atrial fibrillation. Our study suggests that IVV and IVA correlate with PCWP in patients with mitral regurgitation irrespective of systolic function or rhythms and, thus, can be alternatives to the tedious IVRT/Te'-E, especially when impossible because Te'-E = 0.
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Affiliation(s)
- Alaa Mabrouk Salem Omar
- Medical Division, Department of Internal Medicine, National Research Centre, Dokki, Cairo, Egypt.
| | | | - Hazem Khorshid
- Department of Cardiology, Ain Shams University, Abbasiya, Cairo, Egypt
| | - Mostafa Helmy
- Department of Cardiology, Ain Shams University, Abbasiya, Cairo, Egypt
| | - Hala Raslan
- Medical Division, Department of Internal Medicine, National Research Centre, Dokki, Cairo, Egypt
| | - Osama Rifaie
- Department of Cardiology, Ain Shams University, Abbasiya, Cairo, Egypt
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18
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Nordbø Ø, Gjuvsland AB, Nermoen A, Land S, Niederer S, Lamata P, Lee J, Smith NP, Omholt SW, Vik JO. Towards causally cohesive genotype-phenotype modelling for characterization of the soft-tissue mechanics of the heart in normal and pathological geometries. J R Soc Interface 2015; 12:rsif.2014.1166. [PMID: 25833237 DOI: 10.1098/rsif.2014.1166] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
A scientific understanding of individual variation is key to personalized medicine, integrating genotypic and phenotypic information via computational physiology. Genetic effects are often context-dependent, differing between genetic backgrounds or physiological states such as disease. Here, we analyse in silico genotype-phenotype maps (GP map) for a soft-tissue mechanics model of the passive inflation phase of the heartbeat, contrasting the effects of microstructural and other low-level parameters assumed to be genetically influenced, under normal, concentrically hypertrophic and eccentrically hypertrophic geometries. For a large number of parameter scenarios, representing mock genetic variation in low-level parameters, we computed phenotypes describing the deformation of the heart during inflation. The GP map was characterized by variance decompositions for each phenotype with respect to each parameter. As hypothesized, the concentric geometry allowed more low-level parameters to contribute to variation in shape phenotypes. In addition, the relative importance of overall stiffness and fibre stiffness differed between geometries. Otherwise, the GP map was largely similar for the different heart geometries, with little genetic interaction between the parameters included in this study. We argue that personalized medicine can benefit from a combination of causally cohesive genotype-phenotype modelling, and strategic phenotyping that captures effect modifiers not explicitly included in the mechanistic model.
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Affiliation(s)
- Øyvind Nordbø
- Department of Mathematical Sciences and Technology, Norwegian University of Life Sciences, PO Box 5003, 1432 Ås, Norway
| | - Arne B Gjuvsland
- Department of Animal and Aquacultural Sciences, Norwegian University of Life Sciences, PO Box 5003, 1432 Ås, Norway
| | - Anders Nermoen
- International Research Institute of Stavanger, PO Box 8046, 4068 Stavanger, Norway
| | - Sander Land
- Biomedical Engineering Department, King's College London, London SE1 7EH, UK
| | - Steven Niederer
- Biomedical Engineering Department, King's College London, London SE1 7EH, UK
| | - Pablo Lamata
- Biomedical Engineering Department, King's College London, London SE1 7EH, UK
| | - Jack Lee
- Biomedical Engineering Department, King's College London, London SE1 7EH, UK
| | - Nicolas P Smith
- Biomedical Engineering Department, King's College London, London SE1 7EH, UK
| | - Stig W Omholt
- Department of Circulation and Medical Imaging, Cardiac Exercise Research Group, NTNU Norwegian University of Science and Technology, PO Box 8905, 7491 Trondheim, Norway
| | - Jon Olav Vik
- Department of Animal and Aquacultural Sciences, Norwegian University of Life Sciences, PO Box 5003, 1432 Ås, Norway
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19
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Poorly understood aspects of striated muscle contraction. BIOMED RESEARCH INTERNATIONAL 2015; 2015:245154. [PMID: 25961006 PMCID: PMC4415482 DOI: 10.1155/2015/245154] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/22/2014] [Accepted: 10/28/2014] [Indexed: 11/23/2022]
Abstract
Muscle contraction results from cyclic interactions between the contractile proteins myosin and actin, driven by the turnover of adenosine triphosphate (ATP). Despite intense studies, several molecular events in the contraction process are poorly understood, including the relationship between force-generation and phosphate-release in the ATP-turnover. Different aspects of the force-generating transition are reflected in the changes in tension development by muscle cells, myofibrils and single molecules upon changes in temperature, altered phosphate concentration, or length perturbations. It has been notoriously difficult to explain all these events within a given theoretical framework and to unequivocally correlate observed events with the atomic structures of the myosin motor. Other incompletely understood issues include the role of the two heads of myosin II and structural changes in the actin filaments as well as the importance of the three-dimensional order. We here review these issues in relation to controversies regarding basic physiological properties of striated muscle. We also briefly consider actomyosin mutation effects in cardiac and skeletal muscle function and the possibility to treat these defects by drugs.
