1
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Pedro B, Mavropoulou A, Oyama MA, Linney C, Neves J, Dukes‐McEwan J, Fontes‐Sousa AP, Gelzer AR. Longitudinal analysis of echocardiographic and cardiac biomarker variables in dogs with atrial fibrillation: The optimal rate control in dogs with atrial fibrillation II study. J Vet Intern Med 2024; 38:2076-2088. [PMID: 38877661 PMCID: PMC11256134 DOI: 10.1111/jvim.17120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Accepted: 05/07/2024] [Indexed: 06/16/2024] Open
Abstract
BACKGROUND Rate control (RC; meanHRHolter ≤ 125 bpm) increases survival in dogs with atrial fibrillation (AF). The mechanisms remain unclear. HYPOTHESIS/OBJECTIVES Investigate echocardiographic and biomarker differences between RC and non-RC (NRC) dogs. Determine if changes post-anti-arrhythmic drugs (AAD) predict successful RC in subsequent Holter monitoring. Evaluate if early vs late RC affects survival. ANIMALS Fifty-two dogs with AF. METHODS Holter-derived mean heart rate, echocardiographic and biomarker variables from dogs receiving AAD were analyzed prospectively at each re-evaluation and grouped into RC or NRC. The primary endpoint was successful RC. Between group comparisons of absolute values, magnitude of change from admission to re-evaluations and end of study were performed using Mann-Whitney tests or unpaired t-tests. Logistic regression explored variables associated with inability to achieve RC at subsequent visits. Kaplan-Meier survival analysis was used to compare survival time of early vs late RC. RESULTS At visit 2, 11/52 dogs were RC; at visit 3, 14/52 were RC; and at visit 4, 4/52 were RC. At the end of study, 25/52 remained NRC. At visit 2, both groups had increased cardiac dimensions, but NRC dogs had larger dimensions; biomarkers did not differ. At the end of study, RC showed decreased cardiac dimensions and end-terminal pro-brain natriuretic peptide (NT-proBNP) compared with NRC. No variables were useful at predicting RC success in subsequent visits. Survival analysis found no differences between early vs late RC. CONCLUSIONS AND CLINICAL IMPORTANCE The RC dogs had decreased cardiac dimensions and NT-proBNP, suggesting HR-mediated reverse-remodeling might benefit survival, even with delayed RC achievement. Pursuit of RC is crucial despite initial failures.
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Affiliation(s)
- Brigite Pedro
- Willows Veterinary Centre and Referral Service, Highlands Road, ShirleySolihull, West Midlands B90 4NHUnited Kingdom
- Hospital Veterinário do Bom Jesus, Avenida General Carrilho da Silva Pinto 52Braga 4715‐380Portugal
- Virtual Veterinary Specialists Ltd, 166 College RoadHarrow, Middlesex HA1 1BHUnited Kingdom
- ICBAS – Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, R. Jorge Viterbo Ferreira 228Porto 4050‐313Portugal
| | - Antonia Mavropoulou
- Plakentia Veterinary Clinic, Al. Panagouli 31, Ag. ParaskeviAthens 153 43Greece
| | - Mark A. Oyama
- Department of Clinical Studies and Advanced Medicine, School of Veterinary MedicineUniversity of Pennsylvania, 3900 Delancey St.Philadelphia, Pennsylvania 19104USA
| | - Christopher Linney
- Willows Veterinary Centre and Referral Service, Highlands Road, ShirleySolihull, West Midlands B90 4NHUnited Kingdom
- Paragon Veterinary ReferralsParagon Business Village, Paragon Way, Red Hall CresWakefield WF1 2DFUnited Kingdom
| | - João Neves
- Willows Veterinary Centre and Referral Service, Highlands Road, ShirleySolihull, West Midlands B90 4NHUnited Kingdom
- Hospital Veterinário do Bom Jesus, Avenida General Carrilho da Silva Pinto 52Braga 4715‐380Portugal
- Virtual Veterinary Specialists Ltd, 166 College RoadHarrow, Middlesex HA1 1BHUnited Kingdom
- Hospital Veterinario de Aveiro, Avenida da Universidade 215Aveiro 3810‐489Portugal
| | - Joanna Dukes‐McEwan
- Small Animal Teaching Hospital, Department of Small Animal Clinical ScienceUniversity of Liverpool Leahurst Campus, Chester High RoadNeston CH64 2UQUnited Kingdom
| | - Ana P. Fontes‐Sousa
- Department of Immuno‐Physiology and Pharmacology, Center for Pharmacological Research and Drug Innovation (MedInUP), Veterinary Hospital of the University of Porto (UPVET), ICBAS – Abel Salazar Institute of Biomedical SciencesUniversity of PortoPortoPortugal
| | - Anna R. Gelzer
- Department of Clinical Studies and Advanced Medicine, School of Veterinary MedicineUniversity of Pennsylvania, 3900 Delancey St.Philadelphia, Pennsylvania 19104USA
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2
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Hunt B, Kwan E, Tasdizen T, Bergquist J, Lange M, Orkild B, MacLeod RS, Dosdall DJ, Ranjan R. Transfer Learning for Improved Classification of Drivers in Atrial Fibrillation. COMPUTING IN CARDIOLOGY 2023; 50:10.22489/cinc.2023.412. [PMID: 38405161 PMCID: PMC10887411 DOI: 10.22489/cinc.2023.412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/27/2024]
Abstract
"Drivers" are theorized mechanisms for persistent atrial fibrillation. Machine learning algorithms have been used to identify drivers, but the small size of current driver datasets limits their performance. We hypothesized that pretraining with unsupervised learning on a large dataset of unlabeled electrograms would improve classifier accuracy on a smaller driver dataset. In this study, we used a SimCLR-based framework to pretrain a residual neural network on a dataset of 113K unlabeled 64-electrode measurements and found weighted testing accuracy to improve over a non-pretrained network (78.6±3.9% vs 71.9±3.3%). This lays ground for development of superior driver detection algorithms and supports use of transfer learning for other datasets of endocardial electrograms.
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Affiliation(s)
- Bram Hunt
- Department of Biomedical Engineering, University of Utah, SLC, UT, USA
- Nora Eccles Cardiovascular Research and Training Institute, University of Utah, SLC, UT, USA
- Division of Cardiovascular Medicine, University of Utah, SLC, UT, USA
| | - Eugene Kwan
- Department of Biomedical Engineering, University of Utah, SLC, UT, USA
- Nora Eccles Cardiovascular Research and Training Institute, University of Utah, SLC, UT, USA
- Division of Cardiovascular Medicine, University of Utah, SLC, UT, USA
| | - Tolga Tasdizen
- Scientific Computing and Imaging Institute, University of Utah, SLC, UT, USA
- Department of Electrical and Computer Engineering, University of Utah, SLC, UT, USA
| | - Jake Bergquist
- Department of Biomedical Engineering, University of Utah, SLC, UT, USA
- Nora Eccles Cardiovascular Research and Training Institute, University of Utah, SLC, UT, USA
- Scientific Computing and Imaging Institute, University of Utah, SLC, UT, USA
| | - Matthias Lange
- Nora Eccles Cardiovascular Research and Training Institute, University of Utah, SLC, UT, USA
- Division of Cardiovascular Medicine, University of Utah, SLC, UT, USA
- Scientific Computing and Imaging Institute, University of Utah, SLC, UT, USA
| | - Benjamin Orkild
- Department of Biomedical Engineering, University of Utah, SLC, UT, USA
- Nora Eccles Cardiovascular Research and Training Institute, University of Utah, SLC, UT, USA
- Division of Cardiovascular Medicine, University of Utah, SLC, UT, USA
| | - Robert S MacLeod
- Department of Biomedical Engineering, University of Utah, SLC, UT, USA
- Nora Eccles Cardiovascular Research and Training Institute, University of Utah, SLC, UT, USA
- Scientific Computing and Imaging Institute, University of Utah, SLC, UT, USA
| | - Derek J Dosdall
- Department of Biomedical Engineering, University of Utah, SLC, UT, USA
- Nora Eccles Cardiovascular Research and Training Institute, University of Utah, SLC, UT, USA
- Division of Cardiovascular Medicine, University of Utah, SLC, UT, USA
- Division of Cardiothoracic Surgery, Department of Surgery, University of Utah, SLC, UT, USA
| | - Ravi Ranjan
- Department of Biomedical Engineering, University of Utah, SLC, UT, USA
- Nora Eccles Cardiovascular Research and Training Institute, University of Utah, SLC, UT, USA
- Division of Cardiovascular Medicine, University of Utah, SLC, UT, USA
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3
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Keefe JA, Hulsurkar MM, Reilly S, Wehrens XHT. Mouse models of spontaneous atrial fibrillation. Mamm Genome 2023; 34:298-311. [PMID: 36173465 PMCID: PMC10898345 DOI: 10.1007/s00335-022-09964-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Accepted: 09/20/2022] [Indexed: 11/30/2022]
Abstract
Atrial fibrillation (AF) is the most common arrhythmia in adults, with a prevalence increasing with age. Current clinical management of AF is focused on tertiary prevention (i.e., treating the symptoms and sequelae) rather than addressing the underlying molecular pathophysiology. Robust animal models of AF, particularly those that do not require supraphysiologic stimuli to induce AF (i.e., showing spontaneous AF), enable studies that can uncover the underlying mechanisms of AF. Several mouse models of AF have been described to exhibit spontaneous AF, but pathophysiologic drivers of AF differ among models. Here, we describe relevant AF mechanisms and provide an overview of large and small animal models of AF. We then provide an in-depth review of the spontaneous mouse models of AF, highlighting the relevant AF mechanisms for each model.
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Affiliation(s)
- Joshua A Keefe
- Cardiovascular Research Institute, Baylor College of Medicine, One Baylor Plaza, BCM335, Houston, TX, 77030, USA
- Department of Integrative Physiology, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Mohit M Hulsurkar
- Cardiovascular Research Institute, Baylor College of Medicine, One Baylor Plaza, BCM335, Houston, TX, 77030, USA
- Department of Integrative Physiology, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Svetlana Reilly
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, John Radcliffe Hospital, University of Oxford, Oxford, UK
| | - Xander H T Wehrens
- Cardiovascular Research Institute, Baylor College of Medicine, One Baylor Plaza, BCM335, Houston, TX, 77030, USA.
- Department of Integrative Physiology, Baylor College of Medicine, Houston, TX, 77030, USA.
- Department of Medicine, Baylor College of Medicine, Houston, TX, 77030, USA.
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, 77030, USA.
- Department of Pediatrics, Baylor College of Medicine, Houston, TX, 77030, USA.
- Center for Space Medicine, Baylor College of Medicine, Houston, TX, 77030, USA.
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4
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Chung CC, Lin YK, Chen YC, Kao YH, Yeh YH, Trang NN, Chen YJ. Empagliflozin suppressed cardiac fibrogenesis through sodium-hydrogen exchanger inhibition and modulation of the calcium homeostasis. Cardiovasc Diabetol 2023; 22:27. [PMID: 36747205 PMCID: PMC9903522 DOI: 10.1186/s12933-023-01756-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Accepted: 01/26/2023] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND The novel sodium-glucose co-transporter 2 inhibitor (SGLT2i) potentially ameliorates heart failure and reduces cardiac arrhythmia. Cardiac fibrosis plays a pivotal role in the pathophysiology of HF and atrial myopathy, but the effect of SGLT2i on fibrogenesis remains to be elucidated. This study investigated whether SGLT2i directly modulates fibroblast activities and its underlying mechanisms. METHODS AND RESULTS Migration, proliferation analyses, intracellular pH assay, intracellular inositol triphosphate (IP3) assay, Ca2+ fluorescence imaging, and Western blotting were applied to human atrial fibroblasts. Empagliflozin (an SGLT2i, 1, or 5 μmol/L) reduced migration capability and collagen type I, and III production. Compared with control cells, empagliflozin (1 μmol/L)- treated atrial fibroblasts exhibited lower endoplasmic reticulum (ER) Ca2+ leakage, Ca2+ entry, inositol trisphosphate (IP3), lower expression of phosphorylated phospholipase C (PLC), and lower intracellular pH. In the presence of cariporide (an Na+-H+ exchanger (NHE) inhibitor, 10 μmol/L), control and empagliflozin (1 μmol/L)-treated atrial fibroblasts revealed similar intracellular pH, ER Ca2+ leakage, Ca2+ entry, phosphorylated PLC, pro-collagen type I, type III protein expression, and migration capability. Moreover, empagliflozin (10 mg/kg/day orally for 28 consecutive days) significantly increased left ventricle systolic function, ß-hydroxybutyrate and decreased atrial fibrosis, in isoproterenol (100 mg/kg, subcutaneous injection)-induced HF rats. CONCLUSIONS By inhibiting NHE, empagliflozin decreases the expression of phosphorylated PLC and IP3 production, thereby reducing ER Ca2+ release, extracellular Ca2+ entry and the profibrotic activities of atrial fibroblasts.
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Affiliation(s)
- Cheng-Chih Chung
- grid.412896.00000 0000 9337 0481Division of Cardiology, Department of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan ,grid.412896.00000 0000 9337 0481Division of Cardiovascular Medicine, Department of Internal Medicine, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan ,grid.412896.00000 0000 9337 0481Taipei Heart Institute, Taipei Medical University, Taipei, Taiwan
| | - Yung-Kuo Lin
- grid.412896.00000 0000 9337 0481Division of Cardiology, Department of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan ,grid.412896.00000 0000 9337 0481Division of Cardiovascular Medicine, Department of Internal Medicine, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan ,grid.412896.00000 0000 9337 0481Taipei Heart Institute, Taipei Medical University, Taipei, Taiwan
| | - Yao-Chang Chen
- grid.260565.20000 0004 0634 0356Department of Biomedical Engineering, National Defense Medical Center, Taipei, Taiwan
| | - Yu-Hsun Kao
- Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, No. 250, Wu-Hsing Street, 11031, Taipei, Taiwan. .,Department of Medical Education and Research, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan.
| | - Yung-Hsin Yeh
- grid.413801.f0000 0001 0711 0593Division of Cardiology, Chang Gung Memorial Hospital, Taoyuan, Taiwan ,grid.145695.a0000 0004 1798 0922College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Nguyen Ngoc Trang
- grid.414163.50000 0004 4691 4377Radiology Center, Bach Mai Hospital, Hanoi, Vietnam
| | - Yi-Jen Chen
- Division of Cardiology, Department of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan. .,Division of Cardiovascular Medicine, Department of Internal Medicine, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan. .,Taipei Heart Institute, Taipei Medical University, Taipei, Taiwan. .,Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, No. 250, Wu-Hsing Street, 11031, Taipei, Taiwan.
