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Iness AN, Shah KM, Kukreja RC. Physiological effects of ivabradine in heart failure and beyond. Mol Cell Biochem 2023:10.1007/s11010-023-04862-5. [PMID: 37768496 DOI: 10.1007/s11010-023-04862-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Accepted: 09/14/2023] [Indexed: 09/29/2023]
Abstract
Ivabradine is a pharmacologic agent that inhibits the funny current responsible for determining heart rate in the sinoatrial node. Ivabradine's clinical potential has been investigated in the context of heart failure since it is associated with reduced myocardial oxygen demand, enhanced diastolic filling, stroke volume, and coronary perfusion time; however, it is yet to demonstrate definitive mortality benefit. Alternative effects of ivabradine include modulation of the renin-angiotensin-aldosterone system, sympathetic activation, and endothelial function. Here, we review key clinical trials informing the clinical use of ivabradine and explore opportunities for leveraging its potential pleiotropic effects in other diseases, including treatment of hyperadrenergic states and mitigating complications of COVID-19 infection.
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Affiliation(s)
- Audra N Iness
- Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA
| | - Keyur M Shah
- Division of Cardiology, Pauley Heart Center, Internal Medicine, Virginia Commonwealth University, Richmond, VA, USA
| | - Rakesh C Kukreja
- Division of Cardiology, Pauley Heart Center, Internal Medicine, Virginia Commonwealth University, Richmond, VA, USA.
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Fontenla A, Tamargo J, Salgado R, López-Gil M, Mejía E, Matía R, Toquero J, Montilla I, Rajjoub EA, García-Fernandez FJ, Miracle A, Rey JR, Bueno H. Ivabradine for controlling heart rate in permanent atrial fibrillation: A translational clinical trial. Heart Rhythm 2023; 20:822-830. [PMID: 37245897 DOI: 10.1016/j.hrthm.2023.02.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 02/10/2023] [Accepted: 02/13/2023] [Indexed: 05/30/2023]
Abstract
BACKGROUND Pharmacological options for rate control in atrial fibrillation are scarce. Ivabradine was postulated to reduce the ventricular rate in this setting. OBJECTIVES The objectives of this study were to evaluate the mechanism of inhibition of atrioventricular conduction produced by ivabradine and to determine its efficacy and safety in atrial fibrillation. METHODS The effects of ivabradine on atrioventricular node and ventricular cells were studied by in vitro whole-cell patch-clamp experiments and mathematical simulation of human action potentials. In parallel, a multicenter, randomized, open-label, phase III clinical trial compared ivabradine with digoxin for uncontrolled permanent atrial fibrillation despite β-blocker or calcium channel blocker treatment. RESULTS Ivabradine 1 μM inhibited "funny" current and rapidly activating delayed rectifier potassium channel current by 28.9% and 22.8%, respectively (P < .05). The sodium channel current and L-type calcium channel current were reduced only at 10 μM. Ivabradine slowed the firing frequency of a modeled human atrioventricular node action potential by 10.6% and induced a minimal prolongation of ventricular action potential. Thirty-five (51.5%) patients were randomized to ivabradine and 33 (49.5%) to digoxin. The mean daytime heart rate decreased by 11.6 beats/min (-11.5%) in the ivabradine arm (P = .02) vs 19.6 (-20.6%) in the digoxin arm (P < .001), although the noninferiority margin of efficacy was not met (Z = -1.95; P = .97). The primary safety end point occurred in 3 patients (8.6%) on ivabradine and in 8 (24.2%) on digoxin (P = .10). CONCLUSION Ivabradine produced a moderate rate reduction in patients with permanent atrial fibrillation. The inhibition of funny current in the atrioventricular node seems to be the main mechanism responsible for this reduction. Compared with digoxin, ivabradine was less effective, was better tolerated, and had a similar rate of serious adverse events.
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Affiliation(s)
- Adolfo Fontenla
- Cardiology Department, Hospital Universitario Quironsalud Madrid, Madrid, Spain; Cardiology Department. Complejo Hospitalario Ruber Juan Bravo, Madrid, Spain; Research Institute Hospital Universitario 12 de Octubre (I+12), Madrid, Spain.
