1
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Lewetag RD, Nimani S, Alerni N, Hornyik T, Jacobi SF, Moss R, Menza M, Pilia N, Walz TP, HajiRassouliha A, Perez-Feliz S, Zehender M, Seemann G, Zgierski-Johnston CM, Lopez R, Odening KE. Mechano-electrical interactions and heterogeneities in wild-type and drug-induced long QT syndrome rabbits. J Physiol 2024; 602:4511-4527. [PMID: 37082830 DOI: 10.1113/jp284604] [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: 02/27/2023] [Accepted: 04/18/2023] [Indexed: 04/22/2023] Open
Abstract
Electromechanical reciprocity - comprising electro-mechanical (EMC) and mechano-electric coupling (MEC) - provides cardiac adaptation to changing physiological demands. Understanding electromechanical reciprocity and its impact on function and heterogeneity in pathological conditions - such as (drug-induced) acquired long QT syndrome (aLQTS) - might lead to novel insights in arrhythmogenesis. Our aim is to investigate how electrical changes impact on mechanical function (EMC) and vice versa (MEC) under physiological conditions and in aLQTS. To measure regional differences in EMC and MEC in vivo, we used tissue phase mapping cardiac MRI and a 24-lead ECG vest in healthy (control) and IKr-blocker E-4031-induced aLQTS rabbit hearts. MEC was studied in vivo by acutely increasing cardiac preload, and ex vivo by using voltage optical mapping (OM) in beating hearts at different preloads. In aLQTS, electrical repolarization (heart rate corrected RT-interval, RTn370) was prolonged compared to control (P < 0.0001) with increased spatial and temporal RT heterogeneity (P < 0.01). Changing electrical function (in aLQTS) resulted in significantly reduced diastolic mechanical function and prolonged contraction duration (EMC), causing increased apico-basal mechanical heterogeneity. Increased preload acutely prolonged RTn370 in both control and aLQTS hearts (MEC). This effect was more pronounced in aLQTS (P < 0.0001). Additionally, regional RT-dispersion increased in aLQTS. Motion-correction allowed us to determine APD-prolongation in beating aLQTS hearts, but limited motion correction accuracy upon preload-changes prevented a clear analysis of MEC ex vivo. Mechano-induced RT-prolongation and increased heterogeneity were more pronounced in aLQTS than in healthy hearts. Acute MEC effects may play an additional role in LQT-related arrhythmogenesis, warranting further mechanistic investigations. KEY POINTS: Electromechanical reciprocity comprising excitation-contraction coupling (EMC) and mechano-electric feedback loops (MEC) is essential for physiological cardiac function. Alterations in electrical and/or mechanical heterogeneity are known to have potentially pro-arrhythmic effects. In this study, we aimed to investigate how electrical changes impact on the mechanical function (EMC) and vice versa (MEC) both under physiological conditions (control) and in acquired long QT syndrome (aLQTS). We show that changing the electrical function (in aLQTS) results in significantly altered mechanical heterogeneity via EMC and, vice versa, that increasing the preload acutely prolongs repolarization duration and increases electrical heterogeneity, particularly in aLQTS as compared to control. Our results substantiate the hypothesis that LQTS is an ‛electro-mechanical', rather than a 'purely electrical', disease and suggest that acute MEC effects may play an additional role in LQT-related arrhythmogenesis.
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Affiliation(s)
- Raphaela D Lewetag
- Department of Cardiology and Angiology I, University Heart Center Freiburg, University Medical Center Freiburg, Freiburg, Germany
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg - Bad Krozingen and Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Saranda Nimani
- Translational Cardiology, Department of Cardiology and Department of Physiology, University Hospital Bern, Bern, Switzerland
| | - Nicolò Alerni
- Translational Cardiology, Department of Cardiology and Department of Physiology, University Hospital Bern, Bern, Switzerland
| | - Tibor Hornyik
- Department of Cardiology and Angiology I, University Heart Center Freiburg, University Medical Center Freiburg, Freiburg, Germany
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg - Bad Krozingen and Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Translational Cardiology, Department of Cardiology and Department of Physiology, University Hospital Bern, Bern, Switzerland
| | - Simon F Jacobi
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg - Bad Krozingen and Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Department of Congenital Heart Defects and Pediatric Cardiology, University Heart Center Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Robin Moss
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg - Bad Krozingen and Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Fraunhofer Institute for High-Speed Dynamics, Ernst-Mach-Institute EMI, Freiburg, Germany
| | - Marius Menza
- Department of Radiology, Medical Physics, University Hospital Freiburg, and Faculty of Medicine, University of Freiburg, Germany
| | - Nicolas Pilia
- Karlsruhe Institute of Technology, Karlsruhe, Germany
| | - Teo P Walz
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg - Bad Krozingen and Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Fraunhofer Institute for High-Speed Dynamics, Ernst-Mach-Institute EMI, Freiburg, Germany
| | | | - Stefanie Perez-Feliz
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg - Bad Krozingen and Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Manfred Zehender
- Department of Cardiology and Angiology I, University Heart Center Freiburg, University Medical Center Freiburg, Freiburg, Germany
| | - Gunnar Seemann
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg - Bad Krozingen and Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Callum M Zgierski-Johnston
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg - Bad Krozingen and Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Ruben Lopez
- Translational Cardiology, Department of Cardiology and Department of Physiology, University Hospital Bern, Bern, Switzerland
| | - Katja E Odening
- Department of Cardiology and Angiology I, University Heart Center Freiburg, University Medical Center Freiburg, Freiburg, Germany
- Translational Cardiology, Department of Cardiology and Department of Physiology, University Hospital Bern, Bern, Switzerland
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2
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Odening KE. Interactions between KCNQ1 and KCNH2 may modulate the long QT type 1 phenotype. Cardiovasc Res 2024; 120:673-674. [PMID: 38630861 DOI: 10.1093/cvr/cvae074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2024] [Revised: 03/15/2024] [Accepted: 03/17/2024] [Indexed: 04/19/2024] Open
Affiliation(s)
- Katja E Odening
- Translational Cardiology, Department of Cardiology and Department of Physiology, University Hospital Bern, University of Bern, Bühlplatz 5, 3012 Bern, Switzerland
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3
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Sedation and anaesthetic strategies during cardiac electrophysiology studies and ablation. Eur J Anaesthesiol 2022; 39:956-960. [DOI: 10.1097/eja.0000000000001750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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4
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Moss R, Wülfers EM, Lewetag R, Hornyik T, Perez-Feliz S, Strohbach T, Menza M, Krafft A, Odening KE, Seemann G. A computational model of rabbit geometry and ECG: Optimizing ventricular activation sequence and APD distribution. PLoS One 2022; 17:e0270559. [PMID: 35771854 PMCID: PMC9246225 DOI: 10.1371/journal.pone.0270559] [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: 07/12/2021] [Accepted: 06/13/2022] [Indexed: 11/19/2022] Open
Abstract
Computational modeling of electrophysiological properties of the rabbit heart is a commonly used way to enhance and/or complement findings from classic lab work on single cell or tissue levels. Yet, thus far, there was no possibility to extend the scope to include the resulting body surface potentials as a way of validation or to investigate the effect of certain pathologies. Based on CT imaging, we developed the first openly available computational geometrical model not only of the whole heart but also the complete torso of the rabbit. Additionally, we fabricated a 32-lead ECG-vest to record body surface potential signals of the aforementioned rabbit. Based on the developed geometrical model and the measured signals, we then optimized the activation sequence of the ventricles, recreating the functionality of the Purkinje network, and we investigated different apico-basal and transmural gradients in action potential duration. Optimization of the activation sequence resulted in an average root mean square error between measured and simulated signal of 0.074 mV/ms for all leads. The best-fit T-Wave, compared to measured data (0.038 mV/ms), resulted from incorporating an action potential duration gradient from base to apex with a respective shortening of 20 ms and a transmural gradient with a shortening of 15 ms from endocardium to epicardium. By making our model and measured data openly available, we hope to give other researchers the opportunity to verify their research, as well as to create the possibility to investigate the impact of electrophysiological alterations on body surface signals for translational research.
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Affiliation(s)
- Robin Moss
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg ⋅ Bad Krozingen, Medical Center—University of Freiburg, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
- * E-mail:
| | - Eike M. Wülfers
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg ⋅ Bad Krozingen, Medical Center—University of Freiburg, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Raphaela Lewetag
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg ⋅ Bad Krozingen, Medical Center—University of Freiburg, Freiburg, Germany
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Medical Faculty, Freiburg, Germany
| | - Tibor Hornyik
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg ⋅ Bad Krozingen, Medical Center—University of Freiburg, Freiburg, Germany
- Translational Cardiology, Department of Cardiology and Department of Physiology, University Hospital Bern, Bern, Switzerland
| | - Stefanie Perez-Feliz
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg ⋅ Bad Krozingen, Medical Center—University of Freiburg, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Medical Faculty, Freiburg, Germany
| | - Tim Strohbach
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Department of Radiology, Medical Physics, University Medical Center Freiburg, Freiburg, Germany
| | - Marius Menza
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Department of Radiology, Medical Physics, University Medical Center Freiburg, Freiburg, Germany
| | - Axel Krafft
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Department of Radiology, Medical Physics, University Medical Center Freiburg, Freiburg, Germany
| | - Katja E. Odening
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Medical Faculty, Freiburg, Germany
- Translational Cardiology, Department of Cardiology and Department of Physiology, University Hospital Bern, Bern, Switzerland
| | - Gunnar Seemann
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg ⋅ Bad Krozingen, Medical Center—University of Freiburg, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
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5
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Crotti L, Odening KE, Sanguinetti MC. Heritable arrhythmias associated with abnormal function of cardiac potassium channels. Cardiovasc Res 2021; 116:1542-1556. [PMID: 32227190 DOI: 10.1093/cvr/cvaa068] [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: 12/20/2019] [Revised: 02/24/2020] [Accepted: 03/26/2020] [Indexed: 12/16/2022] Open
Abstract
Cardiomyocytes express a surprisingly large number of potassium channel types. The primary physiological functions of the currents conducted by these channels are to maintain the resting membrane potential and mediate action potential repolarization under basal conditions and in response to changes in the concentrations of intracellular sodium, calcium, and ATP/ADP. Here, we review the diversity and functional roles of cardiac potassium channels under normal conditions and how heritable mutations in the genes encoding these channels can lead to distinct arrhythmias. We briefly review atrial fibrillation and J-wave syndromes. For long and short QT syndromes, we describe their genetic basis, clinical manifestation, risk stratification, traditional and novel therapeutic approaches, as well as insights into disease mechanisms provided by animal and cellular models.
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Affiliation(s)
- Lia Crotti
- Center for Cardiac Arrhythmias of Genetic Origin, Istituto Auxologico Italiano, IRCCS, Milan, Italy.,Laboratory of Cardiovascular Genetics, Istituto Auxologico Italiano, IRCCS, Milan, Italy.,Department of Cardiovascular, Neural and Metabolic Sciences, Istituto Auxologico Italiano, IRCCS, San Luca Hospital, Milan, Italy.,Department of Medicine and Surgery, University of Milano-Bicocca, Milan, Italy
| | - Katja E Odening
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Medical Faculty, Freiburg, Germany.,Institute of Experimental Cardiovascular Medicine, Heart Center University of Freiburg, Medical Faculty, Freiburg, Germany.,Department of Cardiology, Translational Cardiology, Inselspital, Bern University Hospital, and Institute of Physiology, University of Bern, Bern, Switzerland
| | - Michael C Sanguinetti
- Department of Internal Medicine, Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, UT, USA
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6
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Ellermann C, Wolfes J, Eckardt L, Frommeyer G. Role of the rabbit whole-heart model for electrophysiologic safety pharmacology of non-cardiovascular drugs. Europace 2021; 23:828-836. [PMID: 33200170 DOI: 10.1093/europace/euaa288] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Accepted: 08/27/2020] [Indexed: 11/13/2022] Open
Abstract
Plenty of non-cardiovascular drugs alter cardiac electrophysiology and may ultimately lead to life-threatening arrhythmias. In clinical practice, measuring the QT interval as a marker for the repolarization period is the most common tool to assess the electrophysiologic safety of drugs. However, the sole measurement of the QT interval may be insufficient to determine the proarrhythmic risk of non-cardiovascular agents. Several other markers are considered in pre-clinical safety testing to determine potential harm on cardiac electrophysiology. Besides measuring typical electrophysiologic parameters such as repolarization duration, whole-heart models allow the determination of potential predictors for proarrhythmia. Spatial and temporal heterogeneity as well as changes of shape of the action potential can be easily assessed. In addition, provocation manoeuvers (either by electrolyte imbalances or programmed pacing protocols) may induce sustained arrhythmias and thereby determine ventricular vulnerability to arrhythmias. Compared with the human heart, the rabbit heart possesses a similar distribution of ion currents that govern cardiac repolarization, resulting in a rectangular action potential configuration in both species. In addition, similar biophysical properties of rabbit and human cardiac ion channels lead to a comparable pharmacologic response in human and rabbit hearts. Of note, arrhythmia patterns resemble in both species due to the similar effective size of human and rabbit hearts. Thus, the rabbit heart is particularly suitable for testing the electrophysiologic safety of drugs. Several experimental setups have been developed for studying cardiac electrophysiology in rabbits, ranging from single cell to tissue preparations, whole-heart setups, and in vivo models.