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5
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Zenger B, Bergquist JA, Busatto A, Good WW, Rupp LC, Sharma V, MacLeod RS. Tipping the scales of understanding: An engineering approach to design and implement whole-body cardiac electrophysiology experimental models. Front Physiol 2023; 14:1100471. [PMID: 36744034 PMCID: PMC9893785 DOI: 10.3389/fphys.2023.1100471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Accepted: 01/02/2023] [Indexed: 01/21/2023] Open
Abstract
The study of cardiac electrophysiology is built on experimental models that span all scales, from ion channels to whole-body preparations. Novel discoveries made at each scale have contributed to our fundamental understanding of human cardiac electrophysiology, which informs clinicians as they detect, diagnose, and treat complex cardiac pathologies. This expert review describes an engineering approach to developing experimental models that is applicable across scales. The review also outlines how we applied the approach to create a set of multiscale whole-body experimental models of cardiac electrophysiology, models that are driving new insights into the response of the myocardium to acute ischemia. Specifically, we propose that researchers must address three critical requirements to develop an effective experimental model: 1) how the experimental model replicates and maintains human physiological conditions, 2) how the interventions possible with the experimental model capture human pathophysiology, and 3) what signals need to be measured, at which levels of resolution and fidelity, and what are the resulting requirements of the measurement system and the access to the organs of interest. We will discuss these requirements in the context of two examples of whole-body experimental models, a closed chest in situ model of cardiac ischemia and an isolated-heart, torso-tank preparation, both of which we have developed over decades and used to gather valuable insights from hundreds of experiments.
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Affiliation(s)
- Brian Zenger
- Scientific Computing and Imaging Institute, University of Utah, Salt Lake City, UT, United States
- Nora Eccles Harrison Cardiovascular Research and Training Institute, The University of Utah, Salt Lake City, UT, United States
- Spencer Eccles School of Medicine, University of Utah, Salt Lake City, UT, United States
| | - Jake A. Bergquist
- Scientific Computing and Imaging Institute, University of Utah, Salt Lake City, UT, United States
- Nora Eccles Harrison Cardiovascular Research and Training Institute, The University of Utah, Salt Lake City, UT, United States
- Department of Biomedical Engineering, College of Engineering, University of Utah, Salt Lake City, UT, United States
| | - Anna Busatto
- Scientific Computing and Imaging Institute, University of Utah, Salt Lake City, UT, United States
- Nora Eccles Harrison Cardiovascular Research and Training Institute, The University of Utah, Salt Lake City, UT, United States
- Department of Biomedical Engineering, College of Engineering, University of Utah, Salt Lake City, UT, United States
| | | | - Lindsay C. Rupp
- Scientific Computing and Imaging Institute, University of Utah, Salt Lake City, UT, United States
- Nora Eccles Harrison Cardiovascular Research and Training Institute, The University of Utah, Salt Lake City, UT, United States
- Department of Biomedical Engineering, College of Engineering, University of Utah, Salt Lake City, UT, United States
| | - Vikas Sharma
- Spencer Eccles School of Medicine, University of Utah, Salt Lake City, UT, United States
| | - Rob S. MacLeod
- Scientific Computing and Imaging Institute, University of Utah, Salt Lake City, UT, United States
- Nora Eccles Harrison Cardiovascular Research and Training Institute, The University of Utah, Salt Lake City, UT, United States
- Department of Biomedical Engineering, College of Engineering, University of Utah, Salt Lake City, UT, United States
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6
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Ripplinger CM, Glukhov AV, Kay MW, Boukens BJ, Chiamvimonvat N, Delisle BP, Fabritz L, Hund TJ, Knollmann BC, Li N, Murray KT, Poelzing S, Quinn TA, Remme CA, Rentschler SL, Rose RA, Posnack NG. Guidelines for assessment of cardiac electrophysiology and arrhythmias in small animals. Am J Physiol Heart Circ Physiol 2022; 323:H1137-H1166. [PMID: 36269644 PMCID: PMC9678409 DOI: 10.1152/ajpheart.00439.2022] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 10/11/2022] [Accepted: 10/17/2022] [Indexed: 01/09/2023]
Abstract
Cardiac arrhythmias are a major cause of morbidity and mortality worldwide. Although recent advances in cell-based models, including human-induced pluripotent stem cell-derived cardiomyocytes (iPSC-CM), are contributing to our understanding of electrophysiology and arrhythmia mechanisms, preclinical animal studies of cardiovascular disease remain a mainstay. Over the past several decades, animal models of cardiovascular disease have advanced our understanding of pathological remodeling, arrhythmia mechanisms, and drug effects and have led to major improvements in pacing and defibrillation therapies. There exist a variety of methodological approaches for the assessment of cardiac electrophysiology and a plethora of parameters may be assessed with each approach. This guidelines article will provide an overview of the strengths and limitations of several common techniques used to assess electrophysiology and arrhythmia mechanisms at the whole animal, whole heart, and tissue level with a focus on small animal models. We also define key electrophysiological parameters that should be assessed, along with their physiological underpinnings, and the best methods with which to assess these parameters.
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Affiliation(s)
- Crystal M Ripplinger
- Department of Pharmacology, University of California Davis School of Medicine, Davis, California
| | - Alexey V Glukhov
- Department of Medicine, Cardiovascular Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin
| | - Matthew W Kay
- Department of Biomedical Engineering, The George Washington University, Washington, District of Columbia
| | - Bastiaan J Boukens
- Department Physiology, University Maastricht, Maastricht University Medical Center, Maastricht, The Netherlands
- Department of Medical Biology, University of Amsterdam, Amsterdam University Medical Center, Amsterdam, The Netherlands
| | - Nipavan Chiamvimonvat
- Department of Pharmacology, University of California Davis School of Medicine, Davis, California
- Department of Internal Medicine, University of California Davis School of Medicine, Davis, California
- Veterans Affairs Northern California Healthcare System, Mather, California
| | - Brian P Delisle
- Department of Physiology, University of Kentucky, Lexington, Kentucky
| | - Larissa Fabritz
- University Center of Cardiovascular Science, University Heart and Vascular Center, University Hospital Hamburg-Eppendorf with DZHK Hamburg/Kiel/Luebeck, Germany
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Thomas J Hund
- Department of Internal Medicine, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University, Columbus, Ohio
- Department of Biomedical Engineering, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University, Columbus, Ohio
| | - Bjorn C Knollmann
- Vanderbilt Center for Arrhythmia Research and Therapeutics, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Na Li
- Department of Medicine, Baylor College of Medicine, Houston, Texas
| | - Katherine T Murray
- Departments of Medicine and Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Steven Poelzing
- Virginia Tech Carilon School of Medicine, Center for Heart and Reparative Medicine Research, Fralin Biomedical Research Institute at Virginia Tech, Roanoke, Virginia
- Department of Biomedical Engineering and Mechanics, Virginia Polytechnic Institute and State University, Blacksburg, Virginia
| | - T Alexander Quinn
- Department of Physiology and Biophysics, Dalhousie University, Halifax, Nova Scotia, Canada
- School of Biomedical Engineering, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Carol Ann Remme
- Department of Experimental Cardiology, Heart Centre, Amsterdam Cardiovascular Sciences, Heart Failure and Arrhythmias Amsterdam UMC Location University of Amsterdam, Amsterdam, The Netherlands
| | - Stacey L Rentschler
- Cardiovascular Division, Department of Medicine, Washington University in Saint Louis, School of Medicine, Saint Louis, Missouri
| | - Robert A Rose
- Department of Cardiac Sciences, Libin Cardiovascular Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Nikki G Posnack
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Hospital, Washington, District of Columbia
- Department of Pediatrics, George Washington University School of Medicine, Washington, District of Columbia
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7
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Saura M, Zamorano JL, Zaragoza C. Preclinical models of congestive heart failure, advantages, and limitations for application in clinical practice. Front Physiol 2022; 13:850301. [PMID: 35991184 PMCID: PMC9386157 DOI: 10.3389/fphys.2022.850301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Accepted: 07/11/2022] [Indexed: 11/13/2022] Open
Abstract
Congestive heart failure (CHF) has increased over the years, in part because of recent progress in the management of chronic diseases, thus contributing to the maintenance of an increasingly aging population. CHF represents an unresolved health problem and therefore the establishment of animal models that recapitulates the complexity of CHF will become a critical element to be addressed, representing a serious challenge given the complexity of the pathogenesis of CHF itself, which is further compounded by methodological biases that depend on the animal species in use. Animal models of CHF have been developed in many different species, with different surgical procedures, all with promising results but, for the moment, unable to fully recapitulate the human disease. Large animal models often provide a more promising reality, with all the difficulties that their use entails, and which limit their performance to fewer laboratories, the costly of animal housing, animal handling, specialized facilities, skilled methodological training, and reproducibility as another important limiting factor when considering a valid animal model versus potentially better performing alternatives. In this review we will discuss the different animal models of CHF, their advantages and, above all, the limitations of each procedure with respect to effectiveness of results in terms of clinical application.
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Affiliation(s)
- Marta Saura
- Departamento de Biología de Sistemas, Facultad de Medicina (IRYCIS), Universidad de Alcalá, Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Cardiovasculares (CIBERCV), Instituto de Salud Carlos III (ISCIII), Madrid, Spain
| | - Jose Luis Zamorano
- Centro de Investigación Biomédica en Red de Enfermedades Cardiovasculares (CIBERCV), Instituto de Salud Carlos III (ISCIII), Madrid, Spain
- Departamento de Cardiología, Hospital Universitario Ramón y Cajal (IRYCIS), Madrid, Spain
| | - Carlos Zaragoza
- Centro de Investigación Biomédica en Red de Enfermedades Cardiovasculares (CIBERCV), Instituto de Salud Carlos III (ISCIII), Madrid, Spain
- Unidad de Investigación Cardiovascular, Departamento de Cardiología, Universidad Francisco de Vitoria, Hospital Ramón y Cajal (IRYCIS), Madrid, Spain
- *Correspondence: Carlos Zaragoza,
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8
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Pilz PM, Ward JE, Chang WT, Kiss A, Bateh E, Jha A, Fisch S, Podesser BK, Liao R. Large and Small Animal Models of Heart Failure With Reduced Ejection Fraction. Circ Res 2022; 130:1888-1905. [PMID: 35679365 DOI: 10.1161/circresaha.122.320246] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Heart failure (HF) describes a heterogenous complex spectrum of pathological conditions that results in structural and functional remodeling leading to subsequent impairment of cardiac function, including either systolic dysfunction, diastolic dysfunction, or both. Several factors chronically lead to HF, including cardiac volume and pressure overload that may result from hypertension, valvular lesions, acute, or chronic ischemic injuries. Major forms of HF include hypertrophic, dilated, and restrictive cardiomyopathy. The severity of cardiomyopathy can be impacted by other comorbidities such as diabetes or obesity and external stress factors. Age is another major contributor, and the number of patients with HF is rising worldwide in part due to an increase in the aged population. HF can occur with reduced ejection fraction (HF with reduced ejection fraction), that is, the overall cardiac function is compromised, and typically the left ventricular ejection fraction is lower than 40%. In some cases of HF, the ejection fraction is preserved (HF with preserved ejection fraction). Animal models play a critical role in facilitating the understanding of molecular mechanisms of how hearts fail. This review aims to summarize and describe the strengths, limitations, and outcomes of both small and large animal models of HF with reduced ejection fraction that are currently used in basic and translational research. The driving defect is a failure of the heart to adequately supply the tissues with blood due to impaired filling or pumping. An accurate model of HF with reduced ejection fraction would encompass the symptoms (fatigue, dyspnea, exercise intolerance, and edema) along with the pathology (collagen fibrosis, ventricular hypertrophy) and ultimately exhibit a decrease in cardiac output. Although countless experimental studies have been published, no model completely recapitulates the full human disease. Therefore, it is critical to evaluate the strength and weakness of each animal model to allow better selection of what animal models to use to address the scientific question proposed.
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Affiliation(s)
- Patrick M Pilz
- Stanford Cardiovascular Institute, Stanford University School of Medicine, CA (P.M.P., E.B., R.L.).,Ludwig Boltzmann Institute at the Center for Biomedical Research, Medical University of Vienna, Austria (P.M.P., A.K., B.K.P.)
| | - Jennifer E Ward
- Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, MA (J.E.W., S.F., R.L.)
| | - Wei-Ting Chang
- Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Taiwan (W.-T.C.).,Department of Cardiology, Chi-Mei Medical Center, Taiwan (W.-T.C.)
| | - Attila Kiss
- Ludwig Boltzmann Institute at the Center for Biomedical Research, Medical University of Vienna, Austria (P.M.P., A.K., B.K.P.)
| | - Edward Bateh
- Stanford Cardiovascular Institute, Stanford University School of Medicine, CA (P.M.P., E.B., R.L.)
| | - Alokkumar Jha
- Stanford Cardiovascular Institute, Stanford University School of Medicine, CA (P.M.P., E.B., R.L.)
| | - Sudeshna Fisch
- Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, MA (J.E.W., S.F., R.L.)
| | - Bruno K Podesser
- Ludwig Boltzmann Institute at the Center for Biomedical Research, Medical University of Vienna, Austria (P.M.P., A.K., B.K.P.)
| | - Ronglih Liao
- Stanford Cardiovascular Institute, Stanford University School of Medicine, CA (P.M.P., E.B., R.L.).,Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, MA (J.E.W., S.F., R.L.)
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9
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Prinzen FW, Auricchio A, Mullens W, Linde C, Huizar JF. Electrical management of heart failure: from pathophysiology to treatment. Eur Heart J 2022; 43:1917-1927. [PMID: 35265992 PMCID: PMC9123241 DOI: 10.1093/eurheartj/ehac088] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 12/02/2021] [Accepted: 02/22/2022] [Indexed: 11/14/2022] Open
Abstract
Electrical disturbances, such as atrial fibrillation (AF), dyssynchrony, tachycardia, and premature ventricular contractions (PVCs), are present in most patients with heart failure (HF). While these disturbances may be the consequence of HF, increasing evidence suggests that they may also cause or aggravate HF. Animal studies show that longer-lasting left bundle branch block, tachycardia, AF, and PVCs lead to functional derangements at the organ, cellular, and molecular level. Conversely, electrical treatment may reverse or mitigate HF. Clinical studies have shown the superiority of atrial and pulmonary vein ablation for rhythm control and AV nodal ablation for rate control in AF patients when compared with medical treatment. Ablation of PVCs can also improve left ventricular function. Cardiac resynchronization therapy (CRT) is an established adjunct therapy currently undergoing several interesting innovations. The current guideline recommendations reflect the safety and efficacy of these ablation therapies and CRT, but currently, these therapies are heavily underutilized. This review focuses on the electrical treatment of HF with reduced ejection fraction (HFrEF). We believe that the team of specialists treating an HF patient should incorporate an electrophysiologist in order to achieve a more widespread use of electrical therapies in the management of HFrEF and should also include individual conditions of the patient, such as body size and gender in therapy fine-tuning.
