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van der Waal J, Bear L, Meijborg V, Dubois R, Cluitmans M, Coronel R. Steep repolarization time gradients in pig hearts cause distinct changes in composite electrocardiographic T‐wave parameters. Ann Noninvasive Electrocardiol 2022; 27:e12994. [DOI: 10.1111/anec.12994] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Revised: 06/09/2022] [Accepted: 06/20/2022] [Indexed: 11/30/2022] Open
Affiliation(s)
- Jeanne van der Waal
- Department of Experimental and Clinical Cardiology Amsterdam UMC, Location AMC Amsterdam The Netherlands
| | - Laura Bear
- IHU Liryc, Electrophysiology and Heart Modeling Institute Fondation Bordeaux Université Pessac France
- Université de Bordeaux Pessac France
- Inserm, Cardio‐Thoracix Research Centre of Bordeaux Pessac France
| | - Veronique Meijborg
- Department of Experimental and Clinical Cardiology Amsterdam UMC, Location AMC Amsterdam The Netherlands
| | - Rémi Dubois
- IHU Liryc, Electrophysiology and Heart Modeling Institute Fondation Bordeaux Université Pessac France
- Université de Bordeaux Pessac France
- Inserm, Cardio‐Thoracix Research Centre of Bordeaux Pessac France
| | - Matthijs Cluitmans
- CARIM School for Cardiovascular Diseases Maastricht University Medical Centre Maastricht The Netherlands
| | - Ruben Coronel
- Department of Experimental and Clinical Cardiology Amsterdam UMC, Location AMC Amsterdam The Netherlands
- Université de Bordeaux Pessac France
- Inserm, Cardio‐Thoracix Research Centre of Bordeaux Pessac France
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Husti Z, Varró A, Baczkó I. Arrhythmogenic Remodeling in the Failing Heart. Cells 2021; 10:cells10113203. [PMID: 34831426 PMCID: PMC8623396 DOI: 10.3390/cells10113203] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 11/05/2021] [Accepted: 11/11/2021] [Indexed: 12/12/2022] Open
Abstract
Chronic heart failure is a clinical syndrome with multiple etiologies, associated with significant morbidity and mortality. Cardiac arrhythmias, including ventricular tachyarrhythmias and atrial fibrillation, are common in heart failure. A number of cardiac diseases including heart failure alter the expression and regulation of ion channels and transporters leading to arrhythmogenic electrical remodeling. Myocardial hypertrophy, fibrosis and scar formation are key elements of arrhythmogenic structural remodeling in heart failure. In this article, the mechanisms responsible for increased arrhythmia susceptibility as well as the underlying changes in ion channel, transporter expression and function as well as alterations in calcium handling in heart failure are discussed. Understanding the mechanisms of arrhythmogenic remodeling is key to improving arrhythmia management and the prevention of sudden cardiac death in patients with heart failure.
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Affiliation(s)
- Zoltán Husti
- Department of Pharmacology and Pharmacotherapy, University of Szeged, 6720 Szeged, Hungary; (Z.H.); (A.V.)
- Department of Pharmacology and Pharmacotherapy, Interdisciplinary Excellence Centre, University of Szeged, 6720 Szeged, Hungary
| | - András Varró
- Department of Pharmacology and Pharmacotherapy, University of Szeged, 6720 Szeged, Hungary; (Z.H.); (A.V.)
- Department of Pharmacology and Pharmacotherapy, Interdisciplinary Excellence Centre, University of Szeged, 6720 Szeged, Hungary
- ELKH-SZTE Research Group for Cardiovascular Pharmacology, Eötvös Loránd Research Network, 6720 Szeged, Hungary
| | - István Baczkó
- Department of Pharmacology and Pharmacotherapy, University of Szeged, 6720 Szeged, Hungary; (Z.H.); (A.V.)