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20
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Rossi AC, Pluijmert M, Bovendeerd PHM, Kroon W, Arts T, Delhaas T. Assessment and comparison of left ventricular shear in normal and situs inversus totalis hearts by means of magnetic resonance tagging. Am J Physiol Heart Circ Physiol 2014; 308:H416-23. [PMID: 25527777 DOI: 10.1152/ajpheart.00502.2014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Situs inversus totalis (SIT) is characterized by complete mirroring of gross cardiac anatomy and position combined with an incompletely mirrored myofiber arrangement, being normal at the apex but inverted at the base of the left ventricle (LV). This study relates myocardial structure to mechanical function by analyzing and comparing myocardial deformation patterns of normal and SIT subjects, focusing especially on circumferential-radial shear. In nine control and nine SIT normotensive human subjects, myocardial deformation was assessed from magnetic resonance tagging (MRT) image sequences of five LV short-axis slices. During ejection, no significant difference in either circumferential shortening (εcc) or its axial gradient (Δεcc) is found between corresponding LV levels in control and SIT hearts. Circumferential-radial shear (εcr) has a clear linear trend from apex-to-base in controls, while in SIT it hovers close to zero at all levels. Torsion as well as axial change in εcr (Δεcr) is as in controls in apical sections of SIT hearts but deviates significantly towards the base, changing sign close to the LV equator. Interindividual variability in torsion and Δεcr values is higher in SIT than in controls. Apex-to-base trends of torsion and Δεcr in SIT, changing sign near the LV equator, further substantiate a structural transition in myofiber arrangement close to the LV equator itself. Invariance of εcc and Δεcc patterns between controls and SIT subjects shows that normal LV pump function is achieved in SIT despite partial mirroring of myocardial structure leading to torsional and shear patterns that are far from normality.
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Affiliation(s)
- Alessandro C Rossi
- Department of Biomedical Engineering, Maastricht University, Maastricht, The Netherlands; and
| | - Marieke Pluijmert
- Department of Biomedical Engineering, Maastricht University, Maastricht, The Netherlands; and
| | - Peter H M Bovendeerd
- Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands
| | - Wilco Kroon
- Department of Biomedical Engineering, Maastricht University, Maastricht, The Netherlands; and
| | - Theo Arts
- Department of Biomedical Engineering, Maastricht University, Maastricht, The Netherlands; and
| | - Tammo Delhaas
- Department of Biomedical Engineering, Maastricht University, Maastricht, The Netherlands; and
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21
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Toward understanding the interaction between structure and function: an echocardiographic story. J Am Soc Echocardiogr 2014; 27:1051-2. [PMID: 25249510 DOI: 10.1016/j.echo.2014.08.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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22
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Solovyova O, Katsnelson LB, Konovalov PV, Kursanov AG, Vikulova NA, Kohl P, Markhasin VS. The cardiac muscle duplex as a method to study myocardial heterogeneity. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2014; 115:115-28. [PMID: 25106702 PMCID: PMC4210666 DOI: 10.1016/j.pbiomolbio.2014.07.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Accepted: 07/25/2014] [Indexed: 12/14/2022]
Abstract
This paper reviews the development and application of paired muscle preparations, called duplex, for the investigation of mechanisms and consequences of intra-myocardial electro-mechanical heterogeneity. We illustrate the utility of the underlying combined experimental and computational approach for conceptual development and integration of basic science insight with clinically relevant settings, using previously published and new data. Directions for further study are identified.
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Affiliation(s)
- O Solovyova
- Institute of Immunology and Physiology, Ural Branch of the Russian Academy of Sciences, 106 Pervomayskaya Str, Ekaterinburg 620049, Russia; Ural Federal University, 19 Mira Str, Ekaterinburg 620002, Russia.
| | - L B Katsnelson
- Institute of Immunology and Physiology, Ural Branch of the Russian Academy of Sciences, 106 Pervomayskaya Str, Ekaterinburg 620049, Russia
| | - P V Konovalov
- Institute of Immunology and Physiology, Ural Branch of the Russian Academy of Sciences, 106 Pervomayskaya Str, Ekaterinburg 620049, Russia
| | - A G Kursanov
- Institute of Immunology and Physiology, Ural Branch of the Russian Academy of Sciences, 106 Pervomayskaya Str, Ekaterinburg 620049, Russia; Ural Federal University, 19 Mira Str, Ekaterinburg 620002, Russia
| | - N A Vikulova
- Institute of Immunology and Physiology, Ural Branch of the Russian Academy of Sciences, 106 Pervomayskaya Str, Ekaterinburg 620049, Russia
| | - P Kohl
- National Heart and Lung Institute, Imperial College of London, Heart Science Centre, Harefield Hospital, Hill End Road, Harefield UB9 6JH, UK; Department of Computer Sciences, University of Oxford, UK
| | - V S Markhasin
- Institute of Immunology and Physiology, Ural Branch of the Russian Academy of Sciences, 106 Pervomayskaya Str, Ekaterinburg 620049, Russia; Ural Federal University, 19 Mira Str, Ekaterinburg 620002, Russia
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23
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Buckberg GD, Hoffman JI, Coghlan HC, Nanda NC. Ventricular structure–function relations in health and disease: Part I. The normal heart. Eur J Cardiothorac Surg 2014; 47:587-601. [DOI: 10.1093/ejcts/ezu278] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
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25
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Pluijmert M, Bovendeerd PHM, Kroon W, Prinzen FW, Delhaas T. Effects of activation pattern and active stress development on myocardial shear in a model with adaptive myofiber reorientation. Am J Physiol Heart Circ Physiol 2014; 306:H538-46. [DOI: 10.1152/ajpheart.00571.2013] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
It has been hypothesized that myofiber orientation adapts to achieve a preferred mechanical loading state in the myocardial tissue. Earlier studies tested this hypothesis in a combined model of left ventricular (LV) mechanics and remodeling of myofiber orientation in response to fiber cross-fiber shear, assuming synchronous timing of activation and uniaxial active stress development. Differences between computed and measured patterns of circumferential-radial shear strain Ecr were assumed to be caused by limitations in either the LV mechanics model or the myofiber reorientation model. Therefore, we extended the LV mechanics model with a physiological transmural and longitudinal gradient in activation pattern and with triaxial active stress development. We investigated the effects on myofiber reorientation, LV function, and deformation. The effect on the developed pattern of the transverse fiber angle αt,0 and the effect on global pump function were minor. Triaxial active stress development decreased amplitudes of Ecr towards values within the experimental range and resulted in a similar base-to-apex gradient during ejection in model computed and measured Ecr. The physiological pattern of mechanical activation resulted in better agreement between computed and measured strain in myofiber direction, especially during isovolumic contraction phase and first half of ejection. In addition, remodeling was favorable for LV pump and myofiber function. In conclusion, the outcome of the combined model of LV mechanics and remodeling of myofiber orientation is found to become more physiologic by extending the mechanics model with triaxial active stress development and physiological activation pattern.
