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Bernikova O, Durkina A, Gonotkov M, Minnebaeva E, Arteyeva N, Azarov J. Formation of a border ischemic zone depends on plasma potassium concentration. Can J Physiol Pharmacol 2024; 102:331-341. [PMID: 38118123 DOI: 10.1139/cjpp-2023-0304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2023]
Abstract
Extracellular potassium concentration might modify electrophysiological properties in the border zone of ischemic myocardium. We evaluated the depolarization and repolarization characteristics across the ischemic-normal border under [K+] variation. Sixty-four-lead epicardial mapping was performed in 26 rats ([K+] 2.3-6.4 mM) in a model of acute ischemia/reperfusion. The animals with [K+] < 4.7 mM (low-normal potassium) had an ischemic zone with ST-segment elevation and activation delay, a border zone with ST-segment elevation and no activation delay, and a normal zone without electrophysiological abnormalities. The animals with [K+] >4.7 mM (normal-high potassium) had only the ischemic and normal zones and no transitional area. Activation-repolarization intervals and local conduction velocities were inversely associated with [K+] in linear regression analysis with adjustment for the zone of myocardium. The reperfusion extrasystolic burden (ESB) was greater in the low-normal as compared to normal-high potassium animals. Ventricular tachycardia/fibrillation incidence did not differ between the groups. In patch-clamp experiments, hypoxia shortened action potential duration at 5.4 mM but not at 1.3 mM of [K+]. IK(ATP) current was lower at 1.3 mM than at 5.4 mM of [K+]. We conclude that the border zone formation in low-normal [K+] was associated with attenuation of IK(ATP) response to hypoxia and increased reperfusion ESB.
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Affiliation(s)
- Olesya Bernikova
- Department of Cardiac Physiology, Institute of Physiology, Komi Science Center, Ural Branch, Russian Academy of Sciences, Syktyvkar, Russia
- Department of Mathematical Physiology, Institute of Immunology and Physiology, Ural Branch, Russian Academy of Sciences, Ekaterinburg, Russia
| | - Aleksandra Durkina
- Department of Cardiac Physiology, Institute of Physiology, Komi Science Center, Ural Branch, Russian Academy of Sciences, Syktyvkar, Russia
| | - Mikhail Gonotkov
- Department of Cardiac Physiology, Institute of Physiology, Komi Science Center, Ural Branch, Russian Academy of Sciences, Syktyvkar, Russia
| | - Elena Minnebaeva
- Department of Cardiac Physiology, Institute of Physiology, Komi Science Center, Ural Branch, Russian Academy of Sciences, Syktyvkar, Russia
- Institute of Medicine, Pitirim Sorokin Syktyvkar State University, Syktyvkar, Russia
| | - Natalia Arteyeva
- Department of Cardiac Physiology, Institute of Physiology, Komi Science Center, Ural Branch, Russian Academy of Sciences, Syktyvkar, Russia
| | - Jan Azarov
- Department of Cardiac Physiology, Institute of Physiology, Komi Science Center, Ural Branch, Russian Academy of Sciences, Syktyvkar, Russia
- Department of Mathematical Physiology, Institute of Immunology and Physiology, Ural Branch, Russian Academy of Sciences, Ekaterinburg, Russia
- Institute of Medicine, Pitirim Sorokin Syktyvkar State University, Syktyvkar, Russia
- Department of Biomedical Technology, Faculty of Biomedical Engineering, Czech Technical University in Prague, Kladno, Czech Republic
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Tsvetkova A, Ovechkin A, Azarov J, Bernikova O. Border zone repolarization duration as a predictor of early ischemic ventricular fibrillation. FASEB J 2022. [DOI: 10.1096/fasebj.2022.36.s1.r6365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Alena Tsvetkova
- Cardiac physiologyInstitute of Physiology, Komi Science Center, Ural Branch, Russian Academy of SciencesSyktyvkar
- Institute of Immunology and Physiology of the Ural Branch of the Russian Academy of SciencesEkaterinburg
