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Winters J, Isaacs A, Zeemering S, Kawczynski M, Maesen B, Maessen J, Bidar E, Boukens B, Hermans B, van Hunnik A, Casadei B, Fabritz L, Chua W, Sommerfeld L, Guasch E, Mont L, Batlle M, Hatem S, Kirchhof P, Wakili R, Sinner M, Stoll M, Goette A, Verheule S, Schotten U. Heart Failure, Female Sex, and Atrial Fibrillation Are the Main Drivers of Human Atrial Cardiomyopathy: Results From the CATCH ME Consortium. J Am Heart Assoc 2023; 12:e031220. [PMID: 37982389 PMCID: PMC10727294 DOI: 10.1161/jaha.123.031220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Accepted: 09/22/2023] [Indexed: 11/21/2023]
Abstract
BACKGROUND Atrial cardiomyopathy (atCM) is an emerging prognostic factor in cardiovascular disease. Fibrotic remodeling, cardiomyocyte hypertrophy, and capillary density are hallmarks of atCM. The contribution of etiological factors and atrial fibrillation (AF) to the development of differential atCM phenotypes has not been quantified. This study aimed to evaluate the association between histological features of atCM and the clinical phenotype. METHODS AND RESULTS We examined left atrial (LA, n=95) and right atrial (RA, n=76) appendages from a European cohort of patients undergoing cardiac surgery. Quantification of histological atCM features was performed following wheat germ agglutinin/CD31/vimentin staining. The contributions of AF, heart failure, sex, and age to histological characteristics were determined with multiple linear regression models. Persistent AF was associated with increased endomysial fibrosis (LA: +1.13±0.47 μm, P=0.038; RA: +0.94±0.38 μm, P=0.041), whereas total extracellular matrix content was not. Men had larger cardiomyocytes (LA: +1.92±0.72 μm, P<0.001), while women had more endomysial fibrosis (LA: +0.99±0.56 μm, P=0.003). Patients with heart failure showed more endomysial fibrosis (LA: +1.85±0.48 μm, P<0.001) and extracellular matrix content (LA: +3.07±1.29%, P=0.016), and a higher capillary density (LA: +0.13±0.06, P=0.007) and size (LA: +0.46±0.22 μm, P=0.044). Fuzzy k-means clustering of histological features identified 2 subtypes of atCM: 1 characterized by enhanced endomysial fibrosis (LA: +3.17 μm, P<0.001; RA: +2.86 μm, P<0.001), extracellular matrix content (LA: +3.53%, P<0.001; RA: +6.40%, P<0.001) and fibroblast density (LA: +4.38%, P<0.001), and 1 characterized by cardiomyocyte hypertrophy (LA: +1.16 μm, P=0.008; RA: +2.58 μm, P<0.001). Patients with fibrotic atCM were more frequently female (LA: odds ratio [OR], 1.33, P=0.002; RA: OR, 1.54, P=0.004), with persistent AF (LA: OR, 1.22, P=0.036) or heart failure (LA: OR, 1.62, P<0.001). Hypertrophic features were more common in men (LA: OR=1.33, P=0.002; RA: OR, 1.54, P=0.004). CONCLUSIONS Fibrotic atCM is associated with female sex, persistent AF, and heart failure, while hypertrophic features are more common in men.
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Affiliation(s)
- Joris Winters
- Department of Physiology, Cardiovascular Research Institute Maastricht University Maastricht Maastricht The Netherlands
| | - Aaron Isaacs
- Department of Physiology, Cardiovascular Research Institute Maastricht University Maastricht Maastricht The Netherlands
- Maastricht Centre for Systems Biology University Maastricht Maastricht The Netherlands
| | - Stef Zeemering
- Department of Physiology, Cardiovascular Research Institute Maastricht University Maastricht Maastricht The Netherlands
| | - Michal Kawczynski
- Department of Physiology, Cardiovascular Research Institute Maastricht University Maastricht Maastricht The Netherlands
- Department of Cardiothoracic Surgery Maastricht University Medical Centre+ Maastricht The Netherlands
| | - Bart Maesen
- Department of Cardiothoracic Surgery Maastricht University Medical Centre+ Maastricht The Netherlands
| | - Jos Maessen
- Department of Cardiothoracic Surgery Maastricht University Medical Centre+ Maastricht The Netherlands
| | - Elham Bidar
- Department of Cardiothoracic Surgery Maastricht University Medical Centre+ Maastricht The Netherlands
| | - Bas Boukens
- Department of Physiology, Cardiovascular Research Institute Maastricht University Maastricht Maastricht The Netherlands
| | - Ben Hermans
- Department of Physiology, Cardiovascular Research Institute Maastricht University Maastricht Maastricht The Netherlands
| | - Arne van Hunnik
- Department of Physiology, Cardiovascular Research Institute Maastricht University Maastricht Maastricht The Netherlands
| | - Barbara Casadei
- Division of Cardiovascular Medicine, BHF Centre of Research Excellence University of Oxford Oxford United Kingdom
| | - Larissa Fabritz
- Institute of Cardiovascular Sciences Birmingham United Kingdom
- University Center of Cardiovascular Science UKE Hamburg Hamburg Germany
- University Heart and Vascular Center, University Hospital Hamburg Eppendorf Hamburg Germany
- DZHK, Standort Hamburg/Kiel/Lübeck Lübeck Germany
| | - Winnie Chua
- Institute of Cardiovascular Sciences Birmingham United Kingdom
| | - Laura Sommerfeld
- Institute of Cardiovascular Sciences Birmingham United Kingdom
- University Center of Cardiovascular Science UKE Hamburg Hamburg Germany
- University Heart and Vascular Center, University Hospital Hamburg Eppendorf Hamburg Germany
- DZHK, Standort Hamburg/Kiel/Lübeck Lübeck Germany
| | - Eduard Guasch
- Institute of Biomedical Research August Pi Sunyer (IDIBAPS) Barcelona Spain
| | - Luis Mont
- Clinic Barcelona, Universitat de Barcelona Barcelona Spain
| | - Montserrat Batlle
- Institute of Biomedical Research August Pi Sunyer (IDIBAPS) Barcelona Spain
- Centro de Investigación Biomédica en Red-Cardiovascular (CIBERCV) Madrid Spain
| | | | - Paulus Kirchhof
- Institute of Cardiovascular Sciences Birmingham United Kingdom
- University Heart and Vascular Center, University Hospital Hamburg Eppendorf Hamburg Germany
- DZHK, Standort Hamburg/Kiel/Lübeck Lübeck Germany
| | - Reza Wakili
- Department of Medicine and Cardiology Goethe University Frankfurt Germany
| | - Mortiz Sinner
- University Heart and Vascular Center, University Hospital Hamburg Eppendorf Hamburg Germany
- DZHK, Standort Hamburg/Kiel/Lübeck Lübeck Germany
- Department of Cardiology University Hospital of Munich Munich Germany
| | - Monica Stoll
- Maastricht Centre for Systems Biology University Maastricht Maastricht The Netherlands
- Department of Biochemistry, Genetic Epidemiology and Statistical Genetics University Maastricht Maastricht The Netherlands
- Department of Genetic Epidemiology, Institute of Human Genetics University of Münster Münster Germany
| | - Andreas Goette
- Department of Cardiology and Intensive Care Medicine St. Vincenz Hospital Paderborn Paderborn Germany
| | - Sander Verheule
- Department of Physiology, Cardiovascular Research Institute Maastricht University Maastricht Maastricht The Netherlands
| | - Ulrich Schotten
- Department of Physiology, Cardiovascular Research Institute Maastricht University Maastricht Maastricht The Netherlands
- Department of Cardiology Maastricht University Medical Centre+ Maastricht The Netherlands
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2
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Hartley A, Shalhoub J, Ng FS, Krahn AD, Laksman Z, Andrade JG, Deyell MW, Kanagaratnam P, Sikkel MB. Size matters in atrial fibrillation: the underestimated importance of reduction of contiguous electrical mass underlying the effectiveness of catheter ablation. Europace 2021; 23:1698-1707. [PMID: 33948648 PMCID: PMC8576280 DOI: 10.1093/europace/euab078] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Accepted: 03/22/2021] [Indexed: 11/13/2022] Open
Abstract
Evidence has accumulated over the last century of the importance of a critical electrical mass in sustaining atrial fibrillation (AF). AF ablation certainly reduces electrically contiguous atrial mass, but this is not widely accepted to be an important part of its mechanism of action. In this article, we review data showing that atrial size is correlated in many settings with AF propensity. Larger mammals are more likely to exhibit AF. This is seen both in the natural world and in animal models, where it is much easier to create a goat model than a mouse model of AF, for example. This also extends to humans-athletes, taller people, and obese individuals all have large atria and are more likely to exhibit AF. Within an individual, risk factors such as hypertension, valvular disease and ischaemia can enlarge the atrium and increase the risk of AF. With respect to AF ablation, we explore how variations in ablation strategy and the relative effectiveness of these strategies may suggest that a reduction in electrical atrial mass is an important mechanism of action. We counter this with examples in which there is no doubt that mass reduction is less important than competing theories such as ganglionated plexus ablation. We conclude that, when considering future strategies for the ablative therapy of AF, it is important not to discount the possibility that contiguous electrical mass reduction is the most important mechanism despite the disappointing consequence being that enhancing success rates in AF ablation may involve greater tissue destruction.
