1
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Mishra A, Cleveland RO. Rheological properties of porcine organs: measurements and fractional viscoelastic model. Front Bioeng Biotechnol 2024; 12:1386955. [PMID: 39148944 PMCID: PMC11324450 DOI: 10.3389/fbioe.2024.1386955] [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: 02/16/2024] [Accepted: 07/19/2024] [Indexed: 08/17/2024] Open
Abstract
The rheological properties of porcine heart, kidney, liver and brain were measured using dynamic oscillatory shear tests over a range of frequencies and shear strains. Frequency sweep tests were performed from 0.1 Hz to a maximum of 9.5 Hz at a shear strain of 0.1%, and strain sweep tests were carried out from 0.01% to 10% at 1 Hz. The effect of pre-compression of samples up to 10% axial strain was considered. The experimental measurements were fit to a Semi-Fractional Kelvin Voight (S-FKV) model. The model was then used to predict the stress relaxation in response to a step strain of 0.1%. The prediction was compared to experimental relaxation data for the porcine organ samples, and the results agreed to within 30%. In conclusion, this study measured the rheological properties of porcine organs and used a fractional viscoelastic model to describe the response in frequency and time domain.
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Affiliation(s)
- Aadarsh Mishra
- Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, Oxford, United Kingdom
| | - Robin O Cleveland
- Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, Oxford, United Kingdom
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2
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Pearce DP, Nemcek MT, Witzenburg CM. Don't go breakin' my heart: cardioprotective alterations to the mechanical and structural properties of reperfused myocardium during post-infarction inflammation. Biophys Rev 2023; 15:329-353. [PMID: 37396449 PMCID: PMC10310682 DOI: 10.1007/s12551-023-01068-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Accepted: 05/21/2023] [Indexed: 07/04/2023] Open
Abstract
Myocardial infarctions (MIs) kickstart an intense inflammatory response resulting in extracellular matrix (ECM) degradation, wall thinning, and chamber dilation that leaves the heart susceptible to rupture. Reperfusion therapy is one of the most effective strategies for limiting adverse effects of MIs, but is a challenge to administer in a timely manner. Late reperfusion therapy (LRT; 3 + hours post-MI) does not limit infarct size, but does reduce incidences of post-MI rupture and improves long-term patient outcomes. Foundational studies employing LRT in the mid-twentieth century revealed beneficial reductions in infarct expansion, aneurysm formation, and left ventricle dysfunction. The mechanism by which LRT acts, however, is undefined. Structural analyses, relying largely on one-dimensional estimates of ECM composition, have found few differences in collagen content between LRT and permanently occluded animal models when using homogeneous samples from infarct cores. Uniaxial testing, on the other hand, revealed slight reductions in stiffness early in inflammation, followed soon after by an enhanced resistance to failure for cases of LRT. The use of one-dimensional estimates of ECM organization and gross mechanical function have resulted in a poor understanding of the infarct's spatially variable mechanical and structural anisotropy. To resolve these gaps in literature, future work employing full-field mechanical, structural, and cellular analyses is needed to better define the spatiotemporal post-MI alterations occurring during the inflammatory phase of healing and how they are impacted following reperfusion therapy. In turn, these studies may reveal how LRT affects the likelihood of rupture and inspire novel approaches to guide scar formation.
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Affiliation(s)
- Daniel P. Pearce
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI 53706 USA
| | - Mark T. Nemcek
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI 53706 USA
| | - Colleen M. Witzenburg
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI 53706 USA
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3
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Mendiola EA, Neelakantan S, Xiang Q, Merchant S, Li K, Hsu EW, Dixon RAF, Vanderslice P, Avazmohammadi R. Contractile Adaptation of the Left Ventricle Post-myocardial Infarction: Predictions by Rodent-Specific Computational Modeling. Ann Biomed Eng 2023; 51:846-863. [PMID: 36394778 PMCID: PMC10023390 DOI: 10.1007/s10439-022-03102-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 10/02/2022] [Indexed: 11/19/2022]
Abstract
Myocardial infarction (MI) results in cardiac myocyte death and the formation of a fibrotic scar in the left ventricular free wall (LVFW). Following an acute MI, LVFW remodeling takes place consisting of several alterations in the structure and properties of cellular and extracellular components with a heterogeneous pattern across the LVFW. The normal function of the heart is strongly influenced by the passive and active biomechanical behavior of the LVFW, and progressive myocardial structural remodeling can have a detrimental effect on both diastolic and systolic functions of the LV leading to heart failure. Despite important advances in understanding LVFW passive remodeling in the setting of MI, heterogeneous remodeling in the LVFW active properties and its relationship to organ-level LV function remain understudied. To address these gaps, we developed high-fidelity finite-element (FE) rodent computational cardiac models (RCCMs) of MI using extensive datasets from MI rat hearts representing the heart remodeling from one-week (1-wk) to four-week (4-wk) post-MI timepoints. The rat-specific models (n = 2 for each timepoint) integrate detailed imaging data of the heart geometry, myocardial fiber architecture, and infarct zone determined using late gadolinium enhancement prior to terminal measurements. The computational models predicted a significantly higher level of active tension in remote myocardium in early post-MI hearts (1-wk post-MI) followed by a return to near the control level in late-stage MI (3- and 4-wk post-MI). The late-stage MI rats showed smaller myofiber ranges in the remote region and in-silico experiments using RCCMs suggested that the smaller fiber helicity is consistent with lower contractile forces needed to meet the measured ejection fractions in late-stage MI. In contrast, in-silico experiments predicted that collagen fiber transmural orientation in the infarct region has little influence on organ-level function. In addition, our MI RCCMs indicated that reduced and potentially positive circumferential strains in the infarct region at end-systole can be used to infer information about the time-varying properties of the infarct region. The detailed description of regional passive and active remodeling patterns can complement and enhance the traditional measures of LV anatomy and function that often lead to a gross and limited assessment of cardiac performance. The translation and implementation of our model in patient-specific organ-level simulations offer to advance the investigation of individualized prognosis and intervention for MI.
