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Gelman I, Sharma N, Mckeeman O, Lee P, Campagna N, Tomei N, Baranchuk A, Zhang S, El-Diasty M. The ion channel basis of pharmacological effects of amiodarone on myocardial electrophysiological properties, a comprehensive review. Biomed Pharmacother 2024; 174:116513. [PMID: 38565056 DOI: 10.1016/j.biopha.2024.116513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Accepted: 03/28/2024] [Indexed: 04/04/2024] Open
Abstract
Amiodarone is a benzofuran-based class III antiarrhythmic agent frequently used for the treatment of atrial and ventricular arrhythmias. The primary target of class III antiarrhythmic drugs is the cardiac human ether-a-go-go-related gene (hERG) encoded channel, KCNH2, commonly known as HERG, that conducts the rapidly activating delayed rectifier potassium current (IKr). Like other class III antiarrhythmic drugs, amiodarone exerts its physiologic effects mainly through IKr blockade, delaying the repolarization phase of the action potential and extending the effective refractory period. However, while many class III antiarrhythmics, including sotalol and dofetilide, can cause long QT syndrome (LQTS) that can progress to torsade de pointes, amiodarone displays less risk of inducing this fatal arrhythmia. This review article discusses the arrhythmogenesis in LQTS from the aspects of the development of early afterdepolarizations (EADs) associated with Ca2+ current, transmural dispersion of repolarization (TDR), as well as reverse use dependence associated with class III antiarrhythmic drugs to highlight electropharmacological effects of amiodarone on the myocardium.
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Affiliation(s)
- Illia Gelman
- Department of Biomedical and Molecular Sciences, Queens's University, Kingston, ON, Canada
| | - Neelakshi Sharma
- Department of Biomedical and Molecular Sciences, Queens's University, Kingston, ON, Canada
| | - Olivia Mckeeman
- Department of Biomedical and Molecular Sciences, Queens's University, Kingston, ON, Canada
| | - Peter Lee
- Division of Cardiology, Department of Medicine, Queen's University, Kingston, ON, Canada
| | - Noah Campagna
- Department of Biomedical and Molecular Sciences, Queens's University, Kingston, ON, Canada
| | - Nicole Tomei
- Department of Biomedical and Molecular Sciences, Queens's University, Kingston, ON, Canada
| | - Adrian Baranchuk
- Division of Cardiology, Department of Medicine, Queen's University, Kingston, ON, Canada
| | - Shetuan Zhang
- Department of Biomedical and Molecular Sciences, Queens's University, Kingston, ON, Canada.
| | - Mohammad El-Diasty
- Department of Biomedical and Molecular Sciences, Queens's University, Kingston, ON, Canada; Harrington Heart and Vascular Institute, Department of Cardiac Surgery, University Hospitals Cleveland Medical Center, Cleveland, Ohio 44106, United States.
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2
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Emigh Cortez AM, DeMarco KR, Furutani K, Bekker S, Sack JT, Wulff H, Clancy CE, Vorobyov I, Yarov-Yarovoy V. Structural modeling of hERG channel-drug interactions using Rosetta. Front Pharmacol 2023; 14:1244166. [PMID: 38035013 PMCID: PMC10682396 DOI: 10.3389/fphar.2023.1244166] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Accepted: 10/23/2023] [Indexed: 12/02/2023] Open
Abstract
The human ether-a-go-go-related gene (hERG) not only encodes a potassium-selective voltage-gated ion channel essential for normal electrical activity in the heart but is also a major drug anti-target. Genetic hERG mutations and blockage of the channel pore by drugs can cause long QT syndrome, which predisposes individuals to potentially deadly arrhythmias. However, not all hERG-blocking drugs are proarrhythmic, and their differential affinities to discrete channel conformational states have been suggested to contribute to arrhythmogenicity. We used Rosetta electron density refinement and homology modeling to build structural models of open-state hERG channel wild-type and mutant variants (Y652A, F656A, and Y652A/F656 A) and a closed-state wild-type channel based on cryo-electron microscopy structures of hERG and EAG1 channels. These models were used as protein targets for molecular docking of charged and neutral forms of amiodarone, nifekalant, dofetilide, d/l-sotalol, flecainide, and moxifloxacin. We selected these drugs based on their different arrhythmogenic potentials and abilities to facilitate hERG current. Our docking studies and clustering provided atomistic structural insights into state-dependent drug-channel interactions that play a key role in differentiating safe and harmful hERG blockers and can explain hERG channel facilitation through drug interactions with its open-state hydrophobic pockets.
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Affiliation(s)
- Aiyana M. Emigh Cortez
- Biophysics Graduate Group, University of California, Davis, Davis, CA, United States
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA, United States
| | - Kevin R. DeMarco
- Biophysics Graduate Group, University of California, Davis, Davis, CA, United States
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA, United States
| | - Kazuharu Furutani
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA, United States
- Department of Pharmacology, Tokushima Bunri University, Tokushima, Japan
| | - Slava Bekker
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA, United States
- American River College, Sacramento, CA, United States
| | - Jon T. Sack
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA, United States
- Department of Anesthesiology and Pain Medicine, University of California, Davis, Davis, CA, United States
| | - Heike Wulff
- Department of Pharmacology, University of California, Davis, Davis, CA, United States
| | - Colleen E. Clancy
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA, United States
- Department of Pharmacology, University of California, Davis, Davis, CA, United States
- Center for Precision Medicine and Data Sciences, University of California, Davis, Davis, CA, United States
| | - Igor Vorobyov
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA, United States
- Department of Pharmacology, University of California, Davis, Davis, CA, United States
| | - Vladimir Yarov-Yarovoy
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA, United States
- Department of Anesthesiology and Pain Medicine, University of California, Davis, Davis, CA, United States
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Furutani K. Facilitation of hERG Activation by Its Blocker: A Mechanism to Reduce Drug-Induced Proarrhythmic Risk. Int J Mol Sci 2023; 24:16261. [PMID: 38003453 PMCID: PMC10671758 DOI: 10.3390/ijms242216261] [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: 10/24/2023] [Revised: 11/08/2023] [Accepted: 11/12/2023] [Indexed: 11/26/2023] Open
Abstract
Modulation of the human Ether-à-go-go-Related Gene (hERG) channel, a crucial voltage-gated potassium channel in the repolarization of action potentials in ventricular myocytes of the heart, has significant implications on cardiac electrophysiology and can be either antiarrhythmic or proarrhythmic. For example, hERG channel blockade is a leading cause of long QT syndrome and potentially life-threatening arrhythmias, such as torsades de pointes. Conversely, hERG channel blockade is the mechanism of action of Class III antiarrhythmic agents in terminating ventricular tachycardia and fibrillation. In recent years, it has been recognized that less proarrhythmic hERG blockers with clinical potential or Class III antiarrhythmic agents exhibit, in addition to their hERG-blocking activity, a second action that facilitates the voltage-dependent activation of the hERG channel. This facilitation is believed to reduce the proarrhythmic potential by supporting the final repolarizing of action potentials. This review covers the pharmacological characteristics of hERG blockers/facilitators, the molecular mechanisms underlying facilitation, and their clinical significance, as well as unresolved issues and requirements for research in the fields of ion channel pharmacology and drug-induced arrhythmias.
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Affiliation(s)
- Kazuharu Furutani
- Department of Pharmacology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, 180 Nishihama-Boji, Yamashiro-cho, Tokushima 770-8514, Japan
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Furutani K, Kawano R, Ichiwara M, Adachi R, Clancy CE, Sack JT, Kita S. Pore opening, not voltage sensor movement, underpins the voltage-dependence of facilitation by a hERG blocker. Mol Pharmacol 2022; 102:MOLPHARM-AR-2022-000569. [PMID: 36041862 PMCID: PMC9595204 DOI: 10.1124/molpharm.122.000569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2022] [Revised: 07/19/2022] [Accepted: 08/04/2022] [Indexed: 11/07/2022] Open
Abstract
A drug that blocks the cardiac myocyte voltage-gated K+ channels encoded by the human Ether-à-go-go-Related Gene (hERG) carries a potential risk of long QT syndrome and life-threatening cardiac arrhythmia, including Torsade de Points Interestingly, certain hERG blockers can also facilitate hERG activation to increase hERG currents, which may reduce proarrhythmic potential. However, the molecular mechanism involved in the facilitation effect of hERG blockers remains unclear. The hallmark feature of the facilitation effect by hERG blockers is that a depolarizing preconditioning pulse shifts voltage-dependence of hERG activation to more negative voltages. Here we utilize a D540K hERG mutant to study the mechanism of the facilitation effect. D540K hERG is activated by not only depolarization but also hyperpolarization. This unusual gating property enables tests of the mechanism by which voltage induces facilitation of hERG by blockers. With D540K hERG, we find that nifekalant, a hERG blocker and Class III antiarrhythmic agent, blocks and facilitates not only current activation by depolarization but also current activation by hyperpolarization, suggesting a shared gating process upon depolarization and hyperpolarization. Moreover, in response to hyperpolarizing conditioning pulses, nifekalant facilitates D540K hERG currents but not wild-type currents. Our results indicate that induction of facilitation is coupled to pore opening, not voltage per se We propose that gated access to the hERG central cavity underlies the voltage-dependence of induction of facilitation. This study identifies hERG channel pore gate opening as the conformational change facilitated by nifekalant, a clinically important antiarrhythmic agent. Significance Statement Nifekalant is a clinically important antiarrhythmic agent and a hERG blocker which can also facilitate voltage-dependent activation of hERG channels after a preconditioning pulse. Here we show that the mechanism of action of the preconditioning pulse is to open a conductance gate to enable drug access to a facilitation site. Moreover, we find that facilitation increases hERG currents by altering pore dynamics, rather than acting through voltage sensors.
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Affiliation(s)
| | - Ryotaro Kawano
- Department of Pharmacology, Tokushima Bunri University, Japan
| | - Minami Ichiwara
- Department of Pharmacology, Tokushima Bunri University, Japan
| | - Ryo Adachi
- Department of Pharmacology, Tokushima Bunri University, Japan
| | | | - Jon T Sack
- UC Davis School of Medicine, United States
| | - Satomi Kita
- Department of Pharmacology, Tokushima Bunri University, Japan
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5
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Tsumoto K, Kurata Y. Bifurcations and Proarrhythmic Behaviors in Cardiac Electrical Excitations. Biomolecules 2022; 12:459. [PMID: 35327651 PMCID: PMC8946197 DOI: 10.3390/biom12030459] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Revised: 03/09/2022] [Accepted: 03/14/2022] [Indexed: 12/23/2022] Open
Abstract
The heart is a hierarchical dynamic system consisting of molecules, cells, and tissues, and acts as a pump for blood circulation. The pumping function depends critically on the preceding electrical activity, and disturbances in the pattern of excitation propagation lead to cardiac arrhythmia and pump failure. Excitation phenomena in cardiomyocytes have been modeled as a nonlinear dynamical system. Because of the nonlinearity of excitation phenomena, the system dynamics could be complex, and various analyses have been performed to understand the complex dynamics. Understanding the mechanisms underlying proarrhythmic responses in the heart is crucial for developing new ways to prevent and control cardiac arrhythmias and resulting contractile dysfunction. When the heart changes to a pathological state over time, the action potential (AP) in cardiomyocytes may also change to a different state in shape and duration, often undergoing a qualitative change in behavior. Such a dynamic change is called bifurcation. In this review, we first summarize the contribution of ion channels and transporters to AP formation and our knowledge of ion-transport molecules, then briefly describe bifurcation theory for nonlinear dynamical systems, and finally detail its recent progress, focusing on the research that attempts to understand the developing mechanisms of abnormal excitations in cardiomyocytes from the perspective of bifurcation phenomena.
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Affiliation(s)
| | - Yasutaka Kurata
- Department of Physiology II, Kanazawa Medical University, Uchinada 920-0293, Japan;
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Andric T, Winckel K, Tanzer TD, Hollingworth S, Smith L, Isoardi K, Tan O, Siskind D. Estimation of cardiac QTc intervals in people prescribed antipsychotics: a comparison of correction factors. Ther Adv Psychopharmacol 2022; 12:20451253221104947. [PMID: 35747226 PMCID: PMC9210090 DOI: 10.1177/20451253221104947] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 05/16/2022] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND A prolonged electrocardiogram (ECG) QT interval is associated with cardiac events and increased mortality. Antipsychotics can prolong the QT interval. The QT interval requires correction (QTc) for heart rate using a formula or QT-nomogram. The QT and QTc can be calculated automatically by the ECG machine or manually; however, machine-measured QT(c) intervals may be inaccurate. OBJECTIVE We aimed to investigate the mean QTc and proportion of prolonged QTc intervals in people taking antipsychotic medicines. METHODS We conducted an observational retrospective chart review and data analysis of all consecutive patients taking antipsychotics, with an ECG record, admitted to the psychiatric unit of a large tertiary hospital in Brisbane, Australia, between 1 January 2017 and 30 January 2019. We investigated the mean QTc of people taking antipsychotics to determine differences using (a) machine versus manual QT interval measurement and (b) QTc correction formulae (Bazett, Fridericia, Framingham, Hodges and Rautaharju) and the QT-nomogram. We also determined the number of people with a prolonged QTc using different methods and compared rates of prolonged QTc with antipsychotic monotherapy and polypharmacy. RESULTS Of 920 included people, the mean (±SD) machine-measured, Bazett-corrected QT interval (recorded from the ECG) was 435 ms (±27), significantly longer (p < 0.001) than the mean manually measured corrected QT intervals with Fridericia 394 ms (±24), Framingham 395 ms (±22), Hodges 398 ms (±22) and Rautaharju 400 ms (±24) formulae. There were significantly more people with a prolonged QTc using machine-measured QT and the Bazett formula (12.0%, 110/920) when compared with manually measured QT and the Fridericia formula (2.2%, 20/920) or QT-nomogram (0.7%, 6/920). Rates of QTc prolongation did not differ between people taking antipsychotic polypharmacy compared with monotherapy. CONCLUSION Machine-measured QTc using the Bazett formula overestimates the QTc interval length and number of people with a prolonged QTc, compared with other formulae and the QT-nomogram. We recommend manually measuring the QT and correcting with the Fridericia formula or QT-nomogram prior to modifying antipsychotic therapies.
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Affiliation(s)
- Teodora Andric
- School of Pharmacy, The University of Queensland, 20 Cornwall Street, Woolloongabba, Brisbane, QLD 4102, Australia
| | - Karl Winckel
- School of Pharmacy, The University of Queensland, Brisbane, QLD, Australia
| | | | | | - Lesley Smith
- Pharmacy Department, Princess Alexandra Hospital, Brisbane, QLD, Australia
| | - Katherine Isoardi
- Faculty of Medicine, The University of Queensland, Brisbane, QLD, Australia
| | - Olivier Tan
- School of Pharmacy, The University of Queensland, Brisbane, QLD, Australia
| | - Dan Siskind
- Faculty of Medicine, The University of Queensland, Brisbane, QLD, Australia
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7
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Mokrov GV. Linked biaromatic compounds as cardioprotective agents. Arch Pharm (Weinheim) 2021; 355:e2100428. [PMID: 34967027 DOI: 10.1002/ardp.202100428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 12/02/2021] [Accepted: 12/03/2021] [Indexed: 11/08/2022]
Abstract
Cardiovascular diseases (CVDs) are widespread in the modern world, and their number is constantly growing. For a long time, CVDs have been the leading cause of morbidity and mortality worldwide. Drugs for the treatment of CVD have been developed almost since the beginning of the 20th century, and a large number of effective cardioprotective agents of various classes have been created. Nevertheless, the need for the design and development of new safe drugs for the treatment of CVD remains. Literature data indicate that a huge number of cardioprotective agents of various generations and mechanisms correspond to a single generalized pharmacophore model containing two aromatic nuclei linked by a linear linker. In this regard, we put forward a concept for the design of a new generation of cardioprotective agents with a multitarget mechanism of action within the indicated pharmacophore model. This review is devoted to a generalization of the currently known compounds with cardioprotective properties and corresponding to the pharmacophore model of biaromatic compounds linked by a linear linker. Particular attention is paid to the history of the creation of these drugs, approaches to their design, and analysis of the structure-action relationship within each class.
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Affiliation(s)
- Grigory V Mokrov
- Department of Medicinal Chemistry, FSBI "Zakusov Institute of Pharmacology", Moscow, Russia
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Inhibition of the hERG potassium channel by phenanthrene: a polycyclic aromatic hydrocarbon pollutant. Cell Mol Life Sci 2021; 78:7899-7914. [PMID: 34727194 PMCID: PMC8629796 DOI: 10.1007/s00018-021-03967-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 09/25/2021] [Accepted: 10/01/2021] [Indexed: 11/07/2022]
Abstract
The lipophilic polycyclic aromatic hydrocarbon (PAH) phenanthrene is relatively abundant in polluted air and water and can access and accumulate in human tissue. Phenanthrene has been reported to interact with cardiac ion channels in several fish species. This study was undertaken to investigate the ability of phenanthrene to interact with hERG (human Ether-à-go-go-Related Gene) encoded Kv11.1 K+ channels, which play a central role in human ventricular repolarization. Pharmacological inhibition of hERG can be proarrhythmic. Whole-cell patch clamp recordings of hERG current (IhERG) were made from HEK293 cells expressing wild-type (WT) and mutant hERG channels. WT IhERG1a was inhibited by phenanthrene with an IC50 of 17.6 ± 1.7 µM, whilst IhERG1a/1b exhibited an IC50 of 1.8 ± 0.3 µM. WT IhERG block showed marked voltage and time dependence, indicative of dependence of inhibition on channel gating. The inhibitory effect of phenanthrene was markedly impaired by the attenuated inactivation N588K mutation. Remarkably, mutations of S6 domain aromatic amino acids (Y652, F656) in the canonical drug binding site did not impair the inhibitory action of phenanthrene; the Y652A mutation augmented IhERG block. In contrast, the F557L (S5) and M651A (S6) mutations impaired the ability of phenanthrene to inhibit IhERG, as did the S624A mutation below the selectivity filter region. Computational docking using a cryo-EM derived hERG structure supported the mutagenesis data. Thus, phenanthrene acts as an inhibitor of the hERG K+ channel by directly interacting with the channel, binding to a distinct site in the channel pore domain.
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Tsumoto K, Ashihara T, Naito N, Shimamoto T, Amano A, Kurata Y, Kurachi Y. Specific decreasing of Na + channel expression on the lateral membrane of cardiomyocytes causes fatal arrhythmias in Brugada syndrome. Sci Rep 2020; 10:19964. [PMID: 33203944 PMCID: PMC7673036 DOI: 10.1038/s41598-020-76681-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Accepted: 11/02/2020] [Indexed: 12/31/2022] Open
Abstract
Reduced cardiac sodium (Na+) channel current (INa) resulting from the loss-of-function of Na+ channel is a major cause of lethal arrhythmias in Brugada syndrome (BrS). Inspired by previous experimental studies which showed that in heart diseases INa was reduced along with expression changes in Na+ channel within myocytes, we hypothesized that the local decrease in INa caused by the alteration in Na+ channel expression in myocytes leads to the occurrence of phase-2 reentry, the major triggering mechanism of lethal arrhythmias in BrS. We constructed in silico human ventricular myocardial strand and ring models, and examined whether the Na+ channel expression changes in each myocyte cause the phase-2 reentry in BrS. Reducing Na+ channel expression in the lateral membrane of each myocyte caused not only the notch-and-dome but also loss-of-dome type action potentials and slowed conduction, both of which are typically observed in BrS patients. Furthermore, the selective reduction in Na+ channels on the lateral membrane of each myocyte together with spatial tissue heterogeneity of Na+ channel expression caused the phase-2 reentry and phase-2 reentry-mediated reentrant arrhythmias. Our data suggest that the BrS phenotype is strongly influenced by expression abnormalities as well as genetic abnormalities of Na+ channels.
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Affiliation(s)
- Kunichika Tsumoto
- Department of Physiology II, Kanazawa Medical University, 1-1 Daigaku, Uchinada, 920-0293, Japan.
- Department of Pharmacology, Graduate School of Medicine, Osaka University, 2-2 Yamada-oka, Suita, 565-0871, Japan.
| | - Takashi Ashihara
- Department of Medical Informatics and Biomedical Engineering, Shiga University of Medical Science, Seta Tsukinowa-cho, Otsu, 520-2192, Japan
| | - Narumi Naito
- Department of Bioinformatics, College of Life Sciences, Ritsumeikan University, 1-1-1 Nojihigashi, Kusatsu, 525-8577, Japan
| | - Takao Shimamoto
- Department of Bioinformatics, College of Life Sciences, Ritsumeikan University, 1-1-1 Nojihigashi, Kusatsu, 525-8577, Japan
| | - Akira Amano
- Department of Bioinformatics, College of Life Sciences, Ritsumeikan University, 1-1-1 Nojihigashi, Kusatsu, 525-8577, Japan
| | - Yasutaka Kurata
- Department of Physiology II, Kanazawa Medical University, 1-1 Daigaku, Uchinada, 920-0293, Japan
| | - Yoshihisa Kurachi
- Department of Pharmacology, Graduate School of Medicine, Osaka University, 2-2 Yamada-oka, Suita, 565-0871, Japan
- Glocal Center for Medical Engineering and Informatics, Osaka University, 2-2 Yamada-oka, Suita, 565-0871, Japan
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Widatalla N, Kasahara Y, Kimura Y, Khandoker A. Model based estimation of QT intervals in non-invasive fetal ECG signals. PLoS One 2020; 15:e0232769. [PMID: 32392232 PMCID: PMC7213701 DOI: 10.1371/journal.pone.0232769] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Accepted: 04/21/2020] [Indexed: 11/18/2022] Open
Abstract
The end timing of T waves in fetal electrocardiogram (fECG) is important for the evaluation of ST and QT intervals which are vital markers to assess cardiac repolarization patterns. Monitoring malignant fetal arrhythmias in utero is fundamental to care in congenital heart anomalies preventing perinatal death. Currently, reliable detection of end of T waves is possible only by using fetal scalp ECG (fsECG) and fetal magnetocardiography (fMCG). fMCG is expensive and less accessible and fsECG is an invasive technique available only during intrapartum period. Another safer and affordable alternative is the non-invasive fECG (nfECG) which can provide similar assessment provided by fsECG and fMECG but with less accuracy (not beat by beat). Detection of T waves using nfECG is challenging because of their low amplitudes and high noise. In this study, a novel model-based method that estimates the end of T waves in nfECG signals is proposed. The repolarization phase has been modeled as the discharging phase of a capacitor. To test the model, fECG signals were collected from 58 pregnant women (age: (34 ± 6) years old) bearing normal and abnormal fetuses with gestational age (GA) 20-41 weeks. QT and QTc intervals have been calculated to test the level of agreement between the model-based and reference values (fsECG and Doppler Ultrasound (DUS) signals) in normal subjects. The results of the test showed high agreement between model-based and reference values (difference < 5%), which implies that the proposed model could be an alternative method to detect the end of T waves in nfECG signals.
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Affiliation(s)
- Namareq Widatalla
- Next Generation Biological Information Technology, Tohoku University Graduate School of Biomedical Engineering, Sendai, Japan
- * E-mail:
| | - Yoshiyuki Kasahara
- Next Generation Biological Information Technology, Tohoku University Graduate School of Biomedical Engineering, Sendai, Japan
- Advanced Interdisciplinary Biomedical Engineering, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Yoshitaka Kimura
- Next Generation Biological Information Technology, Tohoku University Graduate School of Biomedical Engineering, Sendai, Japan
- Advanced Interdisciplinary Biomedical Engineering, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Ahsan Khandoker
- Healthcare Engineering Innovation Center (HEIC), Department of Biomedical Engineering, Khalifa University, Abu Dhabi, UAE
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11
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Ether N, Leishman D, Bailie M, Lauver A. Relationship of clinical adverse event reports to models of arrhythmia risk. J Pharmacol Toxicol Methods 2019; 100:106622. [PMID: 31398384 DOI: 10.1016/j.vascn.2019.106622] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 07/05/2019] [Accepted: 07/27/2019] [Indexed: 10/26/2022]
Abstract
A vital aspect of the drug discovery and development process is the identification and filtering of drugs with high risk of dangerous adverse events. Torsade de Pointes (TdP) is one example of an adverse event that requires thorough in vitro and in vivo drug screening. This is because TdP, a tachycardic ventricular arrhythmia, can develop into fatal cardiac events if left unresolved and has been missed during drug development with profound consequences. These factors led to the development of pre-clinical screening guidelines based on the presence of drug induced QT prolongation (QTp), which has been linked to TdP. These guidelines have high sensitivity, but low specificity, as they tend to predict QTp, which precedes TdP events but does not always lead to TdP. Computational models have the potential to improve these prediction methods by bridging the gaps between preclinical and clinical data. This study proposes the use of adverse event reports obtained from the FDA Adverse Event Reporting System as a representation of clinical TdP risk. By incorporating these reports into computational models, a more accurate risk prediction may be developed.
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Affiliation(s)
- Nicholas Ether
- Michigan State University, East Lansing, MI 48824, United States
| | - Derek Leishman
- Michigan State University, East Lansing, MI 48824, United States; Eli Lilly and Co., Indianapolis, IN 46285, United States
| | - Marc Bailie
- Michigan State University, East Lansing, MI 48824, United States
| | - Adam Lauver
- Michigan State University, East Lansing, MI 48824, United States.
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