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Affiliation(s)
- Adam Hartley
- National Heart and Lung Institute,Imperial College London, London, UK
| | - Joseph Shalhoub
- National Heart and Lung Institute,Imperial College London, London, UK
| | - Fu Siong Ng
- National Heart and Lung Institute,Imperial College London, London, UK
| | - Andrew D Krahn
- Division of Cardiology, University of British Columbia, 740 Hillside Ave, Vancouver, BC V8T 1Z4, Canada
| | - Zachary Laksman
- Division of Cardiology, University of British Columbia, 740 Hillside Ave, Vancouver, BC V8T 1Z4, Canada
| | - Jason G Andrade
- Division of Cardiology, University of British Columbia, 740 Hillside Ave, Vancouver, BC V8T 1Z4, Canada
| | - Marc W Deyell
- Division of Cardiology, University of British Columbia, 740 Hillside Ave, Vancouver, BC V8T 1Z4, Canada
| | | | - Markus B Sikkel
- Division of Cardiology, University of British Columbia, 740 Hillside Ave, Vancouver, BC V8T 1Z4, Canada
- Division of Medical Sciences, University of Victoria, Victoria, Canada
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3
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Citerni C, Kirchhoff J, Olsen LH, Sattler SM, Gentilini F, Forni M, Zannoni A, Grunnet M, Edvardsson N, Bentzen BH, Diness JG. Characterization of Atrial and Ventricular Structural Remodeling in a Porcine Model of Atrial Fibrillation Induced by Atrial Tachypacing. Front Vet Sci 2020; 7:179. [PMID: 32328502 PMCID: PMC7160334 DOI: 10.3389/fvets.2020.00179] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2019] [Accepted: 03/19/2020] [Indexed: 12/12/2022] Open
Abstract
Background: Atrial fibrillation (AF) is characterized by electrical and structural remodeling. Irregular and/or fast atrio-ventricular (AV) conduction during AF can result in AV dyssynchrony, tachymyopathy, pressure and volume overload with subsequent dilatation, valve regurgitation, and ventricular dysfunction with progression to heart failure. Objective: To gain further insight into the myocardial pathophysiological changes induced by right atrial tachypacing (A-TP) in a large animal model. Methods: A total of 28 Landrace pigs were randomized as 14 into AF-induced A-TP group and 14 pigs to control group. AF pigs were tachypaced for 43 ± 4 days until in sustained AF. Functional remodeling was investigated by echocardiography (after cardioversion to sinus rhythm). Structural remodeling was quantified by histological preparations with picrosirius red and immunohistochemical stainings. Results: A-TP resulted in decreased left ventricular ejection fraction (LVEF) accompanied by increased end-diastolic and end-systolic left atrium (LA) volume and area. In addition, A-TP was associated with mitral valve (MV) regurgitation, diastolic dysfunction and increased atrial and ventricular fibrotic extracellular matrix (ECM). Conclusions: A-TP induced AF with concomitant LV systolic and diastolic dysfunction, increased LA volume and area, and atrial and ventricular fibrosis.
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Affiliation(s)
- Carlotta Citerni
- Biomedical Institute, University of Copenhagen, Copenhagen, Denmark.,Acesion Pharma, Copenhagen, Denmark
| | | | - Lisbeth Høier Olsen
- Department of Veterinary and Animal Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Stefan Michael Sattler
- Biomedical Institute, University of Copenhagen, Copenhagen, Denmark.,Department of Cardiology, Heart Center, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark.,Medical Department I, University Hospital Grosshadern, LMU Munich, Munich, Germany
| | - Fabio Gentilini
- Department of Veterinary Medical Sciences, University of Bologna, Bologna, Italy
| | - Monica Forni
- Department of Veterinary Medical Sciences, University of Bologna, Bologna, Italy
| | - Augusta Zannoni
- Department of Veterinary Medical Sciences, University of Bologna, Bologna, Italy
| | | | - Nils Edvardsson
- Acesion Pharma, Copenhagen, Denmark.,Department of Molecular and Clinical Medicine/Cardiology, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Bo Hjorth Bentzen
- Biomedical Institute, University of Copenhagen, Copenhagen, Denmark.,Acesion Pharma, Copenhagen, Denmark
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Reese-Petersen AL, Olesen MS, Karsdal MA, Svendsen JH, Genovese F. Atrial fibrillation and cardiac fibrosis: A review on the potential of extracellular matrix proteins as biomarkers. Matrix Biol 2020; 91-92:188-203. [PMID: 32205152 DOI: 10.1016/j.matbio.2020.03.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Revised: 03/04/2020] [Accepted: 03/04/2020] [Indexed: 01/06/2023]
Abstract
The involvement of fibrosis as an underlying pathology in heart diseases is becoming increasingly clear. In recent years, fibrosis has been granted a causative role in heart diseases and is now emerging as a major contributor to Atrial Fibrillation (AF) pathogenesis. AF is the most common arrhythmia encountered in the clinic, but the substrate for AF is still being debated. Consensus in the field is a combination of cardiac tissue remodeling, inflammation and genetic predisposition. The extracellular matrix (ECM) is subject of growing investigation, since measuring circulatory biomarkers of ECM formation and degradation provides both diagnostic and prognostic information. However, fibrosis is not just fibrosis. Each specific collagen biomarker holds information on regulatory mechanisms, as well as information about which section of the ECM is being remodeled, providing a detailed description of cardiac tissue homeostasis. This review entails an overview of the implication of fibrosis in AF, the different collagens and their significance, and the potential of using biomarkers of ECM remodeling as tools for understanding AF pathogenesis and identifying patients at risk for further disease progression.
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Affiliation(s)
| | - Morten S Olesen
- Labratory of Molecular Cardiology, Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark.
| | | | - Jesper H Svendsen
- Department of Cardiology, The Heart Centre, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
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5
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Cerveró J, Segura V, Macías A, Gavira J, Montes R, Hermida J. Atrial fibrillation in pigs induces left atrial endocardial transcriptional remodelling. Thromb Haemost 2017; 108:742-9. [DOI: 10.1160/th12-05-0285] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2012] [Accepted: 07/21/2012] [Indexed: 11/05/2022]
Abstract
SummaryThe leading cause of cardioembolic stroke is atrial fibrillation (AF), which predisposes to atrial thrombus formation. Although rheological alterations promote a hypercoagulable environment, as yet undefined factors contribute to thrombogenesis. The role of the endocardium has barely been explored. To approach this topic, rapid atrial pacing (RAP) was applied in four pigs to mimic A F. Left and right endocardial cells were isolated separately and their gene expression pattern was compared with that of four control pigs. The AF-characteristic rhythm disorders and endothelial nitric oxide synthase down-regulation were successfully reproduced, and validated RAP to mimic A F. A change was observed in the transcriptomic endocardial profile after RAP: the expression of 364 genes was significantly altered (p<0.01), 29 of them having passed the B>0 criteria. The left atrial endocardium [325 genes (7 genes, B>0)] was largely responsible for such alterations. Blood coagulation, blood vessel morphogenesis and inflammatory response are among the most significant altered functions, and help to explain the activation of coagulation observed after RAP: D-dimer, 0.49 (1.63) vs. 0.23 (0.24) mg/l [median (interquartile range)] in controls, p=0.02. Furthermore, three genes directly related to thrombotic processes were differentially expressed after RAP: FGL2 [fold change (FC)=0.85; p=0.007], APLP2 (FC=-0.47; p=0.005) and ADAMTS-18 (FC=-0.69; p=0.004). We demonstrate for the first time that AF induces a global expression change in the left atrial endocardium associated with an activation of blood coagulation. The nature of some of the altered functions and genes provides clues to identify new therapeutic targets.
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6
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Doñate Puertas R, Meugnier E, Romestaing C, Rey C, Morel E, Lachuer J, Gadot N, Scridon A, Julien C, Tronc F, Chapuis B, Valla C, Janin A, Pirola L, Méjat A, Rome S, Chevalier P. Atrial fibrillation is associated with hypermethylation in human left atrium, and treatment with decitabine reduces atrial tachyarrhythmias in spontaneously hypertensive rats. Transl Res 2017; 184:57-67.e5. [PMID: 28427903 DOI: 10.1016/j.trsl.2017.03.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Revised: 03/13/2017] [Accepted: 03/17/2017] [Indexed: 10/19/2022]
Abstract
Atrial fibrillation (AF) is the most common cardiac arrhythmia. As the molecular mechanisms underlying the pathology are largely unknown, this cardiac arrhythmia remains difficult to treat. To identify specific molecular actors involved in AF, we have performed a transcriptomic analysis on left atrium (LA) from patients with valvular heart disease with or without AF. We showed that 1627 genes had altered basal expression level in LA tissue of AF patients compared with the control group. The significantly enriched gene ontology biological process "anatomical structure morphogenesis" contained the highest number of genes in line with changes in structure that occur when the human heart remodels following AF development (ie, LA dilatation and interstitial fibrosis). We then focused the study on Pitx2 (paired-like homeodomain 2), being the most altered transcription factor in LA from AF patients and from which compelling evidence have indicated that its reduced expression can be considered as a marker for the disease. In addition, its expression was inversely correlated with LA size. We demonstrated that AF is associated with Pitx2 promoter hypermethylation both in humans and arrhythmic aging spontaneously hypertensive rats. Chronic administration of a DNA methylation inhibitor (ie, 5-Aza-2'-deoxycitidine) improved ECG arrhythmic profiles and superoxide dismutase activities and reduced fibrosis in the left ventricle of spontaneously hypertensive rats. Taken together, these data support the notion that AF is associated with epigenetic changes in LA and provide a proof-of-concept that hypomethylating agents have to be considered in the treatment of atrial arrhythmias.