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Affiliation(s)
- Marieke Pluijmert
- Cardiovascular Research Institute Maastricht, Departments of Biomedical Engineering/Physiology, Maastricht University, Maastricht, The Netherlands
- Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands; and
| | - Peter H. M. Bovendeerd
- Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands; and
| | - Wilco Kroon
- Institute of Computational Science, University of Lugano, Lugano, Switzerland
| | - Frits W. Prinzen
- Cardiovascular Research Institute Maastricht, Departments of Biomedical Engineering/Physiology, Maastricht University, Maastricht, The Netherlands
| | - Tammo Delhaas
- Cardiovascular Research Institute Maastricht, Departments of Biomedical Engineering/Physiology, Maastricht University, Maastricht, The Netherlands
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26
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Stöhr EJ, González-Alonso J, Bezodis IN, Shave R. Left ventricular energetics: new insight into the plasticity of regional contributions at rest and during exercise. Am J Physiol Heart Circ Physiol 2014; 306:H225-32. [DOI: 10.1152/ajpheart.00938.2012] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Although the human left ventricle (LV) operates as a functional syncytium and previous studies have reported a single value for LV stroke work at rest, more intricate plasticity of regional LV energetics may be required during enhanced cardiovascular demand. We compared kinetic energy of the LV base and apex, respectively, during ventricular contraction and relaxation at rest and during continuous and discontinuous incremental exercise. At rest, prior to both exercise trials, the accumulated kinetic energy during contraction and relaxation was significantly higher at the LV base compared with the apex ( P ≤ 0.05). With increasing exercise intensity, kinetic energy during contraction increased significantly more at the LV base (interaction effect: P < 0.0001), while kinetic energy during relaxation increased significantly more at the apex during high-intensity exercise (interaction effect: P < 0.001). Total kinetic energy produced over the entire cardiac cycle was significantly greater at the LV apex during high exercise intensities ( P < 0.05). We further show that the region-specific differences in kinetic energy at rest and during exercise are explained by significantly different wall mechanics, showing heterogenic contributions from radial, circumferential, and angular components at the base and apex, respectively. In conclusion, the present findings provide unique insight into human LV function by demonstrating that within this functional syncytium, significant differences in the regional contributions of kinetic energy to overall LV work exist. Importantly, regional contributions are not fixed but highly plastic and the underpinning LV wall energetics adjust according to the prevailing cardiovascular demand.
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Affiliation(s)
- Eric J. Stöhr
- Cardiff Metropolitan University, Cardiff, United Kingdom; and
| | - José González-Alonso
- Centre for Sports Medicine and Human Performance, Brunel University, Uxbridge, United Kingdom
| | - Ian N. Bezodis
- Cardiff Metropolitan University, Cardiff, United Kingdom; and
| | - Rob Shave
- Cardiff Metropolitan University, Cardiff, United Kingdom; and
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27
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The importance of non-uniformities in mechano-electric coupling for ventricular arrhythmias. J Interv Card Electrophysiol 2013; 39:25-35. [DOI: 10.1007/s10840-013-9852-0] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Accepted: 10/16/2013] [Indexed: 12/31/2022]
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28
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Crendal E, Walther G, Vinet A, Dutheil F, Naughton G, Lesourd B, Chapier R, Rupp T, Courteix D, Obert P. Myocardial deformation and twist mechanics in adults with metabolic syndrome: impact of cumulative metabolic burden. Obesity (Silver Spring) 2013; 21:E679-86. [PMID: 23804526 DOI: 10.1002/oby.20537] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2012] [Accepted: 05/25/2013] [Indexed: 12/15/2022]
Abstract
OBJECTIVE The aim of the study is to characterize left ventricular (LV) myocardial mechanics in adults with metabolic syndrome (MetS), and elucidate the effects of multiple risk-factors on myocardial function using speckle tracking echocardiography (STE); a more sensitive method than conventional echocardiography for detecting subclinical myocardial dysfunction. DESIGN AND METHODS Cross-sectional analyses of 92 adults (50-70 years) with MetS, and 50 healthy controls included conventional echocardiography, blood biochemistry, and STE-derived myocardial longitudinal, circumferential, and twist mechanics. RESULTS Using conventional measures, MetS participants revealed LV hypertrophy and reduced diastolic function compared with controls, while systolic function was preserved. From STE, MetS participants showed attenuated longitudinal strain (-16.8% ± 2.8% vs. -20.6% ± 2.7%), and both diastolic (1.1 ± 0.2 vs. 1.4 ± 0.3 s s(-1) ) and systolic (-1.0 ± 0.1 vs. -1.2 ± 0.2 s s(-1) ) strain rate (SR). Circumferential strain, SR, and twist mechanics did not differ. Participants with the highest number of MetS factors or diabetes demonstrated the greatest reduction in longitudinal strain and SR. Abdominal obesity, TNF-α, HbA1c , and systolic dyssynchrony explained 48% of impairment in longitudinal strain. CONCLUSIONS Impaired longitudinal myocardial diastolic and systolic function, but preserved circumferential function and twist mechanics were found in MetS participants, indicative of altered subendocardial function. This dysfunction was best predicted by abdominal obesity, inflammation, glucose-intolerance, and systolic dyssynchrony.