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Affiliation(s)
- Emilio A Mendiola
- Computational Cardiovascular Bioengineering Laboratory, Department of Biomedical Engineering, Texas A&M University, College Station, TX, USA
| | - Sunder Neelakantan
- Computational Cardiovascular Bioengineering Laboratory, Department of Biomedical Engineering, Texas A&M University, College Station, TX, USA
| | - Qian Xiang
- Department of Molecular Cardiology, Texas Heart Institute, Houston, TX, USA
| | - Samer Merchant
- Department of Biomedical Engineering, University of Utah, Salt Lake City, UT, USA
| | - Ke Li
- Department of Molecular Cardiology, Texas Heart Institute, Houston, TX, USA
| | - Edward W Hsu
- Department of Biomedical Engineering, University of Utah, Salt Lake City, UT, USA
| | - Richard A F Dixon
- Department of Molecular Cardiology, Texas Heart Institute, Houston, TX, USA
| | - Peter Vanderslice
- Department of Molecular Cardiology, Texas Heart Institute, Houston, TX, USA
| | - Reza Avazmohammadi
- Computational Cardiovascular Bioengineering Laboratory, Department of Biomedical Engineering, Texas A&M University, College Station, TX, USA.
- J. Mike Walker '66 Department of Mechanical Engineering, Texas A&M University, College Station, TX, USA.
- Department of Cardiovascular Sciences, Houston Methodist Academic Institute, Houston, TX, USA.
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4
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Validating MRI-Derived Myocardial Stiffness Estimates Using In Vitro Synthetic Heart Models. Ann Biomed Eng 2023:10.1007/s10439-023-03164-7. [PMID: 36914919 DOI: 10.1007/s10439-023-03164-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Accepted: 02/07/2023] [Indexed: 03/16/2023]
Abstract
Impaired cardiac filling in response to increased passive myocardial stiffness contributes to the pathophysiology of heart failure. By leveraging cardiac MRI data and ventricular pressure measurements, we can estimate in vivo passive myocardial stiffness using personalized inverse finite element models. While it is well-known that this approach is subject to uncertainties, only few studies quantify the accuracy of these stiffness estimates. This lack of validation is, at least in part, due to the absence of ground truth in vivo passive myocardial stiffness values. Here, using 3D printing, we created soft, homogenous, isotropic, hyperelastic heart phantoms of varying geometry and stiffness and simulate diastolic filling by incorporating the phantoms into an MRI-compatible left ventricular inflation system. We estimate phantom stiffness from MRI and pressure data using inverse finite element analyses based on a Neo-Hookean model. We demonstrate that our identified softest and stiffest values of 215.7 and 512.3 kPa agree well with the ground truth of 226.2 and 526.4 kPa. Overall, our estimated stiffnesses revealed a good agreement with the ground truth ([Formula: see text] error) across all models. Our results suggest that MRI-driven computational constitutive modeling can accurately estimate synthetic heart material stiffnesses in the range of 200-500 kPa.
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Sutherland DW, McEleney A, de Almeida M, Kajimoto M, Ventura G, Isenberg BC, Portman MA, Stapleton SE, Williams C. Characterization of main pulmonary artery and valve annulus region of piglets using echocardiography, uniaxial tensile testing, and a novel non-destructive technique. Front Cardiovasc Med 2022; 9:884116. [PMID: 36093160 PMCID: PMC9459108 DOI: 10.3389/fcvm.2022.884116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Accepted: 08/08/2022] [Indexed: 11/23/2022] Open
Abstract
Characterization of cardiovascular tissue geometry and mechanical properties of large animal models is essential when developing cardiovascular devices such as heart valve replacements. These datasets are especially critical when designing devices for pediatric patient populations, as there is often limited data for guidance. Here, we present a previously unavailable dataset capturing anatomical measurements and mechanical properties of juvenile Yorkshire (YO) and Yucatan (YU) porcine main pulmonary artery (PA) and pulmonary valve (PV) tissue regions that will inform pediatric heart valve design requirements for preclinical animal studies. In addition, we developed a novel radial balloon catheter-based method to measure tissue stiffness and validated it against a traditional uniaxial tensile testing method. YU piglets, which were significantly lower weight than YO counterparts despite similar age, had smaller PA and PV diameters (7.6–9.9 mm vs. 10.1–12.8 mm). Young’s modulus (stiffness) was measured for the PA and the PV region using both the radial and uniaxial testing methods. There was no significant difference between the two breeds for Young’s modulus measured in the elastic (YU PA 84.7 ± 37.3 kPa, YO PA 79.3 ± 15.7 kPa) and fibrous regimes (YU PA 308.6 ± 59.4 kPa, YO PA 355.7 ± 68.9 kPa) of the stress-strain curves. The two testing techniques also produced similar stiffness measurements for the PA and PV region, although PV data showed greater variation between techniques. Overall, YU and YO piglets had similar PA and PV diameters and tissue stiffness to previously reported infant pediatric patients. These results provide a previously unavailable age-specific juvenile porcine tissue geometry and stiffness dataset critical to the development of pediatric cardiovascular prostheses. Additionally, the data demonstrates the efficacy of a novel balloon catheter-based technique that could be adapted to non-destructively measure tissue stiffness in situ.