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Affiliation(s)
| | - E Meugnier
- CarMeN Laboratory (UMR INSERM 1060-INRA 1397, INSA), Lyon-Sud Faculty of Medicine, University of Lyon, Pierre-Bénite, France
| | - C Romestaing
- LEHNA Laboratory, CNRS, UMR 5023, University of Lyon, Villeurbanne, France
| | - C Rey
- ProfilXpert, UNIV-US7 INSERM-UMS 3453 CNRS, Lyon, France
| | - E Morel
- Rhythmology Unit, Louis Pradel Cardiology Hospital, Hospices Civils de Lyon, Bron, France
| | - J Lachuer
- ProfilXpert, UNIV-US7 INSERM-UMS 3453 CNRS, Lyon, France
| | - N Gadot
- Plateform Anipath, Laënnec Faculty of Medecine, University of Lyon, Lyon, France
| | - A Scridon
- Physiology Department, University of Medicine and Pharmacy of Tîrgu Mures, Tîrgu Mures, Romania
| | - C Julien
- EA 4612 Neurocardiology unit, University of Lyon, Lyon, France
| | - F Tronc
- Pneumology Unit, Louis Pradel Cardiology Hospital, Hospices Civils de Lyon, Bron, France
| | - B Chapuis
- EA 4612 Neurocardiology unit, University of Lyon, Lyon, France
| | - C Valla
- Institut NeuroMyoGene (INMG), UMR CNRS 5310-INSERM U1217 / University of Lyon, Lyon, France
| | - A Janin
- Institut NeuroMyoGene (INMG), UMR CNRS 5310-INSERM U1217 / University of Lyon, Lyon, France
| | - L Pirola
- CarMeN Laboratory (UMR INSERM 1060-INRA 1397, INSA), Lyon-Sud Faculty of Medicine, University of Lyon, Pierre-Bénite, France
| | - A Méjat
- Institut NeuroMyoGene (INMG), UMR CNRS 5310-INSERM U1217 / University of Lyon, Lyon, France
| | - S Rome
- CarMeN Laboratory (UMR INSERM 1060-INRA 1397, INSA), Lyon-Sud Faculty of Medicine, University of Lyon, Pierre-Bénite, France
| | - Philippe Chevalier
- EA 4612 Neurocardiology unit, University of Lyon, Lyon, France; Rhythmology Unit, Louis Pradel Cardiology Hospital, Hospices Civils de Lyon, Bron, France.
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7
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Polejaeva IA, Rutigliano HM, Wells KD. Livestock in biomedical research: history, current status and future prospective. Reprod Fertil Dev 2017; 28:112-24. [PMID: 27062879 DOI: 10.1071/rd15343] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Livestock models have contributed significantly to biomedical and surgical advances. Their contribution is particularly prominent in the areas of physiology and assisted reproductive technologies, including understanding developmental processes and disorders, from ancient to modern times. Over the past 25 years, biomedical research that traditionally embraced a diverse species approach shifted to a small number of model species (e.g. mice and rats). The initial reasons for focusing the main efforts on the mouse were the availability of murine embryonic stem cells (ESCs) and genome sequence data. This powerful combination allowed for precise manipulation of the mouse genome (knockouts, knockins, transcriptional switches etc.) leading to ground-breaking discoveries on gene functions and regulation, and their role in health and disease. Despite the enormous contribution to biomedical research, mouse models have some major limitations. Their substantial differences compared with humans in body and organ size, lifespan and inbreeding result in pronounced metabolic, physiological and behavioural differences. Comparative studies of strategically chosen domestic species can complement mouse research and yield more rigorous findings. Because genome sequence and gene manipulation tools are now available for farm animals (cattle, pigs, sheep and goats), a larger number of livestock genetically engineered (GE) models will be accessible for biomedical research. This paper discusses the use of cattle, goats, sheep and pigs in biomedical research, provides an overview of transgenic technology in farm animals and highlights some of the beneficial characteristics of large animal models of human disease compared with the mouse. In addition, status and origin of current regulation of GE biomedical models is also reviewed.
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Affiliation(s)
- Irina A Polejaeva
- Department of Animal, Dairy and Veterinary Sciences, Utah State University, Logan, UT 84322, USA
| | - Heloisa M Rutigliano
- Department of Animal, Dairy and Veterinary Sciences, Utah State University, Logan, UT 84322, USA
| | - Kevin D Wells
- Division of Animal Sciences, Animal Sciences Research Center, University of Missouri, Columbia, MO 65211, USA
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8
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Fukumoto K, Habibi M, Ipek EG, Zahid S, Khurram IM, Zimmerman SL, Zipunnikov V, Spragg D, Ashikaga H, Trayanova N, Tomaselli GF, Rickard J, Marine JE, Berger RD, Calkins H, Nazarian S. Association of Left Atrial Local Conduction Velocity With Late Gadolinium Enhancement on Cardiac Magnetic Resonance in Patients With Atrial Fibrillation. Circ Arrhythm Electrophysiol 2016; 9:e002897. [PMID: 26917814 DOI: 10.1161/circep.115.002897] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
BACKGROUND Prior studies have demonstrated regional left atrial late gadolinium enhancement (LGE) heterogeneity on magnetic resonance imaging. Heterogeneity in regional conduction velocities is a critical substrate for functional reentry. We sought to examine the association between left atrial conduction velocity and LGE in patients with atrial fibrillation. METHODS AND RESULTS LGE imaging and left atrial activation mapping were performed during sinus rhythm in 22 patients before pulmonary vein isolation. The locations of 1468 electroanatomic map points were registered to the corresponding anatomic sites on 469 axial LGE image planes. The local conduction velocity at each point was calculated using previously established methods. The myocardial wall thickness and image intensity ratio defined as left atrial myocardial LGE signal intensity divided by the mean left atrial blood pool intensity was calculated for each mapping site. The local conduction velocity and image intensity ratio in the left atrium (mean ± SD) were 0.98 ± 0.46 and 0.95 ± 0.26 m/s, respectively. In multivariable regression analysis, clustered by patient, and adjusting for left atrial wall thickness, conduction velocity was associated with the local image intensity ratio (0.20 m/s decrease in conduction velocity per increase in unit image intensity ratio, P<0.001). CONCLUSIONS In this clinical in vivo study, we demonstrate that left atrial myocardium with increased gadolinium uptake has lower local conduction velocity. Identification of such regions may facilitate the targeting of the substrate for reentrant arrhythmias.
