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Federspiel JM, Reil JC, Xu A, Scholtz S, Batzner A, Maack C, Sequeira V. Retrofitting the Heart: Explaining the Enigmatic Septal Thickening in Hypertrophic Cardiomyopathy. Circ Heart Fail 2024; 17:e011435. [PMID: 38695186 DOI: 10.1161/circheartfailure.123.011435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Accepted: 02/26/2024] [Indexed: 05/23/2024]
Abstract
Hypertrophic cardiomyopathy is the most common genetic cardiac disease and is characterized by left ventricular hypertrophy. Although this hypertrophy often associates with sarcomeric gene mutations, nongenetic factors also contribute to the disease, leading to diastolic dysfunction. Notably, this dysfunction manifests before hypertrophy and is linked to hypercontractility, as well as nonuniform contraction and relaxation (myofibril asynchrony) of the myocardium. Although the distribution of hypertrophy in hypertrophic cardiomyopathy can vary both between and within individuals, in most cases, it is primarily confined to the interventricular septum. The reasons for septal thickening remain largely unknown. In this article, we propose that alterations in muscle fiber geometry, present from birth, dictate the septal shape. When combined with hypercontractility and exacerbated by left ventricular outflow tract obstruction, these factors predispose the septum to an isometric type of contraction during systole, consequently constraining its mobility. This contraction, or more accurately, this focal increase in biomechanical stress, prompts the septum to adapt and undergo remodeling. Drawing a parallel, this is reminiscent of how earthquake-resistant buildings are retrofitted with vibration dampers to absorb the majority of the shock motion and load. Similarly, the heart adapts by synthesizing viscoelastic elements such as microtubules, titin, desmin, collagen, and intercalated disc components. This pronounced remodeling in the cytoskeletal structure leads to noticeable septal hypertrophy. This structural adaptation acts as a protective measure against damage by attenuating myofibril shortening while reducing cavity tension according to Laplace Law. By examining these events, we provide a coherent explanation for the septum's predisposition toward hypertrophy.
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Affiliation(s)
- Jan M Federspiel
- Comprehensive Heart Failure Center, Department of Translational Science University Clinic Würzburg, Germany (J.M.F., A.X., A.B., C.M., V.S.)
- Saarland University, Faculty of Medicine, Institute for Legal Medicine, Homburg (Saar), Germany (J.M.F.)
| | - Jan-Christian Reil
- Klinik für allgemeine und interventionelle Kardiologie, Herz- und Diabetes-Zentrum Nordrhein-Westphalen, Germany (J.-C.R., S.S.)
| | - Anton Xu
- Comprehensive Heart Failure Center, Department of Translational Science University Clinic Würzburg, Germany (J.M.F., A.X., A.B., C.M., V.S.)
| | - Smita Scholtz
- Klinik für allgemeine und interventionelle Kardiologie, Herz- und Diabetes-Zentrum Nordrhein-Westphalen, Germany (J.-C.R., S.S.)
| | - Angelika Batzner
- Comprehensive Heart Failure Center, Department of Translational Science University Clinic Würzburg, Germany (J.M.F., A.X., A.B., C.M., V.S.)
- Department of Internal Medicine I, University Hospital Würzburg, Germany (A.B.)
| | - Christoph Maack
- Comprehensive Heart Failure Center, Department of Translational Science University Clinic Würzburg, Germany (J.M.F., A.X., A.B., C.M., V.S.)
| | - Vasco Sequeira
- Comprehensive Heart Failure Center, Department of Translational Science University Clinic Würzburg, Germany (J.M.F., A.X., A.B., C.M., V.S.)
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Lunkenheimer PP, Hagendorff A, Lunkenheimer JM, Gülker HK, Niederer P. Antagonism of contractile forces in left ventricular hypertrophy: a diagnostic challenge for better pathophysiological and clinical understanding. Open Heart 2023; 10:e002351. [PMID: 37827810 PMCID: PMC10582970 DOI: 10.1136/openhrt-2023-002351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/11/2023] [Indexed: 10/14/2023] Open
Abstract
Cardiac function is characterised by haemodynamic parameters in the clinical scenario. Due to recent development in imaging techniques, the clinicians focus on the quantitative assessment of left ventricular size, shape and motion patterns mostly analysed by echocardiography and cardiac magnetic resonance. Because of the physiologically known antagonistic structure and function of the heart muscle, the effective performance of the heart remains hidden behind haemodynamic parameters. In fact, a smaller component of oblique transmural netting of cardiac muscle fibres simultaneously engenders contracting and dilating force vectors, while the predominant mass of the tangentially aligned fibres only acts in one direction. In case of hypertrophy, an increased influence of the dilating transmural fibre component might counteract systolic wall thickening, thereby counteract cardiac output. A further important aspect is the response to inotropic stimulation that is different for the tangentially aligned fibre component in comparison to the transmural component. Both aspects highlight the importance to integrate the analysis of intramural fibre architecture into the clinical cardiac diagnostics.
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Affiliation(s)
- Paul Peter Lunkenheimer
- Department of Experimental Thoracic, Cardiac and Vascular Surgery, University of Münster, Münster, Germany
| | | | | | - Hartmut Karl Gülker
- Department of Cardiology, HELIOS University Hospital Wuppertal, Wuppertal, Nordrhein-Westfalen, Germany
| | - Peter Niederer
- Institute of Biomedical Engineering, University and ETH (Eidgenössische Technische Hochschule), Zürich, Switzerland
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Wei L, Wang S, Shan M, Li Y, Wang Y, Wang F, Wang L, Mao J. Conductive fibers for biomedical applications. Bioact Mater 2023; 22:343-364. [PMID: 36311045 PMCID: PMC9588989 DOI: 10.1016/j.bioactmat.2022.10.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 09/12/2022] [Accepted: 10/07/2022] [Indexed: 11/26/2022] Open
Abstract
Bioelectricity has been stated as a key factor in regulating cell activity and tissue function in electroactive tissues. Thus, various biomedical electronic constructs have been developed to interfere with cell behaviors to promote tissue regeneration, or to interface with cells or tissue/organ surfaces to acquire physiological status via electrical signals. Benefiting from the outstanding advantages of flexibility, structural diversity, customizable mechanical properties, and tunable distribution of conductive components, conductive fibers are able to avoid the damage-inducing mechanical mismatch between the construct and the biological environment, in return to ensure stable functioning of such constructs during physiological deformation. Herein, this review starts by presenting current fabrication technologies of conductive fibers including wet spinning, microfluidic spinning, electrospinning and 3D printing as well as surface modification on fibers and fiber assemblies. To provide an update on the biomedical applications of conductive fibers and fiber assemblies, we further elaborate conductive fibrous constructs utilized in tissue engineering and regeneration, implantable healthcare bioelectronics, and wearable healthcare bioelectronics. To conclude, current challenges and future perspectives of biomedical electronic constructs built by conductive fibers are discussed.
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Affiliation(s)
- Leqian Wei
- Key Laboratory of Textile Science & Technology, Ministry of Education, College of Textiles, Donghua University, Shanghai, 201620, China
- Key Laboratory of Textile Industry for Biomedical Textile Materials and Technology, Donghua University, Shanghai, 201620, China
| | - Shasha Wang
- Key Laboratory of Textile Science & Technology, Ministry of Education, College of Textiles, Donghua University, Shanghai, 201620, China
- Key Laboratory of Textile Industry for Biomedical Textile Materials and Technology, Donghua University, Shanghai, 201620, China
| | - Mengqi Shan
- Key Laboratory of Textile Science & Technology, Ministry of Education, College of Textiles, Donghua University, Shanghai, 201620, China
- Key Laboratory of Textile Industry for Biomedical Textile Materials and Technology, Donghua University, Shanghai, 201620, China
| | - Yimeng Li
- Key Laboratory of Textile Science & Technology, Ministry of Education, College of Textiles, Donghua University, Shanghai, 201620, China
- Key Laboratory of Textile Industry for Biomedical Textile Materials and Technology, Donghua University, Shanghai, 201620, China
| | - Yongliang Wang
- School of Health and Life Sciences, University of Health and Rehabilitation Sciences, Qingdao City, Shandong Province, 266071, China
| | - Fujun Wang
- Key Laboratory of Textile Science & Technology, Ministry of Education, College of Textiles, Donghua University, Shanghai, 201620, China
- Key Laboratory of Textile Industry for Biomedical Textile Materials and Technology, Donghua University, Shanghai, 201620, China
| | - Lu Wang
- Key Laboratory of Textile Science & Technology, Ministry of Education, College of Textiles, Donghua University, Shanghai, 201620, China
- Key Laboratory of Textile Industry for Biomedical Textile Materials and Technology, Donghua University, Shanghai, 201620, China
| | - Jifu Mao
- Key Laboratory of Textile Science & Technology, Ministry of Education, College of Textiles, Donghua University, Shanghai, 201620, China
- Key Laboratory of Textile Industry for Biomedical Textile Materials and Technology, Donghua University, Shanghai, 201620, China
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Prognostic Value of Preprocedural LV Global Longitudinal Strain for Post-TAVR-Related Morbidity and Mortality: A Meta-Analysis. JACC Cardiovasc Imaging 2023; 16:332-341. [PMID: 36889849 DOI: 10.1016/j.jcmg.2023.01.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Revised: 09/26/2022] [Accepted: 01/03/2023] [Indexed: 03/08/2023]
Abstract
BACKGROUND Left ventricular ejection fraction (LVEF) demonstrates limited prognostic value for post-transcatheter aortic valve replacement (TAVR) outcomes. Evidence regarding the potential role of left ventricular global longitudinal strain (LV-GLS) in this setting is inconsistent. OBJECTIVES The aim of this systematic review and meta-analysis of aggregated data was to evaluate the prognostic value of preprocedural LV-GLS for post-TAVR-related morbidity and mortality. METHODS The authors searched PubMed, Embase, and Web of Science for studies investigating the association between preprocedural 2-dimensional speckle-tracking-derived LV-GLS and post-TAVR clinical outcomes. An inversely weighted random effects meta-analysis was adopted to investigate the association between LV-GLS vs primary (ie, all-cause mortality) and secondary (ie, major cardiovascular events [MACE]) post-TAVR outcomes. RESULTS Of the 1,130 identified records, 12 were eligible, all of which had a low-to-moderate risk of bias (Newcastle-Ottawa scale). On average, 2,049 patients demonstrated preserved LVEF (52.6% ± 1.7%), but impaired LV-GLS (-13.6% ± 0.6%). Patients with a lower LV-GLS had a higher all-cause mortality (pooled HR: 2.01; 95% CI: 1.59-2.55) and MACE (pooled odds ratio [OR]: 1.26; 95% CI: 1.08-1.47) risk compared with patients with higher LV-GLS. In addition, each percentage point decrease of LV-GLS (ie, toward 0%) was associated with an increased mortality (HR: 1.06; 95% CI: 1.04-1.08) and MACE risk (OR: 1.08; 95% CI: 1.01-1.15). CONCLUSIONS Preprocedural LV-GLS was significantly associated with post-TAVR morbidity and mortality. This suggests a potential clinically important role of pre-TAVR evaluation of LV-GLS for risk stratification of patients with severe aortic stenosis. (Prognostic value of left ventricular global longitudinal strain in patients with aortic stenosis undergoing Transcatheter Aortic Valve Implantation: a meta-analysis; CRD42021289626).
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Wang S, Cui J, Jing Y, Varray F. Oscillation of the orientation of cardiomyocyte aggregates in human left ventricle free wall. J Anat 2023; 242:373-386. [PMID: 36395157 PMCID: PMC9919520 DOI: 10.1111/joa.13795] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2022] [Revised: 11/08/2022] [Accepted: 11/09/2022] [Indexed: 11/19/2022] Open
Abstract
Orientation of local cardiomyocyte aggregates in the human left ventricle free wall experiences an oscillation in the laminar structure regions, besides its gradual change trend. We described this oscillation using five transmural samples imaged at the European Synchrotron Radiation Facility with an isotropic voxel size of 3.5 × 3.5 × 3.5 μm3 . In the reconstructed volume of each sample, we manually selected a region containing a regular laminar structure as the region of interest and measured the distribution of the orientation of local cardiomyocyte aggregates inside using a Fourier-based method. Then, we extracted the gradual change part of the orientation of cardiomyocyte aggregates with a three-dimensional centered Gaussian filter and measured the angle between the original orientation vector of local cardiomyocyte aggregates and its gradual change part. Further, we assessed the measured angles in different local coordinates. The results indicate that the oscillation amplitude of the orientation of cardiomyocyte aggregates is regional in the left ventricle wall, which may promote our understanding of the rearrangement mechanism of the cardiomyocyte aggregates and provide a new biomarker to study the heart physiological status.