- Department of Pharmacology and Pharmacotherapy, Interdisciplinary Excellence Centre, University of Szeged, 6720 Szeged, Hungary
- Correspondence:
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Ferreira G, Santander A, Chavarría L, Cardozo R, Savio F, Sobrevia L, Nicolson GL. Functional consequences of lead and mercury exposomes in the heart. Mol Aspects Med 2021; 87:101048. [PMID: 34785060 DOI: 10.1016/j.mam.2021.101048] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 11/02/2021] [Accepted: 11/03/2021] [Indexed: 12/20/2022]
Abstract
Lead and mercury are heavy metals that are highly toxic to life forms. There are no known physiological processes that require them, and they do not have a particular threshold concentration to produce biologic damage. They are non-biodegradable, and they slowly accumulate in the environment in a dynamic equilibrium between air, water, soil, food, and living organisms. Their accumulation in the environment has been increasing over time, because they were not banned from use in anthropogenic industrial production. In their +2 cationic state they are powerful oxidizing agents with the ability to interfere significantly with processes that require specific divalent cations. Acute or chronic exposure to lead and mercury can produce multisystemic damage, especially in the developing nervous systems of children and fetuses, resulting in variety of neurological consequences. They can also affect the cardiovascular system and especially the heart, either directly through their action on cardiomyocytes or indirectly through their effects on innervation, humoral responses or blood vessel alterations. For example, heart function modified by these heavy metals are heart rate, contraction, excitability, and rhythm. Some cardiac molecular targets have been identified and characterized. The direct mechanisms of damage of these heavy metals on heart function are discussed. We conclude that exposome to these heavy metals, should be considered as a major relevant risk factor for cardiac diseases.
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Affiliation(s)
- Gonzalo Ferreira
- Laboratory of Ion Channels, Biological Membranes and Cell Signaling. Department of Biophysics, Faculty of Medicine, Universidad de la República, Gral. Flores, 2125, CP 11800, Montevideo, Uruguay.
| | - Axel Santander
- Laboratory of Ion Channels, Biological Membranes and Cell Signaling. Department of Biophysics, Faculty of Medicine, Universidad de la República, Gral. Flores, 2125, CP 11800, Montevideo, Uruguay
| | - Luisina Chavarría
- Laboratory of Ion Channels, Biological Membranes and Cell Signaling. Department of Biophysics, Faculty of Medicine, Universidad de la República, Gral. Flores, 2125, CP 11800, Montevideo, Uruguay
| | - Romina Cardozo
- Laboratory of Ion Channels, Biological Membranes and Cell Signaling. Department of Biophysics, Faculty of Medicine, Universidad de la República, Gral. Flores, 2125, CP 11800, Montevideo, Uruguay
| | - Florencia Savio
- Laboratory of Ion Channels, Biological Membranes and Cell Signaling. Department of Biophysics, Faculty of Medicine, Universidad de la República, Gral. Flores, 2125, CP 11800, Montevideo, Uruguay
| | - Luis Sobrevia
- Cellular and Molecular Physiology Laboratory (CMPL), Department of Obstetrics, Division of Obstetrics and Gynaecology, Universidad Católica de Chile, Santiago, 8330024, Chile; Department of Physiology, Faculty of Pharmacy, Universidad de Sevilla, Seville, E-41012, Spain; Medical School (Faculty of Medicine), São Paulo State University (UNESP), Brazil; University of Queensland Centre for Clinical Research (UQCCR), Faculty of Medicine and Biomedical Sciences, University of Queensland, Herston, QLD 4029, Queensland, Australia; Department of Pathology and Medical Biology, University of Groningen, University Medical Center Groningen, 9713GZ, Groningen, the Netherlands
| | - Garth L Nicolson
- Department of Molecular Pathology, The Institute for Molecular Medicine, 16731 Gothard St. Huntington Beach, California, 92647, USA
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Reiffel JA. Antiarrhythmic Drugs for Atrial Fibrillation: Selected Features of Ventricular Repolarization That Facilitate Proarrhythmic Torsades de Pointes and Favor Inpatient Initiation. J Innov Card Rhythm Manag 2021; 12:4600-4605. [PMID: 34327046 PMCID: PMC8313184 DOI: 10.19102/icrm.2021.120704] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2020] [Accepted: 01/15/2021] [Indexed: 12/18/2022] Open
Abstract
The management approaches to patients with atrial fibrillation (AF) include rhythm-control strategies for those patients who are symptomatic despite rate control and for selected others in whom sinus rhythm is necessary for reasons beyond current symptoms (including commercial pilots, those who are felt likely to develop symptoms as comorbidities progress, and more). First-line therapies among the rhythm-control options are antiarrhythmic drugs (AADs). For many AADs, their initiation in-hospital is either a requirement or strongly advised- especially when the patient is in AF. This article explores some of the rationale behind this requirement to give clinicians a better understanding of the reasons for this undesired inconvenience.