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Affiliation(s)
- Frits W Prinzen
- Department of Physiology, Cardiovascular Research Institute Maastricht, Maastricht University, PO Box 616, 6200 MD Maastricht, The Netherlands
| | - Angelo Auricchio
- Division of Cardiology, Istituto Cardiocentro Ticino, Lugano, Switzerland
| | - Wilfried Mullens
- Ziekenhuis Oost Limburg, Genk, Belgium
- Biomedical Research Institute, Faculty of Medicine and Life Sciences, University Hasselt, Hasselt, Belgium
| | - Cecilia Linde
- Department of Medicine, Karolinska Institutet, Solna, Sweden
- Department of Cardiology, Karolinska University Hospital, Stockholm, Sweden
| | - Jose F Huizar
- Cardiology Division, Virginia Commonwealth University/Pauley Heart Center, Richmond, VA, USA
- Cardiology Division, Hunter Holmes McGuire Veterans Affairs Medical Center, Richmond, VA, USA
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10
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Pabel S, Knierim M, Stehle T, Alebrand F, Paulus M, Sieme M, Herwig M, Barsch F, Körtl T, Pöppl A, Wenner B, Ljubojevic-Holzer S, Molina CE, Dybkova N, Camboni D, Fischer TH, Sedej S, Scherr D, Schmid C, Brochhausen C, Hasenfuß G, Maier LS, Hamdani N, Streckfuss-Bömeke K, Sossalla S. Effects of Atrial Fibrillation on the Human Ventricle. Circ Res 2022; 130:994-1010. [PMID: 35193397 PMCID: PMC8963444 DOI: 10.1161/circresaha.121.319718] [Citation(s) in RCA: 31] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 02/08/2022] [Accepted: 02/14/2022] [Indexed: 11/16/2022]
Abstract
RATIONALE Atrial fibrillation (AF) and heart failure often coexist, but their interaction is poorly understood. Clinical data indicate that the arrhythmic component of AF may contribute to left ventricular (LV) dysfunction. OBJECTIVE This study investigates the effects and molecular mechanisms of AF on the human LV. METHODS AND RESULTS Ventricular myocardium from patients with aortic stenosis and preserved LV function with sinus rhythm or rate-controlled AF was studied. LV myocardium from patients with sinus rhythm and patients with AF showed no differences in fibrosis. In functional studies, systolic Ca2+ transient amplitude of LV cardiomyocytes was reduced in patients with AF, while diastolic Ca2+ levels and Ca2+ transient kinetics were not statistically different. These results were confirmed in LV cardiomyocytes from nonfailing donors with sinus rhythm or AF. Moreover, normofrequent AF was simulated in vitro using arrhythmic or rhythmic pacing (both at 60 bpm). After 24 hours of AF-simulation, human LV cardiomyocytes from nonfailing donors showed an impaired Ca2+ transient amplitude. For a standardized investigation of AF-simulation, human iPSC-cardiomyocytes were tested. Seven days of AF-simulation caused reduced systolic Ca2+ transient amplitude and sarcoplasmic reticulum Ca2+ load likely because of an increased diastolic sarcoplasmic reticulum Ca2+ leak. Moreover, cytosolic Na+ concentration was elevated and action potential duration was prolonged after AF-simulation. We detected an increased late Na+ current as a potential trigger for the detrimentally altered Ca2+/Na+-interplay. Mechanistically, reactive oxygen species were higher in the LV of patients with AF. CaMKII (Ca2+/calmodulin-dependent protein kinase IIδc) was found to be more oxidized at Met281/282 in the LV of patients with AF leading to an increased CaMKII activity and consequent increased RyR2 phosphorylation. CaMKII inhibition and ROS scavenging ameliorated impaired systolic Ca2+ handling after AF-simulation. CONCLUSIONS AF causes distinct functional and molecular remodeling of the human LV. This translational study provides the first mechanistic characterization and the potential negative impact of AF in the absence of tachycardia on the human ventricle.
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Affiliation(s)
- Steffen Pabel
- Department of Internal Medicine II, University Hospital Regensburg, Regensburg, Germany (S.P., M.K., T.S., M.P., T.K., A.P., L.S.M., S. Sossalla)
| | - Maria Knierim
- Department of Internal Medicine II, University Hospital Regensburg, Regensburg, Germany (S.P., M.K., T.S., M.P., T.K., A.P., L.S.M., S. Sossalla)
- Clinic for Cardiology and Pneumology, Georg-August University Göttingen, and DZHK (German Centre for Cardiovascular Research), partner site Göttingen, Germany (M.K., F.A., B.W., N.D., G.H., K.S.-B., S. Sossalla)
| | - Thea Stehle
- Department of Internal Medicine II, University Hospital Regensburg, Regensburg, Germany (S.P., M.K., T.S., M.P., T.K., A.P., L.S.M., S. Sossalla)
| | - Felix Alebrand
- Clinic for Cardiology and Pneumology, Georg-August University Göttingen, and DZHK (German Centre for Cardiovascular Research), partner site Göttingen, Germany (M.K., F.A., B.W., N.D., G.H., K.S.-B., S. Sossalla)
| | - Michael Paulus
- Department of Internal Medicine II, University Hospital Regensburg, Regensburg, Germany (S.P., M.K., T.S., M.P., T.K., A.P., L.S.M., S. Sossalla)
| | - Marcel Sieme
- Institut für Forschung und Lehre (IFL), Department of Molecular and Experimental Cardiology and Department of Cardiology, St. Josef-Hospital, Ruhr University Bochum, Germany (M.S., M.H., N.H.)
| | - Melissa Herwig
- Institut für Forschung und Lehre (IFL), Department of Molecular and Experimental Cardiology and Department of Cardiology, St. Josef-Hospital, Ruhr University Bochum, Germany (M.S., M.H., N.H.)
| | - Friedrich Barsch
- Institute of Pathology, University Hospital Regensburg, Germany (F.B., C.B.)
| | - Thomas Körtl
- Department of Internal Medicine II, University Hospital Regensburg, Regensburg, Germany (S.P., M.K., T.S., M.P., T.K., A.P., L.S.M., S. Sossalla)
| | - Arnold Pöppl
- Department of Internal Medicine II, University Hospital Regensburg, Regensburg, Germany (S.P., M.K., T.S., M.P., T.K., A.P., L.S.M., S. Sossalla)
| | - Brisca Wenner
- Clinic for Cardiology and Pneumology, Georg-August University Göttingen, and DZHK (German Centre for Cardiovascular Research), partner site Göttingen, Germany (M.K., F.A., B.W., N.D., G.H., K.S.-B., S. Sossalla)
| | | | - Cristina E. Molina
- Institute of Experimental Cardiovascular Research, University Medical Centre Hamburg-Eppendorf, Germany (C.E.M.)
| | - Nataliya Dybkova
- Clinic for Cardiology and Pneumology, Georg-August University Göttingen, and DZHK (German Centre for Cardiovascular Research), partner site Göttingen, Germany (M.K., F.A., B.W., N.D., G.H., K.S.-B., S. Sossalla)
| | - Daniele Camboni
- Department of Cardiothoracic Surgery, University Hospital Regensburg, Germany (D.C., C.S.)
| | - Thomas H. Fischer
- Department of Internal Medicine I, University of Würzburg, Germany (T.H.F.)
| | - Simon Sedej
- Department of Cardiology, Medical University of Graz, Austria (S.L.-H., S. Sedej, D.S.)
- Faculty of Medicine, University of Maribor, Maribor, Slovenia (S. Sedej)
- BioTechMed Graz, Graz, Austria (S. Sedej)
| | - Daniel Scherr
- Department of Cardiology, Medical University of Graz, Austria (S.L.-H., S. Sedej, D.S.)
| | - Christof Schmid
- Department of Cardiothoracic Surgery, University Hospital Regensburg, Germany (D.C., C.S.)
| | | | - Gerd Hasenfuß
- Clinic for Cardiology and Pneumology, Georg-August University Göttingen, and DZHK (German Centre for Cardiovascular Research), partner site Göttingen, Germany (M.K., F.A., B.W., N.D., G.H., K.S.-B., S. Sossalla)
| | - Lars S. Maier
- Department of Internal Medicine II, University Hospital Regensburg, Regensburg, Germany (S.P., M.K., T.S., M.P., T.K., A.P., L.S.M., S. Sossalla)
| | - Nazha Hamdani
- Institut für Forschung und Lehre (IFL), Department of Molecular and Experimental Cardiology and Department of Cardiology, St. Josef-Hospital, Ruhr University Bochum, Germany (M.S., M.H., N.H.)
| | - Katrin Streckfuss-Bömeke
- Clinic for Cardiology and Pneumology, Georg-August University Göttingen, and DZHK (German Centre for Cardiovascular Research), partner site Göttingen, Germany (M.K., F.A., B.W., N.D., G.H., K.S.-B., S. Sossalla)
- Institute of Pharmacology and Toxicology, University of Würzburg, Germany (K.S.-B.)
| | - Samuel Sossalla
- Department of Internal Medicine II, University Hospital Regensburg, Regensburg, Germany (S.P., M.K., T.S., M.P., T.K., A.P., L.S.M., S. Sossalla)
- Clinic for Cardiology and Pneumology, Georg-August University Göttingen, and DZHK (German Centre for Cardiovascular Research), partner site Göttingen, Germany (M.K., F.A., B.W., N.D., G.H., K.S.-B., S. Sossalla)
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11
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Miyagi C, Miyamoto T, Kuroda T, Karimov JH, Starling RC, Fukamachi K. Large animal models of heart failure with preserved ejection fraction. Heart Fail Rev 2021; 27:595-608. [PMID: 34751846 DOI: 10.1007/s10741-021-10184-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 10/21/2021] [Indexed: 01/14/2023]
Abstract
Heart failure with preserved ejection fraction (HFpEF) is characterized by diastolic dysfunction and multiple comorbidities. The number of patients is continuously increasing, with no improvement in its unfavorable prognosis, and there is a strong need for novel treatments. New devices and drugs are difficult to assess at the translational preclinical step due to the lack of high-fidelity large animal models of HFpEF. In this review, we describe the summary of historical and evolving techniques for developing large animal models. The representative methods are pressure overload models, including (1) aortic banding, (2) aortic stent, (3) renal hypertension, and (4) mineralocorticoid-induced hypertension. Diet-induced metabolic syndromes are also used. A new technique with an inflatable balloon inside the left ventricle can be used during acute/chronic in vivo surgeries to simulate HFpEF-like hemodynamics for pump-based therapies. Canines and porcine are most widely used, but other non-rodent animals (sheep, non-human primates, felines, or calves) have been used. Feline models present the most well-simulated HFpEF pathology, but small size is a concern, and the information is still very limited. The rapid and reliable establishment of large animal models for HFpEF, and novel methodology based on the past experimental attempts with large animals, are needed.
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Affiliation(s)
- Chihiro Miyagi
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH, 44195, USA
| | - Takuma Miyamoto
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH, 44195, USA
| | - Taiyo Kuroda
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH, 44195, USA
| | - Jamshid H Karimov
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH, 44195, USA
| | - Randall C Starling
- Department of Cardiovascular Medicine, Miller Family Heart and Vascular Institute, Cleveland Clinic, Cleveland, OH, USA.,Kaufman Center for Heart Failure Treatment and Recovery, Cleveland Clinic, Cleveland, OH, USA
| | - Kiyotaka Fukamachi
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH, 44195, USA.
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12
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Borgeat K, Pack M, Harris J, Laver A, Seo J, Belachsen O, Hannabuss J, Todd J, Ferasin L, Payne JR. Prevalence of sudden cardiac death in dogs with atrial fibrillation. J Vet Intern Med 2021; 35:2588-2595. [PMID: 34750853 PMCID: PMC8692199 DOI: 10.1111/jvim.16297] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 10/12/2021] [Accepted: 10/13/2021] [Indexed: 11/27/2022] Open
Abstract
Background Atrial fibrillation (AF) is associated with increased risk of sudden cardiac death (SCD) in humans, independent of secondary risk factors such as thrombogenic disorders. In dogs, SCD is described in a number of heart diseases, but an association between AF and SCD is unreported. Hypothesis (a) A higher proportion of dogs with AF will experience SCD, and (b) SCD will be associated with complex ventricular arrhythmias. Animals One‐hundred forty‐two dogs with AF, and 127 dogs without AF. Methods Retrospective, multicenter, case‐control study. Dogs included in the AF group were compared to a control group of dogs in sinus rhythm, matched for echocardiographic diagnosis. Descriptive statistics were used to identify proportions of each group suffering SCD, compared using chi‐squared testing. Risk factors for SCD in dogs with AF were evaluated at the univariable and multivariable level using binary logistic regression. Significance was P < .05. Results A significantly higher proportion of dogs with AF suffered SCD than dogs in the control group (14.8% vs 5.5%; P = .01). Younger age at diagnosis, larger left atrial size, and a history of syncope all were independent predictors of SCD in dogs with AF (χ2, 16.3; P = .04). Conclusions and Clinical Importance Atrial fibrillation was associated with a higher prevalence of SCD in dogs. A history of syncope may be a useful predictor of SCD risk.