| | - Alexey Ovechkin
- Cardiac physiologyInstitute of Physiology, Komi Science Center, Ural Branch, Russian Academy of SciencesSyktyvkar
- Institute of Immunology and Physiology of the Ural Branch of the Russian Academy of SciencesEkaterinburg
| | - Jan Azarov
- Institute of Immunology and Physiology of the Ural Branch of the Russian Academy of SciencesSyktyvkar
- Institute of Medicine, Pitirim Sorokin Syktyvkar State UniversitySyktyvkar
| | - Olesya Bernikova
- Institute of Immunology and Physiology of the Ural Branch of the Russian Academy of SciencesEkaterinburg
- Institute of Physiology, Komi Science Center, Ural Branch, Russian Academy of SciencesSyktyvkar
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Gonotkov MA, Durkina AV, Bernikova OG, Azarov J. Melatonin receptor blockade slows ventricular conduction by IK1 downregulation. Eur Heart J 2021. [DOI: 10.1093/eurheartj/ehab724.3206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Background
Melatonin has been reported to prevent life-threatening arrhythmias in myocardial ischemia and reperfusion. The recent study from our group demonstrated that the antiarrhythmic action of melatonin was associated with enhanced recovery of resting membrane potential (RMP) and shortened activation time delay in the affected myocardium. This effect was independent of melatonin antioxidative properties, which raises a question about the involvement of melatonin receptor-dependent signaling in the electrophysiological action of melatonin. The aim of this study was to evaluate a role of MT1/MT2 melatonin receptors in the regulation of RMP and ventricular conduction velocity (CV).
Methods
Anesthetized male rats underwent coronary occlusion (5 min) and reperfusion (5 min). 5 min before ischemia induction the animals were intravenously injected with saline (control, n=7), melatonin (4 mg/kg, n=8), luzindole (MT1/MT2 receptor blocker, 0.4 mg/kg, n=6), and melatonin/luzindole combination (4 and 0.4 mg/kg, respectively, n=7). CV was measured in baseline and reperfusion by epicardial 64-lead mapping under epicardial pacing. In the enzymatically isolated ventricular myocytes (n=20 cells), voltage- and current-clamp modes of whole cell patch-clamp were used for measurements of IK1 and INa currents, and RMP, respectively. Melatonin (10 uM), luzindole (1 uM) and their combination were added to the bath solution.
Results
Luzindole application decreased baseline longitudinal CV as compared to placebo (52±3 vs 42±2 cm/s, p=0.028, respectively). Paired comparisons demonstrated that longitudinal CV decreased at reperfusion vs baseline in the control group (35±2 vs 53±6 cm/s, p=0.018) and in the luzindole group (33±4 vs 38±3 cm/s, p=0.039), whereas no significant differences were observed in the melatonin and melatonin/luzindole groups (40±5 vs 51±3 cm/s, p=0.114 and 39±3 vs 43±3 cm/s, p=0.498, respectively). Neither melatonin nor luzindole changed INa current characteristics (Figure, panels a and b). The average amplitude of IK1 current was 2.08±0.92 at −50 mV and −16.11±4.70 pA/pF at −120 mV in the normal Tyrode solution. Luzindole significantly reduced IK1 amplitude to 0.82±0.48 (p=0.028) and −5.6±1.6 (p=0.008) pA/pF at −50 and −120 mV, respectively. Addition of melatonin to the luzindole-containing solution partly abolished the luzindole effect (Figure, panel c). Luzindole also reduced RMP from −63±10 mV to −37±12 mV (p=0.013) and caused an increase in APD100 duration from 35±6 ms to 170±43 ms (p=0.003) (Figure, panel d).
Conclusion
Thus, MT1/MT2 receptor block with luzindole did not affect INa but led to the down-regulation of IK1 and depolarization of RMP. These effects can reduce accessibility of sodium channels and be the basis for the observed luzindole-dependent CV slowing. The obtained data support the significance of melatonin receptor-dependent signaling in the realization of antiarrhythmic effects of melatonin.