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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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Alarcon MML, Trentin-Sonoda M, Panico K, Schleier Y, Duque T, Moreno-Loaiza O, de Yurre AR, Ferreira F, Caio-Silva W, Coury PR, Paiva CN, Medei E, Carneiro-Ramos MS. Cardiac arrhythmias after renal I/R depend on IL-1β. J Mol Cell Cardiol 2019; 131:101-111. [PMID: 31029578 DOI: 10.1016/j.yjmcc.2019.04.025] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 04/23/2019] [Accepted: 04/24/2019] [Indexed: 01/10/2023]
Abstract
AIMS Cardiac arrhythmias are one of the most important remote complications after kidney injury. Renal ischemia reperfusion (I/R) is a major cause of acute renal injury predisposing to several remote dysfunctions, including cardiac electrical disturbance. Since IL-1β production dependent on NLRP3 represents a link between tissue malfunctioning and cardiac arrhythmias, here we tested the hypothesis that longer ventricular repolarization and arrhythmias after renal I/R depend on this innate immunity sensor. METHODS AND RESULTS Nlrp3-/- and Casp1-/- mice reacted to renal I/R with no increase in plasma IL-1β, different from WT (wild-type) I/R. A prolonged QJ interval and an increased susceptibility to ventricular arrhythmias were found after I/R compared to Sham controls in wild-type mice at 15 days post-perfusion, but not in Nlrp3-/- or CASP1-/- I/R, indicating that the absence of NLRP3 or CASP1 totally prevented longer QJ interval after renal I/R. In contrast with WT mice, we found no renal atrophy and no renal dysfunction in Nlrp3-/- and Casp1-/- mice after renal I/R. Depletion of macrophages in vivo after I/R and a day before IL-1β peak (at 7 days post-perfusion) totally prevented prolongation of QJ interval, suggesting that macrophages might participate as sensors of tissue injury. Moreover, treatment of I/R-WT mice with IL-1r antagonist (IL-1ra) from 8 to 15 days post perfusion did not interfere with renal function, but reversed QJ prolongation, prevented the increase in susceptibility to ventricular arrhythmias and rescued a close to normal duration and amplitude of calcium transient. CONCLUSION Taken together, these results corroborate the hypothesis that IL-1β is produced after sensing renal injury through NRLP3-CASP1, and IL-1β on its turn triggers longer ventricular repolarization and increase susceptibility to cardiac arrhythmias. Still, they offer a therapeutic approach to treat cardiac arrhythmias that arise after renal I/R.
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Affiliation(s)
| | - Mayra Trentin-Sonoda
- Center of Natural and Human Sciences (CCNH), Universidade Federal do ABC, Santo André, SP, Brazil
| | - Karine Panico
- Center of Natural and Human Sciences (CCNH), Universidade Federal do ABC, Santo André, SP, Brazil
| | - Ygor Schleier
- Laboratory of Cardioimmunology, Federal University of Rio de Janeiro, Institute of Biophysics Carlos Chagas Filho, Rio de Janeiro, Brazil
| | - Thabata Duque
- Laboratory of Cardioimmunology, Federal University of Rio de Janeiro, Institute of Biophysics Carlos Chagas Filho, Rio de Janeiro, Brazil
| | - Oscar Moreno-Loaiza
- Laboratory of Cardioimmunology, Federal University of Rio de Janeiro, Institute of Biophysics Carlos Chagas Filho, Rio de Janeiro, Brazil
| | - Ainhoa Rodriguez de Yurre
- Laboratory of Cardioimmunology, Federal University of Rio de Janeiro, Institute of Biophysics Carlos Chagas Filho, Rio de Janeiro, Brazil
| | - Fabianno Ferreira
- Institute of Microbiology, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Wellington Caio-Silva
- Center of Natural and Human Sciences (CCNH), Universidade Federal do ABC, Santo André, SP, Brazil
| | - Pedrosa Roberto Coury
- Clementino Fraga Filho Hospital - Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Claudia N Paiva
- Institute of Microbiology, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Emiliano Medei
- Laboratory of Cardioimmunology, Federal University of Rio de Janeiro, Institute of Biophysics Carlos Chagas Filho, Rio de Janeiro, Brazil; National Center for Structural Biology and Bioimaging - CENABIO/UFRJ, Rio de Janeiro, Brazil.