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Affiliation(s)
- Shunli Wang
- Center of Ultra-Precision Optoelectronic Instrument Engineering, Harbin Institute of Technology, Harbin, China.,Key Lab of Ultra-Precision Intelligent Instrumentation (Harbin Institute of Technology), Ministry of Industry and Information Technology, Harbin, China
| | - Junning Cui
- Center of Ultra-Precision Optoelectronic Instrument Engineering, Harbin Institute of Technology, Harbin, China.,Key Lab of Ultra-Precision Intelligent Instrumentation (Harbin Institute of Technology), Ministry of Industry and Information Technology, Harbin, China
| | - Yuhan Jing
- Univ Lyon, INSA-Lyon, Université Claude Bernard Lyon 1, CNRS, Inserm, CREATIS UMR 5220 U1294, Lyon, France
| | - François Varray
- Univ Lyon, INSA-Lyon, Université Claude Bernard Lyon 1, CNRS, Inserm, CREATIS UMR 5220 U1294, Lyon, France
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6
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Garcia-Canadilla P, Mohun TJ, Bijnens B, Cook AC. Detailed quantification of cardiac ventricular myocardial architecture in the embryonic and fetal mouse heart by application of structure tensor analysis to high resolution episcopic microscopic data. Front Cell Dev Biol 2022; 10:1000684. [DOI: 10.3389/fcell.2022.1000684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Accepted: 10/31/2022] [Indexed: 11/18/2022] Open
Abstract
The mammalian heart, which is one of the first organs to form and function during embryogenesis, develops from a simple tube into a complex organ able to efficiently pump blood towards the rest of the body. The progressive growth of the compact myocardium during embryonic development is accompanied by changes in its structural complexity and organisation. However, how myocardial myoarchitecture develops during embryogenesis remain poorly understood. To date, analysis of heart development has focused mainly on qualitative descriptions using selected 2D histological sections. High resolution episcopic microscopy (HREM) is a novel microscopic imaging technique that enables to obtain high-resolution three-dimensional images of the heart and perform detailed quantitative analyses of heart development. In this work, we performed a detailed characterization of the development of myocardial architecture in wildtype mice, from E14.5 to E18.5, by means of structure tensor analysis applied to HREM images of the heart. Our results shows that even at E14.5, myocytes are already aligned, showing a gradual change in their helical angle from positive angulation in the endocardium towards negative angulation in the epicardium. Moreover, there is gradual increase in the degree of myocardial organisation concomitant with myocardial growth. However, the development of the myoarchitecture is heterogeneous showing regional differences between ventricles, ventricular walls as well as between myocardial layers, with different growth patterning between the endocardium and epicardium. We also found that the percentage of circumferentially arranged myocytes within the LV significantly increases with gestational age. Finally, we found that fractional anisotropy (FA) within the LV gradually increases with gestational age, while the FA within RV remains unchanged.
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7
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Wilson AJ, Sands GB, LeGrice IJ, Young AA, Ennis DB. Myocardial mesostructure and mesofunction. Am J Physiol Heart Circ Physiol 2022; 323:H257-H275. [PMID: 35657613 PMCID: PMC9273275 DOI: 10.1152/ajpheart.00059.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 05/23/2022] [Accepted: 05/23/2022] [Indexed: 11/22/2022]
Abstract
The complex and highly organized structural arrangement of some five billion cardiomyocytes directs the coordinated electrical activity and mechanical contraction of the human heart. The characteristic transmural change in cardiomyocyte orientation underlies base-to-apex shortening, circumferential shortening, and left ventricular torsion during contraction. Individual cardiomyocytes shorten ∼15% and increase in diameter ∼8%. Remarkably, however, the left ventricular wall thickens by up to 30-40%. To accommodate this, the myocardium must undergo significant structural rearrangement during contraction. At the mesoscale, collections of cardiomyocytes are organized into sheetlets, and sheetlet shear is the fundamental mechanism of rearrangement that produces wall thickening. Herein, we review the histological and physiological studies of myocardial mesostructure that have established the sheetlet shear model of wall thickening. Recent developments in tissue clearing techniques allow for imaging of whole hearts at the cellular scale, whereas magnetic resonance imaging (MRI) and computed tomography (CT) can image the myocardium at the mesoscale (100 µm to 1 mm) to resolve cardiomyocyte orientation and organization. Through histology, cardiac diffusion tensor imaging (DTI), and other modalities, mesostructural sheetlets have been confirmed in both animal and human hearts. Recent in vivo cardiac DTI methods have measured reorientation of sheetlets during the cardiac cycle. We also examine the role of pathological cardiac remodeling on sheetlet organization and reorientation, and the impact this has on ventricular function and dysfunction. We also review the unresolved mesostructural questions and challenges that may direct future work in the field.
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Affiliation(s)
- Alexander J Wilson
- Department of Radiology, Stanford University, Stanford, California
- Stanford Cardiovascular Institute, Stanford University, Stanford, California
| | - Gregory B Sands
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Ian J LeGrice
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
- Department of Physiology, University of Auckland, Auckland, New Zealand
| | - Alistair A Young
- Department of Anatomy and Medical Imaging, University of Auckland, Auckland, New Zealand
- Department of Biomedical Engineering, King's College London, London, United Kingdom
| | - Daniel B Ennis
- Department of Radiology, Stanford University, Stanford, California
- Veterans Administration Palo Alto Health Care System, Palo Alto, California
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Hirono K, Ichida F. Left ventricular noncompaction: a disorder with genotypic and phenotypic heterogeneity-a narrative review. Cardiovasc Diagn Ther 2022; 12:495-515. [PMID: 36033229 PMCID: PMC9412206 DOI: 10.21037/cdt-22-198] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 07/21/2022] [Indexed: 01/10/2023]
Abstract
Background and Objective Left ventricular noncompaction (LVNC) is a cardiomyopathy characterized by excessive trabecular formation and deep recesses in the ventricular wall, with a bilaminar structure consisting of an endocardial noncompaction layer and an epicardial compacted layer. Although genetic variants have been reported in patients with LVNC, understanding of LVNC and its pathogenesis has not yet been fully elucidated. We addressed the latest findings on genes reported to be associated with LVNC morphogenesis and possible pathologies to understand the diverse spectrum between genotype and phenotype in LVNC. Also, the latest findings and issues related to the diagnosis of LVNC were summarized. Methods This article is written as a commentary narrative review and will provide an update on the current literature and available data on common forms of LVNC published in the past 30 years in English through to May 2022 using PubMed. Key Content and Findings Familial forms of LVNC are frequent, and autosomal dominant mode of inheritance has been predominantly observed. Several of the candidate causative genes are also mutated in other cardiomyopathies, suggesting a possible shared molecular and/or cellular etiology. The most common gene functions were sarcomere function whereas genes in mice LVNC models were involved in heart development. Echocardiography and cardiac magnetic resonance imaging (CMR) are useful for diagnosis although there are no unified criteria due to overdiagnosis of imaging, poor consistency between techniques, and lack of association between trabecular severity and adverse clinical outcomes. Conclusions This review reflects the current lack of clarity regarding the pathogenesis and significance of LVNC and showed the complexity of imaging diagnostic criteria, interpretation of the role of LVNC as a cause, and uncertainty regarding the specific genetic basis of LVNC.
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Affiliation(s)
- Keiichi Hirono
- Department of Pediatrics, Graduate School of Medicine, University of Toyama, Toyama, Japan
| | - Fukiko Ichida
- Department of Pediatrics, International University of Health and Welfare, Tokyo, Japan
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9
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Maleszewski JJ, Lai CK, Nair V, Veinot JP. Anatomic considerations and examination of cardiovascular specimens (excluding devices). Cardiovasc Pathol 2022. [DOI: 10.1016/b978-0-12-822224-9.00013-x] [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: 11/26/2022] Open
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10
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The Myosin Myocardial Mesh Interpreted as a Biological Analogous of Nematic Chiral Liquid Crystals. J Cardiovasc Dev Dis 2021; 8:jcdd8120179. [PMID: 34940534 PMCID: PMC8708414 DOI: 10.3390/jcdd8120179] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 11/26/2021] [Accepted: 12/04/2021] [Indexed: 11/17/2022] Open
Abstract
There are still grey areas in the understanding of the myoarchitecture of the ventricular mass. This is despite the progress of investigation methods since the beginning of the 21st century (diffusion tensor magnetic resonance imaging, microcomputed tomography, and polarised light imaging). The objective of this article is to highlight the specificities and the limitations of polarised light imaging (PLI) of the unstained myocardium embedded in methyl methacrylate (MMA). Thus, to better differentiate our method from other PLI modes, we will refer to it by the acronym PLI-MMA. PLI-MMA shows that the myosin mesh of the compact left ventricular wall behaves like a biological analogous of a nematic chiral liquid crystal. Results obtained by PLI-MMA are: the main direction of the myosin molecules contained in an imaged voxel, the crystal liquid director n, and a regional isotropy index RI that is an orientation tensor, the equivalent of the crystal liquid order parameter. The vector n is collinear with the first eigenvector of diffusion tensor imaging (DTI-MRI). The RI has not been confounded with the diffusion tensor of DTI that gives information about the three eigenvectors of the ellipsoid of diffusion. PLI-MMA gives no information about the collagen network. The physics of soft matter has allowed the revisiting of Streeter’s conjecture on the myoarchitecture of the compact left ventricular wall: “geodesics on a nested set of toroidal surfaces”. Once the torus topology is understood, this characterisation of the myoarchitecture is more accurate and parsimonious than former descriptions. Finally, this article aims to be an enthusiastic invitation to a transdisciplinary approach between physicists of liquid crystals, anatomists, and specialists of imaging.
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Agger P, Stephenson RS. Assessing Myocardial Architecture: The Challenges and Controversies. J Cardiovasc Dev Dis 2020; 7:jcdd7040047. [PMID: 33137874 PMCID: PMC7711767 DOI: 10.3390/jcdd7040047] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 10/04/2020] [Accepted: 10/08/2020] [Indexed: 12/16/2022] Open
Abstract
In recent decades, investigators have strived to describe and quantify the orientation of the cardiac myocytes in an attempt to classify their arrangement in healthy and diseased hearts. There are, however, striking differences between the investigations from both a technical and methodological standpoint, thus limiting their comparability and impeding the drawing of appropriate physiological conclusions from the structural assessments. This review aims to elucidate these differences, and to propose guidance to establish methodological consensus in the field. The review outlines the theory behind myocyte orientation analysis, and importantly has identified pronounced differences in the definitions of otherwise widely accepted concepts of myocytic orientation. Based on the findings, recommendations are made for the future design of studies in the field of myocardial morphology. It is emphasised that projection of myocyte orientations, before quantification of their angulation, introduces considerable bias, and that angles should be assessed relative to the epicardial curvature. The transmural orientation of the cardiomyocytes should also not be neglected, as it is an important determinant of cardiac function. Finally, there is considerable disagreement in the literature as to how the orientation of myocardial aggregates should be assessed, but to do so in a mathematically meaningful way, the normal vector of the aggregate plane should be utilised.
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Affiliation(s)
- Peter Agger
- Comparative Medicine Lab, Department of Clinical Medicine, Aarhus University, 8220 Aarhus N, Denmark
- Department of Pediatrics, Randers Regional Hospital, Skovlyvej 15, 8930 Randers NE, Denmark
- Correspondence:
| | - Robert S. Stephenson
- Institute of Clinical Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham B15 2TT, UK;
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12
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Dejea H, Bonnin A, Cook AC, Garcia-Canadilla P. Cardiac multi-scale investigation of the right and left ventricle ex vivo: a review. Cardiovasc Diagn Ther 2020; 10:1701-1717. [PMID: 33224784 DOI: 10.21037/cdt-20-269] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The heart is a complex multi-scale system composed of components integrated at the subcellular, cellular, tissue and organ levels. The myocytes, the contractile elements of the heart, form a complex three-dimensional (3D) network which enables propagation of the electrical signal that triggers the contraction to efficiently pump blood towards the whole body. Cardiovascular diseases (CVDs), a major cause of mortality in developed countries, often lead to cardiovascular remodeling affecting cardiac structure and function at all scales, from myocytes and their surrounding collagen matrix to the 3D organization of the whole heart. As yet, there is no consensus as to how the myocytes are arranged and packed within their connective tissue matrix, nor how best to image them at multiple scales. Cardiovascular imaging is routinely used to investigate cardiac structure and function as well as for the evaluation of cardiac remodeling in CVDs. For a complete understanding of the relationship between structural remodeling and cardiac dysfunction in CVDs, multi-scale imaging approaches are necessary to achieve a detailed description of ventricular architecture along with cardiac function. In this context, ventricular architecture has been extensively studied using a wide variety of imaging techniques: ultrasound (US), optical coherence tomography (OCT), microscopy (confocal, episcopic, light sheet, polarized light), magnetic resonance imaging (MRI), micro-computed tomography (micro-CT) and, more recently, synchrotron X-ray phase contrast imaging (SR X-PCI). Each of these techniques have their own set of strengths and weaknesses, relating to sample size, preparation, resolution, 2D/3D capabilities, use of contrast agents and possibility of performing together with in vivo studies. Therefore, the combination of different imaging techniques to investigate the same sample, thus taking advantage of the strengths of each method, could help us to extract the maximum information about ventricular architecture and function. In this review, we provide an overview of available and emerging cardiovascular imaging techniques for assessing myocardial architecture ex vivo and discuss their utility in being able to quantify cardiac remodeling, in CVDs, from myocyte to whole organ.