Funding Acknowledgement
Type of funding sources: Foundation. Main funding source(s): Russian Science Foundation
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Affiliation(s)
- M A Gonotkov
- Institute of Physiology, of Komi Science Centre of the Ural Branch of the Russian Academy of Sciences, FRC Komi SC UB RAS, Syktyvkar, Russian Federation
| | - A V Durkina
- Institute of Physiology, of Komi Science Centre of the Ural Branch of the Russian Academy of Sciences, FRC Komi SC UB RAS, Syktyvkar, Russian Federation
| | - O G Bernikova
- Institute of Physiology, of Komi Science Centre of the Ural Branch of the Russian Academy of Sciences, FRC Komi SC UB RAS, Syktyvkar, Russian Federation
| | - J Azarov
- Institute of Physiology, of Komi Science Centre of the Ural Branch of the Russian Academy of Sciences, FRC Komi SC UB RAS, Syktyvkar, Russian Federation
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Pershina E, Azarov J, Vaykshnorayte M, Bernikova O, Ovechkin A. Prolongation of experimental diabetes mellitus increased susceptibility to reperfusion ventricular tachyarrhythmias. Can J Physiol Pharmacol 2021; 99:1097-1101. [PMID: 33951401 DOI: 10.1139/cjpp-2020-0743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Diabetes mellitus (DM) is associated with increased risk of sudden cardiac death, but its role in arrhythmogenesis is not clear. We evaluated contributions of DM duration and hyperglycemia level to development of proarrhythmic electrophysiological changes in the experimental ischemia/reperfusion model. Ventricular epicardial 64-lead mapping and arrhythmia susceptibility burst-pacing testing were performed in 43 healthy and 55 diabetic (alloxan model) anesthetized rabbits undergoing 15 min left anterior descending coronary artery occlusion, followed by 15 min reperfusion. During ischemia, arrhythmia inducibility did not differ between the groups, but the number of reperfusion ventricular tachycardias and (or) fibrillations (VT/VFs) were higher in the DM group (14 out of 55) as compared with control (3 out of 43, p = 0.017). In the diabetic animals, both DM duration and glucose concentration were associated with reperfusion VT/VF development in univariate logistic regression analysis (odds ratio (OR) 1.058, 95% confidence interval (CI) 1.025-1.092, p < 0.001; and OR 1.119, 95% CI 1.045-1.198, p = 0.001, respectively). Only the DM duration, however, remained an independent predictor of reperfusion VT/VF in multivariate logistic regression analysis (OR 1.060, 95% CI 1.006-1.117, p = 0.029). Among mapping parameters, DM duration was associated with the prolongation of total ventricular activation duration (regression coefficient 0.152, 95% CI 0.049-0.255, p = 0.005) and activation-repolarization intervals (ARIs) (regression coefficient 0.900, 95% CI 0.315-1.484, p = 0.003). The prolonged ARI was the only mapping characteristic predicting reperfusion VT/VF development (OR 1.028, 95% CI 1.009-1.048, p = 0.004). The DM duration-dependent prolongation of ventricular repolarization presents a link between DM development and reperfusion VT/VF inducibility.