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Affiliation(s)
- Christian Ellermann
- Department of Cardiology II (Electrophysiology), University Hospital Münster, Albert-Schweitzer-Campus 1, Münster D-48149, Germany
| | - Julian Wolfes
- Department of Cardiology II (Electrophysiology), University Hospital Münster, Albert-Schweitzer-Campus 1, Münster D-48149, Germany
| | - Lars Eckardt
- Department of Cardiology II (Electrophysiology), University Hospital Münster, Albert-Schweitzer-Campus 1, Münster D-48149, Germany
| | - Gerrit Frommeyer
- Department of Cardiology II (Electrophysiology), University Hospital Münster, Albert-Schweitzer-Campus 1, Münster D-48149, Germany
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7
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Hornyik T, Rieder M, Castiglione A, Major P, Baczko I, Brunner M, Koren G, Odening KE. Transgenic rabbit models for cardiac disease research. Br J Pharmacol 2021; 179:938-957. [PMID: 33822374 DOI: 10.1111/bph.15484] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 02/23/2021] [Accepted: 03/11/2021] [Indexed: 12/20/2022] Open
Abstract
To study the pathophysiology of human cardiac diseases and to develop novel treatment strategies, complex interactions of cardiac cells on cellular, tissue and on level of the whole heart need to be considered. As in vitro cell-based models do not depict the complexity of the human heart, animal models are used to obtain insights that can be translated to human diseases. Mice are the most commonly used animals in cardiac research. However, differences in electrophysiological and mechanical cardiac function and a different composition of electrical and contractile proteins limit the transferability of the knowledge gained. Moreover, the small heart size and fast heart rate are major disadvantages. In contrast to rodents, electrophysiological, mechanical and structural cardiac characteristics of rabbits resemble the human heart more closely, making them particularly suitable as an animal model for cardiac disease research. In this review, various methodological approaches for the generation of transgenic rabbits for cardiac disease research, such as pronuclear microinjection, the sleeping beauty transposon system and novel genome-editing methods (ZFN and CRISPR/Cas9)will be discussed. In the second section, we will introduce the different currently available transgenic rabbit models for monogenic cardiac diseases (such as long QT syndrome, short-QT syndrome and hypertrophic cardiomyopathy) in detail, especially in regard to their utility to increase the understanding of pathophysiological disease mechanisms and novel treatment options.
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Affiliation(s)
- Tibor Hornyik
- Translational Cardiology, Department of Cardiology, Inselspital, Bern University Hospital, and Institute of Physiology, University of Bern, Bern, Switzerland.,Department of Cardiology and Angiology I, University Heart Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Marina Rieder
- Translational Cardiology, Department of Cardiology, Inselspital, Bern University Hospital, and Institute of Physiology, University of Bern, Bern, Switzerland
| | - Alessandro Castiglione
- Translational Cardiology, Department of Cardiology, Inselspital, Bern University Hospital, and Institute of Physiology, University of Bern, Bern, Switzerland
| | - Peter Major
- Institute for Genetics and Biotechnology, Hungarian University of Agriculture and Life Sciences, Gödöllő, Hungary
| | - Istvan Baczko
- Department of Pharmacology and Pharmacotherapy, University of Szeged, Szeged, Hungary
| | - Michael Brunner
- Department of Cardiology and Angiology I, University Heart Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Department of Cardiology and Medical Intensive Care, St. Josefskrankenhaus, Freiburg, Germany
| | - Gideon Koren
- Cardiovascular Research Center, Division of Cardiology, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, Rhode Island, USA
| | - Katja E Odening
- Translational Cardiology, Department of Cardiology, Inselspital, Bern University Hospital, and Institute of Physiology, University of Bern, Bern, Switzerland.,Department of Cardiology and Angiology I, University Heart Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
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8
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Arrhythmic risk during pregnancy and postpartum in patients with long QT syndrome. Herzschrittmacherther Elektrophysiol 2021; 32:180-185. [PMID: 33782754 PMCID: PMC8166676 DOI: 10.1007/s00399-021-00757-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Accepted: 03/16/2021] [Indexed: 12/13/2022]
Abstract
Congenital long QT syndrome (LQTS) is a genetic disorder characterized by a prolonged QT interval in the surface electrocardiogram (ECG) that predisposes affected individuals to arrhythmic syncope, ventricular torsades-de-pointes, and sudden cardiac death at a young age. Investigations of large patient cohorts revealed sex-related differences in the LQTS phenotype. Adult women with LQTS are at higher risk for cardiac arrhythmias than are adult men with LQTS. Sex hormones are thought to play the primary role for these gender differences. Clinical experience and translational studies indicated that females with LQTS have a lower risk for cardiac arrhythmias during pregnancy and elevated risk in the postpartum period due to contrasting effects of estradiol and progesterone, as well as postpartum hormones on the action potential and arrhythmia substrate. However, this pro- or anti-arrhythmic potential of hormones varies depending on the underlying genotype, partly since sex hormones have distinct effects on different (affected) cardiac ion channels. Thus, a comprehensive evaluation of women with LQTS prior to and during pregnancy, during labor, and in the postpartum period with consideration of the patient’s disease- and gene-specific risk factors is essential to providing precision management in this patient group. This review discusses the current understanding of hormonal influences in LQTS and provides practical guidance for the optimal management of LQTS patients during pregnancy, delivery, and the postpartum period.
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9
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Asatryan B, Yee L, Ben-Haim Y, Dobner S, Servatius H, Roten L, Tanner H, Crotti L, Skinner JR, Remme CA, Chevalier P, Medeiros-Domingo A, Behr ER, Reichlin T, Odening KE, Krahn AD. Sex-Related Differences in Cardiac Channelopathies: Implications for Clinical Practice. Circulation 2021; 143:739-752. [PMID: 33587657 DOI: 10.1161/circulationaha.120.048250] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Sex-related differences in prevalence, clinical presentation, and outcome of cardiac channelopathies are increasingly recognized, despite their autosomal transmission and hence equal genetic predisposition among sexes. In congenital long-QT syndrome, adult women carry a greater risk for Torsades de pointes and sudden cardiac death than do men. In contrast, Brugada syndrome is observed predominantly in adult men, with a considerably higher risk of arrhythmic sudden cardiac death in adult men than in women. In both conditions, the risk for arrhythmias varies with age. Sex-associated differences appear less evident in other cardiac channelopathies, likely a reflection of their rare(r) occurrence and our limited knowledge. In several cardiac channelopathies, sex-specific predictors of outcome have been identified. Together with genetic and environmental factors, sex hormones contribute to the sex-related disparities in cardiac channelopathies through modulation of the expression and function of cardiac ion channels. Despite these insights, essential knowledge gaps exist in the mechanistic understanding of these differences, warranting further investigation. Precise application of the available knowledge may improve the individualized care of patients with cardiac channelopathies. Promoting the reporting of sex-related phenotype and outcome parameters in clinical and experimental studies and advancing research on cardiac channelopathy animal models should translate into improved patient outcomes. This review provides a critical digest of the current evidence for sex-related differences in cardiac channelopathies and emphasizes their clinical implications and remaining gaps requiring further research.
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Affiliation(s)
- Babken Asatryan
- Department of Cardiology, Inselspital, Bern University Hospital, University of Bern, Switzerland (B.A., S.D., H.S., L.R., H.T., T.R., K.E.O.)
| | - Lauren Yee
- Heart Rhythm Services, Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, Canada (L.Y., A.D.K.)
| | - Yael Ben-Haim
- Institute of Molecular and Clinical Sciences, St George's University of London, United Kingdom (Y.B.-H., E.R.B.).,European Reference Network for Rare and Low Prevalence Complex Diseases of the Heart: ERN GUARD-Heart (Y.B.-H., L.C., P.C., E.R.B.)
| | - Stephan Dobner
- Department of Cardiology, Inselspital, Bern University Hospital, University of Bern, Switzerland (B.A., S.D., H.S., L.R., H.T., T.R., K.E.O.)
| | - Helge Servatius
- Department of Cardiology, Inselspital, Bern University Hospital, University of Bern, Switzerland (B.A., S.D., H.S., L.R., H.T., T.R., K.E.O.)
| | - Laurent Roten
- Department of Cardiology, Inselspital, Bern University Hospital, University of Bern, Switzerland (B.A., S.D., H.S., L.R., H.T., T.R., K.E.O.)
| | - Hildegard Tanner
- Department of Cardiology, Inselspital, Bern University Hospital, University of Bern, Switzerland (B.A., S.D., H.S., L.R., H.T., T.R., K.E.O.)
| | - Lia Crotti
- European Reference Network for Rare and Low Prevalence Complex Diseases of the Heart: ERN GUARD-Heart (Y.B.-H., L.C., P.C., E.R.B.).,Istituto Auxologico Italiano, IRCCS, Center for Cardiac Arrhythmias of Genetic Origin and Laboratory of Cardiovascular Genetics, Milan, Italy (L.C.).,Department of Medicine and Surgery, University of Milano-Bicocca, Milan, Italy (L.C.).,Istituto Auxologico Italiano, IRCCS, Department of Cardiovascular, Neural and Metabolic Sciences, San Luca Hospital, Milan, Italy (L.C.)
| | - Jonathan R Skinner
- The Cardiac Inherited Disease Group, Auckland, New Zealand (J.R.S.).,Greenlane Paediatric and Congenital Cardiac Services, Starship Children's Hospital, Auckland, New Zealand (J.R.S.).,Department of Paediatrics, Child and Youth Health, University of Auckland, New Zealand (J.R.S.)
| | - Carol Ann Remme
- Heart Center, Department of Clinical and Experimental Cardiology, Amsterdam UMC, location AMC, University of Amsterdam, the Netherlands (C.A.R.)
| | - Philippe Chevalier
- Department of Rhythmology, Hospices Civils de Lyon, Louis Pradel Cardiovascular Hospital, France (P.C.).,Lyon Reference Center for Inherited Arrhythmias, Louis Pradel Cardiovascular Hospital, Bron, France (P.C.).,Université de Lyon, France (P.C.)
| | | | - Elijah R Behr
- Institute of Molecular and Clinical Sciences, St George's University of London, United Kingdom (Y.B.-H., E.R.B.).,European Reference Network for Rare and Low Prevalence Complex Diseases of the Heart: ERN GUARD-Heart (Y.B.-H., L.C., P.C., E.R.B.).,Cardiology Clinical Academic Group, St George's University Hospitals NHS Foundation Trust, London, United Kingdom (E.R.B.)
| | - Tobias Reichlin
- Department of Cardiology, Inselspital, Bern University Hospital, University of Bern, Switzerland (B.A., S.D., H.S., L.R., H.T., T.R., K.E.O.)
| | - Katja E Odening
- Department of Cardiology, Inselspital, Bern University Hospital, University of Bern, Switzerland (B.A., S.D., H.S., L.R., H.T., T.R., K.E.O.)
| | - Andrew D Krahn
- Heart Rhythm Services, Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, Canada (L.Y., A.D.K.)
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10
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Niimi N, Yuki K, Zaleski K. Long QT Syndrome and Perioperative Torsades de Pointes: What the Anesthesiologist Should Know. J Cardiothorac Vasc Anesth 2020; 36:286-302. [PMID: 33495078 DOI: 10.1053/j.jvca.2020.12.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 11/16/2020] [Accepted: 12/07/2020] [Indexed: 02/08/2023]
Affiliation(s)
- Naoko Niimi
- Department of Anesthesiology, Juntendo University, Tokyo, Japan.
| | - Koichi Yuki
- Department of Anesthesiology, Critical Care and Pain Medicine, Boston Children's Hospital, Boston, MA; Department of Anesthesia, Harvard Medical School, Boston, MA
| | - Katherine Zaleski
- Department of Anesthesiology, Critical Care and Pain Medicine, Boston Children's Hospital, Boston, MA; Department of Anesthesia, Harvard Medical School, Boston, MA
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11
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Rieder M, Castiglione A, Asatryan B, Odening KE. [Why do we need genetics in cardiac rhythmology?]. Herzschrittmacherther Elektrophysiol 2020; 31:394-400. [PMID: 32661562 DOI: 10.1007/s00399-020-00697-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 06/21/2020] [Indexed: 06/11/2023]
Abstract
A variety of arrhythmogenic cardiac diseases such as channelopathies and cardiomyopathies are caused by genetic alterations. In patients with these diseases, malignant arrhythmias or sudden cardiac death frequently manifest already during young adulthood. Early recognition, risk stratification and adequate therapy is therefore essential to avoid sudden cardiac death. This review summarizes the implications of genetic testing for diagnosis, risk stratification and therapy of patients with cardiac channelopathies (long-QT syndrome, short-QT syndrome, Brugada syndrome, catecholaminergic polymorphic ventricular tachycardia) and inherited cardiomyopathies (hypertrophic, dilatative or arrhythmogenic right ventricular cardiomyopathy).
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Affiliation(s)
- Marina Rieder
- Universitätsklinik für Kardiologie, Inselspital, Universitätsspital Bern, Freiburgstrasse 8, 3010, Bern, Schweiz
- Klinik für Kardiologie und Angiologie I, Universitäts-Herzzentrum Freiburg, Freiburg, Deutschland
| | - Alessandro Castiglione
- Universitätsklinik für Kardiologie, Inselspital, Universitätsspital Bern, Freiburgstrasse 8, 3010, Bern, Schweiz
- Klinik für Kardiologie und Angiologie I, Universitäts-Herzzentrum Freiburg, Freiburg, Deutschland
| | - Babken Asatryan
- Universitätsklinik für Kardiologie, Inselspital, Universitätsspital Bern, Freiburgstrasse 8, 3010, Bern, Schweiz
| | - Katja E Odening
- Universitätsklinik für Kardiologie, Inselspital, Universitätsspital Bern, Freiburgstrasse 8, 3010, Bern, Schweiz.
- Klinik für Kardiologie und Angiologie I, Universitäts-Herzzentrum Freiburg, Freiburg, Deutschland.
- Institut für Physiologie, Universität Bern, Bühlplatz 5, 3012, Bern, Schweiz.