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Affiliation(s)
- Hector Dejea
- Paul Scherrer Institut, Villigen PSI, Villigen, Switzerland.,Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland
| | - Anne Bonnin
- Paul Scherrer Institut, Villigen PSI, Villigen, Switzerland
| | - Andrew C Cook
- Institute of Cardiovascular Science, University College London, London, UK
| | - Patricia Garcia-Canadilla
- Institute of Cardiovascular Science, University College London, London, UK.,Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
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13
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Taverne YJHJ, Sadeghi A, Bartelds B, Bogers AJJC, Merkus D. Right ventricular phenotype, function, and failure: a journey from evolution to clinics. Heart Fail Rev 2020; 26:1447-1466. [PMID: 32556672 PMCID: PMC8510935 DOI: 10.1007/s10741-020-09982-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The right ventricle has long been perceived as the "low pressure bystander" of the left ventricle. Although the structure consists of, at first glance, the same cardiomyocytes as the left ventricle, it is in fact derived from a different set of precursor cells and has a complex three-dimensional anatomy and a very distinct contraction pattern. Mechanisms of right ventricular failure, its detection and follow-up, and more specific different responses to pressure versus volume overload are still incompletely understood. In order to fully comprehend right ventricular form and function, evolutionary biological entities that have led to the specifics of right ventricular physiology and morphology need to be addressed. Processes responsible for cardiac formation are based on very ancient cardiac lineages and within the first few weeks of fetal life, the human heart seems to repeat cardiac evolution. Furthermore, it appears that most cardiogenic signal pathways (if not all) act in combination with tissue-specific transcriptional cofactors to exert inductive responses reflecting an important expansion of ancestral regulatory genes throughout evolution and eventually cardiac complexity. Such molecular entities result in specific biomechanics of the RV that differs from that of the left ventricle. It is clear that sole descriptions of right ventricular contraction patterns (and LV contraction patterns for that matter) are futile and need to be addressed into a bigger multilayer three-dimensional picture. Therefore, we aim to present a complete picture from evolution, formation, and clinical presentation of right ventricular (mal)adaptation and failure on a molecular, cellular, biomechanical, and (patho)anatomical basis.
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Affiliation(s)
- Yannick J H J Taverne
- Department of Cardiothoracic Surgery, Erasmus University Medical Center, Room Rg627, Dr. Molewaterplein 40, 3015, GD, Rotterdam, The Netherlands. .,Division of Experimental Cardiology, Department of Cardiology, Erasmus University Medical Center, Rotterdam, The Netherlands. .,Unit for Cardiac Morphology and Translational Electrophysiology, Erasmus University Medical Center, Rotterdam, The Netherlands.
| | - Amir Sadeghi
- Department of Cardiothoracic Surgery, Erasmus University Medical Center, Room Rg627, Dr. Molewaterplein 40, 3015, GD, Rotterdam, The Netherlands
| | - Beatrijs Bartelds
- Division of Pediatrics, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Ad J J C Bogers
- Department of Cardiothoracic Surgery, Erasmus University Medical Center, Room Rg627, Dr. Molewaterplein 40, 3015, GD, Rotterdam, The Netherlands
| | - Daphne Merkus
- Division of Experimental Cardiology, Department of Cardiology, Erasmus University Medical Center, Rotterdam, The Netherlands
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14
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Al-Rashid F, Totzeck M, Saur N, Jánosi RA, Lind A, Mahabadi AA, Rassaf T, Mincu RI. Global longitudinal strain is associated with better outcomes in transcatheter aortic valve replacement. BMC Cardiovasc Disord 2020; 20:267. [PMID: 32493384 PMCID: PMC7268397 DOI: 10.1186/s12872-020-01556-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2019] [Accepted: 05/27/2020] [Indexed: 12/30/2022] Open
Abstract
Background Parameters that mark the timing of left ventricular (LV) reverse remodeling following transcatheter aortic valve replacement (TAVR) are incompletely defined. This study aims to identify the dynamics of LV strain derived from speckle tracking echocardiography in a cohort of patients with severe aortic stenosis (AS) who underwent TAVR and its correlation with postprocedural outcomes. Methods We selected 150 consecutive patients (82 ± 4 years old, STS score 6.4 ± 6.2) who underwent transfemoral TAVR between 07/2016 and 12/2017 at our tertiary care center. All patients were evaluated at baseline, 1 week after TAVR, and 3 months following TAVR. Results The global longitudinal strain (GLS) 1 week following TAVR was comparable to that at baseline (− 15,9 ± 4.3 vs − 16.8 ± 4.1; p = NS) but significantly improved at 3 months following TAVR (− 15.9 ± 4.3% vs. -19.5 ± 3.5%; p < 0.001). No significant changes in global circumferential strain (GCS) and global radial strain (GRS) were detectable. The ejection fraction was significantly improved 1 week after the TAVR procedure. The baseline GLS correlated directly with the complication rate (R = 0.36, p = 0.005). The linear regression analysis showed that the main predictors of the improvement in the GLS at 3 months in our cohort were baseline GRS and GCS. Conclusion GLS improves at 3 months after TAVR, while LV ejection fraction does not show a substantial change, signaling an early recovery of LV longitudinal function after the intervention. Additionally, GLS has a direct correlation with the postprocedural outcomes. GLS improvement might emerge as a valuable parameter for a tailored follow-up in TAVR patients.
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Affiliation(s)
- Fadi Al-Rashid
- Department of Cardiology and Vascular Medicine, West German Heart and Vascular Center Essen, University Hospital Essen, Medical Faculty, University Duisburg-Essen, 45122, Essen, Germany.
| | - Matthias Totzeck
- Department of Cardiology and Vascular Medicine, West German Heart and Vascular Center Essen, University Hospital Essen, Medical Faculty, University Duisburg-Essen, 45122, Essen, Germany
| | - Nadine Saur
- Department of Cardiology and Vascular Medicine, West German Heart and Vascular Center Essen, University Hospital Essen, Medical Faculty, University Duisburg-Essen, 45122, Essen, Germany
| | - Rolf Alexander Jánosi
- Department of Cardiology and Vascular Medicine, West German Heart and Vascular Center Essen, University Hospital Essen, Medical Faculty, University Duisburg-Essen, 45122, Essen, Germany
| | - Alexander Lind
- Department of Cardiology and Vascular Medicine, West German Heart and Vascular Center Essen, University Hospital Essen, Medical Faculty, University Duisburg-Essen, 45122, Essen, Germany
| | - Amir A Mahabadi
- Department of Cardiology and Vascular Medicine, West German Heart and Vascular Center Essen, University Hospital Essen, Medical Faculty, University Duisburg-Essen, 45122, Essen, Germany
| | - Tienush Rassaf
- Department of Cardiology and Vascular Medicine, West German Heart and Vascular Center Essen, University Hospital Essen, Medical Faculty, University Duisburg-Essen, 45122, Essen, Germany
| | - Raluca-Ileana Mincu
- Department of Cardiology and Vascular Medicine, West German Heart and Vascular Center Essen, University Hospital Essen, Medical Faculty, University Duisburg-Essen, 45122, Essen, Germany
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15
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Agger P, Omann C, Laustsen C, Stephenson RS, Anderson RH. Anatomically correct assessment of the orientation of the cardiomyocytes using diffusion tensor imaging. NMR IN BIOMEDICINE 2020; 33:e4205. [PMID: 31829484 DOI: 10.1002/nbm.4205] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Revised: 10/04/2019] [Accepted: 10/07/2019] [Indexed: 06/10/2023]
Abstract
Diffusion tensor imaging has been used for assessing the orientation of cardiac myocytes for decades. Striking methodological differences exist between studies when quantifying these orientations. This limits the comparability between studies, and impedes collaboration and the drawing of appropriate physiological conclusions. We have sought to elucidate these differences, permitting us to propose a standardised "tool set" that might better establish consensus in future studies. We fixed hearts from seven 25 kg pigs in formalin, and scanned them using diffusion tensor imaging. Using various angle definitions as found in literature, we assessed the orientations of cardiomyocytes, comparing them in terms of helical and intrusion angles, along with the orientation of their aggregations. The difference between assessment of the helical angle with and without relation to the epicardial curvature was 25.2° (SD: 7.9) at the base, 5.8° (1.9) at the equatorial level, and 28.0° (7.0) at the apex, ANOVA P = 0.001. In comparable fashion, the intrusion angle differed by 25.9° (12.9), 7.6° (0.98) and 17.5° (4.7), P = 0.01, and the angle of the aggregates (E3-angle) differed by 25.0° (13.5) at the base, 9.4° (1.7) at the equator, and 23.1° (6.2) apically, P = 0.003. When assessing 14 definitions used in literature to calculate the orientation of aggregates, only 4 rendered identical results. The findings show that any attempt to use projection of eigenvectors introduces considerable bias. The epicardial curvature of the ventricular cone needs to be taken into account when seeking to provide accurate quantification of the orientation of the aggregated cardiomyocytes, especially in the apical and basal regions. This means that projection of eigenvectors should be avoided prior to quantifying myocyte orientation, especially when assessing radial orientation. Based on our results, we suggest appropriate methods for valid assessment of myocyte orientation using diffusion tensor imaging.
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Affiliation(s)
- Peter Agger
- Comparative Medicine Lab, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Camilla Omann
- Dept. of Cardiothoracic & Vascular Surgery, Aarhus University Hospital, Aarhus, Denmark
| | | | - Robert S Stephenson
- Comparative Medicine Lab, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Institute of Clinical Sciences, The University of Birmingham, Birmingham, UK
| | - Robert H Anderson
- Institute Genetic Medicine, Newcastle University, Newcastle-upon-Tyne, UK
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16
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Karbassi E, Fenix A, Marchiano S, Muraoka N, Nakamura K, Yang X, Murry CE. Cardiomyocyte maturation: advances in knowledge and implications for regenerative medicine. Nat Rev Cardiol 2020; 17:341-359. [PMID: 32015528 DOI: 10.1038/s41569-019-0331-x] [Citation(s) in RCA: 397] [Impact Index Per Article: 99.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 12/12/2019] [Indexed: 12/20/2022]
Abstract
Our knowledge of pluripotent stem cell (PSC) biology has advanced to the point where we now can generate most cells of the human body in the laboratory. PSC-derived cardiomyocytes can be generated routinely with high yield and purity for disease research and drug development, and these cells are now gradually entering the clinical research phase for the testing of heart regeneration therapies. However, a major hurdle for their applications is the immature state of these cardiomyocytes. In this Review, we describe the structural and functional properties of cardiomyocytes and present the current approaches to mature PSC-derived cardiomyocytes. To date, the greatest success in maturation of PSC-derived cardiomyocytes has been with transplantation into the heart in animal models and the engineering of 3D heart tissues with electromechanical conditioning. In conventional 2D cell culture, biophysical stimuli such as mechanical loading, electrical stimulation and nanotopology cues all induce substantial maturation, particularly of the contractile cytoskeleton. Metabolism has emerged as a potent means to control maturation with unexpected effects on electrical and mechanical function. Different interventions induce distinct facets of maturation, suggesting that activating multiple signalling networks might lead to increased maturation. Despite considerable progress, we are still far from being able to generate PSC-derived cardiomyocytes with adult-like phenotypes in vitro. Future progress will come from identifying the developmental drivers of maturation and leveraging them to create more mature cardiomyocytes for research and regenerative medicine.
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Affiliation(s)
- Elaheh Karbassi
- Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, WA, USA.,Center for Cardiovascular Biology, University of Washington, Seattle, WA, USA.,Department of Pathology, University of Washington, Seattle, WA, USA
| | - Aidan Fenix
- Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, WA, USA.,Center for Cardiovascular Biology, University of Washington, Seattle, WA, USA.,Department of Pathology, University of Washington, Seattle, WA, USA
| | - Silvia Marchiano
- Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, WA, USA.,Center for Cardiovascular Biology, University of Washington, Seattle, WA, USA.,Department of Pathology, University of Washington, Seattle, WA, USA
| | - Naoto Muraoka
- Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, WA, USA.,Center for Cardiovascular Biology, University of Washington, Seattle, WA, USA.,Department of Pathology, University of Washington, Seattle, WA, USA
| | - Kenta Nakamura
- Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, WA, USA.,Center for Cardiovascular Biology, University of Washington, Seattle, WA, USA.,Division of Cardiology, Department of Medicine, University of Washington, Seattle, WA, USA
| | - Xiulan Yang
- Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, WA, USA.,Center for Cardiovascular Biology, University of Washington, Seattle, WA, USA.,Department of Pathology, University of Washington, Seattle, WA, USA
| | - Charles E Murry
- Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, WA, USA. .,Center for Cardiovascular Biology, University of Washington, Seattle, WA, USA. .,Department of Pathology, University of Washington, Seattle, WA, USA. .,Division of Cardiology, Department of Medicine, University of Washington, Seattle, WA, USA. .,Department of Bioengineering, University of Washington, Seattle, WA, USA.
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17
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Zhang W, Wang Z, Xie C, Wang X, Luo F, Hong M, Zhou R, Ma C, Lin N, Zhang J, Hu X, Chan JKY, Wen F, Wang Y. Scaffold with Micro/Macro-Architecture for Myocardial Alignment Engineering into Complex 3D Cell Patterns. Adv Healthc Mater 2019; 8:e1901015. [PMID: 31599123 DOI: 10.1002/adhm.201901015] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 09/26/2019] [Indexed: 12/21/2022]
Abstract
Tissue structural anisotropy is an important basis for heart function. Attempts to regenerate the complicated heart-tissue alignment has rarely featured macroscale 3D constructs required for myocardial tissue engineering. The feasibility of engineered scaffolds with micro/macro-architecture for guiding spatial cell alignment following complex patterns is reported. The scaffold is composed of stackable dual-structured layers with linear micro-ridge/groove patterns and macro-through-hole arrays, which enable tailorable anisotropy and interconnective free space. When human mesenchymal stem cells are seeded on the scaffold, well-organized spreading alignment showing the precise control in cellular orientation is significantly introduced over nonpatterned controls. Moreover, spatial cell distribution in the scaffold and directional changes of the layered linear patterns that made cell alignment orientations turning accordingly are observed, leading to the complex 3D pattern reconstruction of cellular alignment resembling natural myocardial tissue. This work validates the potential of micro/macro-architecture engineering for spatial cell guidance. Scaffolds with this capability can be potentially used for biomanufacturing of the structural alignment in myocardial tissue engineering.