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Affiliation(s)
- Kotaro Fukumoto
- From the Section of Cardiac Electrophsyiology (K.F., M.H., E.G.I., I.M.K., D.S., H.A., N.T., G.F.T., J.R., J.E.M., R.D.B., H.C., S.N.), Department of Biomedical Engineering (S.Z., H.A., N.T., R.D.B.), Department of Radiology (S.L.Z.), Department of Biostatistics (V.Z.), and Department of Epidemiology (S.N.), Johns Hopkins University, Baltimore, MD
| | - Mohammadali Habibi
- From the Section of Cardiac Electrophsyiology (K.F., M.H., E.G.I., I.M.K., D.S., H.A., N.T., G.F.T., J.R., J.E.M., R.D.B., H.C., S.N.), Department of Biomedical Engineering (S.Z., H.A., N.T., R.D.B.), Department of Radiology (S.L.Z.), Department of Biostatistics (V.Z.), and Department of Epidemiology (S.N.), Johns Hopkins University, Baltimore, MD
| | - Esra Gucuk Ipek
- From the Section of Cardiac Electrophsyiology (K.F., M.H., E.G.I., I.M.K., D.S., H.A., N.T., G.F.T., J.R., J.E.M., R.D.B., H.C., S.N.), Department of Biomedical Engineering (S.Z., H.A., N.T., R.D.B.), Department of Radiology (S.L.Z.), Department of Biostatistics (V.Z.), and Department of Epidemiology (S.N.), Johns Hopkins University, Baltimore, MD
| | - Sohail Zahid
- From the Section of Cardiac Electrophsyiology (K.F., M.H., E.G.I., I.M.K., D.S., H.A., N.T., G.F.T., J.R., J.E.M., R.D.B., H.C., S.N.), Department of Biomedical Engineering (S.Z., H.A., N.T., R.D.B.), Department of Radiology (S.L.Z.), Department of Biostatistics (V.Z.), and Department of Epidemiology (S.N.), Johns Hopkins University, Baltimore, MD
| | - Irfan M Khurram
- From the Section of Cardiac Electrophsyiology (K.F., M.H., E.G.I., I.M.K., D.S., H.A., N.T., G.F.T., J.R., J.E.M., R.D.B., H.C., S.N.), Department of Biomedical Engineering (S.Z., H.A., N.T., R.D.B.), Department of Radiology (S.L.Z.), Department of Biostatistics (V.Z.), and Department of Epidemiology (S.N.), Johns Hopkins University, Baltimore, MD
| | - Stefan L Zimmerman
- From the Section of Cardiac Electrophsyiology (K.F., M.H., E.G.I., I.M.K., D.S., H.A., N.T., G.F.T., J.R., J.E.M., R.D.B., H.C., S.N.), Department of Biomedical Engineering (S.Z., H.A., N.T., R.D.B.), Department of Radiology (S.L.Z.), Department of Biostatistics (V.Z.), and Department of Epidemiology (S.N.), Johns Hopkins University, Baltimore, MD
| | - Vadim Zipunnikov
- From the Section of Cardiac Electrophsyiology (K.F., M.H., E.G.I., I.M.K., D.S., H.A., N.T., G.F.T., J.R., J.E.M., R.D.B., H.C., S.N.), Department of Biomedical Engineering (S.Z., H.A., N.T., R.D.B.), Department of Radiology (S.L.Z.), Department of Biostatistics (V.Z.), and Department of Epidemiology (S.N.), Johns Hopkins University, Baltimore, MD
| | - David Spragg
- From the Section of Cardiac Electrophsyiology (K.F., M.H., E.G.I., I.M.K., D.S., H.A., N.T., G.F.T., J.R., J.E.M., R.D.B., H.C., S.N.), Department of Biomedical Engineering (S.Z., H.A., N.T., R.D.B.), Department of Radiology (S.L.Z.), Department of Biostatistics (V.Z.), and Department of Epidemiology (S.N.), Johns Hopkins University, Baltimore, MD
| | - Hiroshi Ashikaga
- From the Section of Cardiac Electrophsyiology (K.F., M.H., E.G.I., I.M.K., D.S., H.A., N.T., G.F.T., J.R., J.E.M., R.D.B., H.C., S.N.), Department of Biomedical Engineering (S.Z., H.A., N.T., R.D.B.), Department of Radiology (S.L.Z.), Department of Biostatistics (V.Z.), and Department of Epidemiology (S.N.), Johns Hopkins University, Baltimore, MD
| | - Natalia Trayanova
- From the Section of Cardiac Electrophsyiology (K.F., M.H., E.G.I., I.M.K., D.S., H.A., N.T., G.F.T., J.R., J.E.M., R.D.B., H.C., S.N.), Department of Biomedical Engineering (S.Z., H.A., N.T., R.D.B.), Department of Radiology (S.L.Z.), Department of Biostatistics (V.Z.), and Department of Epidemiology (S.N.), Johns Hopkins University, Baltimore, MD
| | - Gordon F Tomaselli
- From the Section of Cardiac Electrophsyiology (K.F., M.H., E.G.I., I.M.K., D.S., H.A., N.T., G.F.T., J.R., J.E.M., R.D.B., H.C., S.N.), Department of Biomedical Engineering (S.Z., H.A., N.T., R.D.B.), Department of Radiology (S.L.Z.), Department of Biostatistics (V.Z.), and Department of Epidemiology (S.N.), Johns Hopkins University, Baltimore, MD
| | - John Rickard
- From the Section of Cardiac Electrophsyiology (K.F., M.H., E.G.I., I.M.K., D.S., H.A., N.T., G.F.T., J.R., J.E.M., R.D.B., H.C., S.N.), Department of Biomedical Engineering (S.Z., H.A., N.T., R.D.B.), Department of Radiology (S.L.Z.), Department of Biostatistics (V.Z.), and Department of Epidemiology (S.N.), Johns Hopkins University, Baltimore, MD
| | - Joseph E Marine
- From the Section of Cardiac Electrophsyiology (K.F., M.H., E.G.I., I.M.K., D.S., H.A., N.T., G.F.T., J.R., J.E.M., R.D.B., H.C., S.N.), Department of Biomedical Engineering (S.Z., H.A., N.T., R.D.B.), Department of Radiology (S.L.Z.), Department of Biostatistics (V.Z.), and Department of Epidemiology (S.N.), Johns Hopkins University, Baltimore, MD
| | - Ronald D Berger
- From the Section of Cardiac Electrophsyiology (K.F., M.H., E.G.I., I.M.K., D.S., H.A., N.T., G.F.T., J.R., J.E.M., R.D.B., H.C., S.N.), Department of Biomedical Engineering (S.Z., H.A., N.T., R.D.B.), Department of Radiology (S.L.Z.), Department of Biostatistics (V.Z.), and Department of Epidemiology (S.N.), Johns Hopkins University, Baltimore, MD
| | - Hugh Calkins
- From the Section of Cardiac Electrophsyiology (K.F., M.H., E.G.I., I.M.K., D.S., H.A., N.T., G.F.T., J.R., J.E.M., R.D.B., H.C., S.N.), Department of Biomedical Engineering (S.Z., H.A., N.T., R.D.B.), Department of Radiology (S.L.Z.), Department of Biostatistics (V.Z.), and Department of Epidemiology (S.N.), Johns Hopkins University, Baltimore, MD
| | - Saman Nazarian
- From the Section of Cardiac Electrophsyiology (K.F., M.H., E.G.I., I.M.K., D.S., H.A., N.T., G.F.T., J.R., J.E.M., R.D.B., H.C., S.N.), Department of Biomedical Engineering (S.Z., H.A., N.T., R.D.B.), Department of Radiology (S.L.Z.), Department of Biostatistics (V.Z.), and Department of Epidemiology (S.N.), Johns Hopkins University, Baltimore, MD.
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Chung YW, Yang YH, Wu CK, Yu CC, Juang JMJ, Wang YC, Tsai CT, Lin LY, Lai LP, Hwang JJ, Chiang FT, Chen PC, Lin JL. Spironolactone is associated with reduced risk of new-onset atrial fibrillation in patients receiving renal replacement therapy. Int J Cardiol 2016; 202:962-6. [DOI: 10.1016/j.ijcard.2015.05.167] [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] [Received: 04/02/2015] [Revised: 05/27/2015] [Accepted: 05/29/2015] [Indexed: 10/23/2022]
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10
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GOUDIS CHRISTOSA, KALLERGIS ELEFTHERIOSM, KANOUPAKIS EMMANUELM, MAVRAKIS HERCULESE, MALLIARAKI NIKIE, VARDAS PANOSE. Electrophysiological and Electroanatomical Mapping of the Right Atrium in Persistent Atrial Fibrillation: Relation to Collagen Turnover. PACING AND CLINICAL ELECTROPHYSIOLOGY: PACE 2015; 38:1039-48. [DOI: 10.1111/pace.12662] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Revised: 04/23/2015] [Accepted: 04/30/2015] [Indexed: 11/29/2022]
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11
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WITT CHANCE, KAPA SURAJ. The Inflammatory Hypothesis of Atrial Fibrillation: Diagnostic Marker, Therapeutic Target, or Innocent Bystander? J Cardiovasc Electrophysiol 2015; 26:641-3. [DOI: 10.1111/jce.12680] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- CHANCE WITT
- Division of Cardiovascular Diseases; Mayo Clinic College of Medicine; Rochester Minnesota USA
| | - SURAJ KAPA
- Division of Cardiovascular Diseases; Mayo Clinic College of Medicine; Rochester Minnesota USA
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12
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Comparison of preexisting and ablation-induced late gadolinium enhancement on left atrial magnetic resonance imaging. Heart Rhythm 2014; 12:668-72. [PMID: 25533586 DOI: 10.1016/j.hrthm.2014.12.021] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Indexed: 11/23/2022]
Abstract
BACKGROUND Postablation atrial fibrillation recurrence is positively associated with the extent of preexisting left atrial (LA) late gadolinium enhancement (LGE) on magnetic resonance imaging (MRI), but negatively associated with the extent of postablation LGE regardless of proximity to the pulmonary vein antra. The characteristics of pre- vs postablation LA LGE may provide insight into this seeming paradox and inform future strategies for ablation. OBJECTIVE The purpose of this study was to define the characteristics of preexisting vs ablation-induced LA LGE. METHODS LGE-MRI was prospectively performed before and ≥3 months after initial ablation in 20 patients. The intracardiac locations of ablation points were coregistered with the corresponding sites on axial planes of postablation LGE-MRI. The image intensity ratio (IIR), defined as the LA myocardial MRI signal intensity divided by the mean LA blood pool intensity, and LA myocardial wall thickness were calculated on pre- and postablation images. RESULTS Imaging data from 409 pairs of pre- and postablation axial LGE-MRI planes and 6961 pairs of pre- and postablation image sectors were analyzed. Ablation-induced LGE revealed a higher IIR, suggesting greater contrast uptake and denser fibrosis, than did preexisting LGE (1.25 ± 0.25 vs 1.14 ± 0.15; P < .001). In addition, ablation-induced LGE regions had thinner LA myocardium (2.10 ± 0.67 mm vs 2.37 ± 0.74 mm; P < .001). CONCLUSION Regions with ablation-induced LGE exhibit increased contrast uptake, likely signifying higher scar density, and thinner myocardium as compared with regions with preexisting LGE. Future studies examining the association of postablation LGE intensity and nonuniformity with ablation success are warranted and may inform strategies to optimize ablation outcome.