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12
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Functional evaluation of gene mutations in Long QT Syndrome: strength of evidence from in vitro assays for deciphering variants of uncertain significance. JOURNAL OF CONGENITAL CARDIOLOGY 2020. [DOI: 10.1186/s40949-020-00037-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
Genetic screening is now commonplace for patients suspected of having inherited cardiac conditions. Variants of uncertain significance (VUS) in disease-associated genes pose problems for the diagnostician and reliable methods for evaluating VUS function are required. Although function is difficult to interrogate for some genes, heritable channelopathies have established mechanisms that should be amenable to well-validated evaluation techniques.
The cellular electrophysiology techniques of ‘voltage-’ and ‘patch-’ clamp have a long history of successful use and have been central to identifying both the roles of genes involved in different forms of congenital Long QT Syndrome (LQTS) and the mechanisms by which mutations lead to aberrant ion channel function underlying clinical phenotypes. This is particularly evident for KCNQ1, KCNH2 and SCN5A, mutations in which underlie > 90% of genotyped LQTS cases (the LQT1-LQT3 subtypes). Recent studies utilizing high throughput (HT) planar patch-clamp recording have shown it to discriminate effectively between rare benign and pathological variants, studied through heterologous expression of recombinant channels. In combination with biochemical methods for evaluating channel trafficking and supported by biophysical modelling, patch clamp also provides detailed mechanistic insight into the functional consequences of identified mutations. Whilst potentially powerful, patient-specific stem-cell derived cardiomyocytes and genetically modified animal models are currently not well-suited to high throughput VUS study.
Conclusion
The widely adopted 2015 American College of Medical Genetics (ACMG) and Association for Molecular Pathology (AMP) guidelines for the interpretation of sequence variants include the PS3 criterion for consideration of evidence from well-established in vitro or in vivo assays. The wealth of information on underlying mechanisms of LQT1-LQT3 and recent HT patch clamp data support consideration of patch clamp data together (for LQT1 and LQT2) with information from biochemical trafficking assays as meeting the PS3 criterion of well established assays, able to provide ‘strong’ evidence for functional pathogenicity of identified VUS.
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13
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Abstract
Transgenic rabbits have contributed to the progress of biomedical science as human disease models because of their unique features, such as the lipid metabolism system similar to humans and medium body size that facilitates handling and experimental manipulation. In fact, many useful transgenic rabbits have been generated and used in research fields such as lipid metabolism and atherosclerosis, cardiac failure, immunology, and oncogenesis. However, there have been long-term problems, namely that the transgenic efficiency when using pronuclear microinjection is low compared with transgenic mice and production of knockout rabbits is impossible owing to the lack of embryonic stem cells for gene targeting in rabbits. Despite these limitations, the emergence of novel genome editing technology has changed the production of genetically modified animals including the rabbit. We are finally able to produce both transgenic and knockout rabbit models to analyze gain- and loss-of-functions of specific genes. It is expected that the use of genetically modified rabbits will extend to various research fields. In this review, we describe the unique features of rabbits as laboratory animals, the current status of their development and use, and future perspectives of transgenic rabbit models for human diseases.
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Propofol abolishes torsade de pointes in different models of acquired long QT syndrome. Sci Rep 2020; 10:12133. [PMID: 32699382 PMCID: PMC7376147 DOI: 10.1038/s41598-020-69193-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Accepted: 07/07/2020] [Indexed: 12/11/2022] Open
Abstract
There is conflicting evidence regarding the impact of propofol on cardiac repolarization and the risk of torsade de pointes (TdP). The purpose of this study was to elucidate the risk of propofol-induced TdP and to investigate the impact of propofol in drug-induced long QT syndrome. 35 rabbit hearts were perfused employing a Langendorff-setup. 10 hearts were perfused with increasing concentrations of propofol (50, 75, 100 µM). Propofol abbreviated action potential duration (APD90) in a concentration-dependent manner without altering spatial dispersion of repolarization (SDR). Consequently, no proarrhythmic effects of propofol were observed. In 12 further hearts, erythromycin was employed to induce prolongation of cardiac repolarization. Erythromycin led to an amplification of SDR and triggered 36 episodes of TdP. Additional infusion of propofol abbreviated repolarization and reduced SDR. No episodes of TdP were observed with propofol. Similarly, ondansetron prolonged cardiac repolarization in another 13 hearts. SDR was increased and 36 episodes of TdP occurred. With additional propofol infusion, repolarization was abbreviated, SDR reduced and triggered activity abolished. In this experimental whole-heart study, propofol abbreviated repolarization without triggering TdP. On the contrary, propofol reversed prolongation of repolarization caused by erythromycin or ondansetron, reduced SDR and thereby eliminated drug-induced TdP.
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15
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Hornyik T, Castiglione A, Franke G, Perez-Feliz S, Major P, Hiripi L, Koren G, Bősze Z, Varró A, Zehender M, Brunner M, Bode C, Baczkó I, Odening KE. Transgenic LQT2, LQT5, and LQT2-5 rabbit models with decreased repolarisation reserve for prediction of drug-induced ventricular arrhythmias. Br J Pharmacol 2020; 177:3744-3759. [PMID: 32436214 PMCID: PMC7393202 DOI: 10.1111/bph.15098] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 04/09/2020] [Accepted: 04/23/2020] [Indexed: 12/21/2022] Open
Abstract
Background and Purpose Reliable prediction of pro‐arrhythmic side effects of novel drug candidates is still a major challenge. Although drug‐induced pro‐arrhythmia occurs primarily in patients with pre‐existing repolarisation disturbances, healthy animals are employed for pro‐arrhythmia testing. To improve current safety screening, transgenic long QT (LQTS) rabbit models with impaired repolarisation reserve were generated by overexpressing loss‐of‐function mutations of human HERG (HERG‐G628S, loss of IKr; LQT2), KCNE1 (KCNE1‐G52R, decreased IKs; LQT5), or both transgenes (LQT2‐5) in the heart. Experimental Approach Effects of K+ channel blockers on cardiac repolarisation and arrhythmia susceptibility were assessed in healthy wild‐type (WT) and LQTS rabbits using in vivo ECG and ex vivo monophasic action potential and ECG recordings in Langendorff‐perfused hearts. Key Results LQTS models reflect patients with clinically “silent” (LQT5) or “manifest” (LQT2 and LQT2‐5) impairment in cardiac repolarisation reserve: they were more sensitive in detecting IKr‐blocking (LQT5) or IK1/IKs‐blocking (LQT2 and LQT2‐5) properties of drugs compared to healthy WT animals. Impaired QT‐shortening capacity at fast heart rates was observed due to disturbed IKs function in LQT5 and LQT2‐5. Importantly, LQTS models exhibited higher incidence, longer duration, and more malignant types of ex vivo arrhythmias than WT. Conclusion and Implications LQTS models represent patients with reduced repolarisation reserve due to different pathomechanisms. As they demonstrate increased sensitivity to different specific ion channel blockers (IKr blockade in LQT5 and IK1 and IKs blockade in LQT2 and LQT2‐5), their combined use could provide more reliable and more thorough prediction of (multichannel‐based) pro‐arrhythmic potential of novel drug candidates.
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Affiliation(s)
- Tibor Hornyik
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Medical Faculty, Freiburg, Germany.,Institute of Experimental Cardiovascular Medicine, Heart Center University of Freiburg, Medical Faculty, Freiburg, Germany.,Department of Pharmacology and Pharmacotherapy, University of Szeged, Szeged, Hungary
| | - Alessandro Castiglione
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Medical Faculty, Freiburg, Germany
| | - Gerlind Franke
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Medical Faculty, Freiburg, Germany
| | - Stefanie Perez-Feliz
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Medical Faculty, Freiburg, Germany.,Institute of Experimental Cardiovascular Medicine, Heart Center University of Freiburg, Medical Faculty, Freiburg, Germany
| | - Péter Major
- NARIC-Agricultural Biotechnology Institute, Animal Biotechnology Department, Gödöllő, Hungary
| | - László Hiripi
- NARIC-Agricultural Biotechnology Institute, Animal Biotechnology Department, Gödöllő, Hungary
| | - Gideon Koren
- Cardiovascular Research Center, Brown University, Providence, Rhode Island, USA
| | - Zsuzsanna Bősze
- NARIC-Agricultural Biotechnology Institute, Animal Biotechnology Department, Gödöllő, Hungary
| | - András Varró
- Department of Pharmacology and Pharmacotherapy, University of Szeged, Szeged, Hungary
| | - Manfred Zehender
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Medical Faculty, Freiburg, Germany
| | - Michael Brunner
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Medical Faculty, Freiburg, Germany.,Department of Cardiology and Medical Intensive Care, St. Josefskrankenhaus, Freiburg, Germany
| | - Christoph Bode
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Medical Faculty, Freiburg, Germany
| | - István Baczkó
- Department of Pharmacology and Pharmacotherapy, University of Szeged, Szeged, Hungary
| | - Katja E Odening
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Medical Faculty, Freiburg, Germany.,Institute of Experimental Cardiovascular Medicine, Heart Center University of Freiburg, Medical Faculty, Freiburg, Germany.,Translational Cardiology, Department of Cardiology, Inselspital, Bern University Hospital, and Institute of Physiology, University of Bern, Bern, Switzerland
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16
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Baczkó I, Hornyik T, Brunner M, Koren G, Odening KE. Transgenic Rabbit Models in Proarrhythmia Research. Front Pharmacol 2020; 11:853. [PMID: 32581808 PMCID: PMC7291951 DOI: 10.3389/fphar.2020.00853] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 05/22/2020] [Indexed: 12/23/2022] Open
Abstract
Drug-induced proarrhythmia constitutes a potentially lethal side effect of various drugs. Most often, this proarrhythmia is mechanistically linked to the drug's potential to interact with repolarizing cardiac ion channels causing a prolongation of the QT interval in the ECG. Despite sophisticated screening approaches during drug development, reliable prediction of proarrhythmia remains very challenging. Although drug-induced long-QT-related proarrhythmia is often favored by conditions or diseases that impair the individual's repolarization reserve, most cellular, tissue, and whole animal model systems used for drug safety screening are based on normal, healthy models. In recent years, several transgenic rabbit models for different types of long QT syndromes (LQTS) with differences in the extent of impairment in repolarization reserve have been generated. These might be useful for screening/prediction of a drug's potential for long-QT-related proarrhythmia, particularly as different repolarizing cardiac ion channels are impaired in the different models. In this review, we summarize the electrophysiological characteristics of the available transgenic LQTS rabbit models, and the pharmacological proof-of-principle studies that have been performed with these models—highlighting the advantages and disadvantages of LQTS models for proarrhythmia research. In the end, we give an outlook on potential future directions and novel models.
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Affiliation(s)
- István Baczkó
- Department of Pharmacology and Pharmacotherapy, University of Szeged, Szeged, Hungary
| | - Tibor Hornyik
- Department of Pharmacology and Pharmacotherapy, University of Szeged, Szeged, Hungary.,Department of Cardiology and Angiology I, Heart Center, University of Freiburg, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Michael Brunner
- Department of Cardiology and Angiology I, Heart Center, University of Freiburg, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Department of Cardiology and Medical Intensive Care, St. Josefskrankenhaus, Freiburg, Germany
| | - Gideon Koren
- Cardiovascular Research Center, Division of Cardiology, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, RI, United States
| | - Katja E Odening
- Department of Cardiology and Angiology I, Heart Center, University of Freiburg, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Translational Cardiology, Department of Cardiology, Inselspital, Bern University Hospital, Bern, Switzerland.,Institute of Physiology, University of Bern, Bern, Switzerland
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17
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Kim TY, Jeng P, Hwang J, Pfeiffer Z, Patel D, Cooper LL, Kossidas K, Centracchio J, Peng X, Koren G, Qu Z, Choi BR. Short-Long Heart Rate Variation Increases Dispersion of Action Potential Duration in Long QT Type 2 Transgenic Rabbit Model. Sci Rep 2019; 9:14849. [PMID: 31619700 PMCID: PMC6795902 DOI: 10.1038/s41598-019-51230-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Accepted: 09/24/2019] [Indexed: 01/21/2023] Open
Abstract
The initiation of polymorphic ventricular tachycardia in long QT syndrome type 2 (LQT2) has been associated with a characteristic ECG pattern of short-long RR intervals. We hypothesize that this characteristic pattern increases APD dispersion in LQT2, thereby promoting arrhythmia. We investigated APD dispersion and its dependence on two previous cycle lengths (CLs) in transgenic rabbit models of LQT2, LQT1, and their littermate controls (LMC) using random stimulation protocols. The results show that the short-long RR pattern was associated with a larger APD dispersion in LQT2 but not in LQT1 rabbits. The multivariate analyses of APD as a function of two previous CLs (APDn = C + α1CLn−1 + α2CLn−2) showed that α1 (APD restitution slope) is largest and heterogeneous in LQT2 but uniform in LQT1, enhancing APD dispersion under long CLn−1 in LQT2. The α2 (short-term memory) was negative in LQT2 while positive in LQT1, and the spatial pattern of α1 was inversely correlated to α2 in LQT2, which explains why a short-long combination causes a larger APD dispersion in LQT2 but not in LQT1 rabbits. In conclusion, short-long RR pattern increased APD dispersion only in LQT2 rabbits through heterogeneous APD restitution and the short-term memory, underscoring the genotype-specific triggering of arrhythmias in LQT syndrome.