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Affiliation(s)
- David W. Sutherland
- Bioengineering Division, The Charles Stark Draper Laboratory, Inc., Cambridge, MA, United States
| | - Aisling McEleney
- Bioengineering Division, The Charles Stark Draper Laboratory, Inc., Cambridge, MA, United States
| | - Matheus de Almeida
- Bioengineering Division, The Charles Stark Draper Laboratory, Inc., Cambridge, MA, United States
| | - Masaki Kajimoto
- Seattle Children’s Research Institute, Seattle Children’s Hospital, Seattle, WA, United States
| | - Giselle Ventura
- Bioengineering Division, The Charles Stark Draper Laboratory, Inc., Cambridge, MA, United States
| | - Brett C. Isenberg
- Bioengineering Division, The Charles Stark Draper Laboratory, Inc., Cambridge, MA, United States
| | - Michael A. Portman
- Seattle Children’s Research Institute, Seattle Children’s Hospital, Seattle, WA, United States
- *Correspondence: Michael A. Portman,
| | - Scott E. Stapleton
- Department of Mechanical Engineering, University of Massachusetts, Lowell, MA, United States
- Scott E. Stapleton,
| | - Corin Williams
- Bioengineering Division, The Charles Stark Draper Laboratory, Inc., Cambridge, MA, United States
- Corin Williams,
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6
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Harbo MB, Stokke MK, Sjaastad I, Espe EKS. One step closer to myocardial physiology: From PV loop analysis to state-of-the-art myocardial imaging. Acta Physiol (Oxf) 2022; 234:e13759. [PMID: 34978759 DOI: 10.1111/apha.13759] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 12/14/2021] [Accepted: 01/01/2022] [Indexed: 11/29/2022]
Abstract
Recent advances in cardiac imaging have revitalized the assessment of fundamental physiological concepts. In the field of cardiac physiology, invasive measurements with pressure-volume (PV) loops have served as the gold standard methodology for the characterization of left ventricular (LV) function. From PV loop data, fundamental aspects of LV chamber function are derived such as work, efficiency, stiffness and contractility. However, the parametrization of these aspects is limited because of the need for invasive procedures. Through the utilization of recent advances in echocardiography, magnetic resonance imaging and positron emission tomography, it has become increasingly feasible to quantify these fundamental aspects of LV function non-invasively. Importantly, state-of-the-art imaging technology enables direct assessment of myocardial performance, thereby extending functional assessment from the net function of the LV chamber, as is done with PV loops, to the myocardium itself. With a strong coupling to underlying myocardial physiology, imaging measurements of myocardial work, efficiency, stiffness and contractility could represent the next generation of functional parameters. The purpose of this review is to discuss how the new imaging parameters of myocardial work, efficiency, stiffness and contractility can bring cardiac physiologists, researchers and clinicians alike one step closer to underlying myocardial physiology.
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Affiliation(s)
- Markus Borge Harbo
- Institute for Experimental Medical Research Oslo University Hospital and University of Oslo Oslo Norway
- K.G. Jebsen Center for Cardiac Research University of Oslo Oslo Norway
| | - Mathis Korseberg Stokke
- Institute for Experimental Medical Research Oslo University Hospital and University of Oslo Oslo Norway
- K.G. Jebsen Center for Cardiac Research University of Oslo Oslo Norway
- Department of Cardiology Oslo University Hospital Rikshospitalet Oslo Norway
| | - Ivar Sjaastad
- Institute for Experimental Medical Research Oslo University Hospital and University of Oslo Oslo Norway
- K.G. Jebsen Center for Cardiac Research University of Oslo Oslo Norway
| | - Emil Knut Stenersen Espe
- Institute for Experimental Medical Research Oslo University Hospital and University of Oslo Oslo Norway
- K.G. Jebsen Center for Cardiac Research University of Oslo Oslo Norway
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7
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Wang X, Pierre V, Senapati S, Park PSH, Senyo SE. Microenvironment Stiffness Amplifies Post-ischemia Heart Regeneration in Response to Exogenous Extracellular Matrix Proteins in Neonatal Mice. Front Cardiovasc Med 2021; 8:773978. [PMID: 34805326 PMCID: PMC8602555 DOI: 10.3389/fcvm.2021.773978] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Accepted: 10/14/2021] [Indexed: 11/13/2022] Open
Abstract
The cardiogenesis of the fetal heart is absent in juveniles and adults. Cross-transplantation of decellularized extracellular matrix (dECM) can stimulate regeneration in myocardial infarct (MI) models. We have previously shown that dECM and tissue stiffness have cooperative regulation of heart regeneration in transiently regenerative day 1 neonatal mice. To investigate underlying mechanisms of mechano-signaling and dECM, we pharmacologically altered heart stiffness and administered dECM hydrogels in non-regenerative mice after MI. The dECM combined with softening exhibits preserved cardiac function, LV geometry, increased cardiomyocyte mitosis and lowered fibrosis while stiffening further aggravated ischemic damage. Transcriptome analysis identified a protein in cardiomyocytes, CLCA2, confirmed to be upregulated after MI and downregulated by dECM in a mechanosensitive manner. Synthetic knock-down of CLCA2 expression induced mitosis in primary rat cardiomyocytes in the dish. Together, our results indicate that therapeutic efficacy of extracellular molecules for heart regeneration can be modulated by heart microenvironment stiffness in vivo.
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Affiliation(s)
- Xinming Wang
- Department of Biomedical Engineering, Case School of Engineering, Case Western Reserve University, Cleveland, OH, United States
| | - Valinteshley Pierre
- Department of Biomedical Engineering, Case School of Engineering, Case Western Reserve University, Cleveland, OH, United States
| | - Subhadip Senapati
- Department of Ophthalmology and Visual Sciences, School of Medicine, Case Western Reserve University, Cleveland, OH, United States
| | - Paul S.-H. Park
- Department of Ophthalmology and Visual Sciences, School of Medicine, Case Western Reserve University, Cleveland, OH, United States
| | - Samuel E. Senyo
- Department of Biomedical Engineering, Case School of Engineering, Case Western Reserve University, Cleveland, OH, United States
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8
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Emig R, Zgierski-Johnston CM, Timmermann V, Taberner AJ, Nash MP, Kohl P, Peyronnet R. Passive myocardial mechanical properties: meaning, measurement, models. Biophys Rev 2021; 13:587-610. [PMID: 34765043 PMCID: PMC8555034 DOI: 10.1007/s12551-021-00838-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Accepted: 08/26/2021] [Indexed: 02/06/2023] Open
Abstract
Passive mechanical tissue properties are major determinants of myocardial contraction and relaxation and, thus, shape cardiac function. Tightly regulated, dynamically adapting throughout life, and affecting a host of cellular functions, passive tissue mechanics also contribute to cardiac dysfunction. Development of treatments and early identification of diseases requires better spatio-temporal characterisation of tissue mechanical properties and their underlying mechanisms. With this understanding, key regulators may be identified, providing pathways with potential to control and limit pathological development. Methodologies and models used to assess and mimic tissue mechanical properties are diverse, and available data are in part mutually contradictory. In this review, we define important concepts useful for characterising passive mechanical tissue properties, and compare a variety of in vitro and in vivo techniques that allow one to assess tissue mechanics. We give definitions of key terms, and summarise insight into determinants of myocardial stiffness in situ. We then provide an overview of common experimental models utilised to assess the role of environmental stiffness and composition, and its effects on cardiac cell and tissue function. Finally, promising future directions are outlined.