| | - Juan Tamargo
- Pharmacology and Toxicology Department, School of Medicine, Universidad Complutense de Madrid, Madrid Spain
| | - Ricardo Salgado
- Cardiology Department, Hospital Clínico Universitario San Carlos, Madrid, Spain
| | - María López-Gil
- Research Institute Hospital Universitario 12 de Octubre (I+12), Madrid, Spain
| | - Elena Mejía
- Cardiology Department, Hospital Universitario Rey Juan Carlos, Móstoles, Spain
| | - Roberto Matía
- Cardiology Department, Hospital Universitario Ramón y Cajal, Madrid, Spain
| | - Jorge Toquero
- Cardiology Department, Hospital Universitario Puerta de Hierro, Majadahonda, Spain
| | - Isabel Montilla
- Cardiology Department, Hospital Clínico Universitario Lozano Blesa, Zaragoza, Spain
| | - Ez-Alddin Rajjoub
- Research Institute Hospital Universitario 12 de Octubre (I+12), Madrid, Spain
| | | | - Angel Miracle
- Cardiology Department, Hospital Universitario Fundación Jiménez Díaz, Madrid, Spain
| | - Juan-Ramón Rey
- Cardiology Department, Hospital Universitario La Paz, Madrid, Spain
| | - Hector Bueno
- Research Institute Hospital Universitario 12 de Octubre (I+12), Madrid, Spain; Centro de Investigación Biomédica en Red de Enfermedades Cardiovasculares (CIBERCV), Carlos III Health Institute, Madrid, Spain; Medicine Department, School of Medicine, Universidad Complutense de Madrid, Madrid, Spain; Centro Nacional de Investigaciones Cardiovasculares (CNIC), Madrid, Spain
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Zhang H, Li L, Hao M, Chen K, Lu Y, Qi J, Chen W, Ren L, Cai X, Chen C, Liu Z, Zhao B, Li Z, Hou P. Yixin-Fumai granules improve sick sinus syndrome in aging mice through Nrf-2/HO-1 pathway: A new target for sick sinus syndrome. J Ethnopharmacol 2021; 277:114254. [PMID: 34062246 DOI: 10.1016/j.jep.2021.114254] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 05/13/2021] [Accepted: 05/25/2021] [Indexed: 06/12/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Yixin-Fumai granules (YXFMs)-composed of Ginseng quinquefolium (L.) Alph. Wood, Ophiopogon japonicus (Thunb.) Ker Gawl, Schisandra arisanensis Hayata, Astragalus aaronsohnianus Eig, Salvia cryptantha Montbret & Aucher ex Benth, and Ligusticum striatum DC-are compound granules used in traditional Chinese medicine to increase heart rate and thus treat bradyarrhythmia. It may be effective in treating sick sinus syndrome (SSS). AIM To observe the effect of YXFMs on aging-induced SSS in mice and explore whether this effect is related to the Nrf-2/HO-1 signaling pathway. MATERIALS AND METHODS Mice with a significant decrease in the heart rate due to natural aging were selected to construct an SSS model. After the mice were administered YXFMs, the damage to their sinoartrial node (SAN) was assessed through electrocardiography, Masson's trichrome staining, and terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL). Dihydroethidium staining and immunofluorescence staining were used to assay reactive oxygen species (ROS) content and HCN4, respectively. Moreover, to observe the effects of YXFMs in vitro, the HL-1 cell line, derived from mouse atrial myocytes, was used to simulate SAN pacemaker cells, with H2O2 used as the cellular oxidative stress (OS) inducer. 2,7-Dichlorodihydrofluorescein diacetate staining was used to assay ROS content, whereas immunofluorescence staining and Western blotting were used to elucidate the related protein expression. Finally, mice were injected the Nrf-2 inhibitor ML385 to reversely verify the effects of YXFMs. RESULTS In our in vivo experiments, YXFMs significantly inhibited aging-induced SSS, shortened the R-R interval, increased heart rate, alleviated fibrosis, reduced apoptosis rate and ROS content, and promote HCN4 expression in the SAN. In our in vitro experiments, YXFMs significantly inhibited H2O2-induced cell peroxidation damage, promoted Nrf-2 activation and nuclear metastasis, increased HO-1 expression- thereby inhibiting ROS accumulation-and finally, upregulated HCN4 expression through the inhibition of histone deacetylase 4 (HDAC4) expression and its nuclear metastasis. Finally, injection of the Nrf-2 inhibitor ML385 after YXFMs administration inhibited their protective effect in the mice. CONCLUSION Here, we elaborated on the relationship between aging-induced SSS and the Nrf-2/HO-1 pathway for the first time and proposed that YXFMs improve SSS via the Nrf-2/HO-1 axis. Specifically, YXFMs promoted Nrf-2 activation and plasma-nuclear transfer to enhance HO-1 expression via the Nrf-2/HO-1 axis. This inhibited OS and reduced ROS accumulation in the SAN, and then, through the ROS/HDAC4 axis, reduced HDAC4 expression and plasma-nuclear transfer. Thereby, the OS-induced HCN4 loss in the SAN was inhibited-improving the function of If channel and thus producing SAN protection effect against SSS and improving the heart rate and R-R interval. In the future, we plan to use bioinformatics analysis technology to execute the next step of our research, namely to determine the effect of isolated, purified components of YXFMs in SSS, to increase its efficiency and reduce the toxicity of YXFMs.