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Affiliation(s)
- Edward Crendal
- Avignon University, LAPEC EA4278, Avignon, France; School of Exercise Science, Australian Catholic University, Melbourne, Australia
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Lo CI, Lai YH, Wu JJ, Yun CH, Hung CL, Bulwer BE, Yeh HI. Cardiac Systolic Mechanics in Heart Failure with Preserved Ejection Fraction: New Insights and Controversies. ACTA CARDIOLOGICA SINICA 2013; 29:515-523. [PMID: 27122752 PMCID: PMC4805030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 09/12/2013] [Accepted: 10/04/2013] [Indexed: 06/05/2023]
Abstract
UNLABELLED Heart failure with preserved ejection fraction (HFpEF) is a cardinal and complex syndrome tightly linked to several co-morbidities, and is currently emerging as a new public health problem in the elderly population. However, despite aggressive intervention, patients with HFpEF typically have a poor prognosis. Part of the reason underlying this phenomenon can be attributed to the insufficiently understood pathophysiology behind this syndrome. Traditional echocardiography-derived parameters such as left ventricular (LV) ejection fraction (LVEF) may not be useful in characterizing such a clinical disorder, or in further identifying the subjects at risk, owing in part to its lack of power to disclose subclinical systolic dysfunction in such a clinical scenario. Herein, we briefly reviewed the clinical manifestations and risk factors of HFpEF, and further provided insights into the understanding of the ventricular architecture and cardiac mechanics underlying HFpEF by utilizing advanced cardiovascular imaging modalities, with a special focus on myocardial deformation. KEY WORDS Heart failure; Speckle tracking imaging; Strain.
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Affiliation(s)
- Chi-In Lo
- Division of Cardiology, Department of Internal Medicine, Mackay Memorial Hospital, Taipei
- Mackay Medicine, Nursing and Management College
| | - Yau-Hui Lai
- Division of Cardiology, Department of Internal Medicine, Mackay Memorial Hospital, Taipei
- Mackay Medicine, Nursing and Management College
| | - Jih-Jer Wu
- Division of Cardiology, Department of Internal Medicine, Mackay Memorial Hospital, Taipei
- Department of Medicine, Mackay Medical College, New Taipei City
| | - Chun-Ho Yun
- Mackay Medicine, Nursing and Management College
- Department of Medicine, Mackay Medical College, New Taipei City
- Department of Radiology, Mackay Memorial Hospital
| | - Chung-Lieh Hung
- Division of Cardiology, Department of Internal Medicine, Mackay Memorial Hospital, Taipei
- Mackay Medicine, Nursing and Management College
- Department of Medicine, Mackay Medical College, New Taipei City
- Institute of Clinical Medicine, and Cardiovascular Research Center, National Yang-Ming University, Taipei, Taiwan
| | - Bernard E. Bulwer
- Brigham and Women’s Hospital
- Massachusetts College of Pharmacy and Health Sciences, Boston, MA, USA
| | - Hung-I Yeh
- Division of Cardiology, Department of Internal Medicine, Mackay Memorial Hospital, Taipei
- Department of Medicine, Mackay Medical College, New Taipei City
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Sengupta PP, Kramer CM, Narula J. Cardiac Resynchronization: The Flow of Activation Sequence. JACC Cardiovasc Imaging 2013; 6:924-6. [DOI: 10.1016/j.jcmg.2013.07.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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31
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Influence of heart rate on myocardial function using two-dimensional speckle-tracking echocardiography in healthy dogs. J Vet Cardiol 2013; 15:139-46. [DOI: 10.1016/j.jvc.2012.12.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2012] [Revised: 12/13/2012] [Accepted: 12/13/2012] [Indexed: 12/24/2022]
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Decloedt A, Verheyen T, Sys S, De Clercq D, Bijnens B, van Loon G. Influence of Atrioventricular Interaction on Mitral Valve Closure and Left Ventricular Isovolumic Contraction Measured by Tissue Doppler Imaging. Circ Cardiovasc Imaging 2013. [DOI: 10.1161/circimaging.112.978692] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Annelies Decloedt
- From the Department of Large Animal Internal Medicine, Faculty of Veterinary Medicine, Ghent University, Gent, Belgium (A.D., T.V., S.S., D.D.C., G.v.L.); and ICREA-Universitat Pompeu Fabra, Barcelona, Spain (B.B.)
| | - Tinne Verheyen
- From the Department of Large Animal Internal Medicine, Faculty of Veterinary Medicine, Ghent University, Gent, Belgium (A.D., T.V., S.S., D.D.C., G.v.L.); and ICREA-Universitat Pompeu Fabra, Barcelona, Spain (B.B.)
| | - Stanislas Sys
- From the Department of Large Animal Internal Medicine, Faculty of Veterinary Medicine, Ghent University, Gent, Belgium (A.D., T.V., S.S., D.D.C., G.v.L.); and ICREA-Universitat Pompeu Fabra, Barcelona, Spain (B.B.)
| | - Dominique De Clercq
- From the Department of Large Animal Internal Medicine, Faculty of Veterinary Medicine, Ghent University, Gent, Belgium (A.D., T.V., S.S., D.D.C., G.v.L.); and ICREA-Universitat Pompeu Fabra, Barcelona, Spain (B.B.)
| | - Bart Bijnens
- From the Department of Large Animal Internal Medicine, Faculty of Veterinary Medicine, Ghent University, Gent, Belgium (A.D., T.V., S.S., D.D.C., G.v.L.); and ICREA-Universitat Pompeu Fabra, Barcelona, Spain (B.B.)
| | - Gunther van Loon
- From the Department of Large Animal Internal Medicine, Faculty of Veterinary Medicine, Ghent University, Gent, Belgium (A.D., T.V., S.S., D.D.C., G.v.L.); and ICREA-Universitat Pompeu Fabra, Barcelona, Spain (B.B.)