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Affiliation(s)
- Ramona Emig
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg, Bad Krozingen, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
- CIBSS Centre for Integrative Biological Signalling Studies, University of Freiburg, Freiburg, Germany
- Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Callum M. Zgierski-Johnston
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg, Bad Krozingen, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Viviane Timmermann
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg, Bad Krozingen, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Andrew J. Taberner
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
- Department of Engineering Science, The University of Auckland, Auckland, New Zealand
| | - Martyn P. Nash
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
- Department of Engineering Science, The University of Auckland, Auckland, New Zealand
| | - Peter Kohl
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg, Bad Krozingen, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
- CIBSS Centre for Integrative Biological Signalling Studies, University of Freiburg, Freiburg, Germany
- Faculty of Engineering, University of Freiburg, Freiburg, Germany
| | - Rémi Peyronnet
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg, Bad Krozingen, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
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9
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Troelstra MA, Runge JH, Burnhope E, Polcaro A, Guenthner C, Schneider T, Razavi R, Ismail TF, Martorell J, Sinkus R. Shear wave cardiovascular MR elastography using intrinsic cardiac motion for transducer-free non-invasive evaluation of myocardial shear wave velocity. Sci Rep 2021; 11:1403. [PMID: 33446701 PMCID: PMC7809276 DOI: 10.1038/s41598-020-79231-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Accepted: 11/30/2020] [Indexed: 01/29/2023] Open
Abstract
Changes in myocardial stiffness may represent a valuable biomarker for early tissue injury or adverse remodeling. In this study, we developed and validated a novel transducer-free magnetic resonance elastography (MRE) approach for quantifying myocardial biomechanics using aortic valve closure-induced shear waves. Using motion-sensitized two-dimensional pencil beams, septal shear waves were imaged at high temporal resolution. Shear wave speed was measured using time-of-flight of waves travelling between two pencil beams and corrected for geometrical biases. After validation in phantoms, results from twelve healthy volunteers and five cardiac patients (two left ventricular hypertrophy, two myocardial infarcts, and one without confirmed pathology) were obtained. Torsional shear wave speed in the phantom was 3.0 ± 0.1 m/s, corresponding with reference speeds of 2.8 ± 0.1 m/s. Geometrically-biased flexural shear wave speed was 1.9 ± 0.1 m/s, corresponding with simulation values of 2.0 m/s. Corrected septal shear wave speeds were significantly higher in patients than healthy volunteers [14.1 (11.0-15.8) m/s versus 3.6 (2.7-4.3) m/s, p = 0.001]. The interobserver 95%-limits-of-agreement in healthy volunteers were ± 1.3 m/s and interstudy 95%-limits-of-agreement - 0.7 to 1.2 m/s. In conclusion, myocardial shear wave speed can be measured using aortic valve closure-induced shear waves, with cardiac patients showing significantly higher shear wave speeds than healthy volunteers. This non-invasive measure may provide valuable insights into the pathophysiology of heart failure.
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Affiliation(s)
- Marian Amber Troelstra
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, UK
- Department of Radiology and Nuclear Medicine, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Jurgen Henk Runge
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, UK
- Department of Radiology and Nuclear Medicine, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Emma Burnhope
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, UK
- Department of Cardiology, Guy's and St Thomas' NHS Foundation Trust, London, UK
| | - Alessandro Polcaro
- Department of Chemical Engineering and Material Sciences, IQS School of Engineering, Universitat Ramon Llull, Via Augusta 390, 08017, Barcelona, Spain
| | - Christian Guenthner
- Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland
- Philips Research, Hamburg, Germany
| | - Torben Schneider
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, UK
- Philips, Guildford, UK
| | - Reza Razavi
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, UK
| | - Tevfik F Ismail
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, UK
- Department of Cardiology, Guy's and St Thomas' NHS Foundation Trust, London, UK
| | - Jordi Martorell
- Department of Chemical Engineering and Material Sciences, IQS School of Engineering, Universitat Ramon Llull, Via Augusta 390, 08017, Barcelona, Spain.
| | - Ralph Sinkus
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, UK
- Inserm U1148, LVTS, University Paris Diderot, University Paris 13, Paris, France
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10
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Zhu D, Wu P, Xiao C, Hu W, Zhang T, Hu X, Chen W, Wang J. Inflammatory Cytokines Alter Mesenchymal Stem Cell Mechanosensing and Adhesion on Stiffened Infarct Heart Tissue After Myocardial Infarction. Front Cell Dev Biol 2020; 8:583700. [PMID: 33195229 PMCID: PMC7645114 DOI: 10.3389/fcell.2020.583700] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Accepted: 10/01/2020] [Indexed: 12/12/2022] Open
Abstract
Mesenchymal stem cell (MSC) transplantation has demonstrated its potential in repairing infarct heart tissue and recovering heart function after myocardial infarction (MI). However, its therapeutic effect is still limited due to poor MSC engraftment at the injury site whose tissue stiffness and local inflammation both dynamically and rapidly change after MI. Whether and how inflammatory cytokines could couple with stiffness change to affect MSC engraftment in the infarct zone still remain unclear. In this study, we characterized dynamic stiffness changes of and inflammatory cytokine expression in the infarct region of rat heart within a month after MI. We found that the tissue stiffness of the heart tissue gradually increased and peaked 21 days after MI along with the rapid upregulation of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interleukin-1β (IL-1β) in the first 3 days, followed by a sharp decline. We further demonstrated in vitro that immobilized inflammatory cytokine IL-6 performed better than the soluble form in enhancing MSC adhesion to stiffened substrate through IL-6/src homology 2 (SH2) domain-containing tyrosine phosphatase-2 (SHP2)/integrin signaling axis. We also confirmed such mechano-immune coupling of tissue stiffness and inflammatory cytokines in modulating MSC engraftment in the rat heart after MI in vivo. Our study provides new mechanistic insights of mechanical–inflammation coupling to improve MSC mechanosensing and adhesion, potentially benefiting MSC engraftment and its clinical therapy for MI.