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Affiliation(s)
- Heng Zhang
- Liaoning University of Traditional Chinese Medicine, Shenyang, 110000, China
| | - Lingkang Li
- Liaoning University of Traditional Chinese Medicine, Shenyang, 110000, China
| | - Miao Hao
- Liaoning University of Traditional Chinese Medicine, Shenyang, 110000, China
| | - Keyan Chen
- Department of Laboratory Animal Science, China Medical University, Shenyang, 110000, China
| | - Yongping Lu
- Department of NHC Key Laboratory of Reproductive Health and Medical Genetics, Liaoning Research Institute of Family Planning (The Affiliated Reproductive Hospital of China Medical University), Shenyang, 110000, China
| | - Jing Qi
- Department of Cardiology, Affiliated Hospital of Liaoning University of Traditional Chinese Medicine, Shenyang, 110000, China
| | - Wei Chen
- Department of Cardiology, Affiliated Hospital of Liaoning University of Traditional Chinese Medicine, Shenyang, 110000, China
| | - Lu Ren
- Liaoning University of Traditional Chinese Medicine, Shenyang, 110000, China; Department of Cardiology, Affiliated Hospital of Liaoning University of Traditional Chinese Medicine, Shenyang, 110000, China
| | - Xintong Cai
- Liaoning University of Traditional Chinese Medicine, Shenyang, 110000, China
| | - Chen Chen
- Liaoning University of Traditional Chinese Medicine, Shenyang, 110000, China
| | - Zhuang Liu
- Liaoning University of Traditional Chinese Medicine, Shenyang, 110000, China
| | - Bin Zhao
- Liaoning University of Traditional Chinese Medicine, Shenyang, 110000, China
| | - Zhishuang Li
- Liaoning University of Traditional Chinese Medicine, Shenyang, 110000, China
| | - Ping Hou
- Liaoning University of Traditional Chinese Medicine, Shenyang, 110000, China; Department of Cardiology, Affiliated Hospital of Liaoning University of Traditional Chinese Medicine, Shenyang, 110000, China.
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DiFrancesco ML, Mesirca P, Bidaud I, Isbrandt D, Mangoni ME. The funny current in genetically modified mice. Prog Biophys Mol Biol 2021; 166:39-50. [PMID: 34129872 DOI: 10.1016/j.pbiomolbio.2021.06.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 05/18/2021] [Accepted: 06/07/2021] [Indexed: 12/27/2022]
Abstract
Since its first description in 1979, the hyperpolarization-activated funny current (If) has been the object of intensive research aimed at understanding its role in cardiac pacemaker activity and its modulation by the sympathetic and parasympathetic branches of the autonomic nervous system. If was described in isolated tissue strips of the rabbit sinoatrial node using the double-electrode voltage-clamp technique. Since then, the rabbit has been the principal animal model for studying pacemaker activity and If for more than 20 years. In 2001, the first study describing the electrophysiological properties of mouse sinoatrial pacemaker myocytes and those of If was published. It was soon followed by the description of murine myocytes of the atrioventricular node and the Purkinje fibres. The sinoatrial node of genetically modified mice has become a very popular model for studying the mechanisms of cardiac pacemaker activity. This field of research benefits from the impressive advancement of in-vivo exploration techniques of physiological parameters, imaging, genetics, and large-scale genomic approaches. The present review discusses the influence of mouse genetic on the most recent knowledge of the funny current's role in the physiology and pathophysiology of cardiac pacemaker activity. Genetically modified mice have provided important insights into the role of If in determining intrinsic automaticity in vivo and in myocytes of the conduction system. In addition, gene targeting of f-(HCN) channel isoforms have contributed to elucidating the current's role in the regulation of heart rate by the parasympathetic nervous system. This review is dedicated to Dario DiFrancesco on his retirement.
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Affiliation(s)
- Mattia L DiFrancesco
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Genoa, Italy; IRCCS Ospedale Policlinico San Martino, Genoa, Italy; Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, Montpellier, France; LabEx Ion Channels Science and Therapeutics (ICST), France.
| | - Pietro Mesirca
- Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, Montpellier, France; LabEx Ion Channels Science and Therapeutics (ICST), France
| | - Isabelle Bidaud
- Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, Montpellier, France; LabEx Ion Channels Science and Therapeutics (ICST), France
| | - Dirk Isbrandt
- Deutsches Zentrum für Neurodegenerative Erktankungen (DZNE), Bonn, Germany; University of Cologne, Institute for Molecular and Behavioral Neuroscience, Cologne, Germany
| | - Matteo E Mangoni
- Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, Montpellier, France; LabEx Ion Channels Science and Therapeutics (ICST), France.