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Affiliation(s)
- Tae Yun Kim
- Cardiovascular Research Center, Division of Cardiology, Rhode Island Hospital, Warren Alpert Medical School of Brown University, Providence, RI, USA
| | - Paul Jeng
- Cardiovascular Research Center, Division of Cardiology, Rhode Island Hospital, Warren Alpert Medical School of Brown University, Providence, RI, USA
| | - JungMin Hwang
- College of Pharmacy, University of Rhode Island, Kingston, RI, USA
| | - Zachary Pfeiffer
- Cardiovascular Research Center, Division of Cardiology, Rhode Island Hospital, Warren Alpert Medical School of Brown University, Providence, RI, USA
| | - Divyang Patel
- Department of Cardiovascular Medicine, Heart and Vascular Institute, Cleveland Clinic Foundation, Cleveland, Ohio, USA
| | - Leroy L Cooper
- Biology Department, Vassar College, Poughkeepsie, NY, USA
| | - Konstantinos Kossidas
- Cardiovascular Research Center, Division of Cardiology, Rhode Island Hospital, Warren Alpert Medical School of Brown University, Providence, RI, USA
| | - Jason Centracchio
- Cardiovascular Research Center, Division of Cardiology, Rhode Island Hospital, Warren Alpert Medical School of Brown University, Providence, RI, USA
| | - Xuwen Peng
- Department of Comparative Medicine, Pennsylvania State University College of Medicine, Hershey, PA, USA
| | - Gideon Koren
- Cardiovascular Research Center, Division of Cardiology, Rhode Island Hospital, Warren Alpert Medical School of Brown University, Providence, RI, USA
| | - Zhilin Qu
- Department of Medicine (Cardiology), David Geffen School of Medicine, University of California, Los Angeles, CA, USA
| | - Bum-Rak Choi
- Cardiovascular Research Center, Division of Cardiology, Rhode Island Hospital, Warren Alpert Medical School of Brown University, Providence, RI, USA.
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18
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Bodi I, Sorge J, Castiglione A, Glatz SM, Wuelfers EM, Franke G, Perez-Feliz S, Koren G, Zehender M, Bugger H, Seemann G, Brunner M, Bode C, Odening KE. Postpartum hormones oxytocin and prolactin cause pro-arrhythmic prolongation of cardiac repolarization in long QT syndrome type 2. Europace 2019; 21:1126-1138. [DOI: 10.1093/europace/euz037] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Accepted: 02/21/2019] [Indexed: 12/16/2022] Open
Abstract
Aims
Women with long QT syndrome 2 (LQT2) have a particularly high postpartal risk for lethal arrhythmias. We aimed at investigating whether oxytocin and prolactin contribute to this risk by affecting repolarization.
Methods and results
In female transgenic LQT2 rabbits (HERG-G628S, loss of IKr), hormone effects on QT/action potential duration (APD) were assessed (0.2–200 ng/L). Hormone effects (200 ng/L) on ion currents and cellular APD were determined in transfected cells and LQT2 cardiomyocytes. Hormone effects on ion channels were assessed with qPCR and western blot. Experimental data were incorporated into in silico models to determine the pro-arrhythmic potential. Oxytocin prolonged QTc and steepened QT/RR-slope in vivo and prolonged ex vivo APD75 in LQT2 hearts. Prolactin prolonged APD75 at high concentrations. As underlying mechanisms, we identified an oxytocin- and prolactin-induced acute reduction of IKs-tail and IKs-steady (−25.5%, oxytocin; −13.3%, prolactin, P < 0.05) in CHO-cells and LQT2-cardiomyocytes. IKr currents were not altered. This oxytocin-/prolactin-induced IKs reduction caused APD90 prolongation (+11.9%/+13%, P < 0.05) in the context of reduced/absent IKr in LQT2 cardiomyocytes. Hormones had no effect on IK1 and ICa,L in cardiomyocytes. Protein and mRNA levels of CACNA1C/Cav1.2 and RyR2 were enhanced by oxytocin and prolactin. Incorporating these hormone effects into computational models resulted in reduced repolarization reserve and increased propensity to pro-arrhythmic permanent depolarization, lack of capture and early afterdepolarizations formation.
Conclusions
Postpartum hormones oxytocin and prolactin prolong QT/APD in LQT2 by reducing IKs and by increasing Cav1.2 and RyR2 expression/transcription, thereby contributing to the increased postpartal arrhythmic risk in LQT2.
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Affiliation(s)
- Ilona Bodi
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Hugstetter Str. 55, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg - Bad Krozingen and Medical Center – University of Freiburg, Freiburg, Germany
| | - Jonathan Sorge
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Hugstetter Str. 55, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Alessandro Castiglione
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Hugstetter Str. 55, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg - Bad Krozingen and Medical Center – University of Freiburg, Freiburg, Germany
| | - Sylva M Glatz
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Hugstetter Str. 55, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Eike M Wuelfers
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg - Bad Krozingen and Medical Center – University of Freiburg, Freiburg, Germany
| | - Gerlind Franke
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Hugstetter Str. 55, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Stefanie Perez-Feliz
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Hugstetter Str. 55, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg - Bad Krozingen and Medical Center – University of Freiburg, Freiburg, Germany
| | - Gideon Koren
- Division of Cardiology, Cardiovascular Research Center, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, RI, USA
| | - Manfred Zehender
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Hugstetter Str. 55, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Heiko Bugger
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Hugstetter Str. 55, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Gunnar Seemann
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg - Bad Krozingen and Medical Center – University of Freiburg, Freiburg, Germany
| | - Michael Brunner
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Hugstetter Str. 55, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Department of Cardiology and Medical Intensive Care, St. Josefskrankenhaus, Freiburg, Germany
| | - Christoph Bode
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Hugstetter Str. 55, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Katja E Odening
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Hugstetter Str. 55, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg - Bad Krozingen and Medical Center – University of Freiburg, Freiburg, Germany
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19
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Ziupa D, Menza M, Koppermann S, Moss R, Beck J, Franke G, Perez Feliz S, Brunner M, Mayer S, Bugger H, Koren G, Zehender M, Jung BA, Seemann G, Foell D, Bode C, Odening KE. Electro-mechanical (dys-)function in long QT syndrome type 1. Int J Cardiol 2019; 274:144-151. [DOI: 10.1016/j.ijcard.2018.07.050] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Revised: 05/18/2018] [Accepted: 07/06/2018] [Indexed: 01/28/2023]
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20
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Thomas D, Christ T, Fabritz L, Goette A, Hammwöhner M, Heijman J, Kockskämper J, Linz D, Odening KE, Schweizer PA, Wakili R, Voigt N. German Cardiac Society Working Group on Cellular Electrophysiology state-of-the-art paper: impact of molecular mechanisms on clinical arrhythmia management. Clin Res Cardiol 2018; 108:577-599. [PMID: 30306295 DOI: 10.1007/s00392-018-1377-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Accepted: 09/24/2018] [Indexed: 12/19/2022]
Abstract
Cardiac arrhythmias remain a common challenge and are associated with significant morbidity and mortality. Effective and safe rhythm control strategies are a primary, yet unmet need in everyday clinical practice. Despite significant pharmacological and technological advances, including catheter ablation and device-based therapies, the development of more effective alternatives is of significant interest to increase quality of life and to reduce symptom burden, hospitalizations and mortality. The mechanistic understanding of pathophysiological pathways underlying cardiac arrhythmias has advanced profoundly, opening up novel avenues for mechanism-based therapeutic approaches. Current management of arrhythmias, however, is primarily guided by clinical and demographic characteristics of patient groups as opposed to individual, patient-specific mechanisms and pheno-/genotyping. With this state-of-the-art paper, the Working Group on Cellular Electrophysiology of the German Cardiac Society aims to close the gap between advanced molecular understanding and clinical decision-making in cardiac electrophysiology. The significance of cellular electrophysiological findings for clinical arrhythmia management constitutes the main focus of this document. Clinically relevant knowledge of pathophysiological pathways of arrhythmias and cellular mechanisms of antiarrhythmic interventions are summarized. Furthermore, the specific molecular background for the initiation and perpetuation of atrial and ventricular arrhythmias and mechanism-based strategies for therapeutic interventions are highlighted. Current "hot topics" in atrial fibrillation are critically appraised. Finally, the establishment and support of cellular and translational electrophysiology programs in clinical rhythmology departments is called for to improve basic-science-guided patient management.
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Affiliation(s)
- Dierk Thomas
- Department of Cardiology, Medical University Hospital, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany. .,HCR (Heidelberg Center for Heart Rhythm Disorders), Heidelberg, Germany. .,DZHK (German Center for Cardiovascular Research), partner site Heidelberg/Mannheim, Heidelberg, Germany.
| | - Torsten Christ
- Department of Experimental Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,DZHK (German Center for Cardiovascular Research), partner site Hamburg/Kiel/Lübeck, Hamburg, Germany
| | - Larissa Fabritz
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK.,Department of Cardiology, UHB NHS Trust, Birmingham, UK.,Department of Cardiovascular Medicine, Division of Rhythmology, University Hospital Münster, Münster, Germany
| | - Andreas Goette
- St. Vincenz-Hospital, Paderborn, Germany.,Working Group: Molecular Electrophysiology, University Hospital Magdeburg, Magdeburg, Germany
| | - Matthias Hammwöhner
- St. Vincenz-Hospital, Paderborn, Germany.,Working Group: Molecular Electrophysiology, University Hospital Magdeburg, Magdeburg, Germany
| | - Jordi Heijman
- Institute of Pharmacology, West German Heart and Vascular Center, University Duisburg-Essen, Essen, Germany.,Cardiovascular Research Institute Maastricht, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Jens Kockskämper
- Biochemical and Pharmacological Center (BPC) Marburg, Institute of Pharmacology and Clinical Pharmacy, University of Marburg, Marburg, Germany
| | - Dominik Linz
- Centre for Heart Rhythm Disorders, South Australian Health and Medical Research Institute, University of Adelaide and Royal Adelaide Hospital, Adelaide, SA, Australia.,Experimental Electrophysiology, University Hospital of Saarland, Homburg, Saar, Germany
| | - Katja E Odening
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Institute for Experimental Cardiovascular Medicine, Heart Center University of Freiburg, Freiburg, Germany
| | - Patrick A Schweizer
- Department of Cardiology, Medical University Hospital, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany.,HCR (Heidelberg Center for Heart Rhythm Disorders), Heidelberg, Germany.,DZHK (German Center for Cardiovascular Research), partner site Heidelberg/Mannheim, Heidelberg, Germany.,Heidelberg Research Center for Molecular Medicine (HRCMM), Heidelberg, Germany
| | - Reza Wakili
- Department of Cardiology and Vascular Medicine, Medical Faculty, West German Heart Center, University Hospital Essen, Essen, Germany
| | - Niels Voigt
- Institute of Pharmacology and Toxicology, University Medical Center Göttingen, Georg-August University Göttingen, Robert-Koch-Straße 40, 37075, Göttingen, Germany. .,DZHK (German Center for Cardiovascular Research), partner site Göttingen, Göttingen, Germany.
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21
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Duras E, İrdem A, Özkaya O. Long QT syndrome diagnosed in two sisters with propionic acidemia: a case report. J Pediatr Endocrinol Metab 2017; 30:1133-1136. [PMID: 28820736 DOI: 10.1515/jpem-2016-0469] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Accepted: 07/17/2017] [Indexed: 12/30/2022]
Abstract
Propionic acidemia (PA) is a rare autosomal recessive metabolic disorder caused by deficiency of the mitochondrial enzyme propionyl-CoA carboxylase (PCC). This disorder mostly progresses with episodes of metabolic acidosis. Cardiomyopathy is among the cardiac complications known to occur during metabolic decompensation episodes. However, several recent papers emphasized the association of PA and long QT syndrome (LQTS) which may lead to extremely serious and fatal consequences. In this report, we describe two sisters with PA who have prolonged QT duration that were incidentally detected in an outpatient setting. LQTS was verified by electrocardiogram, stress test and 24 h rhythm holter monitoring. By this report, we want to emphasize the importance of early diagnosis of LQTS in asymptomatic patients with PA to prevent fatal complications.