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Markhasin VS, Balakin AA, Katsnelson LB, Konovalov P, Lookin ON, Protsenko Y, Solovyova O. Slow force response and auto-regulation of contractility in heterogeneous myocardium. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2012; 110:305-18. [DOI: 10.1016/j.pbiomolbio.2012.08.011] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2012] [Accepted: 08/09/2012] [Indexed: 11/25/2022]
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Mansfield C, West TG, Curtin NA, Ferenczi MA. Stretch of contracting cardiac muscle abruptly decreases the rate of phosphate release at high and low calcium. J Biol Chem 2012; 287:25696-705. [PMID: 22692210 PMCID: PMC3406658 DOI: 10.1074/jbc.m112.373498] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2012] [Revised: 05/25/2012] [Indexed: 11/06/2022] Open
Abstract
The contractile performance of the heart is linked to the energy that is available to it. Yet, the heart needs to respond quickly to changing demands. During diastole, the heart fills with blood and the heart chambers expand. Upon activation, contraction of cardiac muscle expels blood into the circulation. Early in systole, parts of the left ventricle are being stretched by incoming blood, before contraction causes shrinking of the ventricle. We explore here the effect of stretch of contracting permeabilized cardiac trabeculae of the rat on the rate of inorganic phosphate (P(i)) release resulting from ATP hydrolysis, using a fluorescent sensor for P(i) with millisecond time resolution. Stretch immediately reduces the rate of P(i) release, an effect observed both at full calcium activation (32 μmol/liter of Ca(2+)), and at a physiological activation level of 1 μmol/liter of Ca(2+). The results suggest that stretch redistributes the actomyosin cross-bridges toward their P(i)-containing state. The redistribution means that a greater fraction of cross-bridges will be poised to rapidly produce a force-generating transition and movement, compared with cross-bridges that have not been subjected to stretch. At the same time stretch modifies the P(i) balance in the cytoplasm, which may act as a cytoplasmic signal for energy turnover.
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Affiliation(s)
- Catherine Mansfield
- From the Molecular Medicine Section, National Heart and Lung Institute, Imperial College London, London SW7 2AZ and
| | - Tim G. West
- the Royal Veterinary College, University of London, Hertfordshire AL9 7TA,United Kingdom
| | - Nancy A. Curtin
- From the Molecular Medicine Section, National Heart and Lung Institute, Imperial College London, London SW7 2AZ and
| | - Michael A. Ferenczi
- From the Molecular Medicine Section, National Heart and Lung Institute, Imperial College London, London SW7 2AZ and
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van Houwelingen MJ, Merkus D, te Lintel Hekkert M, van Dijk G, Hoeks APG, Duncker DJ. Initiation of ventricular contraction as reflected in the aortic pressure waveform. Physiol Meas 2012; 33:557-69. [PMID: 22415053 DOI: 10.1088/0967-3334/33/4/557] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Prior to aortic valve opening, aortic pressure is perturbed by ventricular contraction. The onset of this pressure perturbation coincides with the onset of the left ventricular (LV) isovolumic contraction, and hence will be referred to as the start of the arterially detected isovolumic contraction (AIC(start)). In the present study we test the hypothesis that the pressure perturbation indeed has a cardiac origin. In ten Yorkshire-Landrace swine, waveform intensity analysis demonstrated that AIC(start) was followed by a positive intensity wave (0.3 × 10(5) ± 0.3 × 10(5) W (m(2) s(2))(-1)). Timing analysis of LV and aortic pressure waveform showed that AIC(start) was preceded by a LV pressure perturbation (3.8 ± 1.8 ms, p < 0.001). These novel cardiac timing and aortic wave intensity findings reveal the cardiac origin of the pressure perturbation. In 15 Yorkshire-Landrace swine, myocardial motion analysis showed a significantly higher rate of segment shortening during the first part of the LV pressure perturbation. Therefore, both the LV and aortic pressure perturbation are most likely caused by the early phase of myocardial contraction, which also causes mitral valve closure. Consequently, AIC(start) is useful in the determination of the isovolumic contraction period, a well-known marker to quantify cardiac dysfunction.
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Affiliation(s)
- Marc J van Houwelingen
- Experimental Cardiology, Thoraxcenter, Cardiovascular Research Institute COEUR, Erasmus MC, University Medical Center Rotterdam, Dr. Molewaterplein 50, 3015 GE Rotterdam, The Netherlands.
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Sun JP, Lee APW, Wu C, Lam YY, Hung MJ, Chen L, Hu Z, Fang F, Yang XS, Merlino JD, Yu CM. Quantification of left ventricular regional myocardial function using two-dimensional speckle tracking echocardiography in healthy volunteers--a multi-center study. Int J Cardiol 2012; 167:495-501. [PMID: 22365315 DOI: 10.1016/j.ijcard.2012.01.071] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2011] [Revised: 01/10/2012] [Accepted: 01/21/2012] [Indexed: 11/30/2022]
Abstract
BACKGROUND Although two-dimensional speckle tracking (2DST) has been validated in animal and early clinical studies for quantitative evaluation of myocardial motion and contractility, there are only limited measurements in large healthy population to be used as reference data, which severely restricts its clinical application. This study aimed at determining the age-specific normal values of left ventricular (LV) longitudinal, circumferential and radial strain in healthy adults. METHODS We studied 228 healthy subjects (109 males, mean age 44 ± 15 years, range 18-78 years). Their LV longitudinal, circumferential and radial strains were measured by 2DST at basal, middle and apical levels of parasternal short-axis and apical 2-, 4- and 3-chamber views. The effects of age, gender and echocardiographic machines (52 patients had measurements obtained by both GE and Philips machines) on these parameters were also evaluated. RESULTS The longitudinal and circumferential strains were -20.4 ± 3.4% and -22.9 ± 3.1%, respectively with higher values being observed at basal than apical segments. On the contrary, the radial strain which ranged 42.6 ± 12.9% decreased towards apical segments. The longitudinal strain declined, the circumferential strain rose and the radial strain remained similar during aging. Adult females had slightly higher circumferential and longitudinal strains than males (23 ± 3% vs -22 ± 3%, -21 ± 3% vs -20 ± 3% respectively; both p<0.01). Strains measured by the 2 different echo machines had good correlations but Phillips-assessed strains (longitudinal and circumferential) were 10% higher than GE measurements. Inter- and intra-observer variabilities were acceptable. CONCLUSIONS Strain measurements by 2DST echocardiography varies with age, gender and echocardiographic vendors in healthy adults. These findings are important to differentiate between health and disease and to assess the severity of disease.