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MONIGATTI-TENKORANG JOANNA, JOUSSET FLORIAN, PASCALE PATRIZIO, VESIN JEANMARC, RUCHAT PATRICK, FROMER MARTIN, NARAYAN SANJIVM, PRUVOT ETIENNE. Intermittent Atrial Tachycardia Promotes Repolarization Alternans and Conduction Slowing During Rapid Rates, and Increases Susceptibility to Atrial Fibrillation in a Free-Behaving Sheep Model. J Cardiovasc Electrophysiol 2014; 25:418-427. [DOI: 10.1111/jce.12353] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Revised: 11/09/2013] [Accepted: 12/02/2013] [Indexed: 11/30/2022]
Affiliation(s)
| | - FLORIAN JOUSSET
- Applied Signal Processing Group; Swiss Federal Institute of Technology; Lausanne Switzerland
| | - PATRIZIO PASCALE
- Department of Cardiology; Lausanne University Hospital; Lausanne Switzerland
| | - JEAN-MARC VESIN
- Applied Signal Processing Group; Swiss Federal Institute of Technology; Lausanne Switzerland
| | - PATRICK RUCHAT
- Department of Cardiovascular Surgery; Lausanne University Hospital; Lausanne Switzerland
| | - MARTIN FROMER
- Department of Cardiology; Lausanne University Hospital; Lausanne Switzerland
| | | | - ETIENNE PRUVOT
- Department of Cardiology; Lausanne University Hospital; Lausanne Switzerland
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14
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Spragg DD, Khurram I, Nazarian S. Role of Magnetic Resonance Imaging of Atrial Fibrosis in Atrial Fibrillation Ablation. Arrhythm Electrophysiol Rev 2013; 2:124-7. [PMID: 26835053 DOI: 10.15420/aer.2013.2.2.124] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2013] [Accepted: 10/14/2013] [Indexed: 12/31/2022] Open
Abstract
Atrial fibrillation (AF) likely involves a complex interplay between triggering activity, usually from pulmonary vein foci, and maintenance of the arrhythmia by an arrhythmogenic substrate. Both components of AF, triggers and substrate have been linked to atrial fibrosis and attendant changes in atrial electrophysiology. Recently, there has been a growing use of imaging modalities, particularly cardiac magnetic resonance (CMR), to quantify the burden of atrial fibrosis and scar in patients either undergoing AF ablation, or who have recently had the procedure. How to use the CMR derived data is still an open area of investigation. The aim of this article is to summarise what is known as atrial fibrosis, as assessed by traditional catheter-based techniques and newer imaging approaches, and to report on novel efforts from our group to advance the use of CMR in AF ablation patients.
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Affiliation(s)
- David D Spragg
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, US
| | - Irfan Khurram
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, US
| | - Saman Nazarian
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, US
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15
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Velagapudi P, Turagam MK, Leal MA, Kocheril AG. Atrial fibrosis: a risk stratifier for atrial fibrillation. Expert Rev Cardiovasc Ther 2013; 11:155-60. [PMID: 23405837 DOI: 10.1586/erc.12.174] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Atrial fibrillation (AF), especially persistent and long-standing persistent AF, may result in electro-anatomical changes in the left atrium, resulting in remodeling and deposition of fibrous tissue. There are emerging data that atrial substrate modification may increase the risk of thromboembolic complications, including stroke. Several studies have reported that atrial fibrosis is due to complex interactions among several cellular and neurohumoral mediators. Late gadolinium enhancement MRI has been reported to allow quantitative assessment of myocardial fibrosis in patients at risk of developing a stroke. Current stroke risk stratification criteria for AF do not utilize atrial fibrosis as an independent risk factor despite its association with AF and stroke. Further research is required in developing adequate risk stratification tools for predicting the stroke risk and catheter ablation outcomes in AF.
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Affiliation(s)
- Poonam Velagapudi
- Department of Medicine, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA
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16
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Dosdall DJ, Ranjan R, Higuchi K, Kholmovski E, Angel N, Li L, Macleod R, Norlund L, Olsen A, Davies CJ, Marrouche NF. Chronic atrial fibrillation causes left ventricular dysfunction in dogs but not goats: experience with dogs, goats, and pigs. Am J Physiol Heart Circ Physiol 2013; 305:H725-31. [PMID: 23812387 DOI: 10.1152/ajpheart.00440.2013] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Structural remodeling in chronic atrial fibrillation (AF) occurs over weeks to months. To study the electrophysiological, structural, and functional changes that occur in chronic AF, the selection of the best animal model is critical. AF was induced by rapid atrial pacing (50-Hz stimulation every other second) in pigs (n = 4), dogs (n = 8), and goats (n = 9). Animals underwent MRIs at baseline and 6 mo to evaluate left ventricular (LV) ejection fraction (EF). Dogs were given metoprolol (50-100 mg po bid) and digoxin (0.0625-0.125 mg po bid) to limit the ventricular response rate to <180 beats/min and to mitigate the effects of heart failure. The pacing leads in pigs became entirely encapsulated and lost the ability to excite the heart, often before the onset of sustained AF. LV EF in dogs dropped from 54 ± 11% at baseline to 33 ± 7% at 6 mo (P < 0.05), whereas LV EF in goats did not drop significantly (69 ± 8% at baseline vs. 60 ± 9% at 6 mo, P = not significant). After 6 mo of AF, fibrosis levels in dog atria and ventricles increased, whereas only atrial fibrosis levels increased in goats compared with control animals. In our experience, the pig model is not appropriate for chronic rapid atrial pacing-induced AF studies. Rate-controlled chronic AF in the dog model developed HF and LV fibrosis, whereas the goat model developed only atrial fibrosis without ventricular dysfunction and fibrosis. Both the dog and goat models are representative of segments of the patient population with chronic AF.
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Affiliation(s)
- Derek J Dosdall
- Comprehensive Arrhythmia Research and Management Center, University of Utah, Salt Lake City, Utah; and
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Cheng KS, Liao YC, Chen MY, Kuan TC, Hong YH, Ko L, Hsieh WY, Wu CL, Chen MR, Lin CS. Circulating matrix metalloproteinase-2 and -9 enzyme activities in the children with ventricular septal defect. Int J Biol Sci 2013; 9:557-63. [PMID: 23847438 PMCID: PMC3708036 DOI: 10.7150/ijbs.6398] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2013] [Accepted: 05/21/2013] [Indexed: 11/05/2022] Open
Abstract
Ventricular septal defect (VSD) is the most common form of congenital heart diseases. Matrix metalloproteinases (MMPs) are a family of zinc-dependent endopeptidases involved in causal cardiac tissue remodeling. We studied the changes of circulating MMP-2 and MMP-9 activities in the patients with VSD severity and closure. There were 96 children with perimembranous VSD enrolled in this study. We assigned the patients into three groups according to the ratio of VSD diameter/diameter of aortic root (Ao). They were classified as below: Trivial (VSD/Ao ratio ≤ 0.2), Small (0.2 < VSD/Ao ≤ 0.3) and Median (0.3 < VSD/Ao) group. Plasma MMP-2 and MMP-9 activities were assayed by gelatin zymography. There was a significant higher MMP-2 activity in the VSD (Trivial, Small and Median) groups compared with that in Control group. The plasma MMP-9 activity showed a similar trend as the findings in MMP-2 activity. After one year follow-up, a significant difference in the MMP-9 activity was found between VSD spontaneous closure and non-closure groups. In conclusion, a positive trend between the severity of VSD and activities of MMP-2 and MMP-9 was found. Our data imply that MMP-2 and MMP-9 activities may play a role in the pathogenesis of VSD.
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Affiliation(s)
- Kun-Shan Cheng
- Department of Biological Science and Technology, National Chiao Tung University, Hsinchu, Taiwan
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Abstract
Atrial fibrillation (AF) is a common clinical problem in elderly patients and especially in those with heart failure (HF). It is a major risk factor for serious cardiovascular events, such as stroke, HF and premature death. Both the prevalence and incidence of AF increase with age and its prevalence in the United States are estimated at more than 2.2 million, with nearly 75% of patients aged >65 years. Aging-related atrial remodeling with fibrosis, dilation and mitochondrial DNA mutations predispose elderly patients to AF. Current management options for AF, including rate control and anticoagulation therapy, can be successfully applied to the elderly population. New antiarrhythmic and anticoagulation medications such as dronedarone and dabigatran, respectively, can impact the approach to therapy in the elderly. Non-pharmacological options such as catheter-based ablation have also gained prominence and have been incorporated into the guidelines for management of AF. However, more trials in the elderly and very elderly segments are needed to clarify the safety and long-term efficacy of the new treatment options.