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Affiliation(s)
- Dan Zhu
- Department of Cardiology of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Peng Wu
- Department of Cardiology of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Department of Pharmacology, Zhejiang University School of Medicine, Hangzhou, China
| | - Changchen Xiao
- Department of Cardiology of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Wei Hu
- Key Laboratory for Biomedical Engineering of the Ministry of Education, College of Biomedical Engineering and Instrument Science, Zhejiang University, Hangzhou, China
| | - Tongtong Zhang
- Key Laboratory for Biomedical Engineering of the Ministry of Education, College of Biomedical Engineering and Instrument Science, Zhejiang University, Hangzhou, China
| | - Xinyang Hu
- Department of Cardiology of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Wei Chen
- Department of Cardiology of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Key Laboratory for Biomedical Engineering of the Ministry of Education, College of Biomedical Engineering and Instrument Science, Zhejiang University, Hangzhou, China
| | - Jian'an Wang
- Department of Cardiology of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
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11
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Wang X, Senapati S, Akinbote A, Gnanasambandam B, Park PSH, Senyo SE. Microenvironment stiffness requires decellularized cardiac extracellular matrix to promote heart regeneration in the neonatal mouse heart. Acta Biomater 2020; 113:380-392. [PMID: 32590172 PMCID: PMC7428869 DOI: 10.1016/j.actbio.2020.06.032] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Revised: 06/16/2020] [Accepted: 06/18/2020] [Indexed: 02/08/2023]
Abstract
The transient period of regeneration potential in the postnatal heart suggests molecular changes with maturation influence the cardiac response to damage. We have previously demonstrated that injury and exercise can stimulate cardiomyocyte proliferation in the adult heart suggesting a sensitivity to exogenous signals. Here, we consider whether exogenous fetal ECM and mechanically unloading interstitial matrix can drive regeneration after myocardial infarction (MI) surgery in low-regenerative hearts of day5 mice. Compared to controls, exogenous fetal ECM increases cardiac function and lowers fibrosis at 3 weeks post-injury and this effect can be augmented by softening heart tissue. In vitro experiments support a mechano-sensitivity to exogenous ECM signaling. We tested potential mechanisms and observed that fetal ECM increases nuclear YAP localization which could be enhanced by pharmacological stabilization of the cytoskeleton. Blocking YAP expression lowered fetal ECM effects though not completely. Lastly we observed mechanically unloading heart interstitial matrix increased agrin expression, an extracellular node in the YAP signaling pathway. Collectively, these data support a combined effect of exogenous factors and mechanical activity in altering agrin expression, cytoskeletal remodeling, and YAP signaling in driving cardiomyocyte cell cycle activity and regeneration in postnatal non-regenerative mice. STATEMENT OF SIGNIFICANCE: With the purpose of developing regenerative strategies, we investigate the influence of the local niche on the cardiac injury response. We conclude tissue stiffness, as anticipated in aging or disease, impairs regenerative therapeutics. Most novel, mechanical unloading facilitates enhanced cardiac regeneration only after cells are pushed into a permissive state by fetal biomolecules. Specifically, mechanical unloading appears to increase extracellular agrin expression that amplifies fetal-stimulation of nuclear YAP signaling which correlates with observed increases of cell cycle activity in cardiomyocytes. The results further suggest the cytoskeleton is critical to this interaction between mechanical unloading and independently actived YAP signaling. Using animal models, tissue explants, and cells, this work indicates that local mechanical stimuli can augment proliferating-permissive cardiomyocytes in the natural cardiac niche.
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Affiliation(s)
- Xinming Wang
- Department of Biomedical Engineering, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, United States
| | - Subhadip Senapati
- Department of Ophthalmology & Visual Sciences, Case Western Reserve University, United States
| | - Akinola Akinbote
- Department of Macromolecular Science & Engineering, Case Western Reserve University, United States
| | - Bhargavee Gnanasambandam
- Department of Biomedical Engineering, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, United States
| | - Paul S-H Park
- Department of Ophthalmology & Visual Sciences, Case Western Reserve University, United States
| | - Samuel E Senyo
- Department of Biomedical Engineering, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, United States.
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Kakkad V, LeFevre M, Hollender P, Kisslo J, Trahey GE. Non-invasive Measurement of Dynamic Myocardial Stiffness Using Acoustic Radiation Force Impulse Imaging. ULTRASOUND IN MEDICINE & BIOLOGY 2019; 45:1112-1130. [PMID: 30890282 PMCID: PMC6462419 DOI: 10.1016/j.ultrasmedbio.2018.12.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Revised: 12/20/2018] [Accepted: 12/21/2018] [Indexed: 05/23/2023]
Abstract
Myocardial stiffness exhibits cyclic variations over the course of the cardiac cycle. These trends are closely tied to the electromechanical and hemodynamic changes in the heart. Characterization of dynamic myocardialstiffness can provide insights into the functional state of the myocardium, as well as allow for differentiation between the underlying physiologic mechanisms that lead to congestive heart failure. Previous work has revealed the potential of acoustic radiation force impulse (ARFI) imaging to capture temporal trends in myocardial stiffness in experimental preparations such as the Langendorff heart, as well as on animals in open-chest and intracardiac settings. This study was aimed at investigating the potential of ARFI to measure dynamic myocardial stiffness in human subjects, in a non-invasive manner through transthoracic imaging windows. ARFI imaging was performed on 12 healthy volunteers to track stiffness changes within the interventricular septum in parasternal long-axis and short-axis views. Myocardial stiffness dynamics over the cardiac cycle was quantified using five indices: stiffness ratio, rates of relaxation and contraction and time constants of relaxation and contraction. The yield of ARFI acquisitions was evaluated based on metrics of signal strength and tracking fidelity such as displacement signal-to-noise ratio, signal-to-clutter level, temporal coherence of speckle and spatial similarity within the region of excitation. These were quantified using the mean ARF-induced displacements over the cardiac cycle, the contrast between the myocardium and the cardiac chambers, the minimum correlation coefficients of radiofrequency signals and the correlation between displacement traces across simultaneously acquired azimuthal beams, respectively. Forty-one percent of ARFI acquisitions were determined to be "successful" using a mean ARF-induced displacement threshold of 1.5 μm. "Successful" acquisitions were found to have higher (i) signal-to-clutter levels, (ii) temporal coherence and (iii) spatial similarity compared with "unsuccessful" acquisitions. Median values of these three metrics, between the two groups, were measured to be 13.42dB versus 5.42dB, 0.988 versus 0.976 and 0.984 versus 0.849, respectively. Signal-to-clutter level, temporal coherence and spatial similarity were also found to correlate with each other. Across the cohort of healthy volunteers, the stiffness ratio measured was 2.74 ± 0.86; the rate of relaxation, 7.82 ± 4.69/s; and the rate of contraction, -7.31±3.79 /s. The time constant of relaxation was 35.90 ± 20.04ms, and that of contraction was 37.24 ± 19.85ms. ARFI-derived indices of myocardial stiffness were found to be similar in both views. These results indicate the feasibility of using ARFI to measure dynamic myocardial stiffness trends in a non-invasive manner and also highlightthe technical challenges of implementing this method in the transthoracic imaging environment.