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Affiliation(s)
- Ekaterina Pershina
- Department of Cardiac Physiology, Institute of Physiology, Komi Science Center, Ural Branch, Russian Academy of Sciences, 50 Pervomayskaya Street, 167982 Syktyvkar, Russia.,Department of Therapy, Institute of Medicine, Pitirim Sorokin Syktyvkar State University, Syktyvkar, Russia
| | - Jan Azarov
- Department of Cardiac Physiology, Institute of Physiology, Komi Science Center, Ural Branch, Russian Academy of Sciences, 50 Pervomayskaya Street, 167982 Syktyvkar, Russia.,Department of Biochemistry and Physiology, Institute of Medicine, Pitirim Sorokin Syktyvkar State University, Syktyvkar, Russia
| | - Marina Vaykshnorayte
- Department of Cardiac Physiology, Institute of Physiology, Komi Science Center, Ural Branch, Russian Academy of Sciences, 50 Pervomayskaya Street, 167982 Syktyvkar, Russia
| | - Olesya Bernikova
- Department of Cardiac Physiology, Institute of Physiology, Komi Science Center, Ural Branch, Russian Academy of Sciences, 50 Pervomayskaya Street, 167982 Syktyvkar, Russia
| | - Alexey Ovechkin
- Department of Cardiac Physiology, Institute of Physiology, Komi Science Center, Ural Branch, Russian Academy of Sciences, 50 Pervomayskaya Street, 167982 Syktyvkar, Russia.,Department of Therapy, Institute of Medicine, Pitirim Sorokin Syktyvkar State University, Syktyvkar, Russia
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Ovechkin A, Vaykshnorayte M, Bernikova O, Pershina E, Azarov J. Prolonged alloxan diabetes mellitus in rabbits, an experimental model associated with increased susceptibility to reperfusion ventricular tachyarrhythmias. FASEB J 2021. [DOI: 10.1096/fasebj.2021.35.s1.00413] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Alexey Ovechkin
- Department of Cardiac PhysiologyInstitute of Physiology, Komi Science Center, Ural Branch, Russian Academy of SciencesSyktyvkar
- Department of TherapyInstitute of Medicine, Pitirim Sorokin Syktyvkar State University,Syktyvkar, RussiaSyktyvkar
| | - Marina Vaykshnorayte
- Department of Cardiac PhysiologyInstitute of Physiology, Komi Science Center, Ural Branch, Russian Academy of SciencesSyktyvkar
| | - Olesya Bernikova
- Department of Cardiac PhysiologyInstitute of Physiology, Komi Science Center, Ural Branch, Russian Academy of SciencesSyktyvkar
| | - Ekaterina Pershina
- Department of Cardiac PhysiologyInstitute of Physiology, Komi Science Center, Ural Branch, Russian Academy of SciencesSyktyvkar
- Department of TherapyInstitute of Medicine, Pitirim Sorokin Syktyvkar State University,Syktyvkar, RussiaSyktyvkar
| | - Jan Azarov
- Department of Cardiac PhysiologyInstitute of Physiology, Komi Science Center, Ural Branch, Russian Academy of SciencesSyktyvkar
- Department of Biochemistry and PhysiologyInstitute of Medicine, Pitirim Sorokin Syktyvkar State University, Syktyvkar, RussiaSyktyvkar
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Durkina A, Bernikova O, Mikhaleva N, Paderin N, Gudyreva J, Mamedova T, Sedova K, Gonotkov M, Kuzmin V, Azarov J. Melatonin Treatment Does Not Modify Ectopic Activity During Ischemia and Reperfusion in Rats. FASEB J 2021. [DOI: 10.1096/fasebj.2021.35.s1.03795] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Aleksandra Durkina
- Department of Cardiac PhysiologyInstitute of Physiology, Komi Science Center, Ural Branch of Russian Academy of SciencesSyktyvkar
| | - Olesya Bernikova
- Department of Cardiac PhysiologyInstitute of Physiology, Komi Science Center, Ural Branch of Russian Academy of SciencesSyktyvkar
| | - Natalia Mikhaleva
- Department of Cardiac PhysiologyInstitute of Physiology, Komi Science Center, Ural Branch of Russian Academy of SciencesSyktyvkar
| | - Nikita Paderin
- Department of Molecular Immunology and BiotechnologyInstitute of Physiology, Komi Science Center, Ural Branch of Russian Academy of SciencesSyktyvkar
| | - Julia Gudyreva
- Department of PhysiologyInstitute of Medicine, Pitirim Sorokin Syktyvkar State UniversitySyktyvkar
| | - Telli Mamedova
- Department of PhysiologyInstitute of Medicine, Pitirim Sorokin Syktyvkar State UniversitySyktyvkar
| | - Ksenia Sedova
- Department of Biomedical Technology, Faculty of Biomedical EngineeringFaculty of Biomedical EngineeringCzech Technical University in PragueKladno