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Affiliation(s)
- Kieran Borgeat
- Small Animal Hospital, Langford Vets, University of Bristol, Bristol, United Kingdom
| | - Matthew Pack
- Small Animal Hospital, Langford Vets, University of Bristol, Bristol, United Kingdom
| | | | | | - Joonbum Seo
- Queen Mother Hospital for Animals, Royal Veterinary College, London, United Kingdom
| | - Omri Belachsen
- Southern Counties Veterinary Specialists, Ringwood, United Kingdom
| | - Joshua Hannabuss
- Queen Mother Hospital for Animals, Royal Veterinary College, London, United Kingdom
| | - Julie Todd
- Pride Veterinary Centre, Derby, United Kingdom
| | - Luca Ferasin
- Specialist Veterinary Cardiology Consultancy, Alton, United Kingdom
| | - Jessie Rose Payne
- Small Animal Hospital, Langford Vets, University of Bristol, Bristol, United Kingdom
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13
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Lange M, Hirahara AM, Ranjan R, Stoddard GJ, Dosdall DJ. Atrial slow conduction develops and dynamically expands during premature stimulation in an animal model of persistent atrial fibrillation. PLoS One 2021; 16:e0258285. [PMID: 34618871 PMCID: PMC8496790 DOI: 10.1371/journal.pone.0258285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Accepted: 09/24/2021] [Indexed: 11/18/2022] Open
Abstract
Slow conduction areas and conduction block in the atria are considered pro-arrhythmic conditions. Studies examining the size and distribution of slow conduction regions in the context of persistent atrial fibrillation (AF) may help to develop improved therapeutic strategies for patients with AF. In this work, we studied the differences of size and number in slow conduction areas between control and persistent AF goats and the influence of propagation direction on the development of these pathological conduction areas. Epicardial atrial electrical activations from the left atrial roof were optically mapped with physiological pacing cycle lengths and for the shortest captured cycle lengths. The recordings were converted to local activation times and conduction velocity measures. Regions with slow conduction velocity (less than [Formula: see text]) were identified. The size of the connected regions and the number of non-connected regions were counted for propagation from different orthogonal directions. We found that regions of slow conduction significantly increases in our 15 persistent AF goat recordings in response to premature stimulation (24.4±4.3% increase to 36.6±4.4%, p < 0.001). This increase is driven by an increase of size from (3.70±0.89[mm2] to 6.36±0.91[mm2], p = 0.014) for already existing regions and not by generation of new slow conduction regions (11.6±1.8 vs. 13±1.9, p = 0.242). In 12 control goat recordings, no increase from baseline pacing to premature pacing was found. Similarly, size of the slow conduction areas and the count did not change significantly in control animals.
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Affiliation(s)
- Matthias Lange
- Nora Eccles Harrison Cardiovasular Research and Training Institute, University of Utah, Salt Lake City, Utah, United States of America
| | - Annie M. Hirahara
- Nora Eccles Harrison Cardiovasular Research and Training Institute, University of Utah, Salt Lake City, Utah, United States of America
- Biomedical Engineering, University of Utah, Salt Lake City, Utah, United States of America
| | - Ravi Ranjan
- Nora Eccles Harrison Cardiovasular Research and Training Institute, University of Utah, Salt Lake City, Utah, United States of America
- Biomedical Engineering, University of Utah, Salt Lake City, Utah, United States of America
- Division of Cardiovascular Medicine, Department of Internal Medicine, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
| | - Gregory J. Stoddard
- Division of Epidemiology, Department of Internal Medicine, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
| | - Derek J. Dosdall
- Nora Eccles Harrison Cardiovasular Research and Training Institute, University of Utah, Salt Lake City, Utah, United States of America
- Biomedical Engineering, University of Utah, Salt Lake City, Utah, United States of America
- Division of Cardiovascular Medicine, Department of Internal Medicine, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
- Division of Cardiothoracic Surgery, Department of Surgery, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
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14
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Banda LJ, Tanganyika J. Livestock provide more than food in smallholder production systems of developing countries. Anim Front 2021; 11:7-14. [PMID: 34026310 PMCID: PMC8127680 DOI: 10.1093/af/vfab001] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Affiliation(s)
- Liveness Jessica Banda
- Animal Science Department, Bunda College, Lilongwe University of Agriculture and Natural Resources, Lilongwe, Malawi
| | - Jonathan Tanganyika
- Animal Science Department, Bunda College, Lilongwe University of Agriculture and Natural Resources, Lilongwe, Malawi
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15
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Quah JX, Dharmaprani D, Tiver K, Lahiri A, Hecker T, Perry R, Selvanayagam JB, Joseph MX, McGavigan A, Ganesan A. Atrial fibrosis and substrate based characterization in atrial fibrillation: Time to move forwards. J Cardiovasc Electrophysiol 2021; 32:1147-1160. [PMID: 33682258 DOI: 10.1111/jce.14987] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Revised: 02/15/2021] [Accepted: 02/22/2021] [Indexed: 12/15/2022]
Abstract
Atrial fibrillation (AF) is the most commonly encountered cardiac arrhythmia in clinical practice. However, current therapeutic interventions for atrial fibrillation have limited clinical efficacy as a consequence of major knowledge gaps in the mechanisms sustaining atrial fibrillation. From a mechanistic perspective, there is increasing evidence that atrial fibrosis plays a central role in the maintenance and perpetuation of atrial fibrillation. Electrophysiologically, atrial fibrosis results in alterations in conduction velocity, cellular refractoriness, and produces conduction block promoting meandering, unstable wavelets and micro-reentrant circuits. Clinically, atrial fibrosis has also linked to poor clinical outcomes including AF-related thromboembolic complications and arrhythmia recurrences post catheter ablation. In this article, we review the pathophysiology behind the formation of fibrosis as AF progresses, the role of fibrosis in arrhythmogenesis, surrogate markers for detection of fibrosis using cardiac magnetic resonance imaging, echocardiography and electroanatomic mapping, along with their respective limitations. We then proceed to review the current evidence behind therapeutic interventions targeting atrial fibrosis, including drugs and substrate-based catheter ablation therapies followed by the potential future use of electro phenotyping for AF characterization to overcome the limitations of contemporary substrate-based methodologies.
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Affiliation(s)
- Jing X Quah
- College of Medicine and Public Health, Flinders University of South Australia, Adelaide, Australia.,Department of Cardiovascular Medicine, Flinders Medical Centre, Adelaide, Australia
| | - Dhani Dharmaprani
- College of Medicine and Public Health, Flinders University of South Australia, Adelaide, Australia.,College of Science and Engineering, Flinders University of South Australia, Adelaide, Australia
| | - Kathryn Tiver
- Department of Cardiovascular Medicine, Flinders Medical Centre, Adelaide, Australia
| | - Anandaroop Lahiri
- Department of Cardiovascular Medicine, Flinders Medical Centre, Adelaide, Australia
| | - Teresa Hecker
- Department of Cardiovascular Medicine, Flinders Medical Centre, Adelaide, Australia
| | - Rebecca Perry
- Department of Cardiovascular Medicine, Flinders Medical Centre, Adelaide, Australia.,UniSA Allied Health and Human Performance, University of South Australia, Adelaide, Australia
| | | | - Majo X Joseph
- Department of Cardiovascular Medicine, Flinders Medical Centre, Adelaide, Australia
| | | | - Anand Ganesan
- College of Medicine and Public Health, Flinders University of South Australia, Adelaide, Australia.,Department of Cardiovascular Medicine, Flinders Medical Centre, Adelaide, Australia
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16
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Mandour AS, Samir H, Yoshida T, Matsuura K, Abdelmageed HA, Elbadawy M, Al-Rejaie S, El-Husseiny HM, Elfadadny A, Ma D, Takahashi K, Watanabe G, Tanaka R. Assessment of the Cardiac Functions Using Full Conventional Echocardiography with Tissue Doppler Imaging before and after Xylazine Sedation in Male Shiba Goats. Animals (Basel) 2020; 10:E2320. [PMID: 33297474 PMCID: PMC7762359 DOI: 10.3390/ani10122320] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 11/25/2020] [Accepted: 12/01/2020] [Indexed: 01/26/2023] Open
Abstract
The present study aimed to provide a complete conventional echocardiographic protocol in adult male Shiba goats by using two-dimensional, M-mode, Pulsed Wave Doppler, and tissue Doppler imaging (TDI) echocardiography, and to study concomitantly xylazine-induced alteration of cardiac functions in a highly sensitive species. For this purpose, 12 male Shiba goats were included and complete conventional echocardiography from the standard right and left parasternal views was carried to report the echocardiographic data in male Shiba goats, and also before and after xylazine (Pre-Xyl and Post-Xyl) administration (0.05 mg/IM/kg). Results revealed that the full echocardiographic protocol was feasible in all goats through different cardiac windows and good Doppler alignment was achieved with non-significant variability for assessment of the left ventricular dimensions, trans-pulmonary, trans-aortic, and trans-mitral blood flow. The TDI, which was not reported previously in goats, was successfully assessed from the standard left apical view and showed distinct systolic and diastolic patterns. Xylazine administration was found to significantly reduce heart rate, fractional shortening, and cardiac output as well as the Doppler hemodynamic parameters of the pulmonary artery, aortic and mitral inflows (p < 0.05). For TDI, the Post-Xyl group revealed a significant decrease in the myocardial velocities of the septal and lateral wall of the left ventricle. The present study provides, for the first time, complete data of conventional echocardiography in male goats using the full protocol, which is routinely used in pet's practice. Further, we illustrate in-depth the adverse effect of short-term sedative, xylazine, as used under field conditions and emphasize a simultaneous reduction in both systolic and diastolic cardiac function in goats based on full echocardiography assessment of the heart.
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Affiliation(s)
- Ahmed S. Mandour
- Department of Animal Medicine (Internal Medicine), Faculty of Veterinary Medicine, Suez Canal University, Ismailia 41522, Egypt
- Laboratory of Veterinary Surgery, Tokyo University of Agriculture and Technology, Tokyo 183-8509, Japan; (T.Y.); (K.M.); (H.M.E.-H.); (D.M.)
| | - Haney Samir
- Department of Theriogenology, Faculty of Veterinary Medicine, Cairo University, Giza 12211, Egypt;
- Laboratory of Veterinary Physiology, Tokyo University of Agriculture and Technology, Tokyo 183-8509, Japan;
| | - Tomohiko Yoshida
- Laboratory of Veterinary Surgery, Tokyo University of Agriculture and Technology, Tokyo 183-8509, Japan; (T.Y.); (K.M.); (H.M.E.-H.); (D.M.)
| | - Katsuhiro Matsuura
- Laboratory of Veterinary Surgery, Tokyo University of Agriculture and Technology, Tokyo 183-8509, Japan; (T.Y.); (K.M.); (H.M.E.-H.); (D.M.)
| | - Hend A. Abdelmageed
- Laboratory of Veterinary Microbiology, Animal Health Research Institute, Ismailia lab, First District, Ismailia 41522, Egypt;
- Laboratory of Veterinary Microbiology, Cooperative Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Tokyo 183-8509, Japan
| | - Mohamed Elbadawy
- Department of Pharmacology, Faculty of Veterinary Medicine, Benha University, Moshtohor, Toukh, Elqaliobiya 13736, Egypt;
| | - Salim Al-Rejaie
- Department of Pharmacology & Toxicology, College of Pharmacy, King Saud University, Riyadh 11564, Saudi Arabia;
| | - Hussein M. El-Husseiny
- Laboratory of Veterinary Surgery, Tokyo University of Agriculture and Technology, Tokyo 183-8509, Japan; (T.Y.); (K.M.); (H.M.E.-H.); (D.M.)
- Department of Surgery, Anesthesiology and Radiology, Faculty of Veterinary Medicine, Benha University, Moshtohor, Toukh, Elqaliobiya 13736, Egypt
| | - Ahmed Elfadadny
- Department of Animal Medicine, Faculty of Veterinary Medicine, Damanhur University, Damanhur, El-Beheira 22511, Egypt;
| | - Danfu Ma
- Laboratory of Veterinary Surgery, Tokyo University of Agriculture and Technology, Tokyo 183-8509, Japan; (T.Y.); (K.M.); (H.M.E.-H.); (D.M.)
| | - Ken Takahashi
- Department of Pediatrics and Adolescent Medicine, Juntendo University Graduate School of Medicine, Tokyo 113-8421, Japan;
| | - Gen Watanabe
- Laboratory of Veterinary Physiology, Tokyo University of Agriculture and Technology, Tokyo 183-8509, Japan;
| | - Ryou Tanaka
- Laboratory of Veterinary Surgery, Tokyo University of Agriculture and Technology, Tokyo 183-8509, Japan; (T.Y.); (K.M.); (H.M.E.-H.); (D.M.)
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17
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Mikhailov AV, Kalyanasundaram A, Li N, Scott SS, Artiga EJ, Subr MM, Zhao J, Hansen BJ, Hummel JD, Fedorov VV. Comprehensive evaluation of electrophysiological and 3D structural features of human atrial myocardium with insights on atrial fibrillation maintenance mechanisms. J Mol Cell Cardiol 2020; 151:56-71. [PMID: 33130148 DOI: 10.1016/j.yjmcc.2020.10.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 10/22/2020] [Accepted: 10/23/2020] [Indexed: 12/14/2022]
Abstract
Atrial fibrillation (AF) occurrence and maintenance is associated with progressive remodeling of electrophysiological (repolarization and conduction) and 3D structural (fibrosis, fiber orientations, and wall thickness) features of the human atria. Significant diversity in AF etiology leads to heterogeneous arrhythmogenic electrophysiological and structural substrates within the 3D structure of the human atria. Since current clinical methods have yet to fully resolve the patient-specific arrhythmogenic substrates, mechanism-based AF treatments remain underdeveloped. Here, we review current knowledge from in-vivo, ex-vivo, and in-vitro human heart studies, and discuss how these studies may provide new insights on the synergy of atrial electrophysiological and 3D structural features in AF maintenance. In-vitro studies on surgically acquired human atrial samples provide a great opportunity to study a wide spectrum of AF pathology, including functional changes in single-cell action potentials, ion channels, and gene/protein expression. However, limited size of the samples prevents evaluation of heterogeneous AF substrates and reentrant mechanisms. In contrast, coronary-perfused ex-vivo human hearts can be studied with state-of-the-art functional and structural technologies, such as high-resolution near-infrared optical mapping and contrast-enhanced MRI. These imaging modalities can resolve atrial arrhythmogenic substrates and their role in reentrant mechanisms maintaining AF and validate clinical approaches. Nonetheless, longitudinal studies are not feasible in explanted human hearts. As no approach is perfect, we suggest that combining the strengths of direct human atrial studies with high fidelity approaches available in the laboratory and in realistic patient-specific computer models would elucidate deeper knowledge of AF mechanisms. We propose that a comprehensive translational pipeline from ex-vivo human heart studies to longitudinal clinically relevant AF animal studies and finally to clinical trials is necessary to identify patient-specific arrhythmogenic substrates and develop novel AF treatments.