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Affiliation(s)
- Vaibhav Kakkad
- Department of Biomedical Engineering, Duke University, Durham, North Carolina, USA.
| | - Melissa LeFevre
- Department of Cardiology, Duke University Hospital, Durham, North Carolina, USA
| | - Peter Hollender
- Department of Biomedical Engineering, Duke University, Durham, North Carolina, USA
| | - Joseph Kisslo
- Department of Cardiology, Duke University Hospital, Durham, North Carolina, USA
| | - Gregg E Trahey
- Department of Biomedical Engineering, Duke University, Durham, North Carolina, USA; Department of Radiology, Duke University Medical Center, Durham, North Carolina, USA
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13
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Pattar SS, Fatehi Hassanabad A, Fedak PWM. Acellular Extracellular Matrix Bioscaffolds for Cardiac Repair and Regeneration. Front Cell Dev Biol 2019; 7:63. [PMID: 31080800 PMCID: PMC6497812 DOI: 10.3389/fcell.2019.00063] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Accepted: 04/08/2019] [Indexed: 12/19/2022] Open
Abstract
Heart failure is a progressive deterioration of cardiac pump function over time and is often a manifestation of ischemic injury caused by myocardial infarction (MI). Post-MI, structural remodeling of the infarcted myocardium ensues. Dysregulation of extracellular matrix (ECM) homeostasis is a hallmark of structural cardiac remodeling and is largely driven by cardiac fibroblast activation. While initially adaptive, structural cardiac remodeling leads to irreversible heart failure due to the progressive loss of cardiac function. Loss of pump function is associated with myocardial fibrosis, wall thinning, and left ventricular (LV) dilatation. Surgical revascularization of the damaged myocardium via coronary artery bypass graft (CABG) surgery and/or percutaneous coronary intervention (PCI) can enhance myocardial perfusion and is beneficial. However, these interventions alone are unable to prevent progressive fibrotic remodeling and loss of heart function that leads to clinical end-stage heart failure. Acellular biologic ECM scaffolds can be surgically implanted onto injured myocardial regions during open-heart surgery as an adjunct therapy to surgical revascularization. This presents a novel therapeutic approach to alter maladaptive remodeling and promote functional recovery. Acellular ECM bioscaffolds have been shown to provide passive structural support to the damaged myocardium and also to act as a dynamic bioactive reservoir capable of promoting endogenous mechanisms of tissue repair, such as vasculogenesis. The composition and structure of xenogenic acellular ECM bioscaffolds are determined by the physiological requirements of the tissue from which they are derived. The capacity of different tissue-derived acellular bioscaffolds to attenuate cardiac remodeling and restore ECM homeostasis after injury may depend on such properties. Accordingly, the search and discovery of an optimal ECM bioscaffold for use in cardiac repair is warranted and may be facilitated by comparing bioscaffolds. This review will provide a summary of the acellular ECM bioscaffolds currently available for use in cardiac surgery with a focus on how they attenuate cardiac remodeling by providing the necessary environmental cues to promote endogenous mechanisms of tissue repair.
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Affiliation(s)
- Simranjit S Pattar
- Section of Cardiac Surgery, Department of Cardiac Science, Cumming School of Medicine, Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, AB, Canada
| | - Ali Fatehi Hassanabad
- Section of Cardiac Surgery, Department of Cardiac Science, Cumming School of Medicine, Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, AB, Canada
| | - Paul W M Fedak
- Section of Cardiac Surgery, Department of Cardiac Science, Cumming School of Medicine, Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, AB, Canada
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14
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Molecular Imaging to Monitor Left Ventricular Remodeling in Heart Failure. CURRENT CARDIOVASCULAR IMAGING REPORTS 2019. [DOI: 10.1007/s12410-019-9487-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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15
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Khan S, Fakhouri F, Majeed W, Kolipaka A. Cardiovascular magnetic resonance elastography: A review. NMR IN BIOMEDICINE 2018; 31:e3853. [PMID: 29193358 PMCID: PMC5975119 DOI: 10.1002/nbm.3853] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Revised: 08/25/2017] [Accepted: 09/29/2017] [Indexed: 05/19/2023]
Abstract
Cardiovascular diseases are the leading cause of death worldwide. These cardiovascular diseases are associated with mechanical changes in the myocardium and aorta. It is known that stiffness is altered in many diseases, including the spectrum of ischemia, diastolic dysfunction, hypertension and hypertrophic cardiomyopathy. In addition, the stiffness of the aortic wall is altered in multiple diseases, including hypertension, coronary artery disease and aortic aneurysm formation. For example, in diastolic dysfunction in which the ejection fraction is preserved, stiffness can potentially be an important biomarker. Similarly, in aortic aneurysms, stiffness can provide valuable information with regard to rupture potential. A number of studies have addressed invasive and non-invasive approaches to test and measure the mechanical properties of the myocardium and aorta. One of the non-invasive approaches is magnetic resonance elastography (MRE). MRE is a phase-contrast magnetic resonance imaging technique that measures tissue stiffness non-invasively. This review article highlights the technical details and application of MRE in the quantification of myocardial and aortic stiffness in different disease states.