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Affiliation(s)
- Wanqi Zhang
- College of Materials Science and EngineeringHunan University Changsha 410082 P. R. China
| | - Zuyong Wang
- College of Materials Science and EngineeringHunan University Changsha 410082 P. R. China
| | - Chao Xie
- Department of Vascular SurgeryXiangya HospitalCentral South University Changsha 410008 P. R. China
| | - Xianwei Wang
- Department of Vascular SurgeryXiangya HospitalCentral South University Changsha 410008 P. R. China
| | - Fangfang Luo
- School of ScienceHuzhou University Huzhou Zhejiang 313000 P. R. China
| | - Minghui Hong
- Department of Electrical and Computer EngineeringNational University of Singapore Singapore 117576 Singapore
| | - Rui Zhou
- School of Aerospace EngineeringXiamen University Xiamen 361102 P. R. China
| | - Chao Ma
- College of Materials Science and EngineeringHunan University Changsha 410082 P. R. China
| | - Nan Lin
- College of Materials Science and EngineeringHunan University Changsha 410082 P. R. China
| | - Jieyu Zhang
- National Engineering Research Center for BiomaterialsSichuan University Chengdu 610065 P. R. China
| | - Xuefeng Hu
- National Engineering Research Center for BiomaterialsSichuan University Chengdu 610065 P. R. China
| | - Jerry Kok Yen Chan
- Department of Reproductive MedicineKK Women's and Children's Hospital Singapore 229899 Singapore
| | - Feng Wen
- School of Chemical and Biomedical EngineeringNanyang Technological University Singapore 637457 Singapore
| | - Yunbing Wang
- National Engineering Research Center for BiomaterialsSichuan University Chengdu 610065 P. R. China
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18
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Learn from Your Elders: Developmental Biology Lessons to Guide Maturation of Stem Cell-Derived Cardiomyocytes. Pediatr Cardiol 2019; 40:1367-1387. [PMID: 31388700 PMCID: PMC6786957 DOI: 10.1007/s00246-019-02165-5] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2019] [Accepted: 07/16/2019] [Indexed: 02/07/2023]
Abstract
Human pluripotent stem cells (hPSCs) offer a multifaceted platform to study cardiac developmental biology, understand disease mechanisms, and develop novel therapies. Remarkable progress over the last two decades has led to methods to obtain highly pure hPSC-derived cardiomyocytes (hPSC-CMs) with reasonable ease and scalability. Nevertheless, a major bottleneck for the translational application of hPSC-CMs is their immature phenotype, resembling that of early fetal cardiomyocytes. Overall, bona fide maturation of hPSC-CMs represents one of the most significant goals facing the field today. Developmental biology studies have been pivotal in understanding the mechanisms to differentiate hPSC-CMs. Similarly, evaluation of developmental cues such as electrical and mechanical activities or neurohormonal and metabolic stimulations revealed the importance of these pathways in cardiomyocyte physiological maturation. Those signals cooperate and dictate the size and the performance of the developing heart. Likewise, this orchestra of stimuli is important in promoting hPSC-CM maturation, as demonstrated by current in vitro maturation approaches. Different shades of adult-like phenotype are achieved by prolonging the time in culture, electromechanical stimulation, patterned substrates, microRNA manipulation, neurohormonal or metabolic stimulation, and generation of human-engineered heart tissue (hEHT). However, mirroring this extremely dynamic environment is challenging, and reproducibility and scalability of these approaches represent the major obstacles for an efficient production of mature hPSC-CMs. For this reason, understanding the pattern behind the mechanisms elicited during the late gestational and early postnatal stages not only will provide new insights into postnatal development but also potentially offer new scalable and efficient approaches to mature hPSC-CMs.
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19
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Anderson RH, Niederer PF, Sanchez‐Quintana D, Stephenson RS, Agger P. How are the cardiomyocytes aggregated together within the walls of the left ventricular cone? J Anat 2019; 235:697-705. [PMID: 31206661 PMCID: PMC6742897 DOI: 10.1111/joa.13027] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/14/2019] [Indexed: 12/28/2022] Open
Abstract
The manner of packing together of the cardiomyocytes within the walls of the cardiac ventricles has now been investigated for over half a millennium. In 1669, Lower dissected the ventricular mass, likening the arrangement to skeletal musculature, in the form of a myocardial band extending between the right and left atrioventricular junctions. Pettigrew subsequently showed obvious helical arrangements to be evident within the ventricular walls, but emphasised that the cardiomyocytes were attached to each other, and could not justifiably be compared with skeletal cardiomyocytes. Torrent-Guasp then reactivated the notion that the ventricular mass was formed of a solitary band. Unlike Lower, he dissected the band as extending between the pulmonary to the aortic roots. Multiple investigations conducted using gross dissection and histology, and more recently diffusion tensor magnetic resonance imaging and computed tomographic analysis, have shown an absence of any anatomical boundaries within the walls that might permit the mass uniformly to be dissected so as to reveal the band. A response to a recent letter to the Journal, nonetheless, claimed that the dissections had been validated by clinicians interpreting the findings so as to provide an explanation for ventricular cardiodynamics, arguing that the findings provided a suitable anatomical model for this purpose. Anatomical models, however, are of no value unless they are anatomically correct. In this review, therefore, we summarise the evidence showing that the cardiomyocytes making up the ventricular walls, rather than forming a ventricular myocardial band, are instead aggregated together to form a three-dimensional myocardial mesh.
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Affiliation(s)
| | | | - Damian Sanchez‐Quintana
- Department of Anatomy and Cell BiologyFaculty of MedicineUniversity of ExtremaduraBadajozSpain
| | - Robert S. Stephenson
- Institute of Clinical SciencesCollege of Medical and Dental SciencesThe University of BirminghamBirminghamUK
- Comparative Medicine LaboratoryInstitute of Clinical MedicineAarhus UniversityAarhusDenmark
| | - Peter Agger
- Comparative Medicine LaboratoryInstitute of Clinical MedicineAarhus UniversityAarhusDenmark
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20
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Wright PT, Bhogal NK, Diakonov I, Pannell LMK, Perera RK, Bork NI, Schobesberger S, Lucarelli C, Faggian G, Alvarez-Laviada A, Zaccolo M, Kamp TJ, Balijepalli RC, Lyon AR, Harding SE, Nikolaev VO, Gorelik J. Cardiomyocyte Membrane Structure and cAMP Compartmentation Produce Anatomical Variation in β 2AR-cAMP Responsiveness in Murine Hearts. Cell Rep 2019; 23:459-469. [PMID: 29642004 PMCID: PMC5912947 DOI: 10.1016/j.celrep.2018.03.053] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Revised: 02/02/2018] [Accepted: 03/13/2018] [Indexed: 01/19/2023] Open
Abstract
Cardiomyocytes from the apex but not the base of the heart increase their contractility in response to β2-adrenoceptor (β2AR) stimulation, which may underlie the development of Takotsubo cardiomyopathy. However, both cell types produce comparable cytosolic amounts of the second messenger cAMP. We investigated this discrepancy using nanoscale imaging techniques and found that, structurally, basal cardiomyocytes have more organized membranes (higher T-tubular and caveolar densities). Local membrane microdomain responses measured in isolated basal cardiomyocytes or in whole hearts revealed significantly smaller and more short-lived β2AR/cAMP signals. Inhibition of PDE4, caveolar disruption by removing cholesterol or genetic deletion of Cav3 eliminated differences in local cAMP production and equilibrated the contractile response to β2AR. We conclude that basal cells possess tighter control of cAMP because of a higher degree of signaling microdomain organization. This provides varying levels of nanostructural control for cAMP-mediated functional effects that orchestrate macroscopic, regional physiological differences within the heart. Cardiomyocyte membrane organization varies in degree between regions of the heart Differences in structural organization affect adrenergic signaling via β2AR Reduced organization allows β2AR-cAMP to influence contractility in myocardial apex Variability in cell structure may allow differential response of heart regions
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Affiliation(s)
- Peter T Wright
- Myocardial Function, National Heart and Lung Institute, Imperial College London, ICTEM, Hammersmith Hospital, Du Cane Road, London W12 0NN, UK
| | - Navneet K Bhogal
- Myocardial Function, National Heart and Lung Institute, Imperial College London, ICTEM, Hammersmith Hospital, Du Cane Road, London W12 0NN, UK
| | - Ivan Diakonov
- Myocardial Function, National Heart and Lung Institute, Imperial College London, ICTEM, Hammersmith Hospital, Du Cane Road, London W12 0NN, UK
| | - Laura M K Pannell
- Myocardial Function, National Heart and Lung Institute, Imperial College London, ICTEM, Hammersmith Hospital, Du Cane Road, London W12 0NN, UK
| | - Ruwan K Perera
- Institute of Experimental Cardiovascular Research, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Nadja I Bork
- Institute of Experimental Cardiovascular Research, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Sophie Schobesberger
- Myocardial Function, National Heart and Lung Institute, Imperial College London, ICTEM, Hammersmith Hospital, Du Cane Road, London W12 0NN, UK; Institute of Experimental Cardiovascular Research, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Carla Lucarelli
- Myocardial Function, National Heart and Lung Institute, Imperial College London, ICTEM, Hammersmith Hospital, Du Cane Road, London W12 0NN, UK; Department of Cardiac Surgery, University of Verona School of Medicine, Azienda Ospedalieria Universitaria Integrata, Borgo Trento Piazzale A. Stefani, 37126 Verona, Italy
| | - Giuseppe Faggian
- Department of Cardiac Surgery, University of Verona School of Medicine, Azienda Ospedalieria Universitaria Integrata, Borgo Trento Piazzale A. Stefani, 37126 Verona, Italy
| | - Anita Alvarez-Laviada
- Myocardial Function, National Heart and Lung Institute, Imperial College London, ICTEM, Hammersmith Hospital, Du Cane Road, London W12 0NN, UK
| | - Manuela Zaccolo
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3QX, UK
| | - Timothy J Kamp
- Department of Medicine, University of Wisconsin Madison, 1111 Highland Ave., Madison, WI 53705-2275, USA
| | - Ravi C Balijepalli
- Department of Medicine, University of Wisconsin Madison, 1111 Highland Ave., Madison, WI 53705-2275, USA
| | - Alexander R Lyon
- Myocardial Function, National Heart and Lung Institute, Imperial College London, ICTEM, Hammersmith Hospital, Du Cane Road, London W12 0NN, UK; NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London SW7 3AZ, UK
| | - Sian E Harding
- Myocardial Function, National Heart and Lung Institute, Imperial College London, ICTEM, Hammersmith Hospital, Du Cane Road, London W12 0NN, UK
| | - Viacheslav O Nikolaev
- Institute of Experimental Cardiovascular Research, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Julia Gorelik
- Myocardial Function, National Heart and Lung Institute, Imperial College London, ICTEM, Hammersmith Hospital, Du Cane Road, London W12 0NN, UK.
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21
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Garcia-Canadilla P, Cook AC, Mohun TJ, Oji O, Schlossarek S, Carrier L, McKenna WJ, Moon JC, Captur G. Myoarchitectural disarray of hypertrophic cardiomyopathy begins pre-birth. J Anat 2019; 235:962-976. [PMID: 31347708 PMCID: PMC6794206 DOI: 10.1111/joa.13058] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/17/2019] [Indexed: 01/24/2023] Open
Abstract
Myoarchitectural disarray – the multiscalar disorganisation of myocytes, is a recognised histopathological hallmark of adult human hypertrophic cardiomyopathy (HCM). It occurs before the establishment of left ventricular hypertrophy (LVH) but its early origins and evolution around the time of birth are unknown. Our aim is to investigate whether myoarchitectural abnormalities in HCM are present in the fetal heart. We used wild‐type, heterozygous and homozygous hearts (n = 56) from a Mybpc3‐targeted knock‐out HCM mouse model and imaged the 3D micro‐structure by high‐resolution episcopic microscopy. We developed a novel structure tensor approach to extract, display and quantify myocyte orientation and its local angular uniformity by helical angle, angle of intrusion and myoarchitectural disarray index, respectively, immediately before and after birth. In wild‐type, we demonstrate uniformity of orientation of cardiomyocytes with smooth transitions of helical angle transmurally both before and after birth but with traces of disarray at the septal insertion points of the right ventricle. In comparison, heterozygous mice free of LVH, and homozygous mice showed not only loss of the normal linear helical angulation transmural profiles observed in wild‐type but also fewer circumferentially arranged myocytes at birth. Heterozygous and homozygous showed more disarray with a wider distribution than in wild‐type before birth. In heterozygous mice, disarray was seen in the anterior, septal and inferior walls irrespective of stage, whereas in homozygous mice it extended to the whole LV circumference including the lateral wall. In conclusion, myoarchitectural disarray is detectable in the fetal heart of an HCM mouse model before the development of LVH.
