Publications by authors named "Ksenia Sedova"

9 Publications

  • Page 1 of 1

Clinical Utility of Body Surface Potential Mapping in CRT Patients.

Arrhythm Electrophysiol Rev 2021 Jul;10(2):113-119

Department of Cardiology, Institute for Clinical and Experimental Medicine, Prague, Czech Republic.

This paper reviews the current status of the knowledge on body surface potential mapping (BSPM) and ECG imaging (ECGI) methods for patient selection, left ventricular (LV) lead positioning, and optimisation of CRT programming, to indicate the major trends and future perspectives for the application of these methods in CRT patients. A systematic literature review using PubMed, Scopus, and Web of Science was conducted to evaluate the available clinical evidence regarding the usage of BSPM and ECGI methods in CRT patients. The preferred reporting items for systematic reviews and meta-analyses (PRISMA) statement was used as a basis for this review. BSPM and ECGI methods applied in CRT patients were assessed, and quantitative parameters of ventricular depolarisation delivered from BSPM and ECGI were extracted and summarised. BSPM and ECGI methods can be used in CRT in several ways, namely in predicting CRT outcome, in individualised optimisation of CRT device programming, and the guiding of LV electrode placement, however, further prospective or randomised trials are necessary to verify the utility of BSPM for routine clinical practice.
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http://dx.doi.org/10.15420/aer.2021.14DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8335851PMC
July 2021

Association Between Antiarrhythmic, Electrophysiological, and Antioxidative Effects of Melatonin in Ischemia/Reperfusion.

Int J Mol Sci 2019 Dec 15;20(24). Epub 2019 Dec 15.

Institute of Physiology, Federal Research Centre, Komi Science Centre, Ural Branch of Russian Academy of Sciences, Pervomayskaya st. 50, 167982 Syktyvkar, Russia.

Melatonin is assumed to confer cardioprotective action via antioxidative properties. We evaluated the association between ventricular tachycardia and/or ventricular fibrillation (VT/VF) incidence, oxidative stress, and myocardial electrophysiological parameters in experimental ischemia/reperfusion under melatonin treatment. Melatonin was given to 28 rats (10 mg/kg/day, orally, for 7 days) and 13 animals received placebo. In the anesthetized animals, coronary occlusion was induced for 5 min followed by reperfusion with recording of unipolar electrograms from ventricular epicardium with a 64-lead array. Effects of melatonin on transmembrane potentials were studied in ventricular preparations of 7 rats in normal and "ischemic" conditions. Melatonin treatment was associated with lower VT/VF incidence at reperfusion, shorter baseline activation times (ATs), and activation-repolarization intervals and more complete recovery of repolarization times (RTs) at reperfusion (less baseline-reperfusion difference, ΔRT) ( < 0.05). Superoxide dismutase (SOD) activity was higher in the treated animals and associated with ΔRT ( = 0.001), whereas VT/VF incidence was associated with baseline ATs ( = 0.020). In vitro, melatonin led to a more complete restoration of action potential durations and resting membrane potentials at reoxygenation ( < 0.05). Thus, the antioxidative properties of melatonin were associated with its influence on repolarization duration, whereas the melatonin-related antiarrhythmic effect was associated with its oxidative stress-independent action on ventricular activation.
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http://dx.doi.org/10.3390/ijms20246331DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6941092PMC
December 2019

Multi-lead vs single-lead T -T interval measurements for prediction of reperfusion ventricular tachyarrhythmias.

J Cardiovasc Electrophysiol 2019 10 21;30(10):2090-2097. Epub 2019 Aug 21.

Department of Cardiac Physiology, Institute of Physiology, Komi Science Center, Ural Branch, Russian Academy of Sciences, Syktyvkar, Russia.

Introduction: Electrocardiographic T -T interval (Tp-Te) is a promising marker for the prediction of ventricular tachycardia and/or ventricular fibrillation (VT/VF). The study was aimed to compare single-lead vs multilead Tp-Te variables as VT/VF predictors in experimental ischemia/reperfusion model.

Methods And Results: Computer simulations were done using the ECGSIM model with an ischemic region set in anterior left ventricular apex. In 18 anesthetized cats, myocardial ischemia was induced by 30-minute ligation of left anterior descending coronary artery followed by reperfusion. Body surface ECGs in limb leads and modified precordial leads were recorded. Tp-Te was detected automatically in individual leads with a custom-designed parametric algorithm. Tp-Te dispersion and total Tp-Te were calculated as a difference between the maximal and minimal value of individual Tp-Te(s) and an interval between the earliest Tpeak and the latest Tend throughout all leads, respectively. Simulations showed that the increase of local, but not total, dispersion of repolarization characteristic for ischemic damage led to nonuniform shortening of T-peak times across 12 standard leads, which in turn resulted in the increase of single-lead Tp-Te(s), total Tp-Te and Tp-Te dispersion. Animals experienced VT/VF showed increased Tp-Te dispersion and total Tp-Te during reperfusion. In univariate logistic regression analysis, only the Tp-Te dispersion at the beginning of reperfusion was associated with the VT/VF incidence. According to ROC curve analysis, the optimal cut-off value of the Tp-Te dispersion was 17 ms (sensitivity 0.71, specificity 0.80).

Conclusions: The reperfusion VT/VFs were independently predicted by increased Tp-Te dispersion, which suggests the importance of multi-lead evaluation of Tp-Te intervals.
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http://dx.doi.org/10.1111/jce.14105DOI Listing
October 2019

Repolarization in perfused myocardium predicts reperfusion ventricular tachyarrhythmias.

J Electrocardiol 2018 May - Jun;51(3):542-548. Epub 2017 Dec 6.

Laboratory of Cardiac Physiology, Institute of Physiology, Komi Science Center, Ural Branch, Russian Academy of Sciences, Pervomayskaya st., 50, Syktyvkar, Russia; Department of Physiology, Medical Institute of Pitirim Sorokin Syktyvkar State University, Oktyabrskiy pr., 55, Syktyvkar, Russia.

Background: Aim of the study was to find out which myocardial repolarization parameters predict reperfusion ventricular tachycardia and fibrillation (VT/VF) and determine how these parameters express in ECG.

Methods: Coronary occlusion and reperfusion (30/30min) was induced in 24 cats. Local activation and end of repolarization times (RT) were measured in 88 intramyocardial leads. Computer simulations of precordial electrograms were performed.

Results: Reperfusion VT/VF developed in 10 animals. Arrhythmia-susceptible animals had longer RTs in perfused areas [183(177;202) vs 154(140;170) ms in susceptible and resistant animals, respectively, P<0.05]. In logistic regression analysis, VT/VFs were associated with prolonged RTs in the perfused area (OR 1.068; 95% CI 1.012-1.128; P=0.017). Simulations demonstrated that prolonged repolarization in the perfused/border zone caused precordial terminal T-wave inversion.

Conclusions: The reperfusion VT/VFs were independently predicted by the longer RT in the perfused zone, which was reflected in the terminal negative phase of the electrocardiographic T-wave.
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http://dx.doi.org/10.1016/j.jelectrocard.2017.12.003DOI Listing
March 2019

Functional role of myocardial electrical remodeling in diabetic rabbits.

Can J Physiol Pharmacol 2015 Apr 22;93(4):245