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Moric-Janiszewska E, Hibner G. Microarray analysis in cardiac arrhythmias: a new perspective? PACING AND CLINICAL ELECTROPHYSIOLOGY: PACE 2013; 36:911-7. [PMID: 23614797 DOI: 10.1111/pace.12143] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2012] [Revised: 01/22/2013] [Accepted: 03/06/2013] [Indexed: 11/30/2022]
Abstract
The opportunity to distinguish an accurate set of genes associated with multigenic diseases such as cardiomyopathies or cardiac arrhythmias was very limited before the genomic era. Numerous methods of measuring RNA abundance exist, including northern blotting, multiplex polymerase chain reaction (PCR), and quantitative real-time reverse transcriptase-PCR. However, these techniques might be used to assess the expression levels of only 10-50 genes at time. Today, DNA microarrays provide us with opportunity to simultaneously analyze tens of thousands of genes, giving a remarkable possibility to investigate the genomic contribution to cardiovascular diseases. A particular tissue at any stage of health or disease may be used to generate a genomic profile. Microarray techniques are already used in infectious diseases, oncology, and pharmacology to facilitate clinicians, risk-stratify patients, as well as to predict and assess therapeutic responses to drugs. In this paper, we describe recent advances in the use of various types of microarray technique in the diagnosis of arrhythmogenic heart disease. We also highlight other strategies and methods of differential gene typing comparing with pros and cons of microarray analysis.
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Spragg D. Left Atrial Fibrosis: Role in Atrial Fibrillation Pathophysiology and Treatment Outcomes. J Atr Fibrillation 2013; 5:810. [PMID: 28496835 DOI: 10.4022/jafib.810] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2013] [Revised: 03/01/2013] [Accepted: 03/02/2013] [Indexed: 01/07/2023]
Abstract
The mechanisms of atrial fibrillation are complex, and have been the subject of intensive study for over fifty years. There is likely a complex interplay between triggers and substrate that mediates the initiation and maintenance of AF. Increasingly, atrial fibrosis has been recognized as a key component of that substrate, playing a critical role in conduction abnormalities in the left atrium that appear necessary to maintaining AF. In the last several years, our abilities to quantify left atrial fibrosis - both through catheter- and MRI-based techniques - has shed important light on the underlying mechanisms of AF, and on therapeutic strategies to treat AF. Whether our increased appreciation of the role of atrial fibrosis in AF translates into improved efficacy of catheter ablation or anti-arrhythmic therapy, though, remains to be seen. The aim of this review is to summarize clinical investigations of atrial fibrosis as a factor in the development and treatment of atrial fibrillation.
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Affiliation(s)
- David Spragg
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD USA
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21
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Xu GJ, Gan TY, Tang BP, Chen ZH, Mahemuti A, Jiang T, Song JG, Guo X, Li YD, Miao HJ, Zhou XH, Zhang Y, Li JX. Accelerated fibrosis and apoptosis with ageing and in atrial fibrillation: Adaptive responses with maladaptive consequences. Exp Ther Med 2013; 5:723-729. [PMID: 23403858 PMCID: PMC3570166 DOI: 10.3892/etm.2013.899] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2012] [Accepted: 12/14/2012] [Indexed: 12/16/2022] Open
Abstract
The aim of this study was to investigate whether abnormal expression of matrix metalloproteinase (MMP)-9/tissue inhibitors of MMPs (TIMP)-1 and B cell lymphoma 2 (BCL-2)/BCL-2-associated X protein (BAX) are correlated with the characteristic accelerated fibrosis and apoptosis during ageing and in atrial fibrillation (AF). Four groups of dogs were studied: adult dogs in sinus rhythm (SR), aged dogs in SR, adult dogs with AF induced by rapid atrial pacing and aged dogs with AF induced by rapid atrial pacing. The mRNA and protein expression levels of the target gene in the left atrium were measured by quantitative reverse transcription-polymerase chain reaction (RT-PCR) and western blot analysis. Pathohistological and ultrastructural changes were assessed by light and electron microscopy. The apoptotic indices of myocytes were detected by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate (dUTP) nick end labeling (TUNEL). The mRNA and protein expression levels of MMP-9 and BAX and those of TIMP-1 and BCL-2 were significantly upregulated and down-regulated, respectively, in the aged groups compared with the adult groups. Compared with the control groups, the adult and aged groups with AF exhibited significantly increased mRNA and protein expression levels of MMP-9 and BAX and decreased expression levels of TIMP-1 and BCL-2. Samples of atrial tissue demonstrated abnormal pathohistological and ultrastructural changes, accelerated fibrosis and apoptosis. MMP-9/TIMP-1 and BCL-2/BAX hold potential for use as substrates conducive to AF and their abnormal expression plays a major role in structural remodeling of the atrium.
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Affiliation(s)
- Guo-Jun Xu
- Department of Cardiology, First Affiliated Hospital, Xinjiang Medical University, Urumqi, Xinjiang 830011
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Chin-En Kuo, Sheng-Fu Liang, Shao-Sheng Lu, Tang-Ching Kuan, Chih-Sheng Lin. Estimation and Prediction of Drug Therapy on the Termination of Atrial Fibrillation by Autoregressive Model With Exogenous Inputs. IEEE J Biomed Health Inform 2013; 17:153-61. [DOI: 10.1109/titb.2012.2224877] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Bellini C, Di Martino ES. A mechanical characterization of the porcine atria at the healthy stage and after ventricular tachypacing. J Biomech Eng 2012; 134:021008. [PMID: 22482675 DOI: 10.1115/1.4006026] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Atrial fibrillation (AF) is a cardiac arrhythmia that highly increases the risk of stroke and is associated with significant but still unexplored changes in the mechanical behavior of the tissue. Planar biaxial tests were performed on tissue specimens from pigs at the healthy stage and after ventricular tachypacing (VTP), a procedure applied to reproduce the relevant features of AF. The local arrangement of the fiber bundles in the tissue was investigated on specimens from rabbit atria by means of circularly polarized light. Based on this, mechanical data were fitted to two anisotropic constitutive relationships, including a four-parameter Fung-type model and a microstructurally-motivated model. Accounting for the fiber-induced anisotropy brought average R(2) = 0.807 for the microstructurally-motivated model and average R(2) = 0.949 for the Fung model. Validation of the fitted constitutive relationships was performed by means of FEM simulations coupled to FORTRAN routines. The performances of the two material models in predicting the second Piola-Kirchhoff stress were comparable, with average errors <3.1%. However, the Fung model outperformed the other in the prediction of the Green-Lagrange strain, with 9.2% maximum average error. To increase model generality, a proper averaging procedure accounting for nonlinearities was used to obtain average material parameters. In general, a stiffer behavior after VTP was noted.
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Affiliation(s)
- Chiara Bellini
- Graduate Program in Biomedical Engineering, The University of Calgary, Calgary, Alberta T2N1N4, Canada.
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Burner T, Gohr C, Mitton-Fitzgerald E, Rosenthal AK. Hyperglycemia reduces proteoglycan levels in tendons. Connect Tissue Res 2012; 53:535-41. [PMID: 22891926 DOI: 10.3109/03008207.2012.710670] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
RATIONALE Diabetic tendinopathy is characterized by increased stiffness, thickness, and excess calcification of affected tendons. We investigated the hypothesis that proteoglycans (PGs), as key regulators of tendon structure and calcification, are altered in diabetic tendons. METHODS Adult porcine patellar tendons were incubated in iso-osmolar media with high or normal glucose levels for 2 weeks. The PG fraction was isolated and analyzed. Protein and mRNA levels of five PGs were measured. PG production was assessed in primary tenocyte monolayers by (35)S-sulfate labeling in high and normal glucose conditions with and without exposure to advanced glycation end-products (AGEs). Levels of transforming growth factor β, which commonly mediates some effects of hyperglycemia, were also measured and the effects of free radical scavengers on (35)S-sulfate incorporation were determined. RESULTS PG levels were significantly decreased in tendons exposed to high glucose media compared with tendons in iso-osmolar control media. Relative quantities of individual PGs were unchanged by exposure to hyperglycemia and mRNAs for PGs were variably affected. High glucose media decreased PG production by tenocytes as measured by (35)S-sulfate labeling, whereas AGE-modified type I collagen and free radical scavengers had no effects. Hyperglycemic conditions increased levels of transforming growth factor β1 in an AGE-independent manner. CONCLUSIONS Hyperglycemia produces a reduction in PG levels related to decreased synthesis or sulfation of glycosaminoglycans, which may contribute to the tendon pathology observed clinically in diabetes.