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Rothenberg I, Piccini I, Wrobel E, Stallmeyer B, Müller J, Greber B, Strutz-Seebohm N, Schulze-Bahr E, Schmitt N, Seebohm G. Structural interplay of K V7.1 and KCNE1 is essential for normal repolarization and is compromised in short QT syndrome 2 (K V7.1-A287T). HeartRhythm Case Rep 2016; 2:521-529. [PMID: 28491751 PMCID: PMC5420010 DOI: 10.1016/j.hrcr.2016.08.015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Affiliation(s)
- Ina Rothenberg
- Institute for Genetics of Heart Diseases (IfGH), Department of Cardiovascular Medicine, University Hospital Münster, Münster, Germany
| | - Ilaria Piccini
- Institute for Genetics of Heart Diseases (IfGH), Department of Cardiovascular Medicine, University Hospital Münster, Münster, Germany
| | - Eva Wrobel
- Institute for Genetics of Heart Diseases (IfGH), Department of Cardiovascular Medicine, University Hospital Münster, Münster, Germany
| | - Birgit Stallmeyer
- Institute for Genetics of Heart Diseases (IfGH), Department of Cardiovascular Medicine, University Hospital Münster, Münster, Germany
| | - Jovanca Müller
- Institute for Genetics of Heart Diseases (IfGH), Department of Cardiovascular Medicine, University Hospital Münster, Münster, Germany
| | - Boris Greber
- Human Stem Cell Pluripotency Laboratory, Max Planck Institute for Molecular Biomedicine, Münster, Germany
- Chemical Genomics Centre of the Max Planck Society, Dortmund, Germany
| | - Nathalie Strutz-Seebohm
- Institute for Genetics of Heart Diseases (IfGH), Department of Cardiovascular Medicine, University Hospital Münster, Münster, Germany
| | - Eric Schulze-Bahr
- Institute for Genetics of Heart Diseases (IfGH), Department of Cardiovascular Medicine, University Hospital Münster, Münster, Germany
- Interdisziplinäres Zentrum für Klinische Forschung Münster (IZKF Münster) and Innovative Medizinische Forschung (IMF Münster), Faculty of Medicine, University of Münster, Münster, Germany
| | - Nicole Schmitt
- Danish National Research Foundation Centre for Cardiac Arrhythmia, Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Guiscard Seebohm
- Institute for Genetics of Heart Diseases (IfGH), Department of Cardiovascular Medicine, University Hospital Münster, Münster, Germany
- Interdisziplinäres Zentrum für Klinische Forschung Münster (IZKF Münster) and Innovative Medizinische Forschung (IMF Münster), Faculty of Medicine, University of Münster, Münster, Germany
- Address reprint requests and correspondence: Dr Guiscard Seebohm, Institute for Genetics of Heart Diseases (IfGH), Department of Cardiovascular Medicine, University Hospital Münster, D48149 Münster, Germany.Institute for Genetics of Heart Diseases (IfGH), Department of Cardiovascular Medicine, University Hospital Münster, D48149MünsterGermany
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Han SN, Jing Y, Yang LL, Zhang Z, Zhang LR. Propofol inhibits hERG K + channels and enhances the inhibition effects on its mutations in HEK293 cells. Eur J Pharmacol 2016; 791:168-178. [PMID: 27575519 DOI: 10.1016/j.ejphar.2016.08.028] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Revised: 08/12/2016] [Accepted: 08/25/2016] [Indexed: 12/19/2022]
Abstract
QT interval prolongation, a potential risk for arrhythmias, may result from gene polymorphisms relevant to cardiomyocyte repolarization. Another noted cause of QT interval prolongation is the administration of chemical compounds such as anesthetics, which may affect a specific type of cardiac K+ channel encoded by the human ether-a-go-go-related gene (hERG). hERG K+ current was recorded using whole-cell patch clamp in human embryonic kidney (HEK293) cells expressing wild type (WT) or mutated hERG channels. Expression of hERG K+ channel proteins was evaluated using western blot and confirmed by fluorescent staining and imaging. Computational modeling was adopted to identify the possible binding site(s) of propofol with hERG K+ channels. Propofol had a significant inhibitory effect on WT hERG K+ currents in a concentration-dependent manner, with a half-maximal inhibitory concentration (IC50) of 60.9±6.4μM. Mutations in drug-binding sites (Y652A or F656C) of the hERG channel were found to attenuate hERG current blockage by propofol. However, propofol did not inhibit the trafficking of hERG protein to the cell membrane. Meanwhile, for the three selective hERG K+ channel mutant heterozygotes WT/Q738X-hERG, WT/A422T-hERG, and WT/H562P-hERG, the IC50 of propofol was calculated as 14.2±2.8μM, 3.3±1.2μM, and 5.9±1.9μM, respectively, which were much lower than that for the wild type. These findings indicate that propofol may potentially increase QT interval prolongation risk in patients via direct inhibition of the hERG K+ channel, especially in those with other concurrent triggering factors such as hERG gene mutations.
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Affiliation(s)
- Sheng-Na Han
- Department of Pharmacology, Basic Medical College, Zhengzhou University, Zhengzhou 450001, China
| | - Ying Jing
- Department of Physiology and Neurobiology, Basic Medical College, Zhengzhou University, Zhengzhou 450001, China
| | - Lin-Lin Yang
- Department of Pharmacology, Basic Medical College, Zhengzhou University, Zhengzhou 450001, China; Drug Discovery and Design Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Zhao Zhang
- Jiangsu Key Laboratory for Molecular & Medical Biotechnology, College of Life Science in Nanjing Normal University, Nanjing 210046, China.
| | - Li-Rong Zhang
- Department of Pharmacology, Basic Medical College, Zhengzhou University, Zhengzhou 450001, China.
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Pueyo E, Orini M, Rodríguez JF, Taggart P. Interactive effect of beta-adrenergic stimulation and mechanical stretch on low-frequency oscillations of ventricular action potential duration in humans. J Mol Cell Cardiol 2016; 97:93-105. [DOI: 10.1016/j.yjmcc.2016.05.003] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Revised: 03/21/2016] [Accepted: 05/03/2016] [Indexed: 01/27/2023]
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The potential impact of new generation transgenic methods on creating rabbit models of cardiac diseases. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2016; 121:123-30. [DOI: 10.1016/j.pbiomolbio.2016.05.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Accepted: 05/01/2016] [Indexed: 12/11/2022]
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Abstract
Any disturbance of electrical impulse formation in the heart and of impulse conduction or action potential (AP) repolarization can lead to rhythm disorders. Potassium (K(+)) channels play a prominent role in the AP repolarization process. In this review we describe the causes and mechanisms of proarrhythmic effects that arise as a response to blockers of cardiac K(+) channels. The largest and chemically most diverse groups of compound targets are Kv11.1 (hERG) and Kv7.1 (KvLQT1) channels. Finally, the proarrhythmic propensity of atrial-selective K(+) blockers inhibiting Kv1.5, Kir3.1/3.4, SK, and K2P channels is discussed.
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Affiliation(s)
- Lasse Skibsbye
- Danish Arrhythmia Research Centre, Faculty of Health and Medical Sciences, University of Copenhagen, 3 Blegdamsvej, 3 Copenhagen N DK-2200, Denmark
| | - Ursula Ravens
- Department of Pharmacology and Toxicology, Medical Faculty Carl Gustav Carus, Institut für Pharmakologie und Toxikologie, TU Dresden, Fetscherstrasse 74, Dresden D-01307, Germany.
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Major P, Baczkó I, Hiripi L, Odening KE, Juhász V, Kohajda Z, Horváth A, Seprényi G, Kovács M, Virág L, Jost N, Prorok J, Ördög B, Doleschall Z, Nattel S, Varró A, Bősze Z. A novel transgenic rabbit model with reduced repolarization reserve: long QT syndrome caused by a dominant-negative mutation of the KCNE1 gene. Br J Pharmacol 2016; 173:2046-61. [PMID: 27076034 DOI: 10.1111/bph.13500] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Revised: 03/25/2016] [Accepted: 04/01/2016] [Indexed: 01/26/2023] Open
Abstract
BACKGROUND AND PURPOSE The reliable assessment of proarrhythmic risk of compounds under development remains an elusive goal. Current safety guidelines focus on the effects of blocking the KCNH2/HERG ion channel-in tissues and animals with intact repolarization. Novel models with better predictive value are needed that more closely reflect the conditions in patients with cardiac remodelling and reduced repolarization reserve. EXPERIMENTAL APPROACH We have developed a model for the long QT syndrome type-5 in rabbits (LQT5 ) with cardiac-specific overexpression of a mutant (G52R) KCNE1 β-subunit of the channel that carries the slow delayed-rectifier K(+) -current (IKs ). ECG parameters, including short-term variability of the QT interval (STVQT ), a biomarker for proarrhythmic risk, and arrhythmia development were recorded. In vivo, arrhythmia susceptibility was evaluated by i.v. administration of the IKr blocker dofetilide. K(+) currents were measured with the patch-clamp technique. KEY RESULTS Patch-clamp studies in ventricular myocytes isolated from LQT5 rabbits revealed accelerated IKs and IKr deactivation kinetics. At baseline, LQT5 animals exhibited slightly but significantly prolonged heart-rate corrected QT index (QTi) and increased STVQT . Dofetilide provoked Torsade-de-Pointes arrhythmia in a greater proportion of LQT5 rabbits, paralleled by a further increase in STVQT . CONCLUSION AND IMPLICATIONS We have created a novel transgenic LQT5 rabbit model with increased susceptibility to drug-induced arrhythmias that may represent a useful model for testing proarrhythmic potential and for investigations of the mechanisms underlying arrhythmias and sudden cardiac death due to repolarization disturbances.
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Affiliation(s)
- Péter Major
- Rabbit Genome and Biomodel Group, NARIC - Agricultural Biotechnology Institute, Gödöllő, Hungary
| | - István Baczkó
- Department of Pharmacology & Pharmacotherapy, University of Szeged, Szeged, Hungary
| | - László Hiripi
- Rabbit Genome and Biomodel Group, NARIC - Agricultural Biotechnology Institute, Gödöllő, Hungary
| | - Katja E Odening
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Freiburg, Germany
| | - Viktor Juhász
- Department of Pharmacology & Pharmacotherapy, University of Szeged, Szeged, Hungary
| | - Zsófia Kohajda
- Department of Pharmacology & Pharmacotherapy, University of Szeged, Szeged, Hungary
| | - András Horváth
- Department of Pharmacology & Pharmacotherapy, University of Szeged, Szeged, Hungary
| | - György Seprényi
- Department of Biology, University of Szeged, Szeged, Hungary
| | - Mária Kovács
- Department of Pharmacology & Pharmacotherapy, University of Szeged, Szeged, Hungary
| | - László Virág
- Department of Pharmacology & Pharmacotherapy, University of Szeged, Szeged, Hungary
| | - Norbert Jost
- Department of Pharmacology & Pharmacotherapy, University of Szeged, Szeged, Hungary.,MTA-SZTE Research Group of Cardiovascular Pharmacology, Hungarian Academy of Sciences, Szeged, Hungary
| | - János Prorok
- Department of Pharmacology & Pharmacotherapy, University of Szeged, Szeged, Hungary
| | - Balázs Ördög
- Department of Pharmacology & Pharmacotherapy, University of Szeged, Szeged, Hungary
| | - Zoltán Doleschall
- Department of Pathogenetics, National Institute of Oncology, Budapest, Hungary
| | - Stanley Nattel
- Department of Medicine, Montreal Heart Institute, Université de Montréal, Canada.,Department of Pharmacology and Therapeutics, McGill University, Montréal, Canada.,Institute of Pharmacology, West German Heart and Vascular Center, Faculty of Medicine, University Duisburg-Essen, Essen, Germany
| | - András Varró
- Department of Pharmacology & Pharmacotherapy, University of Szeged, Szeged, Hungary.,MTA-SZTE Research Group of Cardiovascular Pharmacology, Hungarian Academy of Sciences, Szeged, Hungary
| | - Zsuzsanna Bősze
- Rabbit Genome and Biomodel Group, NARIC - Agricultural Biotechnology Institute, Gödöllő, Hungary
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Lang CN, Koren G, Odening KE. Transgenic rabbit models to investigate the cardiac ion channel disease long QT syndrome. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2016; 121:142-56. [PMID: 27210307 DOI: 10.1016/j.pbiomolbio.2016.05.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Accepted: 05/01/2016] [Indexed: 12/13/2022]
Abstract
Long QT syndrome (LQTS) is a rare inherited channelopathy caused mainly by different mutations in genes encoding for cardiac K(+) or Na(+) channels, but can also be caused by commonly used ion-channel-blocking and QT-prolonging drugs, thus affecting a much larger population. To develop novel diagnostic and therapeutic strategies to improve the clinical management of these patients, a thorough understanding of the pathophysiological mechanisms of arrhythmogenesis and potential pharmacological targets is needed. Drug-induced and genetic animal models of various species have been generated and have been instrumental for identifying pro-arrhythmic triggers and important characteristics of the arrhythmogenic substrate in LQTS. However, due to species differences in features of cardiac electrical function, these different models do not entirely recapitulate all aspects of the human disease. In this review, we summarize advantages and shortcomings of different drug-induced and genetically mediated LQTS animal models - focusing on mouse and rabbit models since these represent the most commonly used small animal models for LQTS that can be subjected to genetic manipulation. In particular, we highlight the different aspects of arrhythmogenic mechanisms, pro-arrhythmic triggering factors, anti-arrhythmic agents, and electro-mechanical dysfunction investigated in transgenic LQTS rabbit models and their translational application for the clinical management of LQTS patients in detail. Transgenic LQTS rabbits have been instrumental to increase our understanding of the role of spatial and temporal dispersion of repolarization to provide an arrhythmogenic substrate, genotype-differences in the mechanisms for early afterdepolarization formation and arrhythmia maintenance, mechanisms of hormonal modification of arrhythmogenesis and regional heterogeneities in electro-mechanical dysfunction in LQTS.
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Affiliation(s)
- C N Lang
- Department of Cardiology and Angiology I, University Heart Center Freiburg, Medical Center - University of Freiburg, Germany; Faculty of Medicine, University of Freiburg, Germany
| | - G Koren
- Cardiovascular Research Center, Division of Cardiology, Rhode Island Hospital, Warren Alpert Medical School of Brown University, Providence, RI, USA
| | - K E Odening
- Department of Cardiology and Angiology I, University Heart Center Freiburg, Medical Center - University of Freiburg, Germany; Faculty of Medicine, University of Freiburg, Germany.
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Technical advances in studying cardiac electrophysiology - Role of rabbit models. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2016; 121:97-109. [PMID: 27210306 DOI: 10.1016/j.pbiomolbio.2016.05.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 01/16/2016] [Accepted: 05/01/2016] [Indexed: 12/15/2022]
Abstract
Cardiovascular research has made a major contribution to an unprecedented 10 year increase in life expectancy during the last 50 years: most of this increase due to a decline in mortality from heart disease and stroke. The majority of the basic cardiovascular science discoveries, which have led to this impressive extension of human life, came from investigations conducted in various small and large animal models, ranging from mouse to pig. The small animal models are currently popular because they are amenable to genetic engineering and are relatively inexpensive. The large animal models are favored at the translational stage of the investigation, as they are anatomically and physiologically more proximal to humans, and can be implanted with various devices; however, they are expensive and less amenable to genetic manipulations. With the advent of CRISPR genetic engineering technology and the advances in implantable bioelectronics, the large animal models will continue to advance. The rabbit model is particularly poised to become one of the most popular among the animal models that recapitulate human heart diseases. Here we review an array of the rabbit models of atrial and ventricular arrhythmias, as well as a range of the imaging and device technologies enabling these investigations.