| | - Mikhail Gonotkov
- Department of Cardiac PhysiologyInstitute of Physiology, Komi Science Center, Ural Branch of Russian Academy of SciencesSyktyvkar
| | - Vladislav Kuzmin
- Department of Human and Animal PhysiologyLomonosov Moscow State UniversityMoscow
| | - Jan Azarov
- Department of Cardiac PhysiologyInstitute of Physiology, Komi Science Center, Ural Branch of Russian Academy of SciencesSyktyvkar
- Department of PhysiologyInstitute of Physiology, Komi Science Center, Ural Branch of Russian Academy of SciencesSyktyvkar
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Azarov J, Bernikova O, Ovechkin A, Mikhaleva N, Khramova D, Tsvetkova A. Melatonin Prevents 1A Phase Ventricular Fibrillation in Porcine Acute Myocardial Infarction Model. FASEB J 2020. [DOI: 10.1096/fasebj.2020.34.s1.05826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Jan Azarov
- Institute of Physiology, Komi Science Center Ural Branch of Russian Academy of Sciences
- Pitirim Sorokin Syktyvkar State University
| | - Olesya Bernikova
- Institute of Physiology, Komi Science Center Ural Branch of Russian Academy of Sciences
| | - Alexey Ovechkin
- Institute of Physiology, Komi Science Center Ural Branch of Russian Academy of Sciences
- Pitirim Sorokin Syktyvkar State University
| | - Natalia Mikhaleva
- Institute of Physiology, Komi Science Center Ural Branch of Russian Academy of Sciences
| | - Daria Khramova
- Institute of Physiology, Komi Science Center Ural Branch of Russian Academy of Sciences
| | - Alena Tsvetkova
- Institute of Physiology, Komi Science Center Ural Branch of Russian Academy of Sciences
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Sedova K, Galinyte V, Arteyeva N, Hejda J, Bernikova O, Kneppo P, Azarov J. Multi‐lead vs single‐lead T
peak
‐T
end
interval measurements for prediction of reperfusion ventricular tachyarrhythmias. J Cardiovasc Electrophysiol 2019; 30:2090-2097. [DOI: 10.1111/jce.14105] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Revised: 07/21/2019] [Accepted: 08/03/2019] [Indexed: 11/27/2022]
Affiliation(s)
- Ksenia Sedova
- Department of Biomedical Technology, Faculty of Biomedical EngineeringCzech Technical University in Prague Kladno Czech Republic
| | - Viktorija Galinyte
- Department of Biomedical Technology, Faculty of Biomedical EngineeringCzech Technical University in Prague Kladno Czech Republic
| | - Natalia Arteyeva
- Department of Cardiac Physiology, Institute of Physiology, Komi Science Center, Ural BranchRussian Academy of Sciences Syktyvkar Russia
| | - Jan Hejda
- Department of Biomedical Technology, Faculty of Biomedical EngineeringCzech Technical University in Prague Kladno Czech Republic
| | - Olesya Bernikova
- Department of Cardiac Physiology, Institute of Physiology, Komi Science Center, Ural BranchRussian Academy of Sciences Syktyvkar Russia
| | - Peter Kneppo
- Department of Biomedical Technology, Faculty of Biomedical EngineeringCzech Technical University in Prague Kladno Czech Republic
| | - Jan Azarov
- Department of Cardiac Physiology, Institute of Physiology, Komi Science Center, Ural BranchRussian Academy of Sciences Syktyvkar Russia
- Department of PhysiologyMedical Institute of Pitirim Sorokin Syktyvkar State University Syktyvkar Russia
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Vaikshnoraite MA, Azarov J. Ventricular activation times in rainbow trout and common carp. FASEB J 2018. [DOI: 10.1096/fasebj.2018.32.1_supplement.lb232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Marina Alvirasovna Vaikshnoraite
- Laboratory of Cardiac PhysiologyInstitute of PhysiologyKomi Science CenterUral BranchRussian Academy of SciencesSyktyvkarRussian Federation
| | - Jan Azarov
- Laboratory of Cardiac PhysiologyInstitute of PhysiologyKomi Science CenterUral BranchRussian Academy of SciencesSyktyvkarRussian Federation
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Bernikova O, Azarov J, Sedova K. The assessment of electrophysiological indices and ECG parameters as predictors of fatal arrhythmias under ischemia/reperfusion setting in multivariate regression model. FASEB J 2018. [DOI: 10.1096/fasebj.2018.32.1_supplement.lb315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Olesya Bernikova