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Affiliation(s)
- Aleksei V Mikhailov
- Department of Physiology & Cell Biology, Bob and Corrine Frick Center for Heart Failure and Arrhythmia, The Ohio State University Wexner Medical Center, Columbus, OH, USA; Arrhythmology Research Department, Almazov National Medical Research Centre, Saint-Petersburg, Russia
| | - Anuradha Kalyanasundaram
- Department of Physiology & Cell Biology, Bob and Corrine Frick Center for Heart Failure and Arrhythmia, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Ning Li
- Department of Physiology & Cell Biology, Bob and Corrine Frick Center for Heart Failure and Arrhythmia, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Shane S Scott
- Department of Physiology & Cell Biology, Bob and Corrine Frick Center for Heart Failure and Arrhythmia, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Esthela J Artiga
- Department of Physiology & Cell Biology, Bob and Corrine Frick Center for Heart Failure and Arrhythmia, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Megan M Subr
- Department of Physiology & Cell Biology, Bob and Corrine Frick Center for Heart Failure and Arrhythmia, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Jichao Zhao
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
| | - Brian J Hansen
- Department of Physiology & Cell Biology, Bob and Corrine Frick Center for Heart Failure and Arrhythmia, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - John D Hummel
- Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, USA; Department of Internal Medicine, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Vadim V Fedorov
- Department of Physiology & Cell Biology, Bob and Corrine Frick Center for Heart Failure and Arrhythmia, The Ohio State University Wexner Medical Center, Columbus, OH, USA; Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, USA.
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18
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Silva KAS, Emter CA. Large Animal Models of Heart Failure: A Translational Bridge to Clinical Success. JACC Basic Transl Sci 2020; 5:840-856. [PMID: 32875172 PMCID: PMC7452204 DOI: 10.1016/j.jacbts.2020.04.011] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Accepted: 04/10/2020] [Indexed: 12/12/2022]
Abstract
Preclinical large animal models play a critical and expanding role in translating basic science findings to the development and clinical approval of novel cardiovascular therapeutics. This state-of-the-art review outlines existing methodologies and physiological phenotypes of several HF models developed in large animals. A comprehensive list of porcine, ovine, and canine models of disease are presented, and the translational importance of these studies to clinical success is highlighted through a brief overview of recent devices approved by the FDA alongside associated clinical trials and preclinical animal reports. Increasing the use of large animal models of HF holds significant potential for identifying new mechanisms underlying this disease and providing valuable information regarding the safety and efficacy of new therapies, thus, improving physiological and economical translation of animal research to the successful treatment of human HF.
Preclinical large animal models of heart failure (HF) play a critical and expanding role in translating basic science findings to the development and clinical approval of novel therapeutics and devices. The complex combination of cardiovascular events and risk factors leading to HF has proved challenging for the development of new treatments for these patients. This state-of-the-art review presents historical and recent studies in porcine, ovine, and canine models of HF and outlines existing methodologies and physiological phenotypes. The translational importance of large animal studies to clinical success is also highlighted with an overview of recent devices approved by the Food and Drug Administration, together with preclinical HF animal studies used to aid both development and safety and/or efficacy testing. Increasing the use of large animal models of HF holds significant potential for identifying the novel mechanisms underlying the clinical condition and to improving physiological and economical translation of animal research to successfully treat human HF.
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Key Words
- AF, atrial fibrillation
- ECM, extracellular matrix
- EDP, end-diastolic pressure
- EF, ejection fraction
- FDA, Food and Drug Administration
- HF, heart failure
- HFpEF
- HFpEF, heart failure with preserved ejection fraction
- HFrEF
- HFrEF, heart failure with reduced ejection fraction
- I/R, ischemia/reperfusion
- IABP, intra-aortic balloon pump
- LAD, left anterior descending
- LCx, left circumflex
- LV, left ventricular
- MI, myocardial infarction
- PCI, percutaneous coronary intervention
- RV, right ventricular
- heart failure
- large animal model
- preclinical
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Affiliation(s)
| | - Craig A Emter
- Department of Biomedical Sciences, University of Missouri-Columbia, Columbia, Missouri
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19
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Abstract
Atrial fibrillation (AF) is the most common sustained arrhythmia encountered in humans and is a significant source of morbidity and mortality. Despite its prevalence, our mechanistic understanding is incomplete, the therapeutic options have limited efficacy, and are often fraught with risks. A better biological understanding of AF is needed to spearhead novel therapeutic avenues. Although "natural" AF is nearly nonexistent in most species, animal models have contributed significantly to our understanding of AF and some therapeutic options. However, the impediments of animal models are also apparent and stem largely from the differences in basic physiology as well as the complexities underlying human AF; these preclude the creation of a "perfect" animal model and have obviated the translation of animal findings. Herein, we review the vast array of AF models available, spanning the mouse heart (weighing 1/1000th of a human heart) to the horse heart (10× heavier than the human heart). We attempt to highlight the features of each model that bring value to our understanding of AF but also the shortcomings and pitfalls. Finally, we borrowed the concept of a SWOT analysis from the business community (which stands for strengths, weaknesses, opportunities, and threats) and applied this introspective type of analysis to animal models for AF. We identify unmet needs and stress that is in the context of rapidly advancing technologies, these present opportunities for the future use of animal models.
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Affiliation(s)
- Dominik Schüttler
- From the Department of Medicine I, University Hospital Munich, Campus Großhadern, Ludwig-Maximilians University Munich (LMU), Germany (D.S., S.K., P.T., S.C.).,DZHK (German Centre for Cardiovascular Research), Partner Site Munich, Munich Heart Alliance (MHA), Germany (D.S., S.K., P.T., S.C.).,Walter Brendel Centre of Experimental Medicine, Ludwig-Maximilians University Munich (LMU), Germany (D.S., P.T., S.C.)
| | - Aneesh Bapat
- Cardiovascular Research Center, Massachusetts General Hospital, Harvard Medical School, Boston (A.B., K.L., W.J.H.).,Cardiac Arrhythmia Service, Division of Cardiology, Massachusetts General Hospital, Boston (A.B., W.J.H.)
| | - Stefan Kääb
- From the Department of Medicine I, University Hospital Munich, Campus Großhadern, Ludwig-Maximilians University Munich (LMU), Germany (D.S., S.K., P.T., S.C.).,DZHK (German Centre for Cardiovascular Research), Partner Site Munich, Munich Heart Alliance (MHA), Germany (D.S., S.K., P.T., S.C.)
| | - Kichang Lee
- Cardiovascular Research Center, Massachusetts General Hospital, Harvard Medical School, Boston (A.B., K.L., W.J.H.)
| | - Philipp Tomsits
- From the Department of Medicine I, University Hospital Munich, Campus Großhadern, Ludwig-Maximilians University Munich (LMU), Germany (D.S., S.K., P.T., S.C.).,DZHK (German Centre for Cardiovascular Research), Partner Site Munich, Munich Heart Alliance (MHA), Germany (D.S., S.K., P.T., S.C.).,Walter Brendel Centre of Experimental Medicine, Ludwig-Maximilians University Munich (LMU), Germany (D.S., P.T., S.C.)
| | - Sebastian Clauss
- From the Department of Medicine I, University Hospital Munich, Campus Großhadern, Ludwig-Maximilians University Munich (LMU), Germany (D.S., S.K., P.T., S.C.).,DZHK (German Centre for Cardiovascular Research), Partner Site Munich, Munich Heart Alliance (MHA), Germany (D.S., S.K., P.T., S.C.).,Walter Brendel Centre of Experimental Medicine, Ludwig-Maximilians University Munich (LMU), Germany (D.S., P.T., S.C.)
| | - William J Hucker
- Cardiovascular Research Center, Massachusetts General Hospital, Harvard Medical School, Boston (A.B., K.L., W.J.H.).,Cardiac Arrhythmia Service, Division of Cardiology, Massachusetts General Hospital, Boston (A.B., W.J.H.)
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20
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Angel N, Kholmovski EG, Ghafoori E, Dosdall DJ, MacLeod RS, Ranjan R. Regions of High Dominant Frequency in Chronic Atrial Fibrillation Anchored to Areas of Atrial Fibrosis. COMPUTING IN CARDIOLOGY 2020; 46. [PMID: 32161769 DOI: 10.22489/cinc.2019.403] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Regions within the atria with sustained rapid reentrant or focal activity have been defined as a mechanism of persistent atrial fibrillation (AF). However, the mechanism behind the anchoring of these sites and their stability over time is unknown. We tested the hypothesis that fibrosis anchors sites of high frequency activation during AF and that these sites can be non-invasively determined using cardiac T1 Mapping with MRI. A canine rapid atrial paced model of persistent AF was used (n=12, including 6 controls) for the study. Whole heart T1 Mapping was performed prior to an electrical mapping study. Spatial maps of high dominant frequency (DF) probability were constructed to determine stability of the highest DF sites. These sites were then correlated with fibrotic regions determined by T1 Mapping. The chronic AF animals had at least one site of stable, high DF for at least 22.5 (75%) of 30 minutes of AF. Regions of stable high DF bordered regions of fibrosis as determined by T1 Mapping MRI 82% of the time (p<0.05). Heterogeneous atrial remodeling, specifically fibrosis, arising from chronic AF may provide a substrate that anchors sites of high DF. Cardiac T1 Mapping with MRI may determine such sites non-invasively.
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Affiliation(s)
- Nathan Angel
- Division of Cardiovascular Medicine, University of Utah, Salt Lake City, UT, United States of America.,Department of Biomedical Engineering, University of Utah, Salt Lake City, UT, United States of America
| | - Eugene G Kholmovski
- UCAIR, Department of Radiology and Imaging Sciences, University of Utah, Salt Lake City, UT, United States of America.,CARMA Center, University of Utah, Salt Lake City, UT, United States of America
| | - Elyar Ghafoori
- Division of Cardiovascular Medicine, University of Utah, Salt Lake City, UT, United States of America.,Department of Biomedical Engineering, University of Utah, Salt Lake City, UT, United States of America.,Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, UT, United States of America
| | - Derek J Dosdall
- Department of Biomedical Engineering, University of Utah, Salt Lake City, UT, United States of America.,Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, UT, United States of America.,Department of Surgery, University of Utah, Salt Lake City, UT, United States of America
| | - Rob S MacLeod
- Division of Cardiovascular Medicine, University of Utah, Salt Lake City, UT, United States of America.,Department of Biomedical Engineering, University of Utah, Salt Lake City, UT, United States of America.,Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, UT, United States of America
| | - Ravi Ranjan
- Division of Cardiovascular Medicine, University of Utah, Salt Lake City, UT, United States of America.,Department of Biomedical Engineering, University of Utah, Salt Lake City, UT, United States of America.,Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, UT, United States of America
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21
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Clauss S, Bleyer C, Schüttler D, Tomsits P, Renner S, Klymiuk N, Wakili R, Massberg S, Wolf E, Kääb S. Animal models of arrhythmia: classic electrophysiology to genetically modified large animals. Nat Rev Cardiol 2020; 16:457-475. [PMID: 30894679 DOI: 10.1038/s41569-019-0179-0] [Citation(s) in RCA: 123] [Impact Index Per Article: 30.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Arrhythmias are common and contribute substantially to cardiovascular morbidity and mortality. The underlying pathophysiology of arrhythmias is complex and remains incompletely understood, which explains why mostly only symptomatic therapy is available. The evaluation of the complex interplay between various cell types in the heart, including cardiomyocytes from the conduction system and the working myocardium, fibroblasts and cardiac immune cells, remains a major challenge in arrhythmia research because it can be investigated only in vivo. Various animal species have been used, and several disease models have been developed to study arrhythmias. Although every species is useful and might be ideal to study a specific hypothesis, we suggest a practical trio of animal models for future use: mice for genetic investigations, mechanistic evaluations or early studies to identify potential drug targets; rabbits for studies on ion channel function, repolarization or re-entrant arrhythmias; and pigs for preclinical translational studies to validate previous findings. In this Review, we provide a comprehensive overview of different models and currently used species for arrhythmia research, discuss their advantages and disadvantages and provide guidance for researchers who are considering performing in vivo studies.
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Affiliation(s)
- Sebastian Clauss
- Department of Medicine I, University Hospital Munich, Campus Grosshadern, Ludwig-Maximilians University Munich (LMU), Munich, Germany. .,DZHK (German Centre for Cardiovascular Research), Partner Site Munich, Munich Heart Alliance (MHA), Munich, Germany.
| | - Christina Bleyer
- Department of Medicine I, University Hospital Munich, Campus Grosshadern, Ludwig-Maximilians University Munich (LMU), Munich, Germany.,DZHK (German Centre for Cardiovascular Research), Partner Site Munich, Munich Heart Alliance (MHA), Munich, Germany
| | - Dominik Schüttler
- Department of Medicine I, University Hospital Munich, Campus Grosshadern, Ludwig-Maximilians University Munich (LMU), Munich, Germany.,DZHK (German Centre for Cardiovascular Research), Partner Site Munich, Munich Heart Alliance (MHA), Munich, Germany
| | - Philipp Tomsits
- Department of Medicine I, University Hospital Munich, Campus Grosshadern, Ludwig-Maximilians University Munich (LMU), Munich, Germany.,DZHK (German Centre for Cardiovascular Research), Partner Site Munich, Munich Heart Alliance (MHA), Munich, Germany
| | - Simone Renner
- Institute of Molecular Animal Breeding and Biotechnology, Ludwig-Maximilians University Munich (LMU), Munich, Germany.,DZD (German Centre for Diabetes Research), Neuherberg, Germany
| | - Nikolai Klymiuk
- Institute of Molecular Animal Breeding and Biotechnology, Ludwig-Maximilians University Munich (LMU), Munich, Germany
| | - Reza Wakili
- Universitätsklinikum Essen, Westdeutsches Herz- und Gefäßzentrum Essen, Essen, Germany
| | - Steffen Massberg
- Department of Medicine I, University Hospital Munich, Campus Grosshadern, Ludwig-Maximilians University Munich (LMU), Munich, Germany.,DZHK (German Centre for Cardiovascular Research), Partner Site Munich, Munich Heart Alliance (MHA), Munich, Germany
| | - Eckhard Wolf
- DZHK (German Centre for Cardiovascular Research), Partner Site Munich, Munich Heart Alliance (MHA), Munich, Germany.,Institute of Molecular Animal Breeding and Biotechnology, Ludwig-Maximilians University Munich (LMU), Munich, Germany.,DZD (German Centre for Diabetes Research), Neuherberg, Germany
| | - Stefan Kääb
- Department of Medicine I, University Hospital Munich, Campus Grosshadern, Ludwig-Maximilians University Munich (LMU), Munich, Germany.,DZHK (German Centre for Cardiovascular Research), Partner Site Munich, Munich Heart Alliance (MHA), Munich, Germany
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22
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Hesselkilde EZ, Carstensen H, Flethøj M, Fenner M, Kruse DD, Sattler SM, Tfelt-Hansen J, Pehrson S, Braunstein TH, Carlson J, Platonov PG, Jespersen T, Buhl R. Longitudinal study of electrical, functional and structural remodelling in an equine model of atrial fibrillation. BMC Cardiovasc Disord 2019; 19:228. [PMID: 31638896 PMCID: PMC6805623 DOI: 10.1186/s12872-019-1210-4] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Accepted: 09/26/2019] [Indexed: 06/06/2024] Open
Abstract
Background Large animal models are important in atrial fibrillation (AF) research, as they can be used to study the pathophysiology of AF and new therapeutic approaches. Unlike other animal models, horses spontaneously develop AF and could therefore serve as a bona fide model in AF research. We therefore aimed to study the electrical, functional and structural remodelling caused by chronic AF in a horse model. Method Nine female horses were included in the study, with six horses tachypaced into self-sustained AF and three that served as a time-matched sham-operated control group. Acceleration in atrial fibrillatory rate (AFR), changes in electrocardiographic and echocardiographic variables and response to medical treatment (flecainide 2 mg/kg) were recorded over a period of 2 months. At the end of the study, changes in ion channel expression and fibrosis were measured and compared between the two groups. Results AFR increased from 299 ± 33 fibrillations per minute (fpm) to 376 ± 12 fpm (p < 0.05) and atrial function (active left atrial fractional area change) decreased significantly during the study (p < 0.05). No changes were observed in heart rate or ventricular function. The AF group had more atrial fibrosis compared to the control group (p < 0.05). No differences in ion channel expression were observed. Conclusion Horses with induced AF show signs of atrial remodelling that are similar to humans and other animal models.