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Baczkó I, Jost N, Virág L, Bősze Z, Varró A. Rabbit models as tools for preclinical cardiac electrophysiological safety testing: Importance of repolarization reserve. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2016; 121:157-68. [PMID: 27208697 DOI: 10.1016/j.pbiomolbio.2016.05.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Accepted: 05/01/2016] [Indexed: 01/26/2023]
Abstract
It is essential to more reliably assess the pro-arrhythmic liability of compounds in development. Current guidelines for pre-clinical and clinical testing of drug candidates advocate the use of healthy animals/tissues and healthy individuals and focus on the test compound's ability to block the hERG current and prolong cardiac ventricular repolarization. Also, pre-clinical safety tests utilize several species commonly used in cardiac electrophysiological studies. In this review, important species differences in cardiac ventricular repolarizing ion currents are considered, followed by the discussion on electrical remodeling associated with chronic cardiovascular diseases that leads to altered ion channel and transporter expression and densities in pathological settings. We argue that the choice of species strongly influences experimental outcome and extrapolation of results to human clinical settings. We suggest that based on cardiac cellular electrophysiology, the rabbit is a useful species for pharmacological pro-arrhythmic investigations. In addition to healthy animals and tissues, the use of animal models (e.g. those with impaired repolarization reserve) is suggested that more closely resemble subsets of patients exhibiting increased vulnerability towards the development of ventricular arrhythmias and sudden cardiac death.
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Affiliation(s)
- István Baczkó
- Department of Pharmacology & Pharmacotherapy, University of Szeged, Dóm tér 12., 6720 Szeged, Hungary.
| | - Norbert Jost
- Department of Pharmacology & Pharmacotherapy, University of Szeged, Dóm tér 12., 6720 Szeged, Hungary; MTA-SZTE Research Group of Cardiovascular Pharmacology, Hungarian Academy of Sciences, Dóm tér 12., 6720 Szeged, Hungary
| | - László Virág
- Department of Pharmacology & Pharmacotherapy, University of Szeged, Dóm tér 12., 6720 Szeged, Hungary
| | - Zsuzsanna Bősze
- Rabbit Genome and Biomodel Group, NARIC-Agricultural Biotechnology Institute, 2100 Gödöllő, Hungary
| | - András Varró
- Department of Pharmacology & Pharmacotherapy, University of Szeged, Dóm tér 12., 6720 Szeged, Hungary; MTA-SZTE Research Group of Cardiovascular Pharmacology, Hungarian Academy of Sciences, Dóm tér 12., 6720 Szeged, Hungary
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31
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Odening KE, Kohl P. Editorial to "Disturbances of cardiac wavelength and repolarization precede torsade de pointes and ventricular fibrillation in langendorff perfused rabbit hearts" by Luc Hondeghem: It is difficult to make predictions, especially about the future∗: Thoughts about forecasting cardiotoxicity of pharmacological interventions. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2016; 121:1-2. [PMID: 27137834 DOI: 10.1016/j.pbiomolbio.2016.04.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Affiliation(s)
- Katja E Odening
- Department of Cardiology and Angiology I, University Heart Center Freiburg - Bad Krozingen, Medical Center - University of Freiburg, Germany; Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg - Bad Krozingen, Medical Center - University of Freiburg, Germany; Faculty of Medicine, University of Freiburg, Germany.
| | - Peter Kohl
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg - Bad Krozingen, Medical Center - University of Freiburg, Germany; Faculty of Medicine, University of Freiburg, Germany; Cardiac Biophysics and Systems Biology, National Heart and Lung Institute, London, UK
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Scalese MJ, Herring HR, Rathbun RC, Skrepnek GH, Ripley TL. Propofol-associated QTc prolongation. Ther Adv Drug Saf 2016; 7:68-78. [PMID: 27298717 DOI: 10.1177/2042098616641354] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
OBJECTIVES Propofol is a preferred agent for sedation in patients in the intensive care unit (ICU) due, in part, to its established safety profile. Despite this, recent case reports have suggested a potential for prolongation of the corrected QT interval (QTc) in ICU patients receiving propofol, though limited empirical work has been conducted to evaluate this association. As such, the purpose of this study was to assess the relationship between propofol infusion and QTc prolongation in a historical cohort of ICU patients. METHODS A single-center, historical, observational, pre-post cohort analysis of medical records from admitted patients ⩾18 years old with cardiovascular disease was conducted, involving cases who received propofol infusion for ⩾3 hours with sequential electrocardiogram monitoring from 2006 to 2012. A multivariable, generalized linear model regression was employed to assess the primary outcome of on-propofol QTc interval (QTc2), controlling for various demographic and clinical factors. RESULTS A total of 96 patients met inclusion criteria, averaging 56.1 ± 14.1 years of age and 86.1 ± 25.0 kg, with 37.5% being female. A mean prolongation in QTc interval of 30.4 ± 55.5 ms (p < 0.001) was observed during the propofol infusion, with 43.8% of cases exhibiting an on-infusion QTc2 of ⩾ 500 ms. Regression analyses suggested that prolongation in on-propofol QTc was independently associated with baseline QTc interval and amiodarone use, while weight as inversely associated with QTc2 (p < 0.05). CONCLUSION This historical cohort analysis of adult ICU patients receiving propofol suggests that on-infusion QTc prolongation was associated with increasing baseline QTc interval and with amiodarone use. Further research is needed to evaluate the clinical significance and cause-and-effect relationship between potential QTc changes and propofol use in the ICU.
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Affiliation(s)
- Michael J Scalese
- Auburn University Assistant Clinical Professor, Department of Pharmacy Practice Auburn University Harrison School of Pharmacy 650 Clinic Drive, Rm 2100 Mobile, AL 36688
| | - Holly R Herring
- Pharmacist, Department of Pharmacy, Integris Health Edmond, 4801 Integris Parkway, Edmond Oklahoma 73112
| | - R Chris Rathbun
- Professor and Chair, Department of Pharmacy: Clinical and Administrative Sciences, University of Oklahoma College of Pharmacy, 1110 N Stonewall Ave, Oklahoma City, OK 73117
| | - Grant H Skrepnek
- Associate Professor, Department of Pharmacy: Clinical and Administrative Sciences, University of Oklahoma College of Pharmacy, 1110 N Stonewall Ave, Oklahoma City, OK 73117
| | - Toni L Ripley
- Associate Professor, Department of Pharmacy: Clinical and Administrative Sciences, University of Oklahoma College of Pharmacy, 1110 N Stonewall Ave, Oklahoma City, OK 73117
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Abstract
BACKGROUND Propionic acidemia (PROP) is a rare metabolic disorder caused by deficiency of propionyl-CoA carboxylase. PROP patients demonstrate QT prolongations associated with ventricular tachycardia and syncopes. Mechanisms responsible for this acquired long QT syndrome (acqLQTS) are unknown. OBJECTIVE The aim of the study was to investigate acute and chronic effects of metabolites accumulating in PROP patients on major repolarizing potassium currents (IKs and IKr) and their channel subunits. METHODS Voltage clamp studies were performed in CHO-KCNQ1/KCNE1 or HEK-KCNH2 cells to determine effects of propionic acid (PA; 1-10 mM), propionylcarnitine (PC; 25 µM-10 mM), methylcitrate (MC; 25 µM-10 mM), 0.2 M phosphate buffer (PB), or patient serum on IKs and IKr currents. Metabolite effects on action potentials were recorded in current clamp mode in human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CM). Protein expression of α- and β-subunits of IKs (KCNQ1/KCNE1) and IKr (KCNH2) was evaluated with Western blots. RESULTS Acute application of PA, PC, MC, and patient serum had no direct effect on net IKr densities (and KCNH2 expression), although it changed IKr gating kinetics. In contrast, PA, PC, MC, and patient serum all reduced IKs-tail (-67% ± 4.2%, -27% ± 6.7%, -16% ± 6.3%, -42.8% ± 5.15; P < .001) and IKs-end pulse currents. PA significantly prolonged action potential duration (APD) in hiPSC-CM and QT interval in wild-type but not in LQT1 rabbits lacking IKs. Moreover, PC and MC (1 mM) decreased KCNQ1 protein expression (relative density: 0.58 ± 0.08 and 0.16 ± 0.05; P < .01). Chronic exposure to 10 mM PA, in contrast, increased KCNQ1 5.4-fold (P < .001) owing to decreased protein degradation. CONCLUSION Acute reduction of IKs by PROP metabolites may be responsible for APD prolongation and acqLQTS observed in PROP patients.
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Lau E, Kossidas K, Kim TY, Kunitomo Y, Ziv O, Zhen S, Taylor C, Schofield L, Yammine J, Liu G, Peng X, Qu Z, Koren G, Choi BR. Spatially Discordant Alternans and Arrhythmias in Tachypacing-Induced Cardiac Myopathy in Transgenic LQT1 Rabbits: The Importance of IKs and Ca2+ Cycling. PLoS One 2015; 10:e0122754. [PMID: 25970695 PMCID: PMC4430457 DOI: 10.1371/journal.pone.0122754] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Accepted: 02/12/2015] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Remodeling of cardiac repolarizing currents, such as the downregulation of slowly activating K+ channels (IKs), could underlie ventricular fibrillation (VF) in heart failure (HF). We evaluated the role of Iks remodeling in VF susceptibility using a tachypacing HF model of transgenic rabbits with Long QT Type 1 (LQT1) syndrome. METHODS AND RESULTS LQT1 and littermate control (LMC) rabbits underwent three weeks of tachypacing to induce cardiac myopathy (TICM). In vivo telemetry demonstrated steepening of the QT/RR slope in LQT1 with TICM (LQT1-TICM; pre: 0.26±0.04, post: 0.52±0.01, P<0.05). In vivo electrophysiology showed that LQT1-TICM had higher incidence of VF than LMC-TICM (6 of 11 vs. 3 of 11, respectively). Optical mapping revealed larger APD dispersion (16±4 vs. 38±6 ms, p<0.05) and steep APD restitution in LQT1-TICM compared to LQT1-sham (0.53±0.12 vs. 1.17±0.13, p<0.05). LQT1-TICM developed spatially discordant alternans (DA), which caused conduction block and higher-frequency VF (15±1 Hz in LQT1-TICM vs. 13±1 Hz in LMC-TICM, p<0.05). Ca2+ DA was highly dynamic and preceded voltage DA in LQT1-TICM. Ryanodine abolished DA in 5 out of 8 LQT1-TICM rabbits, demonstrating the importance of Ca2+ in complex DA formation. Computer simulations suggested that HF remodeling caused Ca2+-driven alternans, which was further potentiated in LQT1-TICM due to the lack of IKs. CONCLUSIONS Compared with LMC-TICM, LQT1-TICM rabbits exhibit steepened APD restitution and complex DA modulated by Ca2+. Our results strongly support the contention that the downregulation of IKs in HF increases Ca2+ dependent alternans and thereby the risk of VF.
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Affiliation(s)
- Emily Lau
- Cardiovascular Research Center, Division of Cardiology, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, Rhode Island, United States of America
| | - Konstantinos Kossidas
- Cardiovascular Research Center, Division of Cardiology, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, Rhode Island, United States of America
| | - Tae Yun Kim
- Cardiovascular Research Center, Division of Cardiology, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, Rhode Island, United States of America
| | - Yukiko Kunitomo
- Cardiovascular Research Center, Division of Cardiology, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, Rhode Island, United States of America
| | - Ohad Ziv
- Cardiovascular Research Center, Division of Cardiology, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, Rhode Island, United States of America
| | - Song Zhen
- Department of Medicine (Cardiology), David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
| | - Chantel Taylor
- Cardiovascular Research Center, Division of Cardiology, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, Rhode Island, United States of America
| | - Lorraine Schofield
- Cardiovascular Research Center, Division of Cardiology, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, Rhode Island, United States of America
| | - Joe Yammine
- Cardiovascular Research Center, Division of Cardiology, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, Rhode Island, United States of America
| | - Gongxin Liu
- Cardiovascular Research Center, Division of Cardiology, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, Rhode Island, United States of America
| | - Xuwen Peng
- Department of Comparative Medicine, Pennsylvania State University College of Medicine, Hershey, Pennsylvania, United States of America
| | - Zhilin Qu
- Department of Medicine (Cardiology), David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
| | - Gideon Koren
- Cardiovascular Research Center, Division of Cardiology, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, Rhode Island, United States of America
| | - Bum-Rak Choi
- Cardiovascular Research Center, Division of Cardiology, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, Rhode Island, United States of America
- * E-mail:
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Odening KE, Koren G. How do sex hormones modify arrhythmogenesis in long QT syndrome? Sex hormone effects on arrhythmogenic substrate and triggered activity. Heart Rhythm 2014; 11:2107-15. [PMID: 24954242 PMCID: PMC4394187 DOI: 10.1016/j.hrthm.2014.06.023] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Indexed: 11/28/2022]
Abstract
Gender differences in cardiac repolarization and the arrhythmogenic risk of patients with inherited and acquired long QT syndromes are well appreciated clinically. Enhancing our knowledge of the mechanisms underlying these differences is critical to improve our therapeutic strategies for preventing sudden cardiac death in such patients. This review summarizes the effects of sex hormones on the expression and function of ion channels that control cardiac cell excitation and repolarization as well as key proteins that regulate Ca(2+) dynamics at the cellular level. Moreover, it examines the role of sex hormones in modifying the dynamic spatiotemporal (regional and transmural) heterogeneities in action potential duration (eg, the arrhythmogenic substrate) and the susceptibility to (sympathetic) triggered activity at the tissue, organ, and whole animal levels. Finally, it explores the implications of these effects on the management of patients with LQTS.