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Affiliation(s)
| | - Andrew C Cook
- Institute of Cardiovascular Science, University College London, London, UK
| | | | - Onyedikachi Oji
- Institute of Cardiovascular Science, University College London, London, UK
| | - Saskia Schlossarek
- Cardiovascular Research Centre, Institute of Experimental Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,DZHK (German Center for Cardiovascular Research), partner site Hamburg/Kiel/Lübeck, Hamburg, Germany
| | - Lucie Carrier
- Cardiovascular Research Centre, Institute of Experimental Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,DZHK (German Center for Cardiovascular Research), partner site Hamburg/Kiel/Lübeck, Hamburg, Germany
| | - William J McKenna
- Institute of Cardiovascular Science, University College London, London, UK
| | - James C Moon
- Institute of Cardiovascular Science, University College London, London, UK.,The Cardiovascular Magnetic Resonance Imaging Unit, Barts Heart Centre, St Bartholomew's Hospital, London, UK
| | - Gabriella Captur
- Institute of Cardiovascular Science, University College London, London, UK
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22
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Omann C, Agger P, Bøgh N, Laustsen C, Ringgaard S, Stephenson RS, Anderson RH, Hjortdal VE, Smerup M. Resolving the natural myocardial remodelling brought upon by cardiac contraction; a porcine ex-vivo cardiovascular magnetic resonance study of the left and right ventricle. J Cardiovasc Magn Reson 2019; 21:35. [PMID: 31256759 PMCID: PMC6600899 DOI: 10.1186/s12968-019-0547-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Accepted: 05/29/2019] [Indexed: 01/29/2023] Open
Abstract
BACKGROUND The three-dimensional rearrangement of the right ventricular (RV) myocardium during cardiac deformation is unknown. Previous in-vivo studies have shown that myocardial left ventricular (LV) deformation is driven by rearrangement of aggregations of cardiomyocytes that can be characterised by changes in the so-called E3-angle. Ex-vivo imaging offers superior spatial resolution compared with in-vivo measurements, and can thus provide novel insight into the deformation of the myocardial microstructure in both ventricles. This study sought to describe the dynamic changes of the orientations of the cardiomyocytes in both ventricles brought upon by cardiac contraction, with particular interest in the thin-walled RV, which has not previously been described in terms of its micro-architecture. METHODS The hearts of 14 healthy 20 kg swine were excised and preserved in either a relaxed state or a contracted state. Myocardial architecture was assessed and compared between the two contractional states by quantification of the helical, transmural and E3-angles of the cardiomyocytes using high-resolution diffusion tensor imaging. RESULTS The differences between the two states of contraction were most pronounced in the endocardium where the E3-angle decreased from 78.6° to 24.8° in the LV and from 82.6° to 68.6° in the RV. No significant change in neither the helical nor the transmural angle was found in the cardiomyocytes of the RV. In the endocardium of the LV, however, the helical angle increased from 35.4° to 47.8° and the transmural angle increased from 3.1° to 10.4°. CONCLUSION The entire myocardium rearranges through the cardiac cycle with the change in the orientation of the aggregations of cardiomyocytes being the predominant mediator of myocardial wall thickening. Interestingly, differences also exist between the RV and LV, which helps in the explanation of the different physiological capabilities of the ventricles.
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Affiliation(s)
- Camilla Omann
- Department of Cardiothoracic & Vascular Surgery, Aarhus University Hospital, Skejby, Denmark
- Department of Clinical Medicine, Aarhus University, Palle Juul-Jensens Boulevard 99, 8200 Aarhus N, Denmark
| | - Peter Agger
- Department of Cardiothoracic & Vascular Surgery, Aarhus University Hospital, Skejby, Denmark
- Department of Clinical Medicine, Aarhus University, Palle Juul-Jensens Boulevard 99, 8200 Aarhus N, Denmark
- Comparative Medicine Lab, Aarhus University Hospital, Skejby, Denmark
| | - Nikolaj Bøgh
- Department of Cardiothoracic & Vascular Surgery, Aarhus University Hospital, Skejby, Denmark
- Department of Clinical Medicine, Aarhus University, Palle Juul-Jensens Boulevard 99, 8200 Aarhus N, Denmark
| | - Christoffer Laustsen
- Department of Clinical Medicine, Aarhus University, Palle Juul-Jensens Boulevard 99, 8200 Aarhus N, Denmark
- MR Research Centre, Aarhus University, Aarhus, Denmark
| | | | - Robert S. Stephenson
- Department of Clinical Medicine, Aarhus University, Palle Juul-Jensens Boulevard 99, 8200 Aarhus N, Denmark
- Comparative Medicine Lab, Aarhus University Hospital, Skejby, Denmark
- Institute of Clinical Sciences, College of Medical and Dental Sciences, The University of Birmingham, Birmingham, UK
| | - Robert H. Anderson
- Institute of Genetic Medicine, Newcastle University, Newcastle-upon-Tyne, UK
| | - Vibeke E. Hjortdal
- Department of Cardiothoracic & Vascular Surgery, Aarhus University Hospital, Skejby, Denmark
- Department of Clinical Medicine, Aarhus University, Palle Juul-Jensens Boulevard 99, 8200 Aarhus N, Denmark
| | - Morten Smerup
- Department of Cardiothoracic & Vascular Surgery, Aarhus University Hospital, Skejby, Denmark
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Avazmohammadi R, Soares JS, Li DS, Raut SS, Gorman RC, Sacks MS. A Contemporary Look at Biomechanical Models of Myocardium. Annu Rev Biomed Eng 2019; 21:417-442. [PMID: 31167105 PMCID: PMC6626320 DOI: 10.1146/annurev-bioeng-062117-121129] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Understanding and predicting the mechanical behavior of myocardium under healthy and pathophysiological conditions are vital to developing novel cardiac therapies and promoting personalized interventions. Within the past 30 years, various constitutive models have been proposed for the passive mechanical behavior of myocardium. These models cover a broad range of mathematical forms, microstructural observations, and specific test conditions to which they are fitted. We present a critical review of these models, covering both phenomenological and structural approaches, and their relations to the underlying structure and function of myocardium. We further explore the experimental and numerical techniques used to identify the model parameters. Next, we provide a brief overview of continuum-level electromechanical models of myocardium, with a focus on the methods used to integrate the active and passive components of myocardial behavior. We conclude by pointing to future directions in the areas of optimal form as well as new approaches for constitutive modeling of myocardium.
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Affiliation(s)
- Reza Avazmohammadi
- James T. Willerson Center for Cardiovascular Modeling and Simulation, Oden Institute for Computational Engineering and Sciences, and Department of Biomedical Engineering, University of Texas, Austin, Texas 78712, USA;
| | - João S Soares
- James T. Willerson Center for Cardiovascular Modeling and Simulation, Oden Institute for Computational Engineering and Sciences, and Department of Biomedical Engineering, University of Texas, Austin, Texas 78712, USA;
- Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, Richmond, Virginia 23284, USA
| | - David S Li
- James T. Willerson Center for Cardiovascular Modeling and Simulation, Oden Institute for Computational Engineering and Sciences, and Department of Biomedical Engineering, University of Texas, Austin, Texas 78712, USA;
| | - Samarth S Raut
- James T. Willerson Center for Cardiovascular Modeling and Simulation, Oden Institute for Computational Engineering and Sciences, and Department of Biomedical Engineering, University of Texas, Austin, Texas 78712, USA;
| | - Robert C Gorman
- Gorman Cardiovascular Research Group, Smilow Center for Translational Research, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Michael S Sacks
- James T. Willerson Center for Cardiovascular Modeling and Simulation, Oden Institute for Computational Engineering and Sciences, and Department of Biomedical Engineering, University of Texas, Austin, Texas 78712, USA;
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24
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Qian Z, Sharma D, Jia W, Radke D, Kamp T, Zhao F. Engineering stem cell cardiac patch with microvascular features representative of native myocardium. Theranostics 2019; 9:2143-2157. [PMID: 31149034 PMCID: PMC6531308 DOI: 10.7150/thno.29552] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Accepted: 02/14/2019] [Indexed: 12/11/2022] Open
Abstract
The natural myocardium is a highly aligned tissue with an oriented vasculature. Its characteristic cellular as well as nanoscale extracellular matrix (ECM) organization along with an oriented vascular network ensures appropriate blood supply and functional performance. Although significant efforts have been made to develop anisotropic cardiac structure, currently neither an ideal biomaterial nor an effective vascularization strategy to engineer oriented and high-density capillary-like microvessels has been achieved for clinical cardiovascular therapies. A naturally derived oriented ECM nanofibrous scaffold mimics the physiological structure and components of tissue ECM and guides neovascular network formation. The objective of this study was to create an oriented and dense microvessel network with physiological myocardial microvascular features. METHODS Highly aligned decellularized human dermal fibroblast sheets were used as ECM scaffold to regulate physiological alignment of microvascular networks by co-culturing human mesenchymal stem cells (hMSCs) and endothelial cells (ECs). The influence of topographical features on hMSC and EC interaction was investigated to understand underlying mechanisms of neovasculature formation. RESULTS Results demonstrate that the ECM topography can be translated to ECs via CD166 tracks and significantly improved hMSC-EC crosstalk and vascular network formation. The aligned ECM nanofibers enhanced structure, length, and density of microvascular networks compared to randomly organized nanofibrous ECM. Moreover, hMSC-EC co-culture promoted secretion of pro-angiogenic growth factors and matrix remodeling via metalloprotease-2 (MMP-2) activation, which resulted in highly dense vascular network formation with intercapillary distance (20 μm) similar to the native myocardium. CONCLUSION HMSC-EC co-culture on the highly aligned ECM generates physiologically oriented and dense microvascular network, which holds great potential for cardiac tissue engineering.
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Affiliation(s)
- Zichen Qian
- Department of Biomedical Engineering, Michigan Technological University, Houghton, MI 49931, USA
| | - Dhavan Sharma
- Department of Biomedical Engineering, Michigan Technological University, Houghton, MI 49931, USA
| | - Wenkai Jia
- Department of Biomedical Engineering, Michigan Technological University, Houghton, MI 49931, USA
| | - Daniel Radke
- Department of Biomedical Engineering, Michigan Technological University, Houghton, MI 49931, USA
| | - Timothy Kamp
- Stem Cell and Regenerative Medicine Center, University of Wisconsin, Madison, WI 53705, USA
| | - Feng Zhao
- Department of Biomedical Engineering, Michigan Technological University, Houghton, MI 49931, USA
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25
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Lunkenheimer PP, Niederer P, Stephenson RS, Redmann K, Batista RV, Smerup M, Anderson RH. What is the clinical significance of ventricular mural antagonism? Eur J Cardiothorac Surg 2019; 53:714-723. [PMID: 29136124 DOI: 10.1093/ejcts/ezx382] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Accepted: 10/01/2017] [Indexed: 11/15/2022] Open
Abstract
Recent morphological studies provide evidence that the ventricular walls are arranged as a 3D meshwork of aggregated cardiomyocyte chains, exhibiting marked local structural variations. In contrary to previous findings, up to two-fifths of the chains are found to have a partially transmural alignment, thus deviating from the prevailing tangential orientation. Upon contraction, they produce, in addition to a tangential force, a radial force component that counteracts ventricular constriction and aids widening of the ventricular cavity. In experimental studies, we have provided evidence for the existence of such forces, which are auxotonic in nature. This is in contrast to the tangentially aligned myocytes that produce constrictive forces, which are unloading in nature. The ventricular myocardium is, therefore, able to function in an antagonistic fashion, with the prevailing constrictive forces acting simultaneously with a dilatory force component. The ratio of constrictive to dilating force varies locally according to the specific mural architecture. Such antagonism acts according to local demands to preserve the ventricular shape, store the elastic energy that drives the fast late systolic dilation and apportion mural motion to facilitate the spiralling nature of intracavitary flow. Intracavitary pressure and flow dynamics are thus governed concurrently by ventricular constrictive and dilative force components. Antagonistic activity, however, increases deleteriously in states of cardiac disease, such as hypertrophy and fibrosis. ß-blockade at low dosage acts selectively to temper the auxotonic forces.
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Affiliation(s)
- Paul P Lunkenheimer
- Department of Experimental Cardiac- and Thoraco-Vascular Surgery, University Hospital Muenster, Muenster, Germany
| | - Peter Niederer
- Institute of Biomedical Engineering, ETH, University of Zurich, Zurich, Switzerland
| | - Robert S Stephenson
- Comparative Medicine Laboratory, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Klaus Redmann
- Department of Experimental Cardiac- and Thoraco-Vascular Surgery, University Hospital Muenster, Muenster, Germany
| | | | - Morten Smerup
- University Hospital, Thoraxkirurgisk Klinik, Copenhagen, Denmark
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26
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Liu Y, Chen H, Shou W. Potential Common Pathogenic Pathways for the Left Ventricular Noncompaction Cardiomyopathy (LVNC). Pediatr Cardiol 2018; 39:1099-1106. [PMID: 29766225 PMCID: PMC6093786 DOI: 10.1007/s00246-018-1882-z] [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] [Received: 04/18/2018] [Accepted: 04/24/2018] [Indexed: 01/01/2023]
Abstract
Ventricular trabeculation and compaction are two essential morphogenetic events for generating a functionally competent ventricular wall. A significant reduction in trabeculation is usually associated with hypoplastic wall and ventricular compact zone deficiencies, which commonly leads to embryonic heart failure and early embryonic lethality. In contrast, the arrest of ventricular wall compaction (noncompaction) is believed to be causative to the left ventricular noncompaction (LVNC), a genetically heterogeneous disorder and the third most common cardiomyopathy among pediatric patients. After critically reviewing recent findings from genetically engineered mouse models, we suggest a model which proposes that defects in myofibrillogenesis and polarization in trabecular cardiomyocytes underly the common pathogenic mechanism for ventricular noncompaction.