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Affiliation(s)
- Eva Zander Hesselkilde
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Højbakkegaard Allé 5, 2630, Taastrup, Denmark
| | - Helena Carstensen
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Højbakkegaard Allé 5, 2630, Taastrup, Denmark
| | - Mette Flethøj
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Højbakkegaard Allé 5, 2630, Taastrup, Denmark
| | - Merle Fenner
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Højbakkegaard Allé 5, 2630, Taastrup, Denmark
| | - Ditte Dybvald Kruse
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200, Copenhagen, Denmark
| | - Stefan M Sattler
- Department of Cardiology, The Heart Centre, Copenhagen University Hospital, Blegdamsvej 9, 2100, Copenhagen, Denmark.,Department of Medicine I, University Hospital Munich, Campus Grosshadern, Ludwig-Maximilians University Munich (LMU), Munich, Germany
| | - Jacob Tfelt-Hansen
- Department of Cardiology, The Heart Centre, Copenhagen University Hospital, Blegdamsvej 9, 2100, Copenhagen, Denmark.,Department of Forensic Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Frederik V's vej 11, 2100, Copenhagen, Denmark
| | - Steen Pehrson
- Department of Cardiology, The Heart Centre, Copenhagen University Hospital, Blegdamsvej 9, 2100, Copenhagen, Denmark
| | - Thomas Hartig Braunstein
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200, Copenhagen, Denmark
| | - Jonas Carlson
- Department of Cardiology, Clinical Sciences, Arrhythmia Clinic, Skåne University Hospital, Lund University, 21185, Lund, Sweden
| | - Pyotr G Platonov
- Department of Cardiology, Clinical Sciences, Arrhythmia Clinic, Skåne University Hospital, Lund University, 21185, Lund, Sweden
| | - Thomas Jespersen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200, Copenhagen, Denmark
| | - Rikke Buhl
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Højbakkegaard Allé 5, 2630, Taastrup, Denmark.
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23
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Yuan Y, Liu X, Wan J, Wong J, Bedwell AA, Persohn SA, Shen C, Fishbein MC, Chen LS, Chen Z, Everett TH, Territo PR, Chen PS. Subcutaneous nerve stimulation for rate control in ambulatory dogs with persistent atrial fibrillation. Heart Rhythm 2019; 16:1383-1391. [PMID: 31150819 DOI: 10.1016/j.hrthm.2019.05.029] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Indexed: 11/27/2022]
Abstract
BACKGROUND Subcutaneous nerve stimulation (ScNS) damages the stellate ganglion and improves rhythm control of atrial fibrillation (AF) in ambulatory dogs. OBJECTIVE The purpose of this study was to test the hypothesis that thoracic ScNS can improve rate control in persistent AF. METHODS We created persistent AF in 13 dogs and randomly assigned them to ScNS (n = 6) and sham control (n = 7) groups. 18F-2-Fluoro-2-deoxyglucose positron emission tomography/magnetic resonance imaging of the brain stem was performed at baseline and at the end of the study. RESULTS The average stellate ganglion nerve activity reduced from 4.00 ± 1.68 μV after the induction of persistent AF to 1.72 ± 0.42 μV (P = .032) after ScNS. In contrast, the average stellate ganglion nerve activity increased from 3.01 ± 1.26 μV during AF to 5.52 ± 2.69 μV after sham stimulation (P = .023). The mean ventricular rate during persistent AF reduced from 149 ± 36 to 84 ± 16 beats/min (P = .011) in the ScNS group, but no changes were observed in the sham control group. The left ventricular ejection fraction remained unchanged in the ScNS group but reduced significantly in the sham control group. Immunostaining showed damaged ganglion cells in bilateral stellate ganglia and increased brain stem glial cell reaction in the ScNS group but not in the control group. The 18F-2-fluoro-2-deoxyglucose uptake in the pons and medulla was significantly (P = .011) higher in the ScNS group than the sham control group at the end of the study. CONCLUSION Thoracic ScNS causes neural remodeling in the brain stem and stellate ganglia, controls the ventricular rate, and preserves the left ventricular ejection fraction in ambulatory dogs with persistent AF.
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Affiliation(s)
- Yuan Yuan
- The Krannert Institute of Cardiology and Division of Cardiology, Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana; Department of Cardiothoracic Surgery, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Xiao Liu
- The Krannert Institute of Cardiology and Division of Cardiology, Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana
| | - Juyi Wan
- The Krannert Institute of Cardiology and Division of Cardiology, Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana; Department of Cardiothoracic Surgery, the Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan Province, China
| | - Johnson Wong
- The Krannert Institute of Cardiology and Division of Cardiology, Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana
| | - Amanda A Bedwell
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, Indiana
| | - Scott A Persohn
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, Indiana
| | - Changyu Shen
- Richard and Susan Smith Center for Outcomes Research in Cardiology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - Michael C Fishbein
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine at UCLA, Los Angeles, California
| | - Lan S Chen
- Department of Neurology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Zhenhui Chen
- The Krannert Institute of Cardiology and Division of Cardiology, Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana
| | - Thomas H Everett
- The Krannert Institute of Cardiology and Division of Cardiology, Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana
| | - Paul R Territo
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, Indiana
| | - Peng-Sheng Chen
- The Krannert Institute of Cardiology and Division of Cardiology, Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana.
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Li B, Luo F, Luo X, Li B, Qi L, Zhang D, Tang Y. Effects of atrial fibrosis induced by mitral regurgitation on atrial electrophysiology and susceptibility to atrial fibrillation in pigs. Cardiovasc Pathol 2019; 40:32-40. [DOI: 10.1016/j.carpath.2019.01.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Revised: 01/22/2019] [Accepted: 01/23/2019] [Indexed: 01/28/2023] Open
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25
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Szatmári V, Ji Y, Herwijnen BV, Feng M, Wang MZ, Bossu A, van der Heyden MAG. Efficacy of pentamidine analogue 6 in dogs with chronic atrial fibrillation. J Vet Intern Med 2018; 32:1549-1554. [PMID: 30079486 PMCID: PMC6189345 DOI: 10.1111/jvim.15242] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Revised: 04/25/2018] [Accepted: 05/21/2018] [Indexed: 01/13/2023] Open
Abstract
Background The inward rectifier inhibitor pentamidine analogue 6 (PA‐6) is effective in cardioversion of goats with persistent rapid pacing induced atrial fibrillation (AF) and is not proarrhythmic in dogs with experimental chronic 3rd‐degree AV block. Efficacy and safety in the clinical setting are unknown. Hypothesis That PA‐6 would be effective in converting AF to sinus rhythm (SR) in dogs with naturally occurring AF, without the presence of overt adverse effects. Animals Ten client‐owned large and giant breed dogs. Methods Animals with persistent or permanent AF were recruited for our prospective study. PA‐6 was administered IV as a bolus of 2.5 mg/kg 10 min−1 followed by a maintenance infusion of 0.04 mg/kg min−1 for a maximum of 50 minutes in conscious dogs. Standard 6 lead limb ECG was recorded during the infusion. Visible and audible signs of adverse effects were scored during the entire procedure. Results PA‐6 did not induce changes in QRS duration (54.7 ± 4.6 versus 56.7 ± 6.1 ms, P = .42), QTc interval (241.1 ± 19.5 versus 258.7 ± 19.8 ms, P = .061) or RR interval (363.4 ± 84.6 versus 440.8 ± 96.3 ms, P = .072) at the end of the bolus. No cardioversion to SR was observed in any dog. Three dogs displayed no adverse effects. Five dogs had premature ventricular depolarizations during PA‐6 infusion on the ECG. Respiratory distress with laryngeal stridor, subtle muscle twitching, and mild generalized muscular weakness were noncardiac adverse effects observed in 5 dogs. Adverse effects resolved spontaneously. Conclusions and Clinical importance Chronic naturally occurring AF in large and giant breed dogs could not be cardioverted to SR by PA‐6.
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Affiliation(s)
- Viktor Szatmári
- Department of Clinical Sciences of Companion Animals, Utrecht University, Utrecht, The Netherlands
| | - Yuan Ji
- Department of Medical Physiology, University Medical Center Utrecht, Utrecht, The Netherlands.,Division of Heart and Lungs, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Bianca van Herwijnen
- Department of Medical Physiology, University Medical Center Utrecht, Utrecht, The Netherlands.,Division of Heart and Lungs, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Mei Feng
- Department of Pharmaceutical Chemistry, School of Pharmacy, The University of Kansas, Lawrence, Kansas
| | - Michael Zhou Wang
- Department of Pharmaceutical Chemistry, School of Pharmacy, The University of Kansas, Lawrence, Kansas
| | - Alexandre Bossu
- Department of Medical Physiology, University Medical Center Utrecht, Utrecht, The Netherlands.,Division of Heart and Lungs, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Marcel A G van der Heyden
- Department of Medical Physiology, University Medical Center Utrecht, Utrecht, The Netherlands.,Division of Heart and Lungs, University Medical Center Utrecht, Utrecht, The Netherlands
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26
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Diness JG, Skibsbye L, Simó-Vicens R, Santos JL, Lundegaard P, Citerni C, Sauter DRP, Bomholtz SH, Svendsen JH, Olesen SP, Sørensen US, Jespersen T, Grunnet M, Bentzen BH. Termination of Vernakalant-Resistant Atrial Fibrillation by Inhibition of Small-Conductance Ca 2+-Activated K + Channels in Pigs. Circ Arrhythm Electrophysiol 2017; 10:CIRCEP.117.005125. [PMID: 29018164 PMCID: PMC5647113 DOI: 10.1161/circep.117.005125] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Accepted: 08/21/2017] [Indexed: 11/17/2022]
Abstract
Supplemental Digital Content is available in the text. Background Evidence has emerged that small-conductance Ca2+-activated K+ (SK) channels constitute a new target for treatment of atrial fibrillation (AF). SK channels are predominantly expressed in the atria as compared with the ventricles. Various marketed antiarrhythmic drugs are limited by ventricular adverse effects and efficacy loss as AF progresses. Methods and Results A total of 43 pigs were used for the studies. AF reversion in conscious long-term tachypaced pigs: Pigs were subjected to atrial tachypacing (7 Hz) until they developed sustained AF that could not be reverted by vernakalant 4 mg/kg (18.8±3.3 days of atrial tachypacing). When the SK channel inhibitor AP14145 was tested in these animals, vernakalant-resistant AF was reverted to sinus rhythm, and reinduction of AF by burst pacing (50 Hz) was prevented in 8 of 8 pigs. Effects on refractory period and AF duration in open chest pigs: The effects of AP14145 and vernakalant on the effective refractory periods and acute burst pacing-induced AF were examined in anaesthetized open chest pigs. Both vernakalant and AP14145 significantly prolonged atrial refractoriness and reduced AF duration without affecting the ventricular refractoriness or blood pressure in pigs subjected to 7 days atrial tachypacing, as well as in sham-operated control pigs. Conclusions SK currents play a role in porcine atrial repolarization, and pharmacological inhibition of these with AP14145 demonstrates antiarrhythmic effects in a vernakalant-resistant porcine model of AF. These results suggest SK channel blockers as potentially interesting anti-AF drugs.