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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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Effects of calmodulin-dependent protein kinase II inhibitor, KN-93, on electrophysiological features of rabbit hypertrophic cardiac myocytes. ACTA ACUST UNITED AC 2012; 32:485-489. [PMID: 22886958 DOI: 10.1007/s11596-012-0084-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2011] [Indexed: 10/28/2022]
Abstract
Cardiac hypertrophy is an independent risk factor for sudden cardiac death in clinical settings and the incidence of sudden cardiac death and ventricular arrhythmias are closely related. The aim of this study was to determine the effects of the calmodulin-dependent protein kinase (CaMK) II inhibitor, KN-93, on L-type calcium current (I(Ca, L)) and early after-depolarizations (EADs) in hypertrophic cardiomyocytes. A rabbit model of myocardial hypertrophy was constructed through abdominal aortic coarctation (LVH group). The control group (sham group) received a sham operation, in which the abdominal aortic was dissected but not coarcted. Eight weeks later, the degree of left ventricular hypertrophy (LVH) was evaluated using echocardiography. Individual cardiomyocyte was isolated through collagenase digestion. Action potentials (APs) and I(Ca, L) were recorded using the perforated patch clamp technique. APs were recorded under current clamp conditions and I(Ca, L) was recorded under voltage clamp conditions. The incidence of EADs and I(ca, L) in the hypertrophic cardiomyocytes were observed under the conditions of low potassium (2 mmol/L), low magnesium (0.25 mmol/L) Tyrode's solution perfusion, and slow frequency (0.25-0.5 Hz) electrical stimulation. The incidence of EADs and I(ca, L) in the hypertrophic cardiomyocytes were also evaluated after treatment with different concentrations of KN-92 (KN-92 group) and KN-93 (KN-93 group). Eight weeks later, the model was successfully established. Under the conditions of low potassium, low magnesium Tyrode's solution perfusion, and slow frequency electrical stimulation, the incidence of EADs was 0/12, 11/12, 10/12, and 5/12 in sham group, LVH group, KN-92 group (0.5 μmol/L), and KN-93 group (0.5 μmol/L), respectively. When the drug concentration was increased to 1 μmol/L in KN-92 group and KN-93 group, the incidence of EADs was 10/12 and 2/12, respectively. At 0 mV, the current density was 6.7±1.0 and 6.3±0.7 PA·PF(-1) in LVH group and sham group, respectively (P>0.05, n=12). When the drug concentration was 0.5 μmol/L in KN-92 and KN-93 groups, the peak I(Ca, L) at 0 mV was decreased by (9.4±2.8)% and (10.5±3.0)% in the hypertrophic cardiomyocytes of the two groups, respectively (P>0.05, n=12). When the drug concentration was increased to 1 μmol/L, the peak I(Ca, L) values were lowered by (13.4±3.7)% and (40±4.9)%, respectively (P<0.01, n=12). KN-93, a specific inhibitor of CaMKII, can effectively inhibit the occurrence of EADs in hypertrophic cardiomyocytes partially by suppressing I(Ca, L), which may be the main action mechanism of KN-93 antagonizing the occurrence of ventricular arrhythmias in hypertrophic myocardium.
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Qian JY, Guo L. Altered cytosolic Ca2+ dynamics in cultured Guinea pig cardiomyocytes as an in vitro model to identify potential cardiotoxicants. Toxicol In Vitro 2010; 24:960-72. [PMID: 20064605 DOI: 10.1016/j.tiv.2009.12.027] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2009] [Revised: 12/07/2009] [Accepted: 12/29/2009] [Indexed: 01/07/2023]
Abstract
Altered intracellular calcium (Ca(i)(2+)) handling by cardiomyocytes has been implicated in drug-induced cardiomyopathy and arrhythmogenesis. To explore whether such alterations predict cardiotoxicity, Ca(i)(2+) imaging was conducted in cultured, spontaneously contracting Guinea pig cardiomyocytes to characterize the effects of 13 cardiotoxicants and 2 safe drugs. All cardiotoxicants perturbed Ca(i)(2+) at therapeutically relevant concentrations. The cytotoxic chemotherapeutics doxorubicin and epirubicin, known to cause cardiomyopathy, preferentially reduced Ca(i)(2+) transient amplitude and sarcoplasmic reticulum (SR) Ca(2+) content, whereas Torsade de Pointes (TdP) inducers and potent hERG channel blockers (amiodarone, cisapride, dofetilide, E-4031 and terfenadine) predominately suppressed diastolic Ca(i)(2+) and contraction rate, and prolonged Ca(i)(2+) transient duration. The molecularly targeted cancer therapeutics, sunitinib and imatinib, exhibited profound effects on Ca(i)(2+), combining effects of cytotoxic chemotherapeutics, TdP inducers and potent hERG channel blockers. TdP inducers lacking direct hERG inhibition, ouabain and pentamidine, significantly elevated Ca(i)(2+) transient amplitude and SR Ca(2+) content while aconitine primarily accelerated automaticity and elevated diastolic Ca(i)(2+) similar to ouabain. Finally, amoxicillin and aspirin did not exert any significant effects on Ca(i)(2+) at concentrations up to 100 microM. These results suggest that detecting altered Ca(i)(2+) handling in cultured cardiomyocytes may be used as an in vitro model for early cardiac drug safety assessment.
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Affiliation(s)
- Jian-Yong Qian
- Safety Pharmacology, Department of Toxicology and Pathology, Non-Clinical Safety, Hoffmann-La Roche, Inc, Nutley, NJ 07110, USA
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Kijtawornrat A, Ziolo MT, Nishijima Y, Roche BM, Hamlin RL. Effects of Sarcolemmal Ca2+ Entry, Ryanodine Function, and Kinase Inhibitors on a Rabbit Model of Heart Failure. Int Heart J 2010; 51:285-90. [DOI: 10.1536/ihj.51.285] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
| | - Mark T. Ziolo
- Department of Physiology and Cell Biology, The Ohio State University
| | - Yoshinori Nishijima
- Department of Veterinary Biosciences, The Ohio State University
- QTest Labs, LLC., 6456 Fiesta Drive
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Nadtochiy SM, Burwell LS, Ingraham CA, Spencer CM, Friedman AE, Pinkert CA, Brookes PS. In vivo cardioprotection by S-nitroso-2-mercaptopropionyl glycine. J Mol Cell Cardiol 2009; 46:960-8. [PMID: 19339206 DOI: 10.1016/j.yjmcc.2009.01.012] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2008] [Revised: 01/21/2009] [Accepted: 01/23/2009] [Indexed: 12/12/2022]
Abstract
The reversible S-nitrosation and inhibition of mitochondrial complex I is a potential mechanism of cardioprotection, recruited by ischemic preconditioning (IPC), S-nitrosothiols, and nitrite. Previously, to exploit this mechanism, the mitochondrial S-nitrosating agent S-nitroso-2-mercaptopropionyl glycine (SNO-MPG) was developed, and protected perfused hearts and isolated cardiomyocytes against ischemia-reperfusion (IR) injury. In the present study, the murine left anterior descending coronary artery (LAD) occlusion model of IR injury was employed, to determine the protective efficacy of SNO-MPG in vivo. Intraperitoneal administration of 1 mg/kg SNO-MPG, 30 min prior to occlusion, significantly reduced myocardial infarction and improved EKG parameters, following 30 min occlusion plus 2 or 24 h reperfusion. SNO-MPG protected to the same degree as IPC, and notably was also protective when administered at reperfusion. Cardioprotection was accompanied by increased mitochondrial protein S-nitrosothiol content, and inhibition of complex I, both of which were reversed after 2 h reperfusion. Finally, hearts from mice harboring a heterozygous mutation in the complex I NDUSF4 subunit were refractory to protection by either SNO-MPG or IPC, suggesting that a fully functional complex I, capable of reversible inhibition is critical for cardioprotection. Overall, these results are consistent with a role for mitochondrial S-nitrosation and complex I inhibition in the cardioprotective mechanism of IPC and SNO-MPG in vivo.
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Affiliation(s)
- Sergiy M Nadtochiy
- Department of Anesthesiology, University of Rochester Medical Center, Rochester, NY 14620, USA
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Mali B, Jarm T, Corovic S, Paulin-Kosir MS, Cemazar M, Sersa G, Miklavcic D. The effect of electroporation pulses on functioning of the heart. Med Biol Eng Comput 2008; 46:745-57. [PMID: 18415132 PMCID: PMC2491703 DOI: 10.1007/s11517-008-0346-7] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2007] [Accepted: 03/29/2008] [Indexed: 12/12/2022]
Abstract
Electrochemotherapy is an effective antitumor treatment currently applied to cutaneous and subcutaneous tumors. Electrochemotherapy of tumors located close to the heart could lead to adverse effects, especially if electroporation pulses were delivered within the vulnerable period of the heart or if they coincided with arrhythmias of some types. We examined the influence of electroporation pulses on functioning of the heart of human patients by analyzing the electrocardiogram. We found no pathological morphological changes in the electrocardiogram; however, we demonstrated a transient RR interval decrease after application of electroporation pulses. Although no adverse effects due to electroporation have been reported so far, the probability for complications could increase in treatment of internal tumors, in tumor ablation by irreversible electroporation, and when using pulses of longer durations. We evaluated the performance of our algorithm for synchronization of electroporation pulse delivery with electrocardiogram. The application of this algorithm in clinical electroporation would increase the level of safety for the patient and suitability of electroporation for use in anatomical locations presently not accessible to existing electroporation devices and electrodes.
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Affiliation(s)
- Barbara Mali
- Laboratory of Biocybernetics, Faculty of Electrical Engineering, University of Ljubljana, Trzaska 25, 1000 Ljubljana, Slovenia
| | - Tomaz Jarm
- Laboratory of Biocybernetics, Faculty of Electrical Engineering, University of Ljubljana, Trzaska 25, 1000 Ljubljana, Slovenia
| | - Selma Corovic
- Laboratory of Biocybernetics, Faculty of Electrical Engineering, University of Ljubljana, Trzaska 25, 1000 Ljubljana, Slovenia
| | | | - Maja Cemazar
- Institute of Oncology Ljubljana, Zaloska 2, 1000 Ljubljana, Slovenia
| | - Gregor Sersa
- Institute of Oncology Ljubljana, Zaloska 2, 1000 Ljubljana, Slovenia
| | - Damijan Miklavcic
- Laboratory of Biocybernetics, Faculty of Electrical Engineering, University of Ljubljana, Trzaska 25, 1000 Ljubljana, Slovenia
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Bass AS, Darpo B, Breidenbach A, Bruse K, Feldman HS, Garnes D, Hammond T, Haverkamp W, January C, Koerner J, Lawrence C, Leishman D, Roden D, Valentin JP, Vos MA, Zhou YY, Karluss T, Sager P. International Life Sciences Institute (Health and Environmental Sciences Institute, HESI) initiative on moving towards better predictors of drug-induced torsades de pointes. Br J Pharmacol 2008; 154:1491-501. [PMID: 18663380 PMCID: PMC2492102 DOI: 10.1038/bjp.2008.279] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2008] [Accepted: 06/12/2008] [Indexed: 12/19/2022] Open
Abstract
Knowledge of the cardiac safety of emerging new drugs is an important aspect of assuring the expeditious advancement of the best candidates targeted at unmet medical needs while also assuring the safety of clinical trial subjects or patients. Present methodologies for assessing drug-induced torsades de pointes (TdP) are woefully inadequate in terms of their specificity to select pharmaceutical agents, which are human arrhythmia toxicants. Thus, the critical challenge in the pharmaceutical industry today is to identify experimental models, composite strategies, or biomarkers of cardiac risk that can distinguish a drug, which prolongs cardiac ventricular repolarization, but is not proarrhythmic, from one that prolongs the QT interval and leads to TdP. To that end, the HESI Proarrhythmia Models Project Committee recognized that there was little practical understanding of the relationship between drug effects on cardiac ventricular repolarization and the rare clinical event of TdP. It was on that basis that a workshop was convened in Virginia, USA at which four topics were introduced by invited subject matter experts in the following fields: Molecular and Cellular Biology Underlying TdP, Dynamics of Periodicity, Models of TdP Proarrhythmia, and Key Considerations for Demonstrating Utility of Pre-Clinical Models. Contained in this special issue of the British Journal of Pharmacology are reports from each of the presenters that set out the background and key areas of discussion in each of these topic areas. Based on this information, the scientific community is encouraged to consider the ideas advanced in this workshop and to contribute to these important areas of investigations over the next several years.
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Affiliation(s)
- A S Bass
- Drug Safety and Metabolism, Schering-Plough Research Institute, Kenilworth, NJ 07033-0539, USA.
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Piccirillo G, Magrì D, Matera S, Magnanti M, Pasquazzi E, Schifano E, Velitti S, Mitra M, Marigliano V, Paroli M, Ghiselli A. Effects of pink grapefruit juice on QT variability in patients with dilated or hypertensive cardiomyopathy and in healthy subjects. Transl Res 2008; 151:267-72. [PMID: 18433709 DOI: 10.1016/j.trsl.2008.03.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2008] [Revised: 03/22/2008] [Accepted: 03/24/2008] [Indexed: 12/19/2022]
Abstract
Recent evidence shows that pink grapefruit juice, which is a recommended dietary addition that contains high amounts of the antioxidant flavonoid naringenin, prolongs the corrected QT (QT(c)), a noninvasive electrophysiological marker of spatial myocardial repolarization, and does so by inhibiting the rapid component of the delayed rectifier K+ current (I(Kr)). Prompted by the observation that all class III antiarrhythmic drugs inhibit this current, thereby sometimes provoking torsades de pointes, we compared the effects of a liter of freshly squeezed pink grapefruit juice with those of 2 commonly used class III antiarrhythmics amiodarone and sotalol on the major noninvasive markers of temporal variability in myocardial repolarization used to stratify the risk of sudden death from malignant ventricular arrhythmias. In 32 subjects, 10 with postischemic dilated cardiomyopathy, 12 with hypertensive cardiomyopathy, and 10 healthy, we assessed QT(c) and QT variability index (QTVI) after administration of fresh pink grapefruit juice, placebo, amiodarone, or sotalol. After pink grapefruit juice and sotalol, all these indexes increased significantly from values observed after placebo (P<0.05) and from values after amiodarone (P<0.05). Conversely, after amiodarone, QT(c), but not QTVI, increased significantly from values after placebo (P<0.05). Presumably because of its high naringenin glycoside content, pink grapefruit juice prolongs cardiac repolarization and concurrently increases temporal cardiac repolarization dispersion. The potential proarrhythmic actions of pink grapefruit juice might be of concern in patients with major myocardial structural disorders.
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Affiliation(s)
- Gianfranco Piccirillo
- Dipartimento di Scienze dell'Invecchiamento, Dipartimento di Scienze Cardiovascolari, Respiratorie e Morfologiche, Policlinico Umberto I, Università degli Studi di Roma La Sapienza, Roma, Italy.
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Ng TM, Bell AM, Hong C, Hara JM, Touchette DR, Danskey KN, Lindsay TT, Puumala SE. Pharmacist monitoring of QTc interval-prolonging medications in critically ill medical patients: a pilot study. Ann Pharmacother 2008; 42:475-82. [PMID: 18319393 DOI: 10.1345/aph.1k458] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND No data exist regarding the value of pharmacist monitoring of drugs associated with QTc interval prolongation. OBJECTIVE To assess the capability, clinical impact, and economic impact of pharmacists monitoring for drug-induced QTc interval prolongation in critically ill medical adult patients. METHODS In a prospective, parallel-group study, 149 consecutive medical intensive care unit (ICU) patients prescribed a QTc interval-prolonging drug at the Los Angeles County + University of Southern California Medical Center were assigned on alternating days to an intervention group (clinical pharmacist on physician team monitored drugs using a standardized algorithm) or a standard care group (team without pharmacist using an algorithm). The monitoring algorithm used daily assessments of electrocardiograms and laboratory data to generate pharmacotherapeutic recommendations. The primary endpoint was the frequency of QTc interval prolongation (>500 msec at any time or an increase > or =60 msec over baseline). Secondary endpoints included QTc interval greater than 470 msec in women or greater than 450 msec in men, mean increase in QTc interval at 48 hours, recommendation acceptance rate, and cost of care. RESULTS QTc interval prolongation occurred less frequently in the intervention group compared with the standard care group (19% vs 39%, respectively; p = 0.006). Incidence of QTc interval greater than 500 msec (13% vs 33%, respectively; p = 0.003) was also lower in the intervention group. Incidence of QTc interval increase of 60 msec or more over baseline (12% vs 21%, respectively; p = 0.12) and increase in QTc interval at 48 hours over baseline (mean +/- SD; 6.4 +/- 40.8 vs 18.2 +/- 42.3 msec, respectively; p = 0.097) were not significantly different between the groups. Algorithm-generated recommendations were accepted 70% of the time by the intervention group physician team. Total cost and cost per day were not significantly different between groups. CONCLUSIONS In this preliminary study, pharmacist monitoring of QTc interval-prolonging drugs using a simple algorithm was feasible and reduced the risk of QTc interval prolongation. Further studies that monitor other proarrhythmic medications are warranted.
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Affiliation(s)
- Tien Mh Ng
- Department of Pharmacy, School of Pharmacy, University of Southern California, Los Angeles, CA 90033, USA.
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Abstract
Limitations in understanding of arrhythmias stem from lack of animal models which serve as surrogates for man. The purpose of this review is to discuss iatrogenic and naturally occurring animal models that are useful in our understanding of the mechanisms of ventricular arrhythmia and of antiarrhythmic and proarrhythmic agents. It is not surprising however that some information obtained from studies on infrahuman mammals may not be extrapolated to man. Need for anesthesia affects profoundly the electrophysiology of the heart, including autonomic affects. Most of the animal are modification of the Harris' 2-stage model. A model proposed by Schwartz, Billman and Stone has evolved as one that produces arguably the most information on the pathophysiology of arrhythmia production, including the role of the autonomic nervous system and the interaction with pharmacological agents. Intoxication with digitalis and escalating doses of epinephrine are commonly used models for production of ventricular arrhythmias. No matter what model of ventricular arrhythmias is used, programmed electrical stimulation can be useful to uncover increased tendency for arrhythmia, even if no arrhythmia occurs spontaneously. Models of spontaneous ventricular arrhythmia occur in German shepherd puppies, Boxer dogs, Doberman pinchers with dilated cardiomyopathy, and in large dogs with gastric dilatation or splenic torsion. Models are necessary because they allow for controlled studies and methods of exploration impossible, for legal and ethical reasons, in humans. Nonetheless, ethical considerations in using animal models are still important, and there is a continual search for non-animal models to explore ventricular arrhythmias.
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Affiliation(s)
- Robert L Hamlin
- Department of Veterinary Biosciences, The Ohio State University, OH, USA.
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Kijtawornrat A, Nishijima Y, Roche BM, Keene BW, Hamlin RL. Use of a Failing Rabbit Heart as a Model to Predict Torsadogenicity. Toxicol Sci 2006; 93:205-12. [PMID: 16740615 DOI: 10.1093/toxsci/kfl025] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Humans with underlying cardiovascular disease are at greater risk than humans with normal hearts for developing torsade de pointes (TdP) following exposure to some drugs that prolong ventricular repolarization. This study was designed to test the hypothesis that rabbits with ischemic myocardial failure are at similarly increased risk of developing QTc prolongation and TdP following exposure to escalating doses of drugs, which is known to have a capacity to induce TdP in humans. Coronary artery ligation was performed in 28 rabbits, causing significant (p < 0.05) reduction in left ventricular shortening fraction and systolic myocardial dysfunction 4 weeks after ligation in all operated animals compared to 38 normal, nonoperated controls. All studies were performed on rabbits anesthetized with ketamine (35 mg/kg) and xylazine (5 mg/kg). Rabbits were exposed to escalating doses of amiodarone (3, 10, 30 mg/kg/10 min), cisapride (0.10, 0.25, 0.50 mg/kg/10 min), clofilium (0.1, 0.2, 0.4 mg/kg/10 min), dofetilide (0.005, 0.01, 0.02, 0.04 mg/kg/10 min), quinidine (3, 10, 30 mg/kg/10 min), and verapamil (0.25, 0.5, 1.0 mg/kg/10 min). A greater percentage of rabbits with failing hearts developed TdP following intravenous infusion of escalating doses of dofetilide (85%), clofilium (100%), or cisapride (50%) than did normal rabbits exposed to the same drug protocol (20, 33, and 0%, respectively). None of the rabbits in either group developed TdP when exposed to escalating doses of amiodarone, verapamil, or quinidine. Two out of four test articles lengthened QTc more in rabbits with myocardial failure than in normals, and TdP occurred in 13 out of 28 rabbits with myocardial failure as opposed to only four out of 38 rabbits with normal myocardial function.
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Affiliation(s)
- Anusak Kijtawornrat
- Department of Veterinary Biosciences, The Ohio State University, Columbus, Ohio 43210, USA
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Thomsen MB, Matz J, Volders PGA, Vos MA. Assessing the proarrhythmic potential of drugs: current status of models and surrogate parameters of torsades de pointes arrhythmias. Pharmacol Ther 2006; 112:150-70. [PMID: 16714061 DOI: 10.1016/j.pharmthera.2005.04.009] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2005] [Accepted: 04/06/2005] [Indexed: 02/08/2023]
Abstract
Torsades de pointes (TdP) is a potentially lethal cardiac arrhythmia that can occur as an unwanted adverse effect of various pharmacological therapies. Before a drug is approved for marketing, its effects on cardiac repolarisation are examined clinically and experimentally. This paper expresses the opinion that effects on repolarisation duration cannot directly be translated to risk of proarrhythmia. Current safety assessments of drugs only involve repolarisation assays, however the proarrhythmic profile can only be determined in the predisposed model. The availability of these proarrhythmic animal models is emphasised in the present paper. It is feasible for the pharmaceutical industry to establish one or more of these proarrhythmic animal models and large benefits are potentially available if pharmaceutical industries and patient-care authorities embraced these models. Furthermore, suggested surrogate parameters possessing predictive power of TdP arrhythmia are reviewed. As these parameters are not developed to finalisation, any meaningful study of the proarrhythmic potential of a new drug will include evaluation in an integrated model of TdP arrhythmia.
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Affiliation(s)
- Morten B Thomsen
- Department of Medical Physiology, Heart Lung Centre Utrecht, University Medical Centre Utrecht, Yalelaan 50, NL-3584 CM Utrecht, Netherlands.
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Bergfeldt L. Introduction: 'The long QT syndromes--from molecule to man'. J Intern Med 2006; 259:4-6. [PMID: 16336509 DOI: 10.1111/j.1365-2796.2005.01591.x] [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] [Indexed: 11/27/2022]
Affiliation(s)
- L Bergfeldt
- Department of Cardiology, Sahlgrenska University Hospital, Gothenburg, Sweden.
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