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Affiliation(s)
- Saad Khan
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA
| | - Faisal Fakhouri
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH, 43210, USA
| | - Waqas Majeed
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA
| | - Arunark Kolipaka
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH, 43210, USA
- Department of Internal Medicine-Division of Cardiology, The Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA
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16
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Torres WM, Jacobs J, Doviak H, Barlow SC, Zile MR, Shazly T, Spinale FG. Regional and temporal changes in left ventricular strain and stiffness in a porcine model of myocardial infarction. Am J Physiol Heart Circ Physiol 2018; 315:H958-H967. [PMID: 30004234 DOI: 10.1152/ajpheart.00279.2018] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The aim of the present study was to serially track how myocardial infarction (MI) impacts regional myocardial strain and mechanical properties of the left ventricle (LV) in a large animal model. Post-MI remodeling has distinct regional effects throughout the LV myocardium. Regional quantification of LV biomechanical behavior could help explain changes in global function and thus advance clinical assessment of post-MI remodeling. The present study is based on a porcine MI model to characterize LV biomechanics over 28 days post-MI via speckle-tracking echocardiography (STE). Regional myocardial strain and strain rate were recorded in the circumferential, radial, and longitudinal directions at baseline and at 3, 14, and 28 days post-MI. Regional myocardial wall stress was calculated using standard echocardiographic metrics of geometry and Doppler-derived hemodynamic measurements. Regional diastolic myocardial stiffness was calculated from the resultant stress-strain relations. Peak strain and phasic strain rates were nonuniformly reduced throughout the myocardium post-MI, whereas time to peak strain was increased to a similar degree in the MI region and border zone by 28 days post-MI. Elevations in diastolic myocardial stiffness in the MI region plateaued at 14 days post-MI, after which a significant reduction in MI regional stiffness in the longitudinal direction occurred between 14 and 28 days post-MI. Post-MI biomechanical changes in the LV myocardium were initially limited to the MI region but nonuniformly extended into the neighboring border zone and remote myocardium over 28 days post-MI. STE enabled quantification of regional and temporal differences in myocardial strain and diastolic stiffness, underscoring the potential of this technique for clinical assessment of post-MI remodeling. NEW & NOTEWORTHY For the first time, speckle-tracking echocardiography was used to serially track regional biomechanical behavior and mechanical properties postmyocardial infarction (post-MI). We found that changes initially confined to the MI region extended throughout the myocardium in a nonuniform fashion over 28 days post-MI. Speckle-tracking echocardiography-based evaluation of regional changes in left ventricular biomechanics could advance both clinical assessment of left ventricular remodeling and therapeutic strategies that target aberrant biomechanical behavior post-MI.
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Affiliation(s)
- William M Torres
- College of Engineering and Computing, University of South Carolina , Columbia, South Carolina.,Cardiovascular Translational Research Center, University of South Carolina School of Medicine and the William Jennings Bryan Dorn Veteran Affairs Medical Center , Columbia, South Carolina
| | - Julia Jacobs
- Cardiovascular Translational Research Center, University of South Carolina School of Medicine and the William Jennings Bryan Dorn Veteran Affairs Medical Center , Columbia, South Carolina
| | - Heather Doviak
- Cardiovascular Translational Research Center, University of South Carolina School of Medicine and the William Jennings Bryan Dorn Veteran Affairs Medical Center , Columbia, South Carolina
| | - Shayne C Barlow
- Cardiovascular Translational Research Center, University of South Carolina School of Medicine and the William Jennings Bryan Dorn Veteran Affairs Medical Center , Columbia, South Carolina
| | - Michael R Zile
- Medical University of South Carolina and Ralph H. Johnson Department of Veterans Affairs Medical Center , Charleston, South Carolina
| | - Tarek Shazly
- College of Engineering and Computing, University of South Carolina , Columbia, South Carolina
| | - Francis G Spinale
- College of Engineering and Computing, University of South Carolina , Columbia, South Carolina.,Cardiovascular Translational Research Center, University of South Carolina School of Medicine and the William Jennings Bryan Dorn Veteran Affairs Medical Center , Columbia, South Carolina
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17
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Miller R, Kolipaka A, Nash MP, Young AA. Estimation of transversely isotropic material properties from magnetic resonance elastography using the optimised virtual fields method. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2018; 34. [PMID: 29528568 PMCID: PMC5993646 DOI: 10.1002/cnm.2979] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Magnetic resonance elastography (MRE) has been used to estimate isotropic myocardial stiffness. However, anisotropic stiffness estimates may give insight into structural changes that occur in the myocardium as a result of pathologies such as diastolic heart failure. The virtual fields method (VFM) has been proposed for estimating material stiffness from image data. This study applied the optimised VFM to identify transversely isotropic material properties from both simulated harmonic displacements in a left ventricular (LV) model with a fibre field measured from histology as well as isotropic phantom MRE data. Two material model formulations were implemented, estimating either 3 or 5 material properties. The 3-parameter formulation writes the transversely isotropic constitutive relation in a way that dissociates the bulk modulus from other parameters. Accurate identification of transversely isotropic material properties in the LV model was shown to be dependent on the loading condition applied, amount of Gaussian noise in the signal, and frequency of excitation. Parameter sensitivity values showed that shear moduli are less sensitive to noise than the other parameters. This preliminary investigation showed the feasibility and limitations of using the VFM to identify transversely isotropic material properties from MRE images of a phantom as well as simulated harmonic displacements in an LV geometry.