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Affiliation(s)
- Jonas Goldin Diness
- From the Acesion Pharma, Copenhagen, Denmark (J.G.D., R.S.-V., C.C., D.R.P.S., S.H.B., U.S.S., M.G., B.H.B.); Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark (L.S., J.L.S., P.L., D.R.P.S., S.-P.O., T.J., M.G., B.H.B.); and the Heart Centre, Rigshospitalet, Copenhagen, Denmark (J.H.S.).
| | - Lasse Skibsbye
- From the Acesion Pharma, Copenhagen, Denmark (J.G.D., R.S.-V., C.C., D.R.P.S., S.H.B., U.S.S., M.G., B.H.B.); Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark (L.S., J.L.S., P.L., D.R.P.S., S.-P.O., T.J., M.G., B.H.B.); and the Heart Centre, Rigshospitalet, Copenhagen, Denmark (J.H.S.)
| | - Rafel Simó-Vicens
- From the Acesion Pharma, Copenhagen, Denmark (J.G.D., R.S.-V., C.C., D.R.P.S., S.H.B., U.S.S., M.G., B.H.B.); Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark (L.S., J.L.S., P.L., D.R.P.S., S.-P.O., T.J., M.G., B.H.B.); and the Heart Centre, Rigshospitalet, Copenhagen, Denmark (J.H.S.)
| | - Joana Larupa Santos
- From the Acesion Pharma, Copenhagen, Denmark (J.G.D., R.S.-V., C.C., D.R.P.S., S.H.B., U.S.S., M.G., B.H.B.); Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark (L.S., J.L.S., P.L., D.R.P.S., S.-P.O., T.J., M.G., B.H.B.); and the Heart Centre, Rigshospitalet, Copenhagen, Denmark (J.H.S.)
| | - Pia Lundegaard
- From the Acesion Pharma, Copenhagen, Denmark (J.G.D., R.S.-V., C.C., D.R.P.S., S.H.B., U.S.S., M.G., B.H.B.); Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark (L.S., J.L.S., P.L., D.R.P.S., S.-P.O., T.J., M.G., B.H.B.); and the Heart Centre, Rigshospitalet, Copenhagen, Denmark (J.H.S.)
| | - Carlotta Citerni
- From the Acesion Pharma, Copenhagen, Denmark (J.G.D., R.S.-V., C.C., D.R.P.S., S.H.B., U.S.S., M.G., B.H.B.); Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark (L.S., J.L.S., P.L., D.R.P.S., S.-P.O., T.J., M.G., B.H.B.); and the Heart Centre, Rigshospitalet, Copenhagen, Denmark (J.H.S.)
| | - Daniel Rafael Peter Sauter
- From the Acesion Pharma, Copenhagen, Denmark (J.G.D., R.S.-V., C.C., D.R.P.S., S.H.B., U.S.S., M.G., B.H.B.); Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark (L.S., J.L.S., P.L., D.R.P.S., S.-P.O., T.J., M.G., B.H.B.); and the Heart Centre, Rigshospitalet, Copenhagen, Denmark (J.H.S.)
| | - Sofia Hammami Bomholtz
- From the Acesion Pharma, Copenhagen, Denmark (J.G.D., R.S.-V., C.C., D.R.P.S., S.H.B., U.S.S., M.G., B.H.B.); Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark (L.S., J.L.S., P.L., D.R.P.S., S.-P.O., T.J., M.G., B.H.B.); and the Heart Centre, Rigshospitalet, Copenhagen, Denmark (J.H.S.)
| | - Jesper Hastrup Svendsen
- From the Acesion Pharma, Copenhagen, Denmark (J.G.D., R.S.-V., C.C., D.R.P.S., S.H.B., U.S.S., M.G., B.H.B.); Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark (L.S., J.L.S., P.L., D.R.P.S., S.-P.O., T.J., M.G., B.H.B.); and the Heart Centre, Rigshospitalet, Copenhagen, Denmark (J.H.S.)
| | - Søren-Peter Olesen
- From the Acesion Pharma, Copenhagen, Denmark (J.G.D., R.S.-V., C.C., D.R.P.S., S.H.B., U.S.S., M.G., B.H.B.); Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark (L.S., J.L.S., P.L., D.R.P.S., S.-P.O., T.J., M.G., B.H.B.); and the Heart Centre, Rigshospitalet, Copenhagen, Denmark (J.H.S.)
| | - Ulrik S Sørensen
- From the Acesion Pharma, Copenhagen, Denmark (J.G.D., R.S.-V., C.C., D.R.P.S., S.H.B., U.S.S., M.G., B.H.B.); Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark (L.S., J.L.S., P.L., D.R.P.S., S.-P.O., T.J., M.G., B.H.B.); and the Heart Centre, Rigshospitalet, Copenhagen, Denmark (J.H.S.)
| | - Thomas Jespersen
- From the Acesion Pharma, Copenhagen, Denmark (J.G.D., R.S.-V., C.C., D.R.P.S., S.H.B., U.S.S., M.G., B.H.B.); Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark (L.S., J.L.S., P.L., D.R.P.S., S.-P.O., T.J., M.G., B.H.B.); and the Heart Centre, Rigshospitalet, Copenhagen, Denmark (J.H.S.)
| | - Morten Grunnet
- From the Acesion Pharma, Copenhagen, Denmark (J.G.D., R.S.-V., C.C., D.R.P.S., S.H.B., U.S.S., M.G., B.H.B.); Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark (L.S., J.L.S., P.L., D.R.P.S., S.-P.O., T.J., M.G., B.H.B.); and the Heart Centre, Rigshospitalet, Copenhagen, Denmark (J.H.S.)
| | - Bo Hjorth Bentzen
- From the Acesion Pharma, Copenhagen, Denmark (J.G.D., R.S.-V., C.C., D.R.P.S., S.H.B., U.S.S., M.G., B.H.B.); Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark (L.S., J.L.S., P.L., D.R.P.S., S.-P.O., T.J., M.G., B.H.B.); and the Heart Centre, Rigshospitalet, Copenhagen, Denmark (J.H.S.)
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Fibrosis and Atrial Fibrillation: Computerized and Optical Mapping; A View into the Human Atria at Submillimeter Resolution. JACC Clin Electrophysiol 2017; 3:531-546. [PMID: 29159313 DOI: 10.1016/j.jacep.2017.05.002] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Recent studies strongly suggest that the majority of atrial fibrillation (AF) patients with diagnosed or subclinical cardiac diseases have established or even pre-existing fibrotic structural remodeling, which may lead to conduction abnormalities and reentrant activity that sustain AF. As conventional treatments fail to treat AF in far too many cases, an urgent need exists to identify specific structural arrhythmogenic fibrosis patterns, which may maintain AF, in order to identify effective ablation targets for AF treatment. However, the existing challenge is to define what exact structural remodeling within the complex 3D human atrial wall is arrhythmogenic, as well as linking arrhythmogenic fibrosis to an underlying mechanism of AF maintenance in the clinical setting. This review is focused on the role of 3D fibrosis architecture in the mechanisms of AF maintenance revealed by submillimeter, high-resolution ex-vivo imaging modalities directly of human atria, as well as from in-silico 3D computational techniques that can be able to overcome in-vivo clinical limitations. The systematic integration of functional and structural imaging ex-vivo may inform the necessary integration of electrode and structural mapping in-vivo. A holistic view of AF driver mechanisms may begin to identify the defining characteristics or "fingerprints" of reentrant AF drivers, such as 3D fibrotic architecture, in order to design optimal patient-specific ablation strategies.
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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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29
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Varela M, Colman MA, Hancox JC, Aslanidi OV. Atrial Heterogeneity Generates Re-entrant Substrate during Atrial Fibrillation and Anti-arrhythmic Drug Action: Mechanistic Insights from Canine Atrial Models. PLoS Comput Biol 2016; 12:e1005245. [PMID: 27984585 PMCID: PMC5161306 DOI: 10.1371/journal.pcbi.1005245] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Accepted: 11/12/2016] [Indexed: 12/31/2022] Open
Abstract
Anti-arrhythmic drug therapy is a frontline treatment for atrial fibrillation (AF), but its success rates are highly variable. This is due to incomplete understanding of the mechanisms of action of specific drugs on the atrial substrate at different stages of AF progression. We aimed to elucidate the role of cellular, tissue and organ level atrial heterogeneities in the generation of a re-entrant substrate during AF progression, and their modulation by the acute action of selected anti-arrhythmic drugs. To explore the complex cell-to-organ mechanisms, a detailed biophysical models of the entire 3D canine atria was developed. The model incorporated atrial geometry and fibre orientation from high-resolution micro-computed tomography, region-specific atrial cell electrophysiology and the effects of progressive AF-induced remodelling. The actions of multi-channel class III anti-arrhythmic agents vernakalant and amiodarone were introduced in the model by inhibiting appropriate ionic channel currents according to experimentally reported concentration-response relationships. AF was initiated by applied ectopic pacing in the pulmonary veins, which led to the generation of localized sustained re-entrant waves (rotors), followed by progressive wave breakdown and rotor multiplication in both atria. The simulated AF scenarios were in agreement with observations in canine models and patients. The 3D atrial simulations revealed that a re-entrant substrate was typically provided by tissue regions of high heterogeneity of action potential duration (APD). Amiodarone increased atrial APD and reduced APD heterogeneity and was more effective in terminating AF than vernakalant, which increased both APD and APD dispersion. In summary, the initiation and sustenance of rotors in AF is linked to atrial APD heterogeneity and APD reduction due to progressive remodelling. Our results suggest that anti-arrhythmic strategies that increase atrial APD without increasing its dispersion are effective in terminating AF. The mechanisms behind the most common arrhythmia, atrial fibrillation (AF), remain unclear and anti-arrhythmic drug therapy is often ineffective. In this paper, we develop and apply a novel comprehensive 3D model of canine atria to investigate the role of atrial heterogeneity in the mechanisms of AF and anti-arrhythmic drug action. We find that regions of high heterogeneity of action potential duration (APD) throughout the atria typically provide substrate for arrhythmogenic re-entrant waves during both AF initiation and progression. These mechanistic insights are directly linked with the efficacy of two clinically used class III anti-arrhythmic drugs: amiodarone is more effective at terminating AF than vernakalant, because it leads to an increase in atrial APD without increasing its dispersion. Our computational results are consistent with clinical observations and can help explain the superior efficacy of amiodarone in the clinical treatment of AF at late stages. This framework can easily be extended to investigate the action of other anti-arrhythmic drugs and translated to the human atria. By incorporating patient-specific anatomical and electrophysiological information, and after undergoing careful validation, the proposed in silico approach can become a useful tool to evaluate and potentially guide anti-arrhythmic therapy in the clinic.
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Affiliation(s)
- Marta Varela
- Department of Biomedical Engineering, Division of Imaging Sciences and Biomedical Engineering, King’s College London, London, United Kingdom
| | - Michael A. Colman
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| | - Jules C. Hancox
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University of Bristol, Bristol, United Kingdom
| | - Oleg V. Aslanidi
- Department of Biomedical Engineering, Division of Imaging Sciences and Biomedical Engineering, King’s College London, London, United Kingdom
- * E-mail:
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30
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Suksaranjit P, McGann CJ, Akoum N, Biskupiak J, Stoddard GJ, Kholmovski EG, Navaravong L, Rassa A, Bieging E, Chang L, Haider I, Marrouche NF, Wilson BD. Prognostic Implications of Left Ventricular Scar Determined by Late Gadolinium Enhanced Cardiac Magnetic Resonance in Patients With Atrial Fibrillation. Am J Cardiol 2016; 118:991-7. [PMID: 27553101 DOI: 10.1016/j.amjcard.2016.06.054] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Revised: 06/30/2016] [Accepted: 06/30/2016] [Indexed: 11/17/2022]
Abstract
Left ventricular (LV) scar identified by late gadolinium enhanced (LGE) cardiac magnetic resonance (CMR) is associated with adverse outcomes in coronary artery disease and cardiomyopathies. We sought to determine the prognostic significance of LV-LGE in atrial fibrillation (AF). We studied 778 consecutive patients referred for radiofrequency ablation of AF who underwent CMR. Patients with coronary artery disease, previous myocardial infarction, or hypertrophic or dilated cardiomyopathy were excluded. The end points of interest were major adverse cardiac and cerebrovascular events (MACCE), defined as a composite of cardiovascular death, myocardial infarction, and ischemic stroke/transient ischemic attack. Of the 754 patients who met the inclusion criteria, 60% were men with an average age of 64 years. Most (87%) had a normal LV ejection fraction of ≥55%. LV-LGE was found in 46 patients (6%). There were 32 MACCE over the mean follow-up period of 55 months. The MACCE rate was higher for patients with LV-LGE (13.0% vs 3.7%; p = 0.002). In multivariate analysis, CHA2DS2-VASc score (hazard ratio [HR] 1.36, 95% CI 1.05 to 1.76), the presence of LV-LGE (HR 3.21, 95% CI 1.31 to 7.88), and the LV-LGE extent (HR 1.43, 95% CI 1.15 to 1.78) were independent predictors of MACCE. In addition, the presence of LV-LGE was an independent predictor for ischemic stroke/transient ischemic attack (HR 3.61, 95% CI 1.18 to 11.01) after adjusting for CHA2DS2-VASc score. In conclusion, the presence and extent of LV scar identified by LGE-CMR were independent predictors of MACCE in patients with AF.
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Affiliation(s)
- Promporn Suksaranjit
- Division of Cardiovascular Medicine, University of Utah, Salt Lake City, Utah; Comprehensive Arrhythmia Research & Management Center, Salt Lake City, Utah
| | - Christopher J McGann
- Division of Cardiovascular Medicine, University of Utah, Salt Lake City, Utah; Comprehensive Arrhythmia Research & Management Center, Salt Lake City, Utah
| | - Nazem Akoum
- Comprehensive Arrhythmia Research & Management Center, Salt Lake City, Utah; Division of Cardiology, University of Washington, Seattle, Washington
| | - Joseph Biskupiak
- Department of Pharmacotherapy, University of Utah, Salt Lake City, Utah
| | | | - Eugene G Kholmovski
- Comprehensive Arrhythmia Research & Management Center, Salt Lake City, Utah; Utah Center for Advanced Imaging Research, University of Utah, Salt Lake City, Utah
| | | | - Allen Rassa
- Division of Cardiovascular Medicine, University of Utah, Salt Lake City, Utah
| | - Erik Bieging
- Division of Cardiovascular Medicine, University of Utah, Salt Lake City, Utah; Comprehensive Arrhythmia Research & Management Center, Salt Lake City, Utah
| | - Lowell Chang
- Division of Cardiovascular Medicine, University of Utah, Salt Lake City, Utah; Comprehensive Arrhythmia Research & Management Center, Salt Lake City, Utah
| | - Imran Haider
- Division of Cardiovascular Medicine, University of Utah, Salt Lake City, Utah; Comprehensive Arrhythmia Research & Management Center, Salt Lake City, Utah
| | - Nassir F Marrouche
- Division of Cardiovascular Medicine, University of Utah, Salt Lake City, Utah; Comprehensive Arrhythmia Research & Management Center, Salt Lake City, Utah
| | - Brent D Wilson
- Division of Cardiovascular Medicine, University of Utah, Salt Lake City, Utah; Comprehensive Arrhythmia Research & Management Center, Salt Lake City, Utah.