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Affiliation(s)
- Jing Ping Sun
- Division of Cardiology, S.H. Ho Cardiovascular and Stroke Centre, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, China
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Nagao M, Hatakenaka M, Matsuo Y, Kamitani T, Higuchi K, Shikata F, Nagashima M, Mochizuki T, Honda H. Subendocardial contractile impairment in chronic ischemic myocardium: assessment by strain analysis of 3T tagged CMR. J Cardiovasc Magn Reson 2012; 14:14. [PMID: 22300290 PMCID: PMC3286365 DOI: 10.1186/1532-429x-14-14] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2011] [Accepted: 02/02/2012] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND The purpose of this study was to quantify myocardial strain on the subendocardial and epicardial layers of the left ventricle (LV) using tagged cardiovascular magnetic resonance (CMR) and to investigate the transmural degree of contractile impairment in the chronic ischemic myocardium. METHODS 3T tagged CMR was performed at rest in 12 patients with severe coronary artery disease who had been scheduled for coronary artery bypass grafting. Circumferential strain (C-strain) at end-systole on subendocardial and epicardial layers was measured using the short-axis tagged images of the LV and available software (Intag; Osirix). The myocardial segment was divided into stenotic and non-stenotic segments by invasive coronary angiography, and ischemic and non-ischemic segments by stress myocardial perfusion scintigraphy. The difference in C-strain between the two groups was analyzed using the Mann-Whitney U-test. The diagnostic capability of C-strain was analyzed using receiver operating characteristics analysis. RESULTS The absolute subendocardial C-strain was significantly lower for stenotic (-7.5 ± 12.6%) than non-stenotic segment (-18.8 ± 10.2%, p < 0.0001). There was no difference in epicardial C-strain between the two groups. Use of cutoff thresholds for subendocardial C-strain differentiated stenotic segments from non-stenotic segments with a sensitivity of 77%, a specificity of 70%, and areas under the curve (AUC) of 0.76. The absolute subendocardial C-strain was significantly lower for ischemic (-6.7 ± 13.1%) than non-ischemic segments (-21.6 ± 7.0%, p < 0.0001). The absolute epicardial C-strain was also significantly lower for ischemic (-5.1 ± 7.8%) than non-ischemic segments (-9.6 ± 9.1%, p < 0.05). Use of cutoff thresholds for subendocardial C-strain differentiated ischemic segments from non-ischemic segments with sensitivities of 86%, specificities of 84%, and AUC of 0.86. CONCLUSIONS Analysis of tagged CMR can non-invasively demonstrate predominant impairment of subendocardial strain in the chronic ischemic myocardium at rest.
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Affiliation(s)
- Michinobu Nagao
- Department of Molecular Imaging and Diagnosis, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-Ku Fukuoka-city, Fukuoka, 812-8582, Japan
| | - Masamitsu Hatakenaka
- Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-Ku Fukuoka-city, Fukuoka, 812-8582, Japan
| | - Yoshio Matsuo
- Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-Ku Fukuoka-city, Fukuoka, 812-8582, Japan
| | - Takeshi Kamitani
- Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-Ku Fukuoka-city, Fukuoka, 812-8582, Japan
| | - Ko Higuchi
- Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-Ku Fukuoka-city, Fukuoka, 812-8582, Japan
| | - Fumiaki Shikata
- Department of Cardiovascular Surgery, Ehime University Graduate School of Medicine, Shitsukawa, Toon-city, Ehime, 791-0295, Japan
| | - Mitsugi Nagashima
- Department of Cardiovascular Surgery, Ehime University Graduate School of Medicine, Shitsukawa, Toon-city, Ehime, 791-0295, Japan
| | - Teruhito Mochizuki
- Department of Radiology, Ehime University Graduate School of Medicine, Shitsukawa, Toon-city, Ehime, 791-0295, Japan
| | - Hiroshi Honda
- Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-Ku Fukuoka-city, Fukuoka, 812-8582, Japan
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Choi HF, Rademakers FE, Claus P. Left-ventricular shape determines intramyocardial mechanical heterogeneity. Am J Physiol Heart Circ Physiol 2011; 301:H2351-61. [DOI: 10.1152/ajpheart.00568.2011] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Left-ventricular remodeling is considered to be an important mechanism of disease progression leading to mechanical dysfunction of the heart. However, the interaction between the physiological changes in the remodeling process and the associated mechanical dysfunction is still poorly understood. Clinically, it has been observed that the left ventricle often undergoes large shape changes, but the importance of left-ventricular shape as a contributing factor to alterations in mechanical function has not been clearly determined. Therefore, the interaction between left-ventricular shape and systolic mechanical function was examined in a computational finite-element study. Hereto, finite-element models were constructed with varying shapes, ranging from an elongated ellipsoid to a sphere. A realistic transmural gradient in fiber orientation was considered. The passive myocardium was described by an incompressible hyperelastic material law with transverse isotropic symmetry. Activation was governed by the eikonal-diffusion equation. Contraction was incorporated using a Hill model. For each shape, simulations were performed in which passive filling was followed by isovolumic contraction and ejection. It was found that the intramyocardial distributions of fiber stress, strain, and stroke work density were shape dependent. Ejection performance was reduced with increasing sphericity, which was regionally related to a reduction in the active fiber stress development, fiber shortening, and stroke work in the midwall and subepicardial region at the midheight level in the left-ventricular wall. Based on these results, we conclude that a significant interaction exists between left-ventricular shape and regional myofiber mechanics, but the importance for left-ventricular remodeling requires further investigation.