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Giannetti F, Benzoni P, Campostrini G, Milanesi R, Bucchi A, Baruscotti M, Dell'Era P, Rossini A, Barbuti A. A detailed characterization of the hyperpolarization-activated "funny" current (I f) in human-induced pluripotent stem cell (iPSC)-derived cardiomyocytes with pacemaker activity. Pflugers Arch 2021; 473:1009-1021. [PMID: 33934225 PMCID: PMC8245366 DOI: 10.1007/s00424-021-02571-w] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 04/01/2021] [Accepted: 04/19/2021] [Indexed: 01/09/2023]
Abstract
Properties of the funny current (If) have been studied in several animal and cellular models, but so far little is known concerning its properties in human pacemaker cells. This work provides a detailed characterization of If in human-induced pluripotent stem cell (iPSC)–derived pacemaker cardiomyocytes (pCMs), at different time points. Patch-clamp analysis showed that If density did not change during differentiation; however, after day 30, it activates at more negative potential and with slower time constants. These changes are accompanied by a slowing in beating rate. If displayed the voltage-dependent block by caesium and reversed (Erev) at − 22 mV, compatibly with the 3:1 K+/Na+ permeability ratio. Lowering [Na+]o (30 mM) shifted the Erev to − 39 mV without affecting conductance. Increasing [K+]o (30 mM) shifted the Erev to − 15 mV with a fourfold increase in conductance. pCMs express mainly HCN4 and HCN1 together with the accessory subunits CAV3, KCR1, MiRP1, and SAP97 that contribute to the context-dependence of If. Autonomic agonists modulated the diastolic depolarization, and thus rate, of pCMs. The adrenergic agonist isoproterenol induced rate acceleration and a positive shift of If voltage-dependence (EC50 73.4 nM). The muscarinic agonists had opposite effects (Carbachol EC50, 11,6 nM). Carbachol effect was however small but it could be increased by pre-stimulation with isoproterenol, indicating low cAMP levels in pCMs. In conclusion, we demonstrated that pCMs display an If with the physiological properties expected by pacemaker cells and may thus represent a suitable model for studying human If-related sinus arrhythmias.
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Affiliation(s)
- Federica Giannetti
- The Cell Physiology MiLab, Department of Biosciences, Università degli Studi di Milano, Via Celoria 26, 20133, Milano, Italy
| | - Patrizia Benzoni
- The Cell Physiology MiLab, Department of Biosciences, Università degli Studi di Milano, Via Celoria 26, 20133, Milano, Italy
| | - Giulia Campostrini
- The Cell Physiology MiLab, Department of Biosciences, Università degli Studi di Milano, Via Celoria 26, 20133, Milano, Italy
- Department of Anatomy and Embryology, Leiden University Medical Center, Einthovenweg 20, 2333ZC, Leiden, The Netherlands
| | - Raffaella Milanesi
- The Cell Physiology MiLab, Department of Biosciences, Università degli Studi di Milano, Via Celoria 26, 20133, Milano, Italy
- Dipartimento di Medicina Veterinaria, Università degli Studi di Milano, Via dell'Università 6, 26900, Lodi, Italy
| | - Annalisa Bucchi
- The Cell Physiology MiLab, Department of Biosciences, Università degli Studi di Milano, Via Celoria 26, 20133, Milano, Italy
| | - Mirko Baruscotti
- The Cell Physiology MiLab, Department of Biosciences, Università degli Studi di Milano, Via Celoria 26, 20133, Milano, Italy
| | - Patrizia Dell'Era
- Cellular Fate Reprogramming Unit, Department of Molecular and Translational Medicine, University of Brescia, viale Europa 11, 25123, Brescia, Italy
| | - Alessandra Rossini
- Institute for Biomedicine, Eurac Research, Affiliated Institute of the University of Lübeck, Viale Druso 1, 39100, Bolzano, Italy
| | - Andrea Barbuti
- The Cell Physiology MiLab, Department of Biosciences, Università degli Studi di Milano, Via Celoria 26, 20133, Milano, Italy.
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Erlenhardt N, Kletke O, Wohlfarth F, Komadowski MA, Clasen L, Makimoto H, Rinné S, Kelm M, Jungen C, Decher N, Meyer C, Klöcker N. Disease-associated HCN4 V759I variant is not sufficient to impair cardiac pacemaking. Pflugers Arch 2020; 472:1733-42. [PMID: 33095298 DOI: 10.1007/s00424-020-02481-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 09/11/2020] [Accepted: 10/16/2020] [Indexed: 11/16/2022]
Abstract
The hyperpolarization-activated cation current If is a key determinant for cardiac pacemaker activity. It is conducted by subunits of the hyperpolarization-activated cyclic nucleotide–gated (HCN) channel family, of which HCN4 is predominant in mammalian heart. Both loss-of-function and gain-of-function mutations of the HCN4 gene are associated with sinus node dysfunction in humans; however, their functional impact is not fully understood yet. Here, we sought to characterize a HCN4 V759I variant detected in a patient with a family history of sick sinus syndrome. The genomic analysis yielded a mono-allelic HCN4 V759I variant in a 49-year-old woman presenting with a family history of sick sinus syndrome. This HCN4 variant was previously classified as putatively pathogenic because genetically linked to sudden infant death syndrome and malignant epilepsy. However, detailed electrophysiological and cell biological characterization of HCN4 V759I in Xenopus laevis oocytes and embryonic rat cardiomyocytes, respectively, did not reveal any obvious abnormality. Voltage dependence and kinetics of mutant channel activation, modulation of cAMP-gating by the neuronal HCN channel auxiliary subunit PEX5R, and cell surface expression were indistinguishable from wild-type HCN4. In good agreement, the clinically likewise affected mother of the patient does not exhibit the reported HCN4 variance. HCN4 V759I resembles an innocuous genetic HCN channel variant, which is not sufficient to disturb cardiac pacemaking. Once more, our work emphasizes the importance of careful functional interpretation of genetic findings not only in the context of hereditary cardiac arrhythmias.