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Angel N, Li LI, Macleod RS, Marrouche N, Ranjan R, Dosdall DJ. Diverse Fibrosis Architecture and Premature Stimulation Facilitate Initiation of Reentrant Activity Following Chronic Atrial Fibrillation. J Cardiovasc Electrophysiol 2015; 26:1352-60. [PMID: 26249367 DOI: 10.1111/jce.12773] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Revised: 07/20/2015] [Accepted: 07/26/2015] [Indexed: 11/26/2022]
Abstract
INTRODUCTION Patients with paroxysmal atrial fibrillation (AF) often transition between sinus rhythm and AF. For AF to initiate there must be both a trigger and a substrate that facilitates reentrant activity. This trigger is often caused by a premature atrial contraction or focal activations within the atrium. We hypothesize that specific architectures of fibrosis alter local conduction to enable AF. METHODS AND RESULTS Control goats (n = 13) and goats in chronic AF (for an average of 6 months, n = 6) had a high-density electrode plaque placed on the LA appendage. Conduction patterns following a premature atrial contraction, caused by an electrical stimulation, were quantified to determine regions of conduction slowing. These regions were compared to architecture, either diffuse fibrosis or regions of obstructive fibrosis, and overall fibrosis levels as determined by histology from the mapped region. The chronic AF goats had more obstructive fibrosis than the controls (17.5 ± 8.0 fibers/mm(2) vs. 8.6 ± 3.0 fibers/mm(2)). Conduction velocity of the AF goats was significantly slowed compared to the control goats in the transverse direction (0.40 ± 0.04 m/s vs. 0.53 ± 0.15 m/s) but not in the longitudinal direction (0.70 ± 0.27 m/s vs. 0.76 ± 0.18 m/s). CONCLUSIONS AF-induced atrial remodeling leads to increased obstructive fibrosis and conduction velocity slowing transverse to fiber orientation following premature stimuli. The decrease in conduction velocity causes a decrease in the cardiac wavelength, and increases the likelihood of reentry and AF onset.
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Affiliation(s)
- Nathan Angel
- Comprehensive Arrhythmia Research & Management Center, Division of Cardiovascular Medicine, Salt Lake City, Utah, USA.,Department of Bioengineering, University of Utah, Salt Lake City, Utah, USA
| | - L I Li
- Comprehensive Arrhythmia Research & Management Center, Division of Cardiovascular Medicine, Salt Lake City, Utah, USA
| | - Rob S Macleod
- Comprehensive Arrhythmia Research & Management Center, Division of Cardiovascular Medicine, Salt Lake City, Utah, USA.,Department of Bioengineering, University of Utah, Salt Lake City, Utah, USA
| | - Nassir Marrouche
- Comprehensive Arrhythmia Research & Management Center, Division of Cardiovascular Medicine, Salt Lake City, Utah, USA.,Center for Engineering Innovation, Salt Lake City, Utah, USA
| | - Ravi Ranjan
- Comprehensive Arrhythmia Research & Management Center, Division of Cardiovascular Medicine, Salt Lake City, Utah, USA.,Department of Bioengineering, University of Utah, Salt Lake City, Utah, USA
| | - Derek J Dosdall
- Comprehensive Arrhythmia Research & Management Center, Division of Cardiovascular Medicine, Salt Lake City, Utah, USA.,Center for Engineering Innovation, Salt Lake City, Utah, USA.,Department of Bioengineering, University of Utah, Salt Lake City, Utah, USA
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32
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Suksaranjit P, Akoum N, Kholmovski EG, Stoddard GJ, Chang L, Damal K, Velagapudi K, Rassa A, Bieging E, Challa S, Haider I, Marrouche NF, McGann CJ, Wilson BD. Incidental LV LGE on CMR Imaging in Atrial Fibrillation Predicts Recurrence After Ablation Therapy. JACC Cardiovasc Imaging 2015; 8:793-800. [DOI: 10.1016/j.jcmg.2015.03.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Revised: 03/11/2015] [Accepted: 03/23/2015] [Indexed: 10/23/2022]
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Wijesurendra R, Casadei B. Atrial supply–demand mismatch in atrial fibrillation: The missing link between rapid rate and atrial remodeling? Heart Rhythm 2015; 12:1001-2. [DOI: 10.1016/j.hrthm.2015.01.036] [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: 01/20/2015] [Indexed: 10/24/2022]
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Abstract
Atrial fibrillation (AF) is the most common sustained clinical arrhythmia and is associated with significant morbidity, mostly secondary to heart failure and stroke, and an estimated two-fold increase in premature death. Efforts to increase our understanding of AF and its complications have focused on unravelling the mechanisms of electrical and structural remodelling of the atrial myocardium. Yet, it is increasingly recognized that AF is more than an atrial disease, being associated with systemic inflammation, endothelial dysfunction, and adverse effects on the structure and function of the left ventricular myocardium that may be prognostically important. Here, we review the molecular and in vivo evidence that underpins current knowledge regarding the effects of human or experimental AF on the ventricular myocardium. Potential mechanisms are explored including diffuse ventricular fibrosis, focal myocardial scarring, and impaired myocardial perfusion and perfusion reserve. The complex relationship between AF, systemic inflammation, as well as endothelial/microvascular dysfunction and the effects of AF on ventricular calcium handling and oxidative stress are also addressed. Finally, consideration is given to the clinical implications of these observations and concepts, with particular reference to rate vs. rhythm control.
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Affiliation(s)
- Rohan S Wijesurendra
- Division of Cardiovascular Medicine, BHF Centre of Research Excellence, University of Oxford, John Radcliffe Hospital, Level 6 West Wing, Oxford OX3 9DU, UK
| | - Barbara Casadei
- Division of Cardiovascular Medicine, BHF Centre of Research Excellence, University of Oxford, John Radcliffe Hospital, Level 6 West Wing, Oxford OX3 9DU, UK
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Kirubakaran S, Chowdhury RA, Hall MCS, Patel PM, Garratt CJ, Peters NS. Fractionation of electrograms is caused by colocalized conduction block and connexin disorganization in the absence of fibrosis as AF becomes persistent in the goat model. Heart Rhythm 2014; 12:397-408. [PMID: 25444850 PMCID: PMC4315883 DOI: 10.1016/j.hrthm.2014.10.027] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2014] [Indexed: 01/25/2023]
Abstract
Background Electrogram fractionation and atrial fibrosis are both thought to be pathophysiological hallmarks of evolving persistence of atrial fibrillation (AF), but recent studies in humans have shown that they do not colocalize. The interrelationship and relative roles of fractionation and fibrotic change in AF persistence therefore remain unclear. Objective The aim of the study was to examine the hypothesis that electrogram fractionation with increasing persistence of AF results from localized conduction slowing or block due to changes in atrial connexin distribution in the absence of fibrotic change. Methods Of 12 goats, atrial burst pacemakers maintained AF in 9 goats for up to 3 consecutive 4-week periods. After each 4-week period, 3 goats underwent epicardial mapping studies of the right atrium and examination of the atrial myocardium for immunodetection of connexins 43 and 40 (Cx43 and Cx40) and quantification of connective tissue. Results Despite refractoriness returning to normal in between each 4-week period of AF, there was a cumulative increase in the prevalence of fractionated atrial electrograms during both atrial pacing (control and 1, 2, and 3 months period of AF 0.3%, 1.3% ± 1.5%, 10.6% ± 2%, and 17% ± 5%, respectively; analysis of variance, P < .05) and AF (0.3% ± 0.1%, 2.3% ± 1.2%, 14% ± 2%, and 23% ± 3%; P < .05) caused by colocalized areas of conduction block during both pacing (local conduction velocity <10 cm/s: 0.1% ± 0.1%, 0.3% ± 0.6%, 6.5% ± 3%, and 6.9% ± 4%; P < .05) and AF (1.5% ± 0.5%, 2.7% ± 1.1%, 10.1% ± 1.2%, and 13.6% ± 0.4%; P < .05), associated with an increase in the heterogeneity of Cx40 and lateralization of Cx43 (lateralization scores: 1.75 ± 0.89, 1.44 ± 0.31, 2.85 ± 0.96, and 2.94 ± 0.31; P < .02), but not associated with change in connective tissue content or net conduction velocity. Conclusion Electrogram fractionation with increasing persistence of AF results from slow localized conduction or block associated with changes in atrial connexin distribution in the absence of fibrotic change.
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Affiliation(s)
- Senthil Kirubakaran
- Manchester Heart Centre, Manchester Royal Infirmary, Manchester, M13 9WL, United Kingdom.
| | | | - Mark C S Hall
- Manchester Heart Centre, Manchester Royal Infirmary, Manchester, M13 9WL, United Kingdom
| | | | - Clifford J Garratt
- Manchester Heart Centre, Manchester Royal Infirmary, Manchester, M13 9WL, United Kingdom
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Koopmann M, Hong KP, Kholmovski EG, Huang EC, Hu N, Ying J, Levenson R, Vijayakumar S, Dosdall DJ, Ranjan R, Kim D. Post-contrast myocardial T(1) and ECV disagree in a longitudinal canine study. NMR IN BIOMEDICINE 2014; 27:988-95. [PMID: 24865566 PMCID: PMC4227501 DOI: 10.1002/nbm.3135] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Revised: 04/02/2014] [Accepted: 04/16/2014] [Indexed: 05/18/2023]
Abstract
Both post-contrast myocardial T1 and extracellular volume (ECV) measurements have been associated with diffuse interstitial fibrosis. The cardiovascular magnetic resonance (CMR) field is migrating towards ECV, because it is largely insensitive to confounders that affect post-contrast myocardial T1 . Despite the theoretical advantages of myocardial ECV over post-contrast myocardial T1 , systematic experimental studies comparing the two measurements are largely lacking. We sought to measure the temporal changes in post-contrast myocardial T1 and ECV in an established canine model with chronic atrial fibrillation. Seventeen mongrel dogs, implanted with a pacemaker to induce chronic atrial fibrillation via rapid atrial pacing, were scanned multiple times for a total of 46 CMR scans at 3T. These dogs with different disease durations (0-22 months) were part of a separate longitudinal study aimed at studying the relationship between AF and pathophysiology. In each animal, we measured native and post-contrast T1 values and hematocrit. Temporal changes in post-contrast myocardial T1 and ECV, as well as other CMR parameters, were modeled with linear mixed effect models to account for repeated measurements over disease duration. In 17 animals, post-contrast myocardial T1 decreased significantly from 872 to 698 ms (p < 0.001), which corresponds to a 24.9% relative reduction. In contrast, ECV increased from 21.0 to 22.0% (p = 0.38), which corresponds to only a 4.5% relative increase. To partially investigate this discrepancy, we quantified collagen volume fraction (CVF) in post-mortem heart tissues of six canines sacrificed at different disease durations (0-22 months). CVF quantified by histology increased from 0.9 to 1.9% (p = 0.56), which agrees better with ECV than with post-contrast myocardial T1 . This study shows that post-contrast myocardial T1 and ECV may disagree in a longitudinal canine study. A more comprehensive study, including histologic, cardiac, and renal functional analyses, is warranted to test rigorously which CMR parameter (ECV or post-contrast myocardial T1 ) agrees better with CVF.
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Affiliation(s)
- Matthias Koopmann
- Division of Electrophysiology, Department of Cardiovascular Medicine, University Hospital of Münster, Münster, Germany
| | - Kyung Pyo Hong
- UCAIR, Department of Radiology, University of Utah, Salt Lake City, UT, 84108
| | | | - Eric C. Huang
- Department of Pathology and Laboratory Medicine, University of California, Davis Medical Center, Sacramento, CA, 95817
| | - Nan Hu
- Division of Epidemiology, Internal Medicine, University of Utah, Salt Lake City, UT, 84112
| | - Jian Ying
- Division of Epidemiology, Internal Medicine, University of Utah, Salt Lake City, UT, 84112
| | - Richard Levenson
- Department of Pathology and Laboratory Medicine, University of California, Davis Medical Center, Sacramento, CA, 95817
| | - Sathya Vijayakumar
- Surgical Services Clinical Program, Intermountain Healthcare, Salt Lake City, UT, 84111
| | - Derek J. Dosdall
- Division of Cardiology, Internal Medicine, University of Utah, Salt Lake City, UT, 84112
| | - Ravi Ranjan
- Division of Cardiology, Internal Medicine, University of Utah, Salt Lake City, UT, 84112
| | - Daniel Kim
- UCAIR, Department of Radiology, University of Utah, Salt Lake City, UT, 84108
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Bassett EC, Kholmovski EG, Wilson BD, DiBella EVR, Dosdall DJ, Ranjan R, McGann CJ, Kim D. Evaluation of highly accelerated real-time cardiac cine MRI in tachycardia. NMR IN BIOMEDICINE 2014; 27:175-182. [PMID: 24259281 DOI: 10.1002/nbm.3049] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2013] [Revised: 10/08/2013] [Accepted: 10/10/2013] [Indexed: 06/02/2023]
Abstract
Electrocardiogram (ECG)-gated breath-hold cine MRI is considered to be the gold standard test for the assessment of cardiac function. However, it may fail in patients with arrhythmia, impaired breath-hold capacity and poor ECG gating. Although ungated real-time cine MRI may mitigate these problems, commercially available real-time cine MRI pulse sequences using parallel imaging typically yield relatively poor spatiotemporal resolution because of their low image acquisition efficiency. As an extension of our previous work, the purpose of this study was to evaluate the diagnostic quality and accuracy of eight-fold-accelerated real-time cine MRI with compressed sensing (CS) for the quantification of cardiac function in tachycardia, where it is challenging for real-time cine MRI to provide sufficient spatiotemporal resolution. We evaluated the performances of eight-fold-accelerated cine MRI with CS, three-fold-accelerated real-time cine MRI with temporal generalized autocalibrating partially parallel acquisitions (TGRAPPA) and ECG-gated breath-hold cine MRI in 21 large animals with tachycardia (mean heart rate, 104 beats per minute) at 3T. For each cine MRI method, two expert readers evaluated the diagnostic quality in four categories (image quality, temporal fidelity of wall motion, artifacts and apparent noise) using a Likert scale (1-5, worst to best). One reader evaluated the left ventricular functional parameters. The diagnostic quality scores were significantly different between the three cine pulse sequences, except for the artifact level between CS and TGRAPPA real-time cine MRI. Both ECG-gated breath-hold cine MRI and eight-fold accelerated real-time cine MRI yielded all four scores of ≥ 3.0 (acceptable), whereas three-fold-accelerated real-time cine MRI yielded all scores below 3.0, except for artifact (3.0). The left ventricular ejection fraction (LVEF) measurements agreed better between ECG-gated cine MRI and eight-fold-accelerated real-time cine MRI (mean difference, -1.6%) than between ECG-gated cine MRI and three-fold-accelerated real-time cine MRI (mean difference, -5.7%). Eight-fold-accelerated real-time cine MRI with CS yields acceptable diagnostic quality and relatively accurate LVEF measurements in the challenging setting of tachycardia.
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Affiliation(s)
- Elwin C Bassett
- Department of Physics, University of Utah, Salt Lake City, UT, USA; UCAIR, Department of Radiology, University of Utah, Salt Lake City, UT, USA
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