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Affiliation(s)
- Ying Liu
- Riley Heart Research Center, Herman B. Wells Center for Pediatric Research, Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Hanying Chen
- Riley Heart Research Center, Herman B. Wells Center for Pediatric Research, Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Weinian Shou
- Riley Heart Research Center, Herman B. Wells Center for Pediatric Research, Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN, 46202, USA.
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27
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Lunkenheimer PP, Niederer P, Lunkenheimer JM, Redmann K, Smerup M, Schmitt B, Saggau W, Batista RJV. [Antagonistic function of the heart muscle : Part II: Clinical implications]. Herz 2018; 45:178-185. [PMID: 30054715 DOI: 10.1007/s00059-018-4735-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Accepted: 07/05/2018] [Indexed: 10/28/2022]
Abstract
In the hypertrophic heart the myostructural afterload in the form of endoepicardial networks is predominant, which enhances myocardial hypertrophy. The intrinsic antagonism is derailed. Likewise, the connective tissue scaffold, i.e. the stromatogenic afterload, is enriched in the response to the derailment of antagonism in a hypertrophic heart up to regional captivation of the heart musculature. Due to the selective susceptibility of the auxotonic, contracting oblique transmural myocardial network for low dose negative inotropic medication, this promises to attenuate progress in myocardial hypertrophy. Volume reduction surgery is most effective in reducing wall stress as long as the myocardium is not critically fettered by fibrosis. The use of external mechanical circulatory support is then effective if the heart is supported in its resting mode, which means around a middle width and at minimal amplitude of motion. The takotsubo cardiomyopathy might possibly reflect an isolated, extreme stimulation of the intrinsic antagonism as a response to hormonally induced sensitization of the myocardium to catecholamine. A particular significant conclusion with respect to the diseased heart is that clinical diagnostics need new impulses with a focus on the analysis of local motion patterns and on myocardial stiffness reflecting disease-dependent antagonistic intensity. This would become a relevant diagnostic marker if corresponding (noninvasive) measurement techniques would become available.
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Affiliation(s)
- P P Lunkenheimer
- Experimentelle Thorax‑, Herz- und Gefäßchirurgie, Universitätskliniken Münster, Münster, Deutschland.
| | - P Niederer
- Institute of Biomedical Engineering, ETH and University Zürich, Zürich, Schweiz
| | - J M Lunkenheimer
- Krankenhaus der Augustinerinnen/Severinsklösterchen, Jakobstr. 27-31, Köln, Deutschland
| | - K Redmann
- Universitätskliniken, Münster, Deutschland
| | - M Smerup
- Thoraxkirurgisk Klinik, University Hospital, Kopenhagen, Dänemark
| | - B Schmitt
- Abteilung für angeborene Herzfehler, Deutsches Herzzentrum, Berlin, Deutschland
| | - W Saggau
- Klinik für Herzchirurgie, Klinikum Ludwigshafen, Ludwigshafen, Deutschland
| | - R J V Batista
- , Rua Carlos Rasera 8, Vista Alegre, Curitiba PR, Brasilien
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28
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Lunkenheimer PP, Niederer P, Lunkenheimer JM, Keller H, Redmann K, Smerup M, Anderson RH. [The antagonistic function of the heart muscle sustains the autoregulation according to Frank and Starling : Part I: Structure and function of heart muscle]. Herz 2018; 45:170-177. [PMID: 30054713 DOI: 10.1007/s00059-018-4734-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Accepted: 07/05/2018] [Indexed: 10/28/2022]
Abstract
In the tradition of Harvey and according to Otto Frank the heart muscle structure is arranged in a strictly tangential fashion hence all contractile forces act in the direction of ventricular ejection. In contrast, morphology confirms that the heart consists of a 3-dimensional network of muscle fibers with up to two fifths of the chains of aggregated myocytes deviating from a tangential alignment at variable angles. Accordingly, the myocardial systolic forces contain, in addition to a constrictive also a (albeit smaller) radially acting component. Using needle force probes we have correspondingly measured an unloading type of force in a tangential direction and an auxotonic type in dilatative transversal direction of the ventricular walls to show that the myocardial body contracts actively in a 3-dimensional pattern. This antagonism supports the autoregulation of heart muscle function according to Frank and Starling, preserving ventricular shape, enhances late systolic fast dilation and attenuates systolic constriction of the ventricle wall. Auxotonic dilating forces are particularly sensitive to inotropic medication. Low dose beta-blocker is able to attenuate the antagonistic activity. All myocardial components act against four components of afterload, the hemodynamic, the myostructural, the stromatogenic and the hydraulic component. This complex interplay critically complicates clinical diagnostics. Clinical implications are far-reaching (see Part II, https://doi.org/10.1007/s00059-018-4735-x).
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Affiliation(s)
- P P Lunkenheimer
- Experimentelle Thorax‑, Herz- und Gefäßchirurgie, Universitätskliniken Münster, Münster, Deutschland.
| | - P Niederer
- Institute of Biomedical Engineering, ETH and University Zürich, Zürich, Schweiz
| | - J M Lunkenheimer
- Krankenhaus der Augustinerinnen/Severinsklösterchen, Jakobstr. 27-31, Köln, Deutschland
| | - H Keller
- Klinik Hirslanden, Zürich, Schweiz
| | - K Redmann
- Universitätskliniken, Münster, Deutschland
| | - M Smerup
- Thoraxkirurgisk Klinik, University Hospital, Kopenhagen, Dänemark
| | - R H Anderson
- Institute of Genetic Medicine, Newcastle University, Newcastle, Großbritannien
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29
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Resolving the True Ventricular Mural Architecture. J Cardiovasc Dev Dis 2018; 5:jcdd5020034. [PMID: 29925810 PMCID: PMC6023305 DOI: 10.3390/jcdd5020034] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Revised: 06/10/2018] [Accepted: 06/14/2018] [Indexed: 02/07/2023] Open
Abstract
The precise nature of packing together of the cardiomyocytes within the ventricular walls has still to be determined. The spiraling nature of the chains of interconnected cardiomyocytes has long been recognized. As long ago as the end of the nineteenth century, Pettigrew had emphasized that the ventricular cone was not arranged on the basis of skeletal muscle. Despite this guidance, subsequent anatomists described entities such as “bulbo-spiral muscles”, with this notion of subunits culminating in the suggestion that the ventricular cone could be unwrapped so as to produce a “ventricular myocardial band”. Others, in contrast, had suggested that the ventricular walls were arranged on the basis of “sheets”, or more recently “sheetlets”, with investigators seeking to establishing the angulation of these entities using techniques such as magnetic resonance imaging. Our own investigations, in contrast, have shown that the cardiomyocytes are aggregated together within the supporting fibrous matrix so as to produce a three-dimensional myocardial mesh. In this review, we summarize the previous accounts, and provide the anatomical evidence we have thus far accumulated to support the model of the myocardial mesh. We show how these anatomic findings underscore the concept of the myocardial mesh functioning in antagonistic fashion. They lend evidence to support the notion that the ventricular myocardium works as a muscular hydrostat.
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30
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Hoffman JIE. Will the real ventricular architecture please stand up? Physiol Rep 2018; 5:5/18/e13404. [PMID: 28947592 PMCID: PMC5617926 DOI: 10.14814/phy2.13404] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Accepted: 07/23/2017] [Indexed: 12/28/2022] Open
Abstract
Ventricular twisting, essential for cardiac function, is attributed to the contraction of myocardial helical fibers. The exact relationship between ventricular anatomy and function remains to be determined, but one commonly used explanatory model is the helical ventricular myocardial band (HVMB) model of Torrent‐Guasp. This model has been successful in explaining many aspects of ventricular function, (Torrent‐Guasp et al. Eur. J. Cardiothorac. Surg., 25, 376, 2004; Buckberg et al. Eur. J. Cardiothorac. Surg., 47, 587, 2015; Buckberg et al. Eur. J. Cardiothorac. Surg. 47, 778, 2015) but the model ignores important aspects of ventricular anatomy and should probably be replaced. The purpose of this review is to compare the HVMB model with a different model (nested layers). A complication when interpreting experimental observations that relate anatomy to function is that, in the myocardium, shortening does not always imply activation and lengthening does not always imply inactivation.
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Affiliation(s)
- Julien I E Hoffman
- Department of Pediatrics, University of California, San Francisco, California
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31
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Conduction in the Heart Wall: Helicoidal Fibers Minimize Diffusion Bias. Sci Rep 2018; 8:7165. [PMID: 29739992 PMCID: PMC5940931 DOI: 10.1038/s41598-018-25334-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Accepted: 04/16/2018] [Indexed: 11/23/2022] Open
Abstract
The mammalian heart must function as an efficient pump while simultaneously conducting electrical signals to drive the contraction process. In the ventricles, electrical activation begins at the insertion points of the Purkinje network in the endocardium. How does the diffusion component of the subsequent excitation wave propagate from the endocardium in a healthy heart wall without creating directional biases? We show that this is a consequence of the particular geometric organization of myocytes in the heart wall. Using a generalized helicoid to model fiber orientation, we treat the myocardium as a curved space via Riemannian geometry, and then use stochastic calculus to model local signal diffusion. Our analysis shows that the helicoidal arrangement of myocytes minimizes the directional biases that could lead to aberrant propagation, thereby explaining how electrophysiological principles are consistent with local measurements of cardiac fiber geometry. We discuss our results in the context of the need to balance electrical and mechanical requirements for heart function.
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32
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Pedde RD, Mirani B, Navaei A, Styan T, Wong S, Mehrali M, Thakur A, Mohtaram NK, Bayati A, Dolatshahi-Pirouz A, Nikkhah M, Willerth SM, Akbari M. Emerging Biofabrication Strategies for Engineering Complex Tissue Constructs. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2017; 29:1606061. [PMID: 28370405 DOI: 10.1002/adma.201606061] [Citation(s) in RCA: 219] [Impact Index Per Article: 31.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Revised: 01/16/2017] [Indexed: 05/24/2023]
Abstract
The demand for organ transplantation and repair, coupled with a shortage of available donors, poses an urgent clinical need for the development of innovative treatment strategies for long-term repair and regeneration of injured or diseased tissues and organs. Bioengineering organs, by growing patient-derived cells in biomaterial scaffolds in the presence of pertinent physicochemical signals, provides a promising solution to meet this demand. However, recapitulating the structural and cytoarchitectural complexities of native tissues in vitro remains a significant challenge to be addressed. Through tremendous efforts over the past decade, several innovative biofabrication strategies have been developed to overcome these challenges. This review highlights recent work on emerging three-dimensional bioprinting and textile techniques, compares the advantages and shortcomings of these approaches, outlines the use of common biomaterials and advanced hybrid scaffolds, and describes several design considerations including the structural, physical, biological, and economical parameters that are crucial for the fabrication of functional, complex, engineered tissues. Finally, the applications of these biofabrication strategies in neural, skin, connective, and muscle tissue engineering are explored.
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Affiliation(s)
- R Daniel Pedde
- Laboratory for Innovations in Microengineering (LiME), Department of Mechanical Engineering, University of Victoria, Victoria, BC, V8P 5C2, Canada
| | - Bahram Mirani
- Laboratory for Innovations in Microengineering (LiME), Department of Mechanical Engineering, University of Victoria, Victoria, BC, V8P 5C2, Canada
| | - Ali Navaei
- School of Biological and Health Systems Engineering (SBHSE), Arizona State University, Tempe, AZ, 85281, USA
| | - Tara Styan
- Willerth Laboratory, Department of Mechanical Engineering and Division of Medical Sciences, University of Victoria, Victoria, V8P 5C2, Canada
| | - Sarah Wong
- Willerth Laboratory, Department of Mechanical Engineering and Division of Medical Sciences, University of Victoria, Victoria, V8P 5C2, Canada
| | - Mehdi Mehrali
- Department of Micro- and Nanotechnology, Center for Nanomedicine and Theranostics, Technical University of Denmark, Kgs. Lyngby, 2800, Denmark
| | - Ashish Thakur
- Department of Micro- and Nanotechnology, Center for Nanomedicine and Theranostics, Technical University of Denmark, Kgs. Lyngby, 2800, Denmark
| | - Nima Khadem Mohtaram
- Laboratory for Innovations in Microengineering (LiME), Department of Mechanical Engineering, University of Victoria, Victoria, BC, V8P 5C2, Canada
| | - Armin Bayati
- Willerth Laboratory, Department of Mechanical Engineering and Division of Medical Sciences, University of Victoria, Victoria, V8P 5C2, Canada
| | - Alireza Dolatshahi-Pirouz
- Department of Micro- and Nanotechnology, Center for Nanomedicine and Theranostics, Technical University of Denmark, Kgs. Lyngby, 2800, Denmark
| | - Mehdi Nikkhah
- School of Biological and Health Systems Engineering (SBHSE), Arizona State University, Tempe, AZ, 85281, USA
| | - Stephanie M Willerth
- Willerth Laboratory, Department of Mechanical Engineering and Division of Medical Sciences, University of Victoria, Victoria, V8P 5C2, Canada
| | - Mohsen Akbari
- Laboratory for Innovations in Microengineering (LiME), Department of Mechanical Engineering, University of Victoria, Victoria, BC, V8P 5C2, Canada
- Center for Advanced Materials and Related Technologies (CAMTEC), University of Victoria, Victoria, V8P 5C2, Canada
- Center for Biomedical Research, University of Victoria, Victoria, V8P 5C2, Canada
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Quintana-Villamandos B, Delgado-Martos MJ, Delgado-Baeza E. Adverse remodeling of the obtuse marginal artery in compensatory hypertrophied myocardium from spontaneously hypertensive rats. Cardiovasc Pathol 2016; 26:51-54. [PMID: 27888779 DOI: 10.1016/j.carpath.2016.11.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/28/2016] [Revised: 11/06/2016] [Accepted: 11/09/2016] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND Spontaneously hypertensive rats (SHR) serve as a model of genetic hypertension. Adverse remodeling of a coronary artery has been reported in SHR. This model is used to study new therapies in regression vascular remodeling. However, no data are available that show remodeling of the intramyocardial branch of the obtuse marginal artery in 10-month-old SHR. This study was designed to assess remodeling (changes in vascular structure and fibrosis) of this coronary artery. METHODS AND RESULTS The study was performed on 10-month-old male SHR (n=7) and normotensive control Wistar Kyoto rats (WKY) (n=7). Using histology, we show that the external diameter, lumen diameter, wall width, and cross-sectional area of the intramyocardial artery were significantly greater in SHR than in WKY. The wall-to-lumen ratio was similar in SHR and WKY. The collagen volume density of the intramyocardial artery in SHR was significantly greater than in WKY. CONCLUSIONS Our results show hypertrophic outward remodeling in the intramyocardial branch of the obtuse marginal artery of the left ventricle in SHR. This artery can serve as a new vascular bed from adult SHR to study novel therapies in regression coronary artery remodeling.