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Chakraborty P, Rose RA, Nair K, Downar E, Nanthakumar K. The rationale for repurposing funny current inhibition for management of ventricular arrhythmia. Heart Rhythm 2020; 18:130-137. [PMID: 32738405 DOI: 10.1016/j.hrthm.2020.07.031] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 07/14/2020] [Accepted: 07/25/2020] [Indexed: 11/26/2022]
Abstract
Management of ventricular arrhythmia in structural heart disease is complicated by the toxicity of the limited antiarrhythmic options available. In others, proarrhythmia and deleterious hemodynamic and noncardiac effects prevent practical use. This necessitates new thinking in therapeutic agents for ventricular arrhythmia in structural heart disease. Ivabradine, a funny current (If) inhibitor, has proven safety in heart failure, angina, and inappropriate sinus tachycardia. Although it is commonly known that funny channels are primarily expressed in the sinoatrial node, atrioventricular node, and conducting system of the ventricle, ivabradine is known to exert effects on metabolism, ion homeostasis, and membrane electrophysiology of remodeled ventricular myocardium. This review considers novel concepts and evidence from clinical and experimental studies regarding this paradigm, with a potential role of ivabradine in ventricular arrhythmia.
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Affiliation(s)
- Praloy Chakraborty
- The Hull Family Cardiac Fibrillation Management Laboratory, Toronto General Hospital, University Health Network, Toronto, Ontario, Canada; University Health Network, Toronto, Ontario, Canada
| | - Robert A Rose
- Libin Cardiovascular Institute of Alberta, An entity of the University of Calgary and Alberta Health Services, Calgary, Alberta, Canada
| | - Krishnakumar Nair
- The Hull Family Cardiac Fibrillation Management Laboratory, Toronto General Hospital, University Health Network, Toronto, Ontario, Canada; University Health Network, Toronto, Ontario, Canada
| | - Eugene Downar
- The Hull Family Cardiac Fibrillation Management Laboratory, Toronto General Hospital, University Health Network, Toronto, Ontario, Canada; University Health Network, Toronto, Ontario, Canada
| | - Kumaraswamy Nanthakumar
- The Hull Family Cardiac Fibrillation Management Laboratory, Toronto General Hospital, University Health Network, Toronto, Ontario, Canada; University Health Network, Toronto, Ontario, Canada.
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Aziz Q, Nobles M, Tinker A. Whole-cell and Perforated Patch-clamp Recordings from Acutely-isolated Murine Sino-atrial Node Cells. Bio Protoc 2020; 10:e3478. [PMID: 33654711 PMCID: PMC7842407 DOI: 10.21769/bioprotoc.3478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Revised: 11/19/2019] [Accepted: 11/28/2019] [Indexed: 11/02/2022] Open
Abstract
Cardiac pacemaker cells of the sino-atrial node are responsible for the initiation of the heart beat and express an array of ion channels. The patch-clamp technique is the gold standard method for investigating the function of ion channels expressed in electrically active cells. Conventional whole-cell and perforated patch-clamp techniques can be used to investigate ionic currents in the voltage-clamp mode and changes in membrane potential (e.g., action potential) in the current-clamp mode. Here, we provide details of protocols used to measure spontaneous and triggered action potentials and whole-cell funny current If (HCN4) in single cardiomyocytes isolated from the mouse sino-atrial node (SAN).
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Affiliation(s)
- Qadeer Aziz
- Clinical Pharmacology, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - Muriel Nobles
- Clinical Pharmacology, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - Andrew Tinker
- Clinical Pharmacology, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK
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Zhou Y, Wang J, Meng Z, Zhou S, Peng J, Chen S, Wang Q, Sun K. Pharmacology of Ivabradine and the Effect on Chronic Heart Failure. Curr Top Med Chem 2019; 19:1878-1901. [PMID: 31400267 DOI: 10.2174/1568026619666190809093144] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2019] [Revised: 07/02/2019] [Accepted: 07/25/2019] [Indexed: 11/22/2022]
Abstract
Chronic Heart Failure (CHF) is a complex clinical syndrome with a high incidence worldwide. Although various types of pharmacological and device therapies are available for CHF, the prognosis is not ideal, for which, the control of increased Heart Rate (HR) is critical. Recently, a bradycardic agent, ivabradine, is found to reduce HR by inhibiting the funny current (If). The underlying mechanism states that ivabradine can enter the Hyperpolarization-activated Cyclic Nucleotide-gated (HCN) channels and bind to the intracellular side, subsequently inhibiting the If. This phenomenon can prolong the slow spontaneous phase in the diastolic depolarization, and thus, reduce HR. The clinical trials demonstrated the significant effects of the drug on reducing HR and improving the symptoms of CHF with fewer adverse effects. This review primarily introduces the chemical features and pharmacological characteristics of ivabradine and the mechanism of treating CHF. Also, some expected therapeutic effects on different diseases were also concluded. However, ivabradine, as a typical If channel inhibitor, necessitates additional research to verify its pharmacological functions.
