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Calvet C, Seebeck P. What to consider for ECG in mice-with special emphasis on telemetry. Mamm Genome 2023; 34:166-179. [PMID: 36749381 PMCID: PMC10290603 DOI: 10.1007/s00335-023-09977-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Accepted: 01/16/2023] [Indexed: 02/08/2023]
Abstract
Genetically or surgically altered mice are commonly used as models of human cardiovascular diseases. Electrocardiography (ECG) is the gold standard to assess cardiac electrophysiology as well as to identify cardiac phenotypes and responses to pharmacological and surgical interventions. A variety of methods are used for mouse ECG acquisition under diverse conditions, making it difficult to compare different results. Non-invasive techniques allow only short-term data acquisition and are prone to stress or anesthesia related changes in cardiac activity. Telemetry offers continuous long-term acquisition of ECG data in conscious freely moving mice in their home cage environment. Additionally, it allows acquiring data 24/7 during different activities, can be combined with different challenges and most telemetry systems collect additional physiological parameters simultaneously. However, telemetry transmitters require surgical implantation, the equipment for data acquisition is relatively expensive and analysis of the vast number of ECG data is challenging and time-consuming. This review highlights the limits of non-invasive methods with respect to telemetry. In particular, primary screening using non-invasive methods can give a first hint; however, subtle cardiac phenotypes might be masked or compensated due to anesthesia and stress during these procedures. In addition, we detail the key differences between the mouse and human ECG. It is crucial to consider these differences when analyzing ECG data in order to properly translate the insights gained from murine models to human conditions.
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Affiliation(s)
- Charlotte Calvet
- Zurich Integrative Rodent Physiology (ZIRP), University of Zurich, Zurich, Switzerland
| | - Petra Seebeck
- Zurich Integrative Rodent Physiology (ZIRP), University of Zurich, Zurich, Switzerland
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2
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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: 26] [Impact Index Per Article: 13.0] [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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Shiels HA. Avian cardiomyocyte architecture and what it reveals about the evolution of the vertebrate heart. Philos Trans R Soc Lond B Biol Sci 2022; 377:20210332. [PMID: 36189815 PMCID: PMC9527935 DOI: 10.1098/rstb.2021.0332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Accepted: 04/02/2022] [Indexed: 11/17/2022] Open
Abstract
Bird cardiomyocytes are long, thin and lack transverse (t)-tubules, which is akin to the cardiomyocyte morphology of ectothermic non-avian reptiles, who are typified by low maximum heart rates and low pressure development. However, birds can achieve greater contractile rates and developed pressures than mammals, whose wide cardiomyocytes contain a dense t-tubular network allowing for uniform excitation-contraction coupling and strong contractile force. To address this apparent paradox, this paper functionally links recent electrophysiological studies on bird cardiomyocytes with decades of ultrastructure measurements. It shows that it is the strong transsarcolemmal Ca2+ influx via the L-type Ca2+ current (ICaL) and the high gain of Ca2+-induced Ca2+ release from the sarcoplasmic reticulum (SR), coupled with an internal SR Ca2+ release relay system, that facilitates the strong fast contractions in the long thin bird cardiomyocytes, without the need for t-tubules. The maintenance of an elongated myocyte morphology following the post-hatch transition from ectothermy to endothermy in birds is discussed in relation to cardiac load, myocyte ploidy, and cardiac regeneration potential in adult cardiomyocytes. Overall, the paper shows how little we know about cellular Ca2+ dynamics in the bird heart and suggests how increased research efforts in this area would provide vital information in our quest to understand the role of myocyte architecture in the evolution of the vertebrate heart. This article is part of the theme issue 'The cardiomyocyte: new revelations on the interplay between architecture and function in growth, health, and disease'. Please see glossary at the end of the paper for definitions of specialized terms.
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Affiliation(s)
- Holly A. Shiels
- Division of Cardiovascular Sciences, Faculty of Biology Medicine and Health, University of Manchester, Manchester, UK
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Simultaneous triple-parametric optical mapping of transmembrane potential, intracellular calcium and NADH for cardiac physiology assessment. Commun Biol 2022; 5:319. [PMID: 35388167 PMCID: PMC8987030 DOI: 10.1038/s42003-022-03279-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Accepted: 03/15/2022] [Indexed: 11/08/2022] Open
Abstract
Investigation of the complex relationships and dependencies of multiple cellular processes that govern cardiac physiology and pathophysiology requires simultaneous dynamic assessment of multiple parameters. In this study, we introduce triple-parametric optical mapping to simultaneously image metabolism, electrical excitation, and calcium signaling from the same field of view and demonstrate its application in the field of drug testing and cardiovascular research. We applied this metabolism-excitation-contraction coupling (MECC) methodology to test the effects of blebbistatin, 4-aminopyridine and verapamil on cardiac physiology. While blebbistatin and 4-aminopyridine alter multiple aspects of cardiac function suggesting off-target effects, the effects of verapamil were on-target and it altered only one of ten tested parameters. Triple-parametric optical mapping was also applied during ischemia and reperfusion; and we identified that metabolic changes precede the effects of ischemia on cardiac electrophysiology.