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Affiliation(s)
- Katja E Odening
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Freiburg, Germany.
| | - Gideon Koren
- Division of Cardiology, Cardiovascular Research Center, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, Rhode Island
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Ziupa D, Beck J, Franke G, Perez Feliz S, Hartmann M, Koren G, Zehender M, Bode C, Brunner M, Odening KE. Pronounced effects of HERG-blockers E-4031 and erythromycin on APD, spatial APD dispersion and triangulation in transgenic long-QT type 1 rabbits. PLoS One 2014; 9:e107210. [PMID: 25244401 PMCID: PMC4170956 DOI: 10.1371/journal.pone.0107210] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Accepted: 08/04/2014] [Indexed: 12/13/2022] Open
Abstract
Background Prolongation of action potential duration (APD), increased spatial APD dispersion, and triangulation are major factors promoting drug-induced ventricular arrhythmia. Preclinical identification of HERG/IKr-blocking drugs and their pro-arrhythmic potential, however, remains a challenge. We hypothesize that transgenic long-QT type 1 (LQT1) rabbits lacking repolarizing IKs current may help to sensitively detect HERG/IKr-blocking properties of drugs. Methods Hearts of adult female transgenic LQT1 and wild type littermate control (LMC) rabbits were Langendorff-perfused with increasing concentrations of HERG/IKr-blockers E-4031 (0.001–0.1 µM, n = 9/7) or erythromycin (1–300 µM, n = 9/7) and APD, APD dispersion, and triangulation were analyzed. Results At baseline, APD was longer in LQT1 than in LMC rabbits in LV apex and RV mid. Erythromycin and E-4031 prolonged APD in LQT1 and LMC rabbits in all positions. However, erythromycin-induced percentaged APD prolongation related to baseline (%APD) was more pronounced in LQT1 at LV base-lateral and RV mid positions (100 µM, LQT1, +40.6±9.7% vs. LMC, +24.1±10.0%, p<0.05) and E-4031-induced %APD prolongation was more pronounced in LQT1 at LV base-lateral (0.01 µM, LQT1, +29.6±10.6% vs. LMC, +19.1±3.8%, p<0.05) and LV base-septal positions. Moreover, erythromycin significantly increased spatial APD dispersion only in LQT1 and increased triangulation only in LQT1 in LV base-septal and RV mid positions. Similarly, E-4031 increased triangulation only in LQT1 in LV apex and base-septal positions. Conclusions E-4031 and erythromycin prolonged APD and increased triangulation more pronouncedly in LQT1 than in LMC rabbits. Moreover, erythromycin increased APD dispersion only in LQT1, indicating that transgenic LQT1 rabbits could serve as sensitive model to detect HERG/IKr-blocking properties of drugs.
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Affiliation(s)
- David Ziupa
- Heart Center University of Freiburg, Department of Cardiology and Angiology I, Freiburg, Germany
| | - Julia Beck
- Heart Center University of Freiburg, Department of Cardiology and Angiology I, Freiburg, Germany
| | - Gerlind Franke
- Heart Center University of Freiburg, Department of Cardiology and Angiology I, Freiburg, Germany
| | - Stefanie Perez Feliz
- Heart Center University of Freiburg, Department of Cardiology and Angiology I, Freiburg, Germany
| | - Maximilian Hartmann
- Heart Center University of Freiburg, Department of Cardiology and Angiology I, Freiburg, Germany
| | - Gideon Koren
- Cardiovascular Research Center, Division of Cardiology, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, Rhode Island, United States of America
| | - Manfred Zehender
- Heart Center University of Freiburg, Department of Cardiology and Angiology I, Freiburg, Germany
| | - Christoph Bode
- Heart Center University of Freiburg, Department of Cardiology and Angiology I, Freiburg, Germany
| | - Michael Brunner
- Heart Center University of Freiburg, Department of Cardiology and Angiology I, Freiburg, Germany
| | - Katja E. Odening
- Heart Center University of Freiburg, Department of Cardiology and Angiology I, Freiburg, Germany
- * E-mail:
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VARKEVISSER ROSANNE, VOS MARCA, BEEKMAN JETD, TIELAND RALPHG, VAN DER HEYDEN MARCELA. AV-Block and Conduction Slowing Prevail Over TdP Arrhythmias in the Methoxamine-Sensitized Pro-Arrhythmic Rabbit Model. J Cardiovasc Electrophysiol 2014; 26:82-9. [DOI: 10.1111/jce.12533] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/14/2014] [Revised: 08/14/2014] [Accepted: 08/19/2014] [Indexed: 11/27/2022]
Affiliation(s)
- ROSANNE VARKEVISSER
- Department of Medical Physiology; Division Heart & Lungs University Medical Center Utrecht; Utrecht The Netherlands
| | - MARC A. VOS
- Department of Medical Physiology; Division Heart & Lungs University Medical Center Utrecht; Utrecht The Netherlands
| | - JET D. BEEKMAN
- Department of Medical Physiology; Division Heart & Lungs University Medical Center Utrecht; Utrecht The Netherlands
| | - RALPH G. TIELAND
- Department of Medical Physiology; Division Heart & Lungs University Medical Center Utrecht; Utrecht The Netherlands
| | - MARCEL A. VAN DER HEYDEN
- Department of Medical Physiology; Division Heart & Lungs University Medical Center Utrecht; Utrecht The Netherlands
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Combes RD. A critical review of anaesthetised animal models and alternatives for military research, testing and training, with a focus on blast damage, haemorrhage and resuscitation. Altern Lab Anim 2014; 41:385-415. [PMID: 24329746 DOI: 10.1177/026119291304100508] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Military research, testing, and surgical and resuscitation training, are aimed at mitigating the consequences of warfare and terrorism to armed forces and civilians. Traumatisation and tissue damage due to explosions, and acute loss of blood due to haemorrhage, remain crucial, potentially preventable, causes of battlefield casualties and mortalities. There is also the additional threat from inhalation of chemical and aerosolised biological weapons. The use of anaesthetised animal models, and their respective replacement alternatives, for military purposes -- particularly for blast injury, haemorrhaging and resuscitation training -- is critically reviewed. Scientific problems with the animal models include the use of crude, uncontrolled and non-standardised methods for traumatisation, an inability to model all key trauma mechanisms, and complex modulating effects of general anaesthesia on target organ physiology. Such effects depend on the anaesthetic and influence the cardiovascular system, respiration, breathing, cerebral haemodynamics, neuroprotection, and the integrity of the blood-brain barrier. Some anaesthetics also bind to the NMDA brain receptor with possible differential consequences in control and anaesthetised animals. There is also some evidence for gender-specific effects. Despite the fact that these issues are widely known, there is little published information on their potential, at best, to complicate data interpretation and, at worst, to invalidate animal models. There is also a paucity of detail on the anaesthesiology used in studies, and this can hinder correct data evaluation. Welfare issues relate mainly to the possibility of acute pain as a side-effect of traumatisation in recovered animals. Moreover, there is the increased potential for animals to suffer when anaesthesia is temporary, and the procedures invasive. These dilemmas can be addressed, however, as a diverse range of replacement approaches exist, including computer and mathematical dynamic modelling of the human body, cadavers, interactive human patient simulators for training, in vitro techniques involving organotypic cultures of target organs, and epidemiological and clinical studies. While the first four of these have long proven useful for developing protective measures and predicting the consequences of trauma, and although many phenomena and their sequelae arising from different forms of trauma in vivo can be induced and reproduced in vitro, non-animal approaches require further development, and their validation and use need to be coordinated and harmonised. Recommendations to these ends are proposed, and the scientific and welfare problems associated with animal models are addressed, with the future focus being on the use of batteries of complementary replacement methods deployed in integrated strategies, and on greater transparency and scientific cooperation.
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So EC, Wu KC, Kao FC, Wu SN. Effects of midazolam on ion currents and membrane potential in differentiated motor neuron-like NSC-34 and NG108-15 cells. Eur J Pharmacol 2013; 724:152-60. [PMID: 24374009 DOI: 10.1016/j.ejphar.2013.12.034] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2013] [Revised: 11/22/2013] [Accepted: 12/16/2013] [Indexed: 11/25/2022]
Abstract
Midazolam (MDL) was known to act through stimulation of benzodiazepine receptors (GABA). Whether midazolam affects ion currents and membrane potential in neurons remains largely unclear. Electrophysiological studies of midazolam actions were performed in differentiated motor neuron-like (NSC-34 and NG108-15) cells. Midazolam suppressed the amplitude of delayed rectifier K(+) current (IK(DR)) in a time- and concentration-dependent manner with an IC50 value of 10.4 µM. Addition of midazolam was noted to enhance the rate of IK(DR) inactivation. On the basis of minimal binding scheme, midazolam-induced block of IK(DR) was quantitatively provided with a dissociation constant of 9.8 µM. Recovery of IK(DR) from inactivation in the presence of midazolam was fitted by a single exponential. midazolam had no effect on M-type or erg-mediated K(+) current in these cells. Midazaolam (30 µM) suppressed the peak amplitude of voltage-gated Na(+) current (INa) with no change in the current-voltage relationships of this current. Inactivation kinetics of INa remained unaltered in the presence of this agent. In current-clamp configuration, midazolam (30 µM) prolonged the duration of action potentials (APs) and reduce AP amplitude. Similarly, in differentiated NG108-15 cells, the exposure to midazolam also suppressed IK(DR) with a concomitant increase in current inactivation. Midazolam can act as an open-channel blocker of delayed-rectifier K(+) channels in these cells. The synergistic blocking effects on IK(DR) and INa may contribute to the underlying mechanisms through which midazolam affects neuronal function in vivo.
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Affiliation(s)
- Edmund Cheung So
- Department of Anesthesia, Tainan Municipal An-Nan Hospital, China Medical University, 66# Cheung Ho Road, An-Nan District, Tainan, Taiwan; Department of Anesthesia, China Medical University, 91# Hsueh-Shih Road, Taichung, Taiwan; Department of Cell Biology and Anatomy, Cheng Kung University, 1# University Road, Tainan City, Taiwan; Department of Anesthesia, Taishan Medical University, 619 Chang Cheng Road, Taian 271016, Shandong Province, PR China; Department of Anesthesia, Nan Shan branch of Gilu Hospital, Shandong University, Shandong Province, PR China.
| | - King Chuen Wu
- Department of Anesthesiology, Eda-Hospital/I-Shou University, 1# Yida Road, Jiaosu Village, Yanchao District, Kaohsiung, Taiwan.
| | - Feng Chen Kao
- Department of Orthopedic Surgery, E-Da Hospital/I-Shou University, 1# Yida Road, Jiaosu Village, Yanchao District, Kaohsiung, Taiwan.
| | - Sheng Nan Wu
- Department of Physiology, National Cheng Kung University, 1# University Road, Tainan City, Taiwan.
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Odening KE, Jung BA, Lang CN, Cabrera Lozoya R, Ziupa D, Menza M, Relan J, Franke G, Perez Feliz S, Koren G, Zehender M, Bode C, Brunner M, Sermesant M, Föll D. Spatial correlation of action potential duration and diastolic dysfunction in transgenic and drug-induced LQT2 rabbits. Heart Rhythm 2013; 10:1533-41. [PMID: 23892340 DOI: 10.1016/j.hrthm.2013.07.038] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2013] [Indexed: 11/24/2022]
Abstract
BACKGROUND Enhanced dispersion of action potential duration (APD) is a major contributor to long QT syndrome (LQTS)-related arrhythmias. OBJECTIVE To investigate spatial correlations of regional heterogeneities in cardiac repolarization and mechanical function in LQTS. METHODS Female transgenic LQTS type 2 (LQT2; n = 11) and wild-type littermate control (LMC) rabbits (n = 9 without E4031 and n = 10 with E4031) were subjected to phase contrast magnetic resonance imaging to assess regional myocardial velocities. In the same rabbits' hearts, monophasic APDs were assessed in corresponding segments. RESULTS In LQT2 and E4031-treated rabbits, APD was longer in all left ventricular segments (P < .01) and APD dispersion was greater than that in LMC rabbits (P < .01). In diastole, peak radial velocities (Vr) were reduced in LQT2 and E4031-treated compared to LMC rabbits in LV base and mid (LQT2: -3.36 ± 0.4 cm/s, P < .01; E4031-treated: -3.24 ± 0.6 cm/s, P < .0001; LMC: -4.42 ± 0.5 cm/s), indicating an impaired diastolic function. Regionally heterogeneous diastolic Vr correlated with APD (LQT2: correlation coefficient [CC] 0.38, P = .01; E4031-treated: CC 0.42, P < .05). Time-to-diastolic peak Vr were prolonged in LQT2 rabbits (LQT2: 196.8 ± 2.9 ms, P < .001; E4031-treated: 199.5 ± 2.2 ms, P < .0001, LMC 183.1 ± 1.5), indicating a prolonged contraction duration. Moreover, in transgenic LQT2 rabbits, diastolic time-to-diastolic peak Vr correlated with APD (CC 0.47, P = .001). In systole, peak Vr were reduced in LQT2 and E4031-treated rabbits (P < .01) but longitudinal velocities or ejection fraction did not differ. Finally, random forest machine learning algorithms enabled a differentiation between LQT2, E4031-treated, and LMC rabbits solely based on "mechanical" magnetic resonance imaging data. CONCLUSIONS The prolongation of APD led to impaired diastolic and systolic function in transgenic and drug-induced LQT2 rabbits. APD correlated with regional diastolic dysfunction, indicating that LQTS is not purely an electrical but an electromechanical disorder.
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Affiliation(s)
- Katja E Odening
- Department of Cardiology and Angiology I, Heart Center Freiburg University, Freiburg, Germany.
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Zhang P, Xing J, Luo A, Feng J, Liu Z, Gao C, Ma J. Blockade of the human ether-a-go-go-related gene potassium channel by ketamine. ACTA ACUST UNITED AC 2013; 65:1321-8. [PMID: 23927470 DOI: 10.1111/jphp.12095] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2013] [Accepted: 05/12/2013] [Indexed: 11/27/2022]
Abstract
OBJECTIVES The inhibition of the cardiac rapid delayed rectifier potassium current (IKr ) and its cloned equivalent human ether-a-go-go-related gene (hERG) channel illustrate QT interval prolonging effects of a wide range of clinically used drugs. In this study, the direct interaction of the intravenous anaesthetic ketamine with wild-type (WT) and mutation hERG currents (IhERG ) was investigated. METHODS The hERG channel (WT, Y652A and F656A) was expressed in Xenopus oocytes and studied using standard two-microelectrode voltage-clamp techniques. KEY FINDINGS WT hERG is blocked in a concentration-dependent manner with IC50 = 12.05 ± 1.38 μm by ketamine, and the steady-state inactivation curves are shifted to more negative potentials (about -27 mV). The mutation to Ala of Y652 and F656 located on the S6 domain attenuate IhERG blockade by ketamine, and produced approximately 9-fold and 2.5-fold increases in IC50 compared with that of WT hERG channel, respectively. CONCLUSIONS Ketamine blocks WT IhERG expressed in Xenopus oocytes in a concentration-dependent manner and predominantly interacts with the open hERG channels. The interaction of ketamine with hERG channel may involve the aromatic residues Tyr652 and Phe656.