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Affiliation(s)
- Yue Zhou
- Department of Pediatric Cardiology, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200092, China
| | - Jian Wang
- Department of Pediatric Cardiology, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200092, China
| | - Zhuo Meng
- Department of Pediatric Cardiology, the Second Affiliated Hospital&Yuying Children's Hospital of Wenzhou Medical University, Wenzhou 325000, China
| | - Shuang Zhou
- Department of Pediatric Cardiology, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200092, China
| | - Jiayu Peng
- Department of Pediatric Cardiology, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200092, China
| | - Sun Chen
- Department of Pediatric Cardiology, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200092, China
| | - Qingjie Wang
- Department of Pediatric Cardiology, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200092, China
| | - Kun Sun
- Department of Pediatric Cardiology, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200092, China
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Mengesha HG, Weldearegawi B, Petrucka P, Bekele T, Otieno MG, Hailu A. Effect of ivabradine on cardiovascular outcomes in patients with stable angina: meta-analysis of randomized clinical trials. BMC Cardiovasc Disord 2017; 17:105. [PMID: 28454527 PMCID: PMC5410064 DOI: 10.1186/s12872-017-0540-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2016] [Accepted: 04/22/2017] [Indexed: 11/24/2022] Open
Abstract
Background Although there are established drugs for treatment of cardiovascular diseases, due to adverse effects these drugs may not be clinically applicable to all patients. Recent trends have seen the emergence of drugs which act on funny current channels to induce selective heart rate reduction. Ivabradine is one such drug developed for coronary artery disease and heart failure. There is inconsistent evidence about the effect of this selective inhibitor in reduction of cardiovascular related mortality and morbidity. Such an inconsistency warrants the need for a meta-analysis to consider the effectiveness and efficacy of Ivabradine in the treatment of coronary artery disease and heart failure. Methods Randomized controlled trials with a minimum follow-up period of one year were searched in Pub Med/Medline, Embase, Cochrane Central Register of Controlled Trials published between 1980 and 2016.Each eligible study was assessed for risk of bias by using the Cochrane Risk of Bias Assessment tool. The outcomes assessed in this study included: all cause mortality, cardiovascular-related mortality, hospitalization for new or worsening heart failure, and adverse events. Subgroup analysis and publication bias were assessed. We used Mantel-Haenszel method for random-effects. Analysis was done using RevMan5.1™.This study was registered in PROSPERO as [PROSPERO 2016:CRD42016035597]. Result Three trials with a total of 36,577 participants met the meta-analysis criteria. Pooled analysis showed that ivabradine is not effective in reducing cardiovascular deaths (OR: 1.02; CI:0.91–1.15,P = 0.74), all-cause mortality (OR:1.00; CI:0.91–1.10,P = 0.98), coronary revascularization (OR: 0.93, CI: 0.77–1.11, P = 0.41) and hospital admission for worsening of heart failure (OR: 0.94, CI: 0.71–1.25, P = 0.69). However, the drug was found to significantly increase adverse events: phosphenes (OR:7.77, CI: 4.4–14.6,P < 0.00001), blurred vision (OR:3.07,CI:2.18–4.32,P < 0.00001), symptomatic bradycardia (OR: 6.23, CI: 4.2–9.26, P < 0.00001), and atrial fibrillation (OR: 1.35, CI: 1.19–1.53, P < 0.0001). Subgroup analysis by duration of follow up on cardiovascular outcomes found that there is no difference in effect of ivabradine depending on the duration of follow up. There was no publication bias in reporting of included studies. Conclusion This meta-analysis suggests that ivabradine is not effective in reducing cardiovascular-related morbidity and mortality unless used for specific conditions. On the contrary, the use of this drug was strongly associated with the onset of untoward and new adverse events. This finding strongly supports previous findings and further informs the rational and evidence-informed clinical use of ivabradine. Electronic supplementary material The online version of this article (doi:10.1186/s12872-017-0540-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | - Berhe Weldearegawi
- College of Health Science, School of Public Health, Mekelle University, Mekelle, Ethiopia
| | - Pammala Petrucka
- College of Nursing; Adjunct Nelson Mandela African Institute of Science and Technology, University of Saskatchewan, Saskatoon, Canada
| | - Tadese Bekele
- College of Health Science, Department of Pharmacy, Haramaya University, Harar, Ethiopia
| | - Mala George Otieno
- College of Health Science, Department of Medical Biochemistry, Mekelle University, Mekelle, Ethiopia
| | - Abraha Hailu
- College of Health Science, Department of Internal Medicine, Mekelle University, Mekelle, Ethiopia
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11
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Ravagli E, Bucchi A, Bartolucci C, Paina M, Baruscotti M, DiFrancesco D, Severi S. Cell-specific Dynamic Clamp analysis of the role of funny If current in cardiac pacemaking. Prog Biophys Mol Biol 2015; 120:50-66. [PMID: 26718599 DOI: 10.1016/j.pbiomolbio.2015.12.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Revised: 11/18/2015] [Accepted: 12/16/2015] [Indexed: 01/01/2023]