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Cumberland MJ, Riebel LL, Roy A, O’Shea C, Holmes AP, Denning C, Kirchhof P, Rodriguez B, Gehmlich K. Basic Research Approaches to Evaluate Cardiac Arrhythmia in Heart Failure and Beyond. Front Physiol 2022; 13:806366. [PMID: 35197863 PMCID: PMC8859441 DOI: 10.3389/fphys.2022.806366] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Accepted: 01/10/2022] [Indexed: 12/20/2022] Open
Abstract
Patients with heart failure often develop cardiac arrhythmias. The mechanisms and interrelations linking heart failure and arrhythmias are not fully understood. Historically, research into arrhythmias has been performed on affected individuals or in vivo (animal) models. The latter however is constrained by interspecies variation, demands to reduce animal experiments and cost. Recent developments in in vitro induced pluripotent stem cell technology and in silico modelling have expanded the number of models available for the evaluation of heart failure and arrhythmia. An agnostic approach, combining the modalities discussed here, has the potential to improve our understanding for appraising the pathology and interactions between heart failure and arrhythmia and can provide robust and validated outcomes in a variety of research settings. This review discusses the state of the art models, methodologies and techniques used in the evaluation of heart failure and arrhythmia and will highlight the benefits of using them in combination. Special consideration is paid to assessing the pivotal role calcium handling has in the development of heart failure and arrhythmia.
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Affiliation(s)
- Max J. Cumberland
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Leto L. Riebel
- Department of Computer Science, University of Oxford, Oxford, United Kingdom
| | - Ashwin Roy
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Christopher O’Shea
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Andrew P. Holmes
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
- Institute of Clinical Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Chris Denning
- Stem Cell Biology Unit, Biodiscovery Institute, British Heart Foundation Centre for Regenerative Medicine, University of Nottingham, Nottingham, United Kingdom
| | - Paulus Kirchhof
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
- University Heart and Vascular Center, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Blanca Rodriguez
- Department of Computer Science, University of Oxford, Oxford, United Kingdom
| | - Katja Gehmlich
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
- Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford and British Heart Foundation Centre of Research Excellence Oxford, Oxford, United Kingdom
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6
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Boukens BJD, Joyce W, Kristensen DL, Hooijkaas I, Jongejan A, Wang T, Jensen B. Catecholamines are key modulators of ventricular repolarization patterns in the ball python (Python regius). J Gen Physiol 2022; 154:212914. [PMID: 34910097 PMCID: PMC8679508 DOI: 10.1085/jgp.202012761] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 10/28/2021] [Accepted: 11/19/2021] [Indexed: 12/13/2022] Open
Abstract
Ectothermic vertebrates experience daily changes in body temperature, and anecdotal observations suggest these changes affect ventricular repolarization such that the T-wave in the ECG changes polarity. Mammals, in contrast, can maintain stable body temperatures, and their ventricular repolarization is strongly modulated by changes in heart rate and by sympathetic nervous system activity. The aim of this study was to assess the role of body temperature, heart rate, and circulating catecholamines on local repolarization gradients in the ectothermic ball python (Python regius). We recorded body-surface electrocardiograms and performed open-chest high-resolution epicardial mapping while increasing body temperature in five pythons, in all of which there was a change in T-wave polarity. However, the vector of repolarization differed between individuals, and only a subset of leads revealed T-wave polarity change. RNA sequencing revealed regional differences related to adrenergic signaling. In one denervated and Ringer's solution-perfused heart, heating and elevated heart rates did not induce change in T-wave polarity, whereas noradrenaline did. Accordingly, electrocardiograms in eight awake pythons receiving intra-arterial infusion of the β-adrenergic receptor agonists adrenaline and isoproterenol revealed T-wave inversion in most individuals. Conversely, blocking the β-adrenergic receptors using propranolol prevented T-wave change during heating. Our findings indicate that changes in ventricular repolarization in ball pythons are caused by increased tone of the sympathetic nervous system, not by changes in temperature. Therefore, ventricular repolarization in both pythons and mammals is modulated by evolutionary conserved mechanisms involving catecholaminergic stimulation.
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Affiliation(s)
- Bastiaan J D Boukens
- University of Amsterdam, Amsterdam UMC, Department of Medical Biology, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands
| | - William Joyce
- Department of Biology, Zoophysiology, Aarhus University, Aarhus, Denmark
| | | | - Ingeborg Hooijkaas
- University of Amsterdam, Amsterdam UMC, Department of Medical Biology, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands
| | - Aldo Jongejan
- University of Amsterdam, Amsterdam UMC, Department of Epidemiology & Data Science, Amsterdam, The Netherlands
| | - Tobias Wang
- Department of Biology, Zoophysiology, Aarhus University, Aarhus, Denmark
| | - Bjarke Jensen
- University of Amsterdam, Amsterdam UMC, Department of Medical Biology, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands
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7
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Short B. Catecholamines help snakes have a change of heart. J Gen Physiol 2022; 154:e202213079. [PMID: 35061017 PMCID: PMC8789091 DOI: 10.1085/jgp.202213079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
JGP study on python snakes reveals that the regulation of ventricular repolarization by the sympathetic nervous system is evolutionarily conserved.
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