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Affiliation(s)
- Hon Fai Choi
- Division Imaging and Cardiovascular Dynamics, Department of Cardiovascular Diseases, Katholieke Universiteit Leuven, University Hospitals–Campus Gasthuisberg, Leuven, Belgium
| | - Frank E. Rademakers
- Division Imaging and Cardiovascular Dynamics, Department of Cardiovascular Diseases, Katholieke Universiteit Leuven, University Hospitals–Campus Gasthuisberg, Leuven, Belgium
| | - Piet Claus
- Division Imaging and Cardiovascular Dynamics, Department of Cardiovascular Diseases, Katholieke Universiteit Leuven, University Hospitals–Campus Gasthuisberg, Leuven, Belgium
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Itoh A, Stephens EH, Ennis DB, Carlhall CJ, Bothe W, Nguyen TC, Swanson JC, Miller DC, Ingels NB. Contribution of myocardium overlying the anterolateral papillary muscle to left ventricular deformation. Am J Physiol Heart Circ Physiol 2011; 302:H180-7. [PMID: 22037187 DOI: 10.1152/ajpheart.00687.2011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Previous studies of transmural left ventricular (LV) strains suggested that the myocardium overlying the papillary muscle displays decreased deformation relative to the anterior LV free wall or significant regional heterogeneity. These comparisons, however, were made using different hearts. We sought to extend these studies by examining three equatorial LV regions in the same heart during the same heartbeat. Therefore, deformation was analyzed from transmural beadsets placed in the equatorial LV myocardium overlying the anterolateral papillary muscle (PAP), as well as adjacent equatorial LV regions located more anteriorly (ANT) and laterally (LAT). We found that the magnitudes of LAT normal longitudinal and radial strains, as well as major principal strains, were less than ANT, while those of PAP were intermediate. Subepicardial and midwall myofiber angles of LAT, PAP, and ANT were not significantly different, but PAP subendocardial myofiber angles were significantly higher (more longitudinal as opposed to circumferential orientation). Subepicardial and midwall myofiber strains of ANT, PAP, and LAT were not significantly different, but PAP subendocardial myofiber strains were less. Transmural gradients in circumferential and radial normal strains, and major principal strains, were observed in each region. The two main findings of this study were as follows: 1) PAP strains are largely consistent with adjacent LV equatorial free wall regions, and 2) there is a gradient of strains across the anterolateral equatorial left ventricle despite similarities in myofiber angles and strains. These findings point to graduated equatorial LV heterogeneity and suggest that regional differences in myofiber coupling may constitute the basis for such heterogeneity.
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Affiliation(s)
- Akinobu Itoh
- Department of Cardiothoracic Surgery, Stanford University School of Medicine, California, USA
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Buckberg G, Hoffman JI, Nanda NC, Coghlan C, Saleh S, Athanasuleas C. Ventricular Torsion and Untwisting: Further Insights into Mechanics and Timing Interdependence: A Viewpoint. Echocardiography 2011; 28:782-804. [DOI: 10.1111/j.1540-8175.2011.01448.x] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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Mor-Avi V, Lang RM, Badano LP, Belohlavek M, Cardim NM, Derumeaux G, Galderisi M, Marwick T, Nagueh SF, Sengupta PP, Sicari R, Smiseth OA, Smulevitz B, Takeuchi M, Thomas JD, Vannan M, Voigt JU, Zamorano JL. Current and evolving echocardiographic techniques for the quantitative evaluation of cardiac mechanics: ASE/EAE consensus statement on methodology and indications endorsed by the Japanese Society of Echocardiography. J Am Soc Echocardiogr 2011; 24:277-313. [PMID: 21338865 DOI: 10.1016/j.echo.2011.01.015] [Citation(s) in RCA: 858] [Impact Index Per Article: 66.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Echocardiographic imaging is ideally suited for the evaluation of cardiac mechanics because of its intrinsically dynamic nature. Because for decades, echocardiography has been the only imaging modality that allows dynamic imaging of the heart, it is only natural that new, increasingly automated techniques for sophisticated analysis of cardiac mechanics have been driven by researchers and manufacturers of ultrasound imaging equipment.Several such technique shave emerged over the past decades to address the issue of reader's experience and inter measurement variability in interpretation.Some were widely embraced by echocardiographers around the world and became part of the clinical routine,whereas others remained limited to research and exploration of new clinical applications.Two such techniques have dominated the research arena of echocardiography: (1) Doppler based tissue velocity measurements,frequently referred to as tissue Doppler or myocardial Doppler, and (2) speckle tracking on the basis of displacement measurements.Both types of measurements lend themselves to the derivation of multiple parameters of myocardial function. The goal of this document is to focus on the currently available techniques that allow quantitative assessment of myocardial function via image-based analysis of local myocardial dynamics, including Doppler tissue imaging and speckle-tracking echocardiography, as well as integrated backscatter analysis. This document describes the current and potential clinical applications of these techniques and their strengths and weaknesses,briefly surveys a selection of the relevant published literature while highlighting normal and abnormal findings in the context of different cardiovascular pathologies, and summarizes the unresolved issues, future research priorities, and recommended indications for clinical use.
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Bollensdorff C, Lookin O, Kohl P. Assessment of contractility in intact ventricular cardiomyocytes using the dimensionless 'Frank-Starling Gain' index. Pflugers Arch 2011; 462:39-48. [PMID: 21494804 PMCID: PMC3114067 DOI: 10.1007/s00424-011-0964-z] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2011] [Revised: 03/28/2011] [Accepted: 03/28/2011] [Indexed: 11/29/2022]
Abstract
This paper briefly recapitulates the Frank–Starling law of the heart, reviews approaches to establishing diastolic and systolic force–length behaviour in intact isolated cardiomyocytes, and introduces a dimensionless index called ‘Frank–Starling Gain’, calculated as the ratio of slopes of end-systolic and end-diastolic force–length relations. The benefits and limitations of this index are illustrated on the example of regional differences in Guinea pig intact ventricular cardiomyocyte mechanics. Potential applicability of the Frank–Starling Gain for the comparison of cell contractility changes upon stretch will be discussed in the context of intra- and inter-individual variability of cardiomyocyte properties.
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Affiliation(s)
- Christian Bollensdorff
- Cardiac Biophysics and Systems Biology, The National Heart and Lung Institute, Imperial College, London, UK.
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Cazorla O, Lacampagne A. Regional variation in myofilament length-dependent activation. Pflugers Arch 2011; 462:15-28. [DOI: 10.1007/s00424-011-0933-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2011] [Revised: 02/01/2011] [Accepted: 02/03/2011] [Indexed: 12/17/2022]
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Ashikaga H, Leclercq C, Wang J, Kass DA, McVeigh ER. Hemodynamic improvement in cardiac resynchronization does not require improvement in left ventricular rotation mechanics: three-dimensional tagged MRI analysis. Circ Cardiovasc Imaging 2010; 3:456-63. [PMID: 20478988 DOI: 10.1161/circimaging.109.906305] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Earlier studies have yielded conflicting evidence on whether or not cardiac resynchronization therapy (CRT) improves left ventricular (LV) rotation mechanics. METHODS AND RESULTS In dogs with left bundle branch block and pacing-induced heart failure (n=7), we studied the effects of CRT on LV rotation mechanics in vivo by 3-dimensional tagged magnetic resonance imaging with a temporal resolution of 14 ms. CRT significantly improved hemodynamic parameters but did not significantly change the LV rotation or rotation rate. LV torsion, defined as LV rotation of each slice with respect to that of the most basal slice, was not significantly changed by CRT. CRT did not significantly change the LV torsion rate. There was no significant circumferential regional heterogeneity (anterior, lateral, inferior, and septal) in LV rotation mechanics in either left bundle branch block with pacing-induced heart failure or CRT, but there was significant apex-to-base regional heterogeneity. CONCLUSIONS CRT acutely improves hemodynamic parameters without improving LV rotation mechanics. There is no significant circumferential regional heterogeneity of LV rotation mechanics in the mechanically dyssynchronous heart. These results suggest that LV rotation mechanics is an index of global LV function, which requires coordination of all regions of the left ventricle, and improvement in LV rotation mechanics appears to be a specific but insensitive index of acute hemodynamic response to CRT.
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Affiliation(s)
- Hiroshi Ashikaga
- Laboratory of Cardiac Energetics, National Heart, Lung, and Blood Institute/NIH, Bethesda, MD 20892, USA.
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Provost J, Lee WN, Fujikura K, Konofagou EE. Electromechanical wave imaging of normal and ischemic hearts in vivo. IEEE TRANSACTIONS ON MEDICAL IMAGING 2010; 29:625-35. [PMID: 19709966 PMCID: PMC3093312 DOI: 10.1109/tmi.2009.2030186] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Electromechanical wave imaging (EWI) has recently been introduced as a noninvasive, ultrasound-based imaging modality, which could map the electrical activation of the heart in various echocardiographic planes in mice, dogs, and humans in vivo. By acquiring radio-frequency (RF) frames at very high frame rates (390-520 Hz), the onset of small, localized, transient deformations resulting from the electrical activation of the heart, i.e., generating the electromechanical wave (EMW), can be mapped. The correlation between the EMW and the electrical activation speed and pacing scheme has previously been reported. In this study, we pursue the development of EWI using both displacements and strains and analysis of the EMW properties in dogs in vivo for early detection of ischemia. EWI was performed in normal and ischemic open-chest dogs during sinus rhythm. Ischemia of increasing severity was obtained by gradually obstructing the left-anterior descending (LAD) coronary artery flow. We also introduce the novel method of motion-matching that achieves the reconstruction of the full EWI ciné-loop at very high frame rates even when the ECG may be irregular or unavailable. Incremental displacements were previously used by our group to map the EMW. This paper focuses on the associated incremental strains, which facilitate the interpretation of the EMW by relating it directly to contraction. Moreover, we define the onset of the EMW as the time, at which the incremental strains change sign after the onset of the QRS complex of the ECG. Based on this definition, isochronal representations of the EMW were generated using a semi-automated method. The isochronal representation of the EMW during sinus rhythm was reproducible and shown similar to electrical activation maps previously reported in the literature. After segmentation using a contour-tracking method, the two- and four-chamber views were imaged and displayed in bi-plane views, allowing a 3-D interpretation of the EMW. EWI was shown to be sensitive to the presence of intermediate ischemia. EWI localized the ischemic region when the LAD flow was obstructed at 60% and beyond and was capable of mapping the increase of the ischemic region size as the LAD occlusion level increased. In conclusion, the activation maps and wave patterns obtained with EWI were similar to the electrical equivalents previously reported in the literature. Moreover, EWI was found to be sensitive enough to detect and map intermediate ischemia. Those results indicate that EWI could be used to assess the conduction properties of the myocardium, and detect its ischemic onset and disease progression entirely noninvasively.
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Affiliation(s)
- Jean Provost
- Department of Biomedical Engineering, Columbia University, New York, NY 10027 USA
| | - Wei-Ning Lee
- Department of Biomedical Engineering, Columbia University, New York, NY 10027 USA
| | - Kana Fujikura
- Department of Biomedical Engineering, Columbia University, New York, NY 10027 USA
| | - Elisa E. Konofagou
- Departments of Biomedical Engineering and Radiology, Columbia University, New York, NY 10027 USA
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Sengupta PP. Exploring Left Ventricular Isovolumic Shortening and Stretch Mechanics⁎⁎Editorials published in JACC: Cardiovascular Imaging reflect the views of the authors and do not necessarily represent the views of JACC: Cardiovascular Imaging or the American College of Cardiology. JACC Cardiovasc Imaging 2009; 2:212-5. [DOI: 10.1016/j.jcmg.2008.12.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2008] [Accepted: 12/09/2008] [Indexed: 10/21/2022]
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