Abstract
We used the Dynamic Clamp technique for i) comparative validation of conflicting computational models of the hyperpolarization-activated funny current, If, and ii) quantification of the role of If in mediating autonomic modulation of heart rate. Experimental protocols based on the injection of a real-time recalculated synthetic If current in sinoatrial rabbit cells were developed. Preliminary results of experiments mimicking the autonomic modulation of If demonstrated the need for a customization procedure to compensate for cellular heterogeneity. For this reason, we used a cell-specific approach, scaling the maximal conductance of the injected current based on the cell's spontaneous firing rate. The pacemaking rate, which was significantly reduced after application of Ivabradine, was restored by the injection of synthetic current based on the Severi-DiFrancesco formulation, while the injection of synthetic current based on the Maltsev-Lakatta formulation did not produce any significant variation. A positive virtual shift of the If activation curve, mimicking the Isoprenaline effects, led to a significant increase in pacemaking rate (+17.3 ± 6.7%, p < 0.01), although of lower magnitude than that induced by real Isoprenaline (+45.0 ± 26.1%). Similarly, a negative virtual shift of the activation curve significantly lowered the pacemaking rate (-11.8 ± 1.9%, p < 0.001), as did the application of real Acetylcholine (-20.5 ± 5.1%). The Dynamic Clamp approach, applied to the If study in cardiomyocytes for the first time and rate-adapted to manage intercellular variability, indicated that: i) the quantitative description of the If current in the Severi-DiFrancesco model accurately reproduces the effects of the real current on rabbit sinoatrial cell pacemaking rate and ii) a significant portion (50-60%) of the physiological autonomic rate modulation is due to the shift of the If activation curve.
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Affiliation(s)
- E Ravagli
- Computational Physiopathology Unit, Laboratory of Cellular and Molecular Engineering, D.E.I., University of Bologna, Via Venezia 52, 47521 Cesena, Italy
| | - A Bucchi
- The PaceLab, Department of Biosciences, University of Milan, Via Celoria 26, 20133 Milano, Italy
| | - C Bartolucci
- Computational Physiopathology Unit, Laboratory of Cellular and Molecular Engineering, D.E.I., University of Bologna, Via Venezia 52, 47521 Cesena, Italy
| | - M Paina
- The PaceLab, Department of Biosciences, University of Milan, Via Celoria 26, 20133 Milano, Italy
| | - M Baruscotti
- The PaceLab, Department of Biosciences, University of Milan, Via Celoria 26, 20133 Milano, Italy
| | - D DiFrancesco
- The PaceLab, Department of Biosciences, University of Milan, Via Celoria 26, 20133 Milano, Italy
| | - S Severi
- Computational Physiopathology Unit, Laboratory of Cellular and Molecular Engineering, D.E.I., University of Bologna, Via Venezia 52, 47521 Cesena, Italy.
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Capel RA, Herring N, Kalla M, Yavari A, Mirams GR, Douglas G, Bub G, Channon K, Paterson DJ, Terrar DA, Burton RAB. Hydroxychloroquine reduces heart rate by modulating the hyperpolarization-activated current If: Novel electrophysiological insights and therapeutic potential. Heart Rhythm 2015; 12:2186-94. [PMID: 26025323 PMCID: PMC4689153 DOI: 10.1016/j.hrthm.2015.05.027] [Citation(s) in RCA: 86] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Indexed: 01/01/2023]
Abstract
BACKGROUND Bradycardic agents are of interest for the treatment of ischemic heart disease and heart failure, as heart rate is an important determinant of myocardial oxygen consumption. OBJECTIVES The purpose of this study was to investigate the propensity of hydroxychloroquine (HCQ) to cause bradycardia. METHODS We assessed the effects of HCQ on (1) cardiac beating rate in vitro (mice); (2) the "funny" current (If) in isolated guinea pig sinoatrial node (SAN) myocytes (1, 3, 10 µM); (3) heart rate and blood pressure in vivo by acute bolus injection (rat, dose range 1-30 mg/kg), (4) blood pressure and ventricular function during feeding (mouse, 100 mg/kg/d for 2 wk, tail cuff plethysmography, anesthetized echocardiography). RESULTS In mouse atria, spontaneous beating rate was significantly (P < .05) reduced (by 9% ± 3% and 15% ± 2% at 3 and 10 µM HCQ, n = 7). In guinea pig isolated SAN cells, HCQ conferred a significant reduction in spontaneous action potential firing rate (17% ± 6%, 1 μM dose) and a dose-dependent reduction in If (13% ± 3% at 1 µM; 19% ± 2% at 3 µM). Effects were also observed on L-type calcium ion current (ICaL) (12% ± 4% reduction) and rapid delayed rectifier potassium current (IKr) (35% ± 4%) at 3 µM. Intravenous HCQ decreased heart rate in anesthetized rats (14.3% ± 1.1% at 15mg/kg; n = 6) without significantly reducing mean arterial blood pressure. In vivo feeding studies in mice showed no significant change in systolic blood pressure nor left ventricular function. CONCLUSIONS We have shown that HCQ acts as a bradycardic agent in SAN cells, in atrial preparations, and in vivo. HCQ slows the rate of spontaneous action potential firing in the SAN through multichannel inhibition, including that of If.