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Affiliation(s)
- Todd Burner
- Division of Medicine, Zablocki VA Medical Center, Milwaukee, WI 53295-1000, USA
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Goudis CA, Kallergis EM, Vardas PE. Extracellular matrix alterations in the atria: insights into the mechanisms and perpetuation of atrial fibrillation. Europace 2012; 14:623-30. [PMID: 22237583 DOI: 10.1093/europace/eur398] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Atrial fibrillation is the most common arrhythmia in clinical practice and is associated with increased cardiovascular morbidity and mortality. Atrial fibrosis, a detrimental process that causes imbalance in extracellular matrix deposition and degradation, has been implicated as a substrate for atrial fibrillation, but the precise mechanisms of structural remodelling and the relationship between atrial fibrosis and atrial fibrillation are not completely understood. A large number of experimental and clinical studies have shed light on the mechanisms of atrial fibrosis at the molecular and cellular level, including interactions between matrix metalloproteinases and their endogenous tissue inhibitors, and profibrotic signals through specific molecules and mediators such as angiotensin II, transforming growth factor-β1, connective tissue growth factor, and platelet-derived growth factor. This review focuses on the mechanisms of atrial fibrosis and highlights the relationship between atrial fibrosis and atrial fibrillation.
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Affiliation(s)
- Christos A Goudis
- Department of Cardiology, University General Hospital, Heraklion, Crete, Voutes 71110, Greece
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Katoh Y, Nakazato Y. Can we predict electroanatomical remodeling of left atrium in patients with non-valvular atrial fibrillation by transforming growth factor-β and tissue inhibitor of metalloproteinase-1? Circ J 2011; 75:536-7. [PMID: 21301130 DOI: 10.1253/circj.cj-11-0071] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Ko WC, Hong CY, Hou SM, Lin CH, Ong ET, Lee CF, Tsai CT, Lai LP. Elevated Expression of Connective Tissue Growth Factor in Human Atrial Fibrillation and Angiotensin II-Treated Cardiomyocytes. Circ J 2011; 75:1592-600. [DOI: 10.1253/circj.cj-10-0892] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Wen-Chin Ko
- Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University
- Division of Cardiology, Department of Internal Medicine, Cathay General Hospital
| | - Chuang-Ye Hong
- Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University
- Department of Medicine, Wang Fang Hospital
| | - Shaw-Min Hou
- Division of Cardiovascular Surgery, Department of Surgery, Cathay General Hospital
| | - Chien-Huang Lin
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University
| | - Eng-Thiam Ong
- Division of Cardiology, Department of Internal Medicine, Cathay General Hospital
| | - Chwen-Fang Lee
- Division of Cardiology, Department of Internal Medicine, National Taiwan University Hospital and Institute of Pharmacology, National Taiwan University Hospital
| | - Chia-Ti Tsai
- Division of Cardiology, Department of Internal Medicine, National Taiwan University Hospital and Institute of Pharmacology, National Taiwan University Hospital
| | - Ling-Ping Lai
- Division of Cardiology, Department of Internal Medicine, National Taiwan University Hospital and Institute of Pharmacology, National Taiwan University Hospital
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Chiu YW, Lo MT, Tsai MR, Chang YC, Hsu RB, Yu HY, Sun CK, Ho YL. Applying harmonic optical microscopy for spatial alignment of atrial collagen fibers. PLoS One 2010; 5:e13917. [PMID: 21085489 PMCID: PMC2976704 DOI: 10.1371/journal.pone.0013917] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2010] [Accepted: 10/18/2010] [Indexed: 01/18/2023] Open
Abstract
Background Atrial fibrosis creates a vulnerable tissue for atrial fibrillation (AF), but the spatial disarray of collagen fibers underlying atrial fibrosis is not fully elucidated. Objective This study hypothesizes that harmonics optical microscopy can illuminate the spatial mal-alignment of collagen fibers in AF via a layer-by-layer approach. Patients and Methods Atrial tissues taken from patients who underwent open-heart surgery were examined by harmonics optical microscopy. Using the two-dimensional Fourier transformation method, a spectral-energy description of image texture was constituted and its entropy was used to quantify the mal-alignment of collagen fibers. The amount of collagen fiber was derived from its area ratio to total atrial tissue in each image. Serum C-terminal pro-collagen pro-peptide (CICP), pro-matrix metalloproteinase-1 (pro-MMP-1), and tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) were also evaluated. Results 46 patients were evaluated, including 20 with normal sinus rhythm and 26 with AF. The entropy of spectral-energy distribution of collagen alignment was significantly higher in AF than that in sinus rhythm (3.97±0.33 vs. 2.80±0.18, p<0.005). This difference was more significant in the permanent AF group. The amount of collagen was also significantly higher in AF patients (0.39±0.13 vs. 0.18±0.06, p<0.005) but serum markers of cardiac fibrosis were not significantly different between the two groups. Conclusions Harmonics optical microscopy can quantify the spatial mal-alignment of collagen fibers in AF. The entropy of spectral-energy distribution of collagen alignment is a potential tool for research in atrial remodeling.
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Affiliation(s)
- Yu-Wei Chiu
- Division of Cardiology, Department of Internal Medicine, Far-Eastern Memorial Hospital, Taipei, Taiwan
| | - Men Tzung Lo
- Research Center for Adaptive Data Analysis, National Central University, Taoyuan, Taiwan
| | - Ming-Rung Tsai
- Department of Electrical Engineering, Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei, Taiwan
| | - Yi-Chung Chang
- Graduate Institute of Communication Engineering, National Taiwan University, Taipei, Taiwan
| | - Rong-Bin Hsu
- Department of Surgery, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan
| | - Hsu-Yu Yu
- Department of Surgery, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan
| | - Chi-Kuang Sun
- Department of Electrical Engineering, Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei, Taiwan
| | - Yi-Lwun Ho
- Graduate Institute of Clinical Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan
- Division of Cardiology, Department of Internal Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan
- * E-mail:
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Zhao J, Li J, Li W, Li Y, Shan H, Gong Y, Yang B. Effects of spironolactone on atrial structural remodelling in a canine model of atrial fibrillation produced by prolonged atrial pacing. Br J Pharmacol 2010; 159:1584-94. [PMID: 20082611 DOI: 10.1111/j.1476-5381.2009.00551.x] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND AND PURPOSE Suppression of the renin-angiotensin-aldosterone system can prevent atrial fibrillation (AF) by attenuating atrial structural remodelling but the role of aldosterone in AF prevention has not been investigated thoroughly. We explored whether the aldosterone antagonist, spironolactone, could improve atrial structural remodelling in long-term rapid pacing-induced AF. EXPERIMENTAL APPROACH Three groups of dogs were used, sham-operated, control and spironolactone-treated groups. Dogs in the control and spironolactone groups had right atrial pacing for 6 weeks. The spironolactone group was given spironolactone 1 week before and during the atrial pacing. After 6 weeks of pacing, atrial structural and functional changes were assessed by echocardiography, haemodynamic parameters by cardiac catheterization, histopathological changes by light and electron microscopy and cardiomyocyte apoptosis by TUNEL. Caspase-3, Bcl-2, bax, calpain I, calpastatin, matrix metalloproteinase (MMP)-9 and tissue inhibitors of metalloproteinase (TIMP)-1 were analysed by immunohistochemistry and Western blotting. The inducibility and duration of AF were measured by atrial burst pacing. KEY RESULTS After atrial pacing, the proportion of TUNEL positive cells, myolysis, atrial fibrosis and dilatation were all significantly increased and these changes were inhibited by spironolactone. Spironolactone treatment reversed the increased expression of caspase-3, bax, calpain I and MMP-9 and the decreased level of Bcl-2, calpastatin and TIMP-1, induced by chronic atrial pacing. Also spironolactone prevented the increased inducibility and duration of AF, induced by tachypacing. CONCLUSIONS AND IMPLICATIONS Treatment with spironolactone prevented myocardial apoptosis, myolysis, atrial fibrosis and dilatation, suggesting a possible beneficial effect of aldosterone antagonism on atrial structural remodelling in AF.
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Affiliation(s)
- J Zhao
- Department of Cardiology, The First Affiliated Hospital, Harbin Medical University, Heilongjiang, China
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Pellman J, Lyon RC, Sheikh F. Extracellular matrix remodeling in atrial fibrosis: mechanisms and implications in atrial fibrillation. J Mol Cell Cardiol 2009; 48:461-7. [PMID: 19751740 DOI: 10.1016/j.yjmcc.2009.09.001] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2009] [Revised: 08/29/2009] [Accepted: 09/02/2009] [Indexed: 12/28/2022]
Abstract
Atrial fibrosis has been strongly associated with the presence of heart diseases/arrhythmias, including congestive heart failure (CHF) and atrial fibrillation (AF). Inducibility of AF as a result of atrial fibrosis has been the subject of intense recent investigation since it is the most commonly encountered arrhythmia in adults and can substantially increase the risk of premature death. Rhythm and rate control drugs as well as surgical interventions are used as therapies for AF; however, increased attention has been diverted to mineralocorticoid receptor (MR) antagonists including spironolactone as potential therapies for human AF because of their positive effects on reducing atrial fibrosis and associated AF in animal models. Spironolactone has been shown to exert positive effects in human patients with heart failure; however, the mechanisms and effects in human atrial fibrosis and AF remain undetermined. This review will discuss and highlight developments on (i) the relationship between atrial fibrosis and AF, (ii) spironolactone, as a drug targeted to atrial fibrosis and AF, as well as (iii) the distinct and common mechanisms important for regulating atrial and ventricular fibrosis, inclusive of the key extracellular matrix regulatory proteins involved.