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Affiliation(s)
- Peihua Zhang
- Cardio-Electrophysiological Research Laboratory, Medical College, Wuhan University of Science and Technology, Wuhan, China
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Case scenario: anesthesia-related cardiac arrest in a child with Timothy syndrome. Anesthesiology 2013; 117:1117-26. [PMID: 23011317 DOI: 10.1097/aln.0b013e31826e73b1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
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Wutzler A, Huemer M, Boldt LH, Parwani AS, Attanasio P, Tscholl V, Haverkamp W. Effects of deep sedation on cardiac electrophysiology in patients undergoing radiofrequency ablation of supraventricular tachycardia: impact of propofol and ketamine. ACTA ACUST UNITED AC 2013; 15:1019-24. [DOI: 10.1093/europace/eut025] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Peng X. Transgenic rabbit models for studying human cardiovascular diseases. Comp Med 2012; 62:472-479. [PMID: 23561880 PMCID: PMC3527751] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2012] [Revised: 06/04/2012] [Accepted: 06/11/2012] [Indexed: 06/02/2023]
Abstract
Cardiovascular diseases involve the heart or blood vessels and remain a leading cause of morbidity and mortality in developed countries. A variety of animal models have been used to study cardiovascular diseases and have contributed to our understanding of their pathophysiology and treatment. However, mutations or abnormal expression of specific genes play important roles in the pathophysiology of some heart diseases, for which a closely similar animal model often is not naturally available. With the advent of techniques for specific genomic modification, several transgenic and knockout mouse models have been developed for cardiovascular conditions that result from spontaneous mutations. However, mouse and human heart show marked electrophysiologic differences. In addition, cardiac studies in mouse models are extremely difficult because of their small heart size and fast heart rate. Therefore, larger genetically engineered animal models are needed to overcome the limitations of the mouse models. This review summarizes the transgenic rabbit models that have been developed to study cardiovascular diseases.
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Affiliation(s)
- Xuwen Peng
- Department of Comparative Medicine, College of Medicine, The Pennsylvania State University, Hershey, PA, USA.
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Jindal HK, Merchant E, Balschi JA, Zhangand Y, Koren G. Proteomic analyses of transgenic LQT1 and LQT2 rabbit hearts elucidate an increase in expression and activity of energy producing enzymes. J Proteomics 2012; 75:5254-65. [PMID: 22796357 DOI: 10.1016/j.jprot.2012.06.034] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2011] [Revised: 06/04/2012] [Accepted: 06/11/2012] [Indexed: 01/22/2023]
Abstract
Various biochemical and genomic mechanisms are considered to be a hallmark of metabolic remodeling in the stressed heart, including the hypertrophied and failing heart. In this study, we used quantitative proteomic 2-D Fluorescence Difference In-Gel Electrophoresis (2-D DIGE) in conjunction with mass spectrometry to demonstrate differential protein expression in the hearts of transgenic rabbit models of Long QT Syndrome 1 (LQT1) and Long QT Syndrome 2 (LQT2) as compared to littermate controls (LMC). The results of our proteomic analysis revealed upregulation of key metabolic enzymes involved in all pathways associated with ATP generation, including creatine kinase in both LQT1 and LQT2 rabbit hearts. Additionally, the expression of lamin-A protein was increased in both LQT1 and LQT2 rabbit hearts as was the expression of mitochondrial aldehyde dehydrogenase and desmoplakin in LQT1 and LQT 2 rabbit hearts, respectively. Results of the proteomic analysis also demonstrated down regulation in the expression of protein disulfide-isomerase A3 precuorsor and dynamin-like 120 kDa protein (mitochondrial) in LQT1, and of alpha-actinin 2 in LQT2 rabbit hearts. Up regulation of the expression of the enzymes associated with ATP generation was substantiated by the results of selective enzyme assays in LQT1 and LQT2 hearts, as compared to LMC, which revealed increases in the activities of glycogen phosphorylase (+50%, +65%, respectively), lactate dehydrogenase (+25%, +25%) pyruvate dehydrogenase (+31%, +22%), and succinate dehydrogenase (+32%, +60%). The activity of cytochrome c-oxidase, a marker for the mitochondrial function was also found to be significantly elevated (+80%) in LQT1 rabbit hearts as compared with LMC. Western blot analysis in LQT1 and LQT2 hearts compared to LMC revealed an increase in the expression of very-long chain-specific acyl-CoA dehydrogenase (+35%, +33%), a rate-limiting enzymes in β-oxidation of fatty acids. Collectively, our results demonstrate similar increases in the expression and activities of key ATP-generating enzymes in LQT1 and LQT2 rabbit hearts, suggesting an increased demand, and in turn, increased energy supply across the entire metabolic pathway by virtue of the upregulation of enzymes involved in energy generation.
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Affiliation(s)
- Hitesh K Jindal
- Cardiovascular Research Center, Division of Cardiology, Rhode Island Hospital, Alpert Medical School of Brown University, 1 Hoppin Street, West Coro-5, Providence, RI 02903, USA
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Duranthon V, Beaujean N, Brunner M, Odening KE, Santos AN, Kacskovics I, Hiripi L, Weinstein EJ, Bosze Z. On the emerging role of rabbit as human disease model and the instrumental role of novel transgenic tools. Transgenic Res 2012; 21:699-713. [PMID: 22382461 DOI: 10.1007/s11248-012-9599-x] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2012] [Accepted: 02/04/2012] [Indexed: 12/19/2022]
Abstract
The laboratory rabbit (Oryctolagus cuniculus) is widely used as a model for human diseases, because of its size, which permits non-lethal monitoring of physiological changes and similar disease characteristics. Novel transgenic tools such as, the zinc finger nuclease method and the sleeping beauty transposon mediated or BAC transgenesis were recently adapted to the laboratory rabbit and opened new opportunities in precise tissue and developmental stage specific gene expression/silencing, coupled with increased transgenic efficiencies. Many facets of human development and diseases cannot be investigated in rodents. This is especially true for early prenatal development, its long-lasting effects on health and complex disorders, and some economically important diseases such as atherosclerosis or cardiovascular diseases. The first transgenic rabbits models of arrhythmogenesis mimic human cardiac diseases much better than transgenic mice and hereby underline the importance of non-mouse models. Another emerging field is epigenetic reprogramming and pathogenic mechanisms in diabetic pregnancy, where rabbit models are indispensable. Beyond that rabbit is used for decades as major source of polyclonal antibodies and recently in monoclonal antibody production. Alteration of its genome to increase the efficiency and value of the antibodies by humanization of the immunoglobulin genes, or by increasing the expression of a special receptor (Fc receptor) that augments humoral immune response is a current demand.
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Affiliation(s)
- V Duranthon
- INRA, UMR 1198 Biologie du Développement et Reproduction, 78350 Jouy en Josas, France
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Odening KE, Choi BR, Koren G. Sex hormones and cardiac arrest in long QT syndrome: does progesterone represent a potential new antiarrhythmic therapy? Heart Rhythm 2012; 9:1150-2. [PMID: 22381742 DOI: 10.1016/j.hrthm.2012.02.028] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2012] [Indexed: 11/27/2022]
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Abstract
Transgenic rabbits expressing pore mutants of K(V)7.1 display a long QT syndrome 1 (LQT1) phenotype. Recently, NS1643 has been described to increase I(Kr).We hypothesized that NS1643 would shorten the action potential duration (APD(90)) in LQT1 rabbits. Transgenic LQT1 rabbits were compared with littermate control (LMC) rabbits. In vivo electrocardiogram studies in sedated animals were performed at baseline and during 45 minutes of intravenous infusion of NS1643 or vehicle in a crossover design. Ex vivo monophasic action potentials were recorded from Langendorff-perfused hearts at baseline and during 45-minute perfusion with NS1643. Left ventricular refractory periods were assessed before and after NS1643 infusion. Genotype differences in APD accommodation were also addressed. In vivo NS1643 shortened the QTc significantly in LQT1 compared with vehicle. In Langendorff experiments, NS1643 significantly shortened the APD(90) in LQT1 and LMC [32.0 ± 4.3 milliseconds (ms); 21.0 ± 5.0 ms] and left ventricular refractory periods (23.7 ± 8.3; 22.6 ± 9.9 ms). NS1643 significantly decreased dp/dt (LQT1: 49% ± 3%; LMC: 63% ± 4%) and increased the incidence of arrhythmia. The time course of APD adaptation was impaired in LQT1 rabbits and unaffected by I(Kr) augmentation. In conclusion, K(V)11.1 channel activation shortens the cardiac APD in a rabbit model of inherited LQT1, but it comes with the risk of excessive shortening of APD.
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Odening KE, Choi BR, Liu GX, Hartmann K, Ziv O, Chaves L, Schofield L, Centracchio J, Zehender M, Peng X, Brunner M, Koren G. Estradiol promotes sudden cardiac death in transgenic long QT type 2 rabbits while progesterone is protective. Heart Rhythm 2012; 9:823-32. [PMID: 22245795 DOI: 10.1016/j.hrthm.2012.01.009] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2011] [Indexed: 10/14/2022]
Abstract
BACKGROUND Postpubertal women with inherited long QT syndrome type 2 (LQT2) are at increased risk for polymorphic ventricular tachycardia (pVT) and sudden cardiac death (SCD), particularly during the postpartum period. OBJECTIVE To investigate whether sex hormones directly modulate the arrhythmogenic risk in LQTS. METHODS Prepubertal ovariectomized transgenic LQT2 rabbits were treated with estradiol (EST), progesterone (PROG), dihydrotestosterone (DHT), or placebo (OVX). RESULTS During 8 weeks of treatment, major cardiac events-spontaneous pVT or SCD-occurred in 5 of the 7 EST rabbits and in 2 of the 9 OVX rabbits (P <.05); in contrast, no events occurred in 9 PROG rabbits and 6 DHT rabbits (P <.01 vs PROG; P <.05 vs DHT). Moreover, EST increased the incidence of pVT (P <.05 vs OVX), while PROG reduced premature ventricular contractions, bigeminy, couplets, triplets, and pVT (P <.01 vs OVX; P <.001 vs EST). In vivo electrocardiographic monitoring, in vivo electrophysiological studies, and ex vivo optical mapping studies revealed that EST promoted SCD by steepening the QT/RR slope (P <.05), by prolonging cardiac refractoriness (P <.05), and by altering the spatial pattern of action potential duration dispersion. Isoproterenol-induced Ca(2+) oscillations resulted in early afterdepolarizations in EST-treated hearts (4 of 4), while PROG prevented SCD by eliminating this early afterdepolarization formation in 4 of the 7 hearts (P = .058 vs EST; P <.05 vs OVX). Analyses of ion currents demonstrated that EST increased the density of I(Ca,L) as compared with OVX (P <.05) while PROG decreased it (P <.05). CONCLUSION This study reveals the proarrhythmic effect of EST and the antiarrhythmic effect of PROG in LQT2 in vivo, outlining a new potential antiarrhythmic therapy for LQTS.
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Affiliation(s)
- Katja E Odening
- Alpert Medical School of Brown University, Providence, RI, USA
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Guo J, Wang T, Yang T, Xu J, Li W, Fridman MD, Fisher JT, Zhang S. Interaction between the cardiac rapidly (IKr) and slowly (IKs) activating delayed rectifier potassium channels revealed by low K+-induced hERG endocytic degradation. J Biol Chem 2011; 286:34664-74. [PMID: 21844197 DOI: 10.1074/jbc.m111.253351] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cardiac repolarization is controlled by the rapidly (I(Kr)) and slowly (I(Ks)) activating delayed rectifier potassium channels. The human ether-a-go-go-related gene (hERG) encodes I(Kr), whereas KCNQ1 and KCNE1 together encode I(Ks). Decreases in I(Kr) or I(Ks) cause long QT syndrome (LQTS), a cardiac disorder with a high risk of sudden death. A reduction in extracellular K(+) concentration ([K(+)](o)) induces LQTS and selectively causes endocytic degradation of mature hERG channels from the plasma membrane. In the present study, we investigated whether I(Ks) compensates for the reduced I(Kr) under low K(+) conditions. Our data show that when hERG and KCNQ1 were expressed separately in human embryonic kidney (HEK) cells, exposure to 0 mM K(+) for 6 h completely eliminated the mature hERG channel expression but had no effect on KCNQ1. When hERG and KCNQ1 were co-expressed, KCNQ1 significantly delayed 0 mM K(+)-induced hERG reduction. Also, hERG degradation led to a significant reduction in KCNQ1 in 0 mM K(+) conditions. An interaction between hERG and KCNQ1 was identified in hERG+KCNQ1-expressing HEK cells. Furthermore, KCNQ1 preferentially co-immunoprecipitated with mature hERG channels that are localized in the plasma membrane. Biophysical and pharmacological analyses indicate that although hERG and KCNQ1 closely interact with each other, they form distinct hERG and KCNQ1 channels. These data extend our understanding of delayed rectifier potassium channel trafficking and regulation, as well as the pathology of LQTS.
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Affiliation(s)
- Jun Guo
- Department of Physiology, Queen's University, Kingston, Ontario K7L 3N6, Canada
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