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Affiliation(s)
- Begoña Quintana-Villamandos
- Department of Anesthesiology, Reanimation and Intensive care, Hospital General Universitario Gregorio Marañón, Instituto de investigación sanitaria Gregorio Marañón (liSGM), Doctor Esquerdo 46, 28007, Madrid, Spain; Department of Pharmacology Faculty of Medicine, Universidad Complutense de Madrid, Plaza de Ramón y Cajal s/n, 28040, Madrid, Spain.
| | - María Jesús Delgado-Martos
- Department Experimental Medicine and Surgery, Hospital General Universitario Gregorio Marañón, Instituto de investigación sanitaria Gregorio Marañón (liSGM), Doctor Esquerdo 46, 28007, Madrid, Spain.
| | - Emilio Delgado-Baeza
- Department Experimental Medicine and Surgery, Hospital General Universitario Gregorio Marañón, Instituto de investigación sanitaria Gregorio Marañón (liSGM), Doctor Esquerdo 46, 28007, Madrid, Spain.
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A Mathematical Spline-Based Model of Cardiac Left Ventricle Anatomy and Morphology. COMPUTATION 2016. [DOI: 10.3390/computation4040042] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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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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Maleszewski J, Lai C, Veinot J. Anatomic Considerations and Examination of Cardiovascular Specimens (Excluding Devices). Cardiovasc Pathol 2016. [DOI: 10.1016/b978-0-12-420219-1.00001-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Stephenson RS, Agger P, Lunkenheimer PP, Zhao J, Smerup M, Niederer P, Anderson RH, Jarvis JC. The functional architecture of skeletal compared to cardiac musculature: Myocyte orientation, lamellar unit morphology, and the helical ventricular myocardial band. Clin Anat 2015; 29:316-32. [PMID: 26478993 DOI: 10.1002/ca.22661] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Revised: 10/13/2015] [Accepted: 10/15/2015] [Indexed: 11/06/2022]
Abstract
How the cardiomyocytes are aggregated within the heart walls remains contentious. We still do not fully understand how the end-to-end longitudinal myocytic chains are arranged, nor the true extent and shape of the lamellar units they aggregate to form. In this article, we show that an understanding of the complex arrangement of cardiac musculature requires knowledge of three-dimensional myocyte orientation (helical and intrusion angle), and appreciation of myocyte packing within the connective tissue matrix. We show how visualization and segmentation of high-resolution three-dimensional image data can accurately identify the morphology and orientation of the myocytic chains, and the lamellar units. Some maintain that the ventricles can be unwrapped in the form of a "helical ventricular myocardial band," that is, as a compartmentalized band with selective regional innervation and deformation, and a defined origin and insertion like most skeletal muscles. In contrast to the simpler interpretation of the helical ventricular myocardial band, we provide insight as to how the complex myocytic chains, the heterogeneous lamellar units, and connective tissue matrix form an interconnected meshwork, which facilitates the complex internal deformations of the ventricular wall. We highlight the dangers of disregarding the intruding cardiomyocytes. Preparation of the band destroys intruding myocytic chains, and thus disregards the functional implications of the antagonistic auxotonic forces they produce. We conclude that the ventricular myocardium is not analogous to skeletal muscle, but is a complex three-dimensional meshwork, with a heterogeneous branching lamellar architecture.
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Affiliation(s)
- Robert S Stephenson
- Research Institute for Sport and Exercise Science, Liverpool John Moores University, Liverpool, United Kingdom
| | - Peter Agger
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Paul P Lunkenheimer
- Department of Experimental Thoracic and Cardiovascular Surgery, University Hospital Munster, Munster, DE, Germany
| | - Jichao Zhao
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
| | - Morten Smerup
- Department of Cardiothoracic & Vascular Surgery, Aarhus University, Aarhus, Denmark
| | - Peter Niederer
- Institute for Biomedical Engineering, University of Zurich, Zurich, CH, Switzerland
| | - Robert H Anderson
- Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom.,Division of Biomedical Sciences, University College London, London, United Kingdom
| | - Jonathan C Jarvis
- Research Institute for Sport and Exercise Science, Liverpool John Moores University, Liverpool, United Kingdom
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Schmitt B, Li T, Kutty S, Khasheei A, Schmitt KRL, Anderson RH, Lunkenheimer PP, Berger F, Kühne T, Peters B. Effects of incremental beta-blocker dosing on myocardial mechanics of the human left ventricle: MRI 3D-tagging insight into pharmacodynamics supports theory of inner antagonism. Am J Physiol Heart Circ Physiol 2015; 309:H45-52. [DOI: 10.1152/ajpheart.00746.2014] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Accepted: 04/10/2015] [Indexed: 11/22/2022]
Abstract
Beta-blockers contribute to treatment of heart failure. Their mechanism of action, however, is incompletely understood. Gradients in beta-blocker sensitivity of helically aligned cardiomyocytes compared with counteracting transversely intruding cardiomyocytes seem crucial. We hypothesize that selective blockade of transversely intruding cardiomyocytes by low-dose beta-blockade unloads ventricular performance. Cardiac magnetic resonance imaging (MRI) 3D tagging delivers parameters of myocardial performance. We studied 13 healthy volunteers by MRI 3D tagging during escalated intravenous administration of esmolol. The circumferential, longitudinal, and radial myocardial shortening was determined for each dose. The curves were analyzed for peak value, time-to-peak, upslope, and area-under-the-curve. At low doses, from 5 to 25 μg·kg−1·min−1, peak contraction increased while time-to-peak decreased yielding a steeper upslope. Combining the values revealed a left shift of the curves at low doses compared with baseline without esmolol. At doses of 50 to 150 μg·kg−1·min−1, a right shift with flattening occurred. In healthy volunteers we found more pronounced myocardial shortening at low compared with clinical dosage of beta-blockers. In patients with ventricular hypertrophy and higher prevalence of transversely intruding cardiomyocytes selective low-dose beta-blockade could be even more effective. MRI 3D tagging could help to determine optimal individual beta-blocker dosing avoiding undesirable side effects.
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Affiliation(s)
- Boris Schmitt
- Department of Congenital Heart Disease/Pediatric Cardiology, Deutsches Herzzentrum Berlin, Berlin, Germany
| | - Tieyan Li
- Department of Congenital Heart Disease/Pediatric Cardiology, Deutsches Herzzentrum Berlin, Berlin, Germany
| | - Shelby Kutty
- Department of Pediatric Cardiology, University of Nebraska Medical Center, Children's Hospital and Medical Center, Omaha, Nebraska
| | - Alireza Khasheei
- Department of Congenital Heart Disease/Pediatric Cardiology, Deutsches Herzzentrum Berlin, Berlin, Germany
| | - Katharina R. L. Schmitt
- Department of Congenital Heart Disease/Pediatric Cardiology, Deutsches Herzzentrum Berlin, Berlin, Germany
| | - Robert H. Anderson
- Institute of Medical Genetics, Newcastle University, Newcastle upon Tyne, United Kingdom; and
| | - Paul P. Lunkenheimer
- Department of Experimental Thoracic and Cardiovascular Surgery, University Hospital Münster, Münster, Germany
| | - Felix Berger
- Department of Congenital Heart Disease/Pediatric Cardiology, Deutsches Herzzentrum Berlin, Berlin, Germany
| | - Titus Kühne
- Department of Congenital Heart Disease/Pediatric Cardiology, Deutsches Herzzentrum Berlin, Berlin, Germany
| | - Björn Peters
- Department of Congenital Heart Disease/Pediatric Cardiology, Deutsches Herzzentrum Berlin, Berlin, Germany
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Short-term esmolol improves coronary artery remodeling in spontaneously hypertensive rats through increased nitric oxide bioavailability and superoxide dismutase activity. BIOMED RESEARCH INTERNATIONAL 2014; 2014:531087. [PMID: 24795884 PMCID: PMC3984773 DOI: 10.1155/2014/531087] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/14/2013] [Revised: 02/07/2014] [Accepted: 02/19/2014] [Indexed: 01/19/2023]
Abstract
The aim of this study was to assess the effects of short-term esmolol therapy on coronary artery structure and function and plasma oxidative stress in spontaneously hypertensive rats (SHR). For this purpose, 14-month-old male SHR were treated for 48 hours with esmolol (SHR-E, 300 μg/kg/min). Age-matched untreated male SHR and Wistar Kyoto rats (WKY) were used as hypertensive and normotensive controls, respectively. At the end of intervention we performed a histological study to analyze coronary artery wall width (WW), wall-to-lumen ratio (W/L), and media cross-sectional area (MCSA). Dose-response curves for acetylcholine (ACh) and sodium nitroprusside were constructed. We also assessed several plasma oxidative stress biomarkers, namely, superoxide scavenging activity (SOSA), nitrites, and total antioxidant capacity (TAC). We observed a significant reduction in WW (P < 0.001), W/L (P < 0.05), and MCSA (P < 0.01) and improved endothelium-dependent relaxation (AUCSHR-E = 201.2 ± 33 versus AUCSHR = 97.5 ± 21, P < 0.05) in SHR-E compared with untreated SHR; no differences were observed for WW, MCSA, and endothelium-dependent relaxation by ACh at higher concentrations (10−6 to 10−4 mol/l) for SHR-E with respect to WKY. SOSA (P < 0.001) and nitrite (P < 0.01) values were significantly higher in SHR-E than in untreated SHR; however, TAC did not increase after treatment with esmolol. Esmolol improves early coronary artery remodeling in SHR.
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Freeman K, Tao W, Sun H, Soonpaa MH, Rubart M. In situ three-dimensional reconstruction of mouse heart sympathetic innervation by two-photon excitation fluorescence imaging. J Neurosci Methods 2014; 221:48-61. [PMID: 24056230 PMCID: PMC3858460 DOI: 10.1016/j.jneumeth.2013.09.005] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2013] [Revised: 09/06/2013] [Accepted: 09/08/2013] [Indexed: 12/26/2022]
Abstract
BACKGROUND Sympathetic nerve wiring in the mammalian heart has remained largely unexplored. Resolving the wiring diagram of the cardiac sympathetic network would help establish the structural underpinnings of neurocardiac coupling. NEW METHOD We used two-photon excitation fluorescence microscopy, combined with a computer-assisted 3-D tracking algorithm, to map the local sympathetic circuits in living hearts from adult transgenic mice expressing enhanced green fluorescent protein (EGFP) in peripheral adrenergic neurons. RESULTS Quantitative co-localization analyses confirmed that the intramyocardial EGFP distribution recapitulated the anatomy of the sympathetic arbor. In the left ventricular subepicardium of the uninjured heart, the sympathetic network was composed of multiple subarbors, exhibiting variable branching and looping topology. Axonal branches did not overlap with each other within their respective parental subarbor nor with neurites of annexed subarbors. The sympathetic network in the border zone of a 2-week-old myocardial infarction was characterized by substantive rewiring, which included spatially heterogeneous loss and gain of sympathetic fibers and formation of multiple, predominately nested, axon loops of widely variable circumference and geometry. COMPARISON WITH EXISTING METHODS In contrast to mechanical tissue sectioning methods that may involve deformation of tissue and uncertainty in registration across sections, our approach preserves continuity of structure, which allows tracing of neurites over distances, and thus enables derivation of the three-dimensional and topological morphology of cardiac sympathetic nerves. CONCLUSIONS Our assay should be of general utility to unravel the mechanisms governing sympathetic axon spacing during development and disease.