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Affiliation(s)
- Rebecca A Capel
- Department of Pharmacology, University of Oxford, Oxford, United Kingdom
| | - Neil Herring
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Manish Kalla
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Arash Yavari
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, John Radcliffe Hospital, Oxford, United Kingdom
| | - Gary R Mirams
- Department of Computer Science, University of Oxford, Oxford, United Kingdom
| | - Gillian Douglas
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, John Radcliffe Hospital, Oxford, United Kingdom
| | - Gil Bub
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Keith Channon
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, John Radcliffe Hospital, Oxford, United Kingdom
| | - David J Paterson
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Derek A Terrar
- Department of Pharmacology, University of Oxford, Oxford, United Kingdom
| | - Rebecca-Ann B Burton
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom.
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13
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Kim JJ, Yang L, Lin B, Zhu X, Sun B, Kaplan AD, Bett GCL, Rasmusson RL, London B, Salama G. Mechanism of automaticity in cardiomyocytes derived from human induced pluripotent stem cells. J Mol Cell Cardiol 2015; 81:81-93. [PMID: 25644533 DOI: 10.1016/j.yjmcc.2015.01.013] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Revised: 11/26/2014] [Accepted: 01/15/2015] [Indexed: 10/24/2022]
Abstract
BACKGROUND AND OBJECTIVES The creation of cardiomyocytes derived from human induced pluripotent stem cells (hiPS-CMs) has spawned broad excitement borne out of the prospects to diagnose and treat cardiovascular diseases based on personalized medicine. A common feature of hiPS-CMs is their spontaneous contractions but the mechanism(s) remain uncertain. METHODS Intrinsic activity was investigated by the voltage-clamp technique, optical mapping of action potentials (APs) and intracellular Ca(2+) (Cai) transients (CaiT) at subcellular-resolution and pharmacological interventions. RESULTS The frequency of spontaneous CaiT (sCaiT) in monolayers of hiPS-CMs was not altered by ivabradine, an inhibitor of the pacemaker current, If despite high levels of HCN transcripts (1-4). HiPS-CMs had negligible If and IK1 (inwardly-rectifying K(+)-current) and a minimum diastolic potential of -59.1±3.3mV (n=18). APs upstrokes were preceded by a depolarizing-foot coincident with a rise of Cai. Subcellular Cai wavelets varied in amplitude, propagated and died-off; larger Cai-waves triggered cellular sCaTs and APs. SCaiTs increased in frequency with [Ca(2+)]out (0.05-to-1.8mM), isoproterenol (1μM) or caffeine (100μM) (n≥5, p<0.05). HiPS-CMs became quiescent with ryanodine receptor stabilizers (K201=2μM); tetracaine; Na-Ca exchange (NCX) inhibition (SEA0400=2μM); higher [K(+)]out (5→8mM), and thiol-reducing agents but could still be electrically stimulated to elicit CaiTs. Cell-cell coupling of hiPS-CM in monolayers was evident from connexin-43 expression and CaiT propagation. SCaiTs from an ensemble of dispersed hiPS-CMs were out-of-phase but became synchronous through the outgrowth of inter-connecting microtubules. CONCLUSIONS Automaticity in hiPS-CMs originates from a Ca(2+)-clock mechanism involving Ca(2+) cycling across the sarcoplasmic reticulum linked to NCX to trigger APs.
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Affiliation(s)
- Jong J Kim
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15261, USA; Department of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Lei Yang
- Department of Developmental Biology, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Bo Lin
- Department of Developmental Biology, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Xiaodong Zhu
- University of Iowa, Carver College of Medicine, Division of Cardiovascular Medicine, Iowa City, IA 52242, USA
| | - Bin Sun
- Department of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Aaron D Kaplan
- Center for Cellular and Systems Electrophysiology, University at Buffalo, State University of New York, Buffalo, NY 14214, USA
| | - Glenna C L Bett
- Center for Cellular and Systems Electrophysiology, University at Buffalo, State University of New York, Buffalo, NY 14214, USA; Departments of Physiology and Biophysics, University at Buffalo, State University of New York, Buffalo, NY 14214, USA; Departments of Gynecology-Obstetrics, University at Buffalo, State University of New York, Buffalo, NY 14214, USA
| | - Randall L Rasmusson
- Center for Cellular and Systems Electrophysiology, University at Buffalo, State University of New York, Buffalo, NY 14214, USA; Departments of Physiology and Biophysics, University at Buffalo, State University of New York, Buffalo, NY 14214, USA
| | - Barry London
- University of Iowa, Carver College of Medicine, Division of Cardiovascular Medicine, Iowa City, IA 52242, USA
| | - Guy Salama
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15261, USA; Department of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA.
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