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Affiliation(s)
- Jason Pellman
- Department of Medicine, University of California-San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0613, USA
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Kim AM, Olgin JE, Everett TH. Role of atrial substrate and spatiotemporal organization in atrial fibrillation. Heart Rhythm 2009; 6:S1-7. [DOI: 10.1016/j.hrthm.2009.02.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2008] [Indexed: 10/21/2022]
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Abstract
Animal models of atrial fibrillation have taught us about mechanisms of this common disease. A variety of animal models exist, including models of lone atrial fibrillation and models of atrial fibrillation in the setting of heart failure, aging, or pericardial inflammation. This article reviews these various models.
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Affiliation(s)
- J Emanuel Finet
- The Heart and Vascular Research Center, Case Western Reserve University, MetroHealth Campus, 2500 MetroHealth Drive, Cleveland, OH 44109-1998, USA
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Kourliouros A, Savelieva I, Kiotsekoglou A, Jahangiri M, Camm J. Current concepts in the pathogenesis of atrial fibrillation. Am Heart J 2009; 157:243-52. [PMID: 19185630 DOI: 10.1016/j.ahj.2008.10.009] [Citation(s) in RCA: 127] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2008] [Accepted: 10/12/2008] [Indexed: 01/11/2023]
Abstract
Current evidence suggests that the pathogenesis of atrial fibrillation (AF) is multifactorial. The observation that AF, once present, alters the electrophysiologic properties of the atrial myocardium causing self-perpetuation of the arrhythmia raised the importance of electrical remodeling in its pathogenesis. Although these changes are potentially reversible, maintenance of AF continues even after electrical remodeling has occurred. Clinical and experimental studies have highlighted the role of a susceptible atrial anatomical substrate with features of myocyte degeneration and interstitial fibrosis in the initiation and maintenance of AF. Finally, the association of increased inflammatory burden with the presence and future development of AF has implicated inflammation in the pathogenesis of the arrhythmia. The purpose of this review is to provide current evidence on the dominant theories on AF pathogenesis, namely, electrical remodeling, structural remodeling, and inflammation; describe the various experimental models and methods used; and identify a cause-effect association, when present. In addition, the interrelation between different mechanisms responsible for AF will be demonstrated, providing further insight into the complex pathophysiology.
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Abstract
Atrial fibrillation and congestive heart failure are frequently associated with complex interactions. Patients with both diseases bear a sophisticated therapeutic challenge for the attending physician. The approach to treat atrial fibrillation differs for patients with and without heart failure in several aspects. Basic requirements are the treatment of the underlying diseases and prophylaxis of thromboembolic complications. Rate and rhythm control are the two main therapeutic strategies for atrial fibrillation according to the current guidelines. Large trials including the recently published AF-CHF study (Atrial Fibrillation - Congestive Heart Failure) failed to demonstrate a difference in mortality for both strategies. Thus, the therapeutic decision is mainly based on the patient's symptoms to improve quality of life. Rate control should be applied to asymptomatic patients or if rhythm control has already failed. If beta-blockers and digoxin have failed to control heart rate, His ablation with pacemaker implantation can be considered. In patients without heart disease, class I antiarrhythmic drugs and, in case of ineffectiveness, amiodarone or catheter ablation are recommended for rhythm control. First data concerning catheter ablation of atrial fibrillation in heart failure are promising and randomized studies are on the way. Rhythm control remains first-line therapy in recent-onset or highly symptomatic paroxysmal or persistent atrial fibrillation patients with and without heart failure.
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Chen CL, Huang SKS, Lin JL, Lai LP, Lai SC, Liu CW, Chen WC, Wen CH, Lin CS. Upregulation of matrix metalloproteinase-9 and tissue inhibitors of metalloproteinases in rapid atrial pacing-induced atrial fibrillation. J Mol Cell Cardiol 2008; 45:742-53. [DOI: 10.1016/j.yjmcc.2008.07.007] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2008] [Revised: 06/27/2008] [Accepted: 07/03/2008] [Indexed: 11/28/2022]
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Corradi D, Callegari S, Maestri R, Benussi S, Alfieri O. Structural remodeling in atrial fibrillation. ACTA ACUST UNITED AC 2008; 5:782-96. [DOI: 10.1038/ncpcardio1370] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2008] [Accepted: 08/08/2008] [Indexed: 02/07/2023]
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Membrane translocation of small GTPase Rac1 and activation of STAT1 and STAT3 in pacing-induced sustained atrial fibrillation. Heart Rhythm 2008; 5:1285-93. [DOI: 10.1016/j.hrthm.2008.05.012] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2008] [Accepted: 05/14/2008] [Indexed: 11/20/2022]
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Josephson ME, Rosen MR, Tomaselli GF. The year in arrhythmias 2007: Part II. Heart Rhythm 2008; 5:867-71. [PMID: 18534372 DOI: 10.1016/j.hrthm.2008.03.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2008] [Indexed: 10/22/2022]
Affiliation(s)
- Mark E Josephson
- Department of Medicine, Cardiovascular Division Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
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Burstein B, Nattel S. Atrial fibrosis: mechanisms and clinical relevance in atrial fibrillation. J Am Coll Cardiol 2008; 51:802-9. [PMID: 18294563 DOI: 10.1016/j.jacc.2007.09.064] [Citation(s) in RCA: 886] [Impact Index Per Article: 55.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2007] [Revised: 08/16/2007] [Accepted: 09/07/2007] [Indexed: 01/14/2023]
Abstract
Atrial fibrillation (AF) is the most common arrhythmia in the clinical setting, and traditional pharmacological approaches have proved to have important weaknesses. Structural remodeling has been observed in both clinical and experimental AF paradigms, and is an important feature of the AF substrate, producing fibrosis that alters atrial tissue composition and function. The precise mechanisms underlying atrial fibrosis are not fully elucidated, but recent experimental studies and clinical investigations have provided valuable insights. A variety of signaling systems, particularly involving angiotensin II and related mediators, seem to be centrally involved in the promotion of fibrosis. This paper reviews the current understanding of how atrial fibrosis creates a substrate for AF, summarizes what is known about the mechanisms underlying fibrosis and its progression, and highlights emerging therapeutic approaches aimed at attenuating structural remodeling to prevent AF.
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Affiliation(s)
- Brett Burstein
- Research Center and Department of Medicine, Montreal Heart Institute and Université de Montréal, and Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec, Canada
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Pan CH, Wen CH, Lin CS. Interplay of angiotensin II and angiotensin(1-7) in the regulation of matrix metalloproteinases of human cardiocytes. Exp Physiol 2008; 93:599-612. [PMID: 18296491 DOI: 10.1113/expphysiol.2007.041830] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Angiotensin II (Ang II) is a critical effector in the renin-angiotensin system (RAS), which modulates cardiovascular homeostasis, and the matrix metalloproteinases (MMPs) and tissue inhibitors of matrix metalloproteinases (TIMPs) related metabolism of extracellular matrix (ECM). Angiotensin(1-7) [Ang(1-7)] is another bioactive peptide in the RAS and is considered to have opposite effects to Ang II. However, the modulation of MMPs and TIMPs by Ang(1-7) is largely unclear in cardiocytes, and the antagonistic effects of Ang(1-7) on Ang II-mediated expression of MMPs and TIMPs have yet to be identified. In the present study, we examined the transcript expression of MMPs and TIMPs in human cardiac fibroblasts (HCF) and myocytes (HCM) after Ang II or Ang(1-7) stimulation, and analysed the antagonistic effects of Ang(1-7) to Ang II. The results show that Ang II decreased transcript expression of MMP-1, MMP-2, TIMP-1, TIMP-2 and TIMP-3, but upregulated MMP-9 expression in the HCF cells. Transcript expression of MMP-9 and TIMP-2 was downregulated by Ang(1-7) in the same cells. In the HCM cells, Ang II induced MMP-1 and MMP-9 overexpression but MMP-2 was downregulated. All of the examined MMPs and TIMPs, except MMP-9, were markedly decreased by Ang(1-7). In the studies of antagonistic effects of Ang(1-7) to Ang II, Ang(1-7) counteracted the effects of Ang II-mediated regulation on MMP-9 and TIMP-1 in the HCF cells compared with the control group. The regulations of all examined MMPs by Ang II were reversed to basal expression by Ang(1-7) in the HCM cells. Our results suggest that Ang(1-7) and Ang II have opposite and antagonistic effects on regulation of transcription of MMPs and TIMPs in primary cultures of human cardiocytes. These effects lead to increased ratios of MMPs to TIMPs after Ang II stimulation and decreased ratios of MMPs to TIMPs after Ang(1-7) stimulation; effects which may partly depend of the type of cardiac cells. These results suggest a potential role for Ang(1-7) in attenuatating cardiac damage in Ang II-induced ECM remodelling.
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Affiliation(s)
- Chun-Hsu Pan
- Department of Biological Science and Technology, National Chiao Tung University, Hsinchu, Taiwan
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Duffy HS. Cleft diving: looking in the extracellular matrix for answers to atrial arrhythmias. Heart Rhythm 2007; 4:950-1. [PMID: 17599683 DOI: 10.1016/j.hrthm.2007.03.039] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2007] [Indexed: 11/28/2022]
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