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Affiliation(s)
- Kim Freeman
- Riley Heart Research Center, Wells Center for Pediatric Research, Indiana University School of Medicine, 1044 West Walnut Street, Indianapolis, IN 46202
| | - Wen Tao
- Riley Heart Research Center, Wells Center for Pediatric Research, Indiana University School of Medicine, 1044 West Walnut Street, Indianapolis, IN 46202
| | - Hongli Sun
- Riley Heart Research Center, Wells Center for Pediatric Research, Indiana University School of Medicine, 1044 West Walnut Street, Indianapolis, IN 46202
| | - Mark H. Soonpaa
- Riley Heart Research Center, Wells Center for Pediatric Research, Indiana University School of Medicine, 1044 West Walnut Street, Indianapolis, IN 46202
| | - Michael Rubart
- Riley Heart Research Center, Wells Center for Pediatric Research, Indiana University School of Medicine, 1044 West Walnut Street, Indianapolis, IN 46202
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Smerup M, Agger P, Nielsen EA, Ringgaard S, Pedersen M, Niederer P, Anderson RH, Lunkenheimer PP. Regional and Epi- to Endocardial Differences in Transmural Angles of Left Ventricular Cardiomyocytes Measured inEx VivoPig Hearts: Functional Implications. Anat Rec (Hoboken) 2013; 296:1724-34. [DOI: 10.1002/ar.22787] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 05/27/2013] [Accepted: 07/13/2013] [Indexed: 11/09/2022]
Affiliation(s)
- Morten Smerup
- Department of Cardiothoracic and Vascular Surgery; Aarhus University Hospital Skejby; Aarhus Denmark
| | - Peter Agger
- Department of Cardiothoracic and Vascular Surgery; Aarhus University Hospital Skejby; Aarhus Denmark
| | - Eva Amalie Nielsen
- Department of Cardiothoracic and Vascular Surgery; Aarhus University Hospital Skejby; Aarhus Denmark
| | | | | | - Peter Niederer
- Institute of Biomedical Engineering; ETH Zurich; Zurich Switzerland
| | | | - Paul P. Lunkenheimer
- Klinik und Poliklinik für Thorax-, Herz- und Gefässchirurgie; University Münster; Germany
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Zhang W, Chen H, Qu X, Chang CP, Shou W. Molecular mechanism of ventricular trabeculation/compaction and the pathogenesis of the left ventricular noncompaction cardiomyopathy (LVNC). AMERICAN JOURNAL OF MEDICAL GENETICS PART C-SEMINARS IN MEDICAL GENETICS 2013; 163C:144-56. [PMID: 23843320 DOI: 10.1002/ajmg.c.31369] [Citation(s) in RCA: 100] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Ventricular trabeculation and compaction are two of the many essential steps for generating a functionally competent ventricular wall. A significant reduction in trabeculation is usually associated with ventricular compact zone deficiencies (hypoplastic wall), which commonly leads to embryonic heart failure and early embryonic lethality. In contrast, hypertrabeculation and lack of ventricular wall compaction (noncompaction) are closely related defects in cardiac embryogenesis associated with left ventricular noncompaction (LVNC), a genetically heterogenous disorder. Here we review recent findings through summarizing several genetically engineered mouse models that have defects in cardiac trabeculation and compaction.
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Affiliation(s)
- Wenjun Zhang
- Riley Heart Research Center, Indiana University School of Medicine, Indianapolis, IN 46202, USA
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Pravdin SF, Berdyshev VI, Panfilov AV, Katsnelson LB, Solovyova O, Markhasin VS. Mathematical model of the anatomy and fibre orientation field of the left ventricle of the heart. Biomed Eng Online 2013; 12:54. [PMID: 23773421 PMCID: PMC3699427 DOI: 10.1186/1475-925x-12-54] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2013] [Accepted: 06/05/2013] [Indexed: 11/10/2022] Open
Abstract
Background One of the main factors affecting propagation of electrical waves and contraction in ventricles of the heart is anisotropy of cardiac tissue. Anisotropy is determined by orientation of myocardial fibres. Determining fibre orientation field and shape of the heart is important for anatomically accurate modelling of electrical and mechanical function of the heart. The aim of this paper is to introduce a theoretical rule-based model for anatomy and fibre orientation of the left ventricle (LV) of the heart and to compare it with experimental data. We suggest explicit analytical formulae that allow us to obtain the left ventricle form and its fibre direction field. The ventricle band concept of cardiac architecture given by Torrent-Guasp is chosen as the model postulate. Methods In our approach, anisotropy of the heart is derived from some general principles. The LV is considered as a set of identical spiral surfaces, each of which can be produced from the other by rotation around one vertical axis. Each spiral surface is filled with non-intersecting curves which represent myocardial fibres. For model verification, we use experimental data on fibre orientation in human and canine hearts. Results LV shape and anisotropy are represented by explicit analytical expressions in a curvilinear 3-D coordinate system. The derived fibre orientation field shows good qualitative agreement with experimental data. The model reveals the most thorough quantitative simulation of fibre angles at the LV middle zone. Conclusions Our analysis shows that the band concept can generate realistic anisotropy of the LV. Our model shows good qualitative agreement between the simulated fibre orientation field and the experimental data on LV anisotropy, and the model can be used for various numerical simulations to study the effects of anisotropy on cardiac excitation and mechanical function.
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Affiliation(s)
- Sergey F Pravdin
- Function Approximation Theory Department, Institute of Mathematics and Mechanics, Ekaterinburg, Russia.
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Lunkenheimer PP, Niederer P, Sanchez-Quintana D, Murillo M, Smerup M. Models of ventricular structure and function reviewed for clinical cardiologists. J Cardiovasc Transl Res 2012; 6:176-86. [PMID: 23271645 DOI: 10.1007/s12265-012-9440-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2012] [Accepted: 12/12/2012] [Indexed: 10/27/2022]
Abstract
The architectural arrangement of cardiomyocytes aggregated together within the ventricular walls remains controversial. Two models currently attract clinical attention, with neither model standing rigorous anatomical scrutiny. The first is based on the notion that ventricular mass can be unraveled consistently to produce a unique myocardial band. The second model was initially based on the notion that cardiomyocytes were bundled together in uniform fashion, with fibrous shelves interposed in transmural fashion. This concept was subsequently modified to accept the fact that the fibrous matrix supporting the cardiomyocytes within the ventricular walls does not form transmural sheets. Current observations demonstrate that not all cardiomyocytes are aggregated together in tangential fashion. A significant netting component is aligned in obliquely intruding and transversal fashion. The interaction between the tangential and transversal chains of cardiomyocytes with the fibrous matrix produces antagonistic forces, with both unloading and auxotonic forces necessary to explain normal and abnormal cardiodynamics. This article is part of a JCTR special issue on Cardiac Anatomy.
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Affiliation(s)
- Paul P Lunkenheimer
- Department of Experimental Thoraco-Vascular Surgery, Universitätsklinik, Münster, Domagkstraße 11, 48149 Münster, Germany.
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Habeler W, Peschanski M, Monville C. Organotypic heart slices for cell transplantation and physiological studies. Organogenesis 2012; 5:62-6. [PMID: 19794901 DOI: 10.4161/org.5.2.9091] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2009] [Accepted: 05/23/2009] [Indexed: 11/19/2022] Open
Abstract
Recent studies have significantly improved our ability to investigate cell transplantation and study the physiology of transplanted cells in cardiac tissue. Several previous studies have shown that fully-immersed heart slices can be used for electrophysiological investigations. Additionally, ischemic heart slices induced by glucose and oxygen deprivation offer a useful tool to investigate mechanical integration and to measure forces of contraction of engrafted cells, at least for short term analysis. A recent and novel model of heart slices, prepared from rat and human tissues, can be maintained in culture for up to two months. This new heart slice model can be used for long term in vitro cell transplantation studies and for pharmacological evaluation. This review will focus on describing these models and demonstrating the use of organotypic heart slices as a novel tool for drugs for studying electrophysiology and developing cellular therapeutic approaches to alleviate cardiac tissue damage.
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Wan CR, Frohlich EM, Charest JL, Kamm RD. Effect of Surface Patterning and Presence of Collagen I on the Phenotypic Changes of Embryonic Stem Cell Derived Cardiomyocytes. Cell Mol Bioeng 2010. [DOI: 10.1007/s12195-010-0150-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
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Holland MR, Gibson AA, Bauer AQ, Peterson LR, Schaffer JE, Bach RG, Cresci S, Miller JG. Echocardiographic tissue characterization demonstrates differences in the left and right sides of the ventricular septum. ULTRASOUND IN MEDICINE & BIOLOGY 2010; 36:1653-1661. [PMID: 20800946 PMCID: PMC2942980 DOI: 10.1016/j.ultrasmedbio.2010.07.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2009] [Revised: 06/30/2010] [Accepted: 07/06/2010] [Indexed: 05/29/2023]
Abstract
The left and right ventricular function of the heart are influenced by the complex structure of the ventricular septum. The cyclic variation of ultrasonic backscatter over the cardiac cycle is known to be sensitive to both structural and functional characteristics of the myocardium. The objective of this study was to investigate differences in the measured magnitude and normalized delay of cyclic variation between the left and right sides of the ventricular septum in normal adult subjects (N = 31). The measured mean magnitudes of cyclic variation were found to be 4.9 ± 0.4 dB and 2.4 ± 0.3 dB (mean ± SE; p < 0.0001) and the corresponding normalized delay values were found to be 0.94 ± 0.05 and 1.59 ± 0.12 (mean ± SE; p < 0.0001) for the left and right sides, respectively. These results show significant differences in the measured magnitude and normalized delay of cyclic variation between the left and right sides of the ventricular septum in normal subjects that appear consistent with predictions based on previously described models of cyclic variation of backscatter and reported measurements of transmural differences in strain properties of the septum.
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Models of cardiac tissue electrophysiology: progress, challenges and open questions. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2010; 104:22-48. [PMID: 20553746 DOI: 10.1016/j.pbiomolbio.2010.05.008] [Citation(s) in RCA: 290] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2009] [Revised: 04/09/2010] [Accepted: 05/19/2010] [Indexed: 01/03/2023]
Abstract
Models of cardiac tissue electrophysiology are an important component of the Cardiac Physiome Project, which is an international effort to build biophysically based multi-scale mathematical models of the heart. Models of tissue electrophysiology can provide a bridge between electrophysiological cell models at smaller scales, and tissue mechanics, metabolism and blood flow at larger scales. This paper is a critical review of cardiac tissue electrophysiology models, focussing on the micro-structure of cardiac tissue, generic behaviours of action potential propagation, different models of cardiac tissue electrophysiology, the choice of parameter values and tissue geometry, emergent properties in tissue models, numerical techniques and computational issues. We propose a tentative list of information that could be included in published descriptions of tissue electrophysiology models, and used to support interpretation and evaluation of simulation results. We conclude with a discussion of challenges and open questions.
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Ho SY. Anatomy and myoarchitecture of the left ventricular wall in normal and in disease. EUROPEAN JOURNAL OF ECHOCARDIOGRAPHY 2010; 10:iii3-7. [PMID: 19889656 DOI: 10.1093/ejechocard/jep159] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
The normal left ventricle comprises an inlet, apical trabecular, and an outlet portion although these portions do not have discrete anatomical borders. The ventricular wall is thickest near the cardiac base and thins to 1-2 mm at the apex. Characteristically, the muscle bundles at the apical portion are thin, but there are also thicker bundles and very fine strands that may be mistaken on imaging as pathologies. Transmurally through the ventricular wall, the myoarchitecture has a typical arrangement of myocardial strands that change orientation from being oblique in the subepicardium to circumferential in the middle and to longitudinal in the subendocardium. The circumferential portion is the thickest with the longitudinal portion the thinnest. In the hypertrophied ventricle the circumferential portion is reduced. In combination with alterations in the quality and quantity of the connective tissue matrix, myoarchitecture impacts on myocardial function.
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Affiliation(s)
- Siew Yen Ho
- Cardiac Morphology Unit, Imperial College London, Royal Brompton Hospital, London, UK.
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Ryu S, Yamamoto S, Andersen CR, Nakazawa K, Miyake F, James TN. Intramural Purkinje cell network of sheep ventricles as the terminal pathway of conduction system. Anat Rec (Hoboken) 2009; 292:12-22. [PMID: 19051253 DOI: 10.1002/ar.20827] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
To identify the anatomical basis for cardiac electrical signal conduction, particularly seeking the intramural terminals of conduction pathway within the ventricles, sheep hearts were examined compared with human hearts utilizing the characteristic morphology of Purkinje cells as a histological marker. In 15 sheep and five human autopsies of noncardiac death, prevalence of Purkinje or Purkinje-type cells were histologically examined in the atrioventricular node, its distal conduction pathway, the interventricular septum, and the right- and left-ventricular free walls. Myocardial tissue cleavages were examined in the transmural sections (along cardiac base-to-apex axis) obtained from the septum and ventricular free walls. Serial histological sections through virtually the entirety of the septum in selected sheep were used as the basis of a three-dimensional reconstruction of the conduction pathway, particularly of the intramural Purkinje cell network. Purkinje cells were found within the mural myocardium of sheep ventricles whereas no intramural Purkinje-type cell was detected within the human ventricles. In the sheep septum, every intramural Purkinje cell composed a three-dimensional network throughout the mural myocardium, which proximally connected to the subendocardial extension of the bundle branches and distally formed an occasional junction with ordinary working myocytes. The Purkinje-cell network may participate in the ventricular excitation as the terminal conduction pathway. Individual connections among the Purkinje cells contain the links of through-wall orientation which would benefit the signal conduction crossing the architectural barriers by cleavages in sheep hearts. The myocardial architectural changes found in diseased hearts could disrupt the network links including those with transmural orientation. Anat Rec, 2009. (c) 2008 Wiley-Liss, Inc.
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Affiliation(s)
- Shonosuke Ryu
- Department of Internal Medicine, Division of Cardiology, St. Marianna University School of Medicine, Kawasaki, Kanagawa, Japan
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