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Affiliation(s)
- Renee Miller
- Department of Anatomy and Medical Imaging, University of Auckland, Auckland, New Zealand
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Arunark Kolipaka
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Martyn P. Nash
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
- Department of Engineering Science, University of Auckland, Auckland, New Zealand
| | - Alistair A. Young
- Department of Anatomy and Medical Imaging, University of Auckland, Auckland, New Zealand
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
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18
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Wang S, Singh M, Tran TT, Leach J, Aglyamov SR, Larina IV, Martin JF, Larin KV. Biomechanical assessment of myocardial infarction using optical coherence elastography. BIOMEDICAL OPTICS EXPRESS 2018; 9:728-742. [PMID: 29552408 PMCID: PMC5854074 DOI: 10.1364/boe.9.000728] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Revised: 12/26/2017] [Accepted: 12/27/2017] [Indexed: 05/18/2023]
Abstract
Myocardial infarction (MI) leads to cardiomyocyte loss, impaired cardiac function, and heart failure. Molecular genetic analyses of myocardium in mouse models of ischemic heart disease have provided great insight into the mechanisms of heart regeneration, which is promising for novel therapies after MI. Although biomechanical factors are considered an important aspect in cardiomyocyte proliferation, there are limited methods for mechanical assessment of the heart in the mouse MI model. This prevents further understanding the role of tissue biomechanics in cardiac regeneration. Here we report optical coherence elastography (OCE) of the mouse heart after MI. Surgical ligation of the left anterior descending coronary artery was performed to induce an infarction in the heart. Two OCE methods with assessment of the direction-dependent elastic wave propagation and the spatially resolved displacement damping provide complementary analyses of the left ventricle. In comparison with sham, the infarcted heart features a fibrotic scar region with reduced elastic wave velocity, decreased natural frequency, and less mechanical anisotropy at the tissue level at the sixth week post-MI, suggesting lower and more isotropic stiffness. Our results indicate that OCE can be utilized for nondestructive biomechanical characterization of MI in the mouse model, which could serve as a useful tool in the study of heart repair.
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Affiliation(s)
- Shang Wang
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, One Baylor Plaza, Houston, Texas 77030, USA
- Equal contribution
| | - Manmohan Singh
- Department of Biomedical Engineering, University of Houston, 3605 Cullen Boulevard, Houston, Texas 77204, USA
- Equal contribution
| | - Thuy Tien Tran
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, One Baylor Plaza, Houston, Texas 77030, USA
| | - John Leach
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, One Baylor Plaza, Houston, Texas 77030, USA
| | - Salavat R. Aglyamov
- Department of Mechanical Engineering, University of Houston, 4726 Calhoun Road, Houston, Texas 77204, USA
| | - Irina V. Larina
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, One Baylor Plaza, Houston, Texas 77030, USA
| | - James F. Martin
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, One Baylor Plaza, Houston, Texas 77030, USA
- The Texas Heart Institute, 6770 Bertner Avenue, Houston, Texas 77030, USA
| | - Kirill V. Larin
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, One Baylor Plaza, Houston, Texas 77030, USA
- Department of Biomedical Engineering, University of Houston, 3605 Cullen Boulevard, Houston, Texas 77204, USA
- Interdisciplinary Laboratory of Biophotonics, Tomsk State University, 36 Lenin Ave., Tomsk 634050, Russia
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19
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Sui Y, Arunachalam SP, Arani A, Trzasko JD, Young PM, Glockner JF, Glaser KJ, Lake DS, McGee KP, Manduca A, Rossman PJ, Ehman RL, Araoz PA. Cardiac MR elastography using reduced-FOV, single-shot, spin-echo EPI. Magn Reson Med 2017; 80:231-238. [PMID: 29194738 PMCID: PMC5876088 DOI: 10.1002/mrm.27029] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Revised: 10/29/2017] [Accepted: 11/09/2017] [Indexed: 12/13/2022]
Abstract
Purpose To implement a reduced field of view (rFOV) technique for cardiac MR elastography (MRE) and to demonstrate the improvement in image quality of both magnitude images and post‐processed MRE stiffness maps compared to the conventional full field of view (full‐FOV) acquisition. Methods With Institutional Review Board approval, 17 healthy volunteers underwent both full‐FOV and rFOV cardiac MRE scans using 140‐Hz vibrations. Two cardiac radiologists blindly compared the magnitude images and stiffness maps and graded the images based on several image quality attributes using a 5‐point ordinal scale. Fisher's combined probability test was performed to assess the overall evaluation. The octahedral shear strain‐based signal‐to‐noise ratio (OSS‐SNR) and median stiffness over the left ventricular myocardium were also compared. Results One volunteer was excluded because of an inconsistent imaging resolution during the exam. In the remaining 16 volunteers (9 males, 7 females), the rFOV scans outperformed the full‐FOV scans in terms of subjective image quality and ghosting artifacts in the magnitude images and stiffness maps, as well as the overall preference. The quantitative measurements showed that rFOV had significantly higher OSS‐SNR (median: 1.4 [95% confidence interval (CI): 1.2–1.5] vs. 2.1 [95% CI: 1.8–2.4]), P < 0.05) compared to full‐FOV. Although no significant change was found in the median myocardial stiffness between the 2 scans, we observed a decrease in the stiffness variation within the myocardium from 2.1 kPa (95% CI: [1.9, 2.3]) to 1.9 kPa (95% CI: [1.7, 2.0]) for full‐FOV and rFOV, respectively (P < 0.05) in a subgroup of 7 subjects with ghosting present in the myocardium. Conclusion This pilot volunteer study demonstrated that rFOV cardiac MRE has the capability to reduce ghosting and to improve image quality in both MRE magnitude images and stiffness maps. Magn Reson Med 80:231–238, 2018. © 2017 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.
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Affiliation(s)
- Yi Sui
- Department of Radiology, Mayo Clinic, Rochester, Minnesota, USA
| | | | - Arvin Arani
- Department of Radiology, Mayo Clinic, Rochester, Minnesota, USA
| | | | - Phillip M Young
- Department of Radiology, Mayo Clinic, Rochester, Minnesota, USA
| | | | - Kevin J Glaser
- Department of Radiology, Mayo Clinic, Rochester, Minnesota, USA
| | - David S Lake
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota, USA
| | - Kiaran P McGee
- Department of Radiology, Mayo Clinic, Rochester, Minnesota, USA
| | - Armando Manduca
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota, USA
| | | | - Richard L Ehman
- Department of Radiology, Mayo Clinic, Rochester, Minnesota, USA
| | - Philip A Araoz
- Department of Radiology, Mayo Clinic, Rochester, Minnesota, USA
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