- Laboratory of Cardiac Physiology, Institute of Physiology, Komi Science CenterUral Branch, Russian Academy of SciencesSyktyvkarRussian Federation
| | - Jan Azarov
- Laboratory of Cardiac Physiology, Institute of Physiology, Komi Science CenterUral Branch, Russian Academy of SciencesSyktyvkarRussian Federation
| | - Ksenia Sedova
- Department of Biomedical Technology, Faculty of Biomedical EngineeringCzech Technical UniversityPragueCzech Republic
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Sedova K, Bernikova O, Azarov J, Shmakov D, Vityazev V, Kharin S. Effects of echinochrome on ventricular repolarization in acute ischemia. J Electrocardiol 2015; 48:181-6. [DOI: 10.1016/j.jelectrocard.2015.01.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Indexed: 11/27/2022]
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Arteyeva N, Azarov J. What does reflect the Tpeak-Tend interval? Model study. J Electrocardiol 2011. [DOI: 10.1016/j.jelectrocard.2010.12.061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Vaykshnorayte M, Azarov J. Epicardial activation-to-repolarization coupling differs in the local areas and the entire ventricular surface. J Electrocardiol 2011. [DOI: 10.1016/j.jelectrocard.2010.12.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Tsvetkova A, Kibler N, Ovechkin A, Azarov J, Shmakov D. Effects of short-term vs 2-hour pacing of the right ventricular apex on repolarization and hemodynamics of the canine heart. J Electrocardiol 2011. [DOI: 10.1016/j.jelectrocard.2010.12.091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Sedova K, Vityazev V, Azarov J, Shmakov D. Effect of left ventricular overload on the epicardial repolarization in the rabbit. J Electrocardiol 2007. [DOI: 10.1016/j.jelectrocard.2007.03.229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Vaykshnorayte M, Azarov J, Shmakov D. Cooling effect on cardiac electric field during ventricular repolarization in the frog. J Electrocardiol 2007. [DOI: 10.1016/j.jelectrocard.2007.03.235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Belogolova A, Nuzhniy V, Kibler N, Azarov J, Shmakov D. Effect of pacing on ventricular repolarization in dogs. J Electrocardiol 2007. [DOI: 10.1016/j.jelectrocard.2007.03.226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Sedova K, Vityazev V, Azarov J, Shmakov D. Effect of the left ventricular overload on epicardial repolarization in the rabbit. Anadolu Kardiyol Derg 2007; 7 Suppl 1:93-4. [PMID: 17584693] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
OBJECTIVE We have investigated the local durations and sequence of repolarization in the ventricular epicardium in the rabbit under the increase of the left ventricular (LV) afterload. METHODS The LV overload was produced by the 1-minute aortic stenosis up to systolic blood pressure of 140 mm Hg. The experiments were carried out on eight anaesthetized rabbits (urethane, 1.5 g/kg, ip). Unipolar electrograms were simultaneously recorded from 64 ventricular epicardial leads at 33 degrees C. RESULTS At baseline state, the shortest activation-recovery intervals (ARIs) were observed in the right ventricular (RV) base, the longest ARIs in the LV apex and lateral wall, and ARIs of intermediate durations in the RV apex and LV base. According to ARI distribution, a significant gradient in repolarization times was observed between the apex and base (p<0.01). Under acute LV overload, the repolarization duration increased significantly (p<0.01) locally at the LV apex and adjacent area of the free wall. Dispersion of repolarization is increased in the apex. A decrease of ARIs (p<0.05) was observed at the RV base, as well. CONCLUSION Under acute increase in the LV afterload, ventricular epicardial activation sequence remained largely unaltered which, along with changes in local repolarization durations, resulted in the repolarization sequence being quite similar to the baseline one. The earliest repolarization occurred in posterobasal region of RV whereas the areas over the LV apex and adjacent area of the free wall were the last to repolarize.
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Affiliation(s)
- Ksenia Sedova
- Institute of Physiology, Komi Science Center, Ural Division, Russian Academy of Sciences, Syktyvkar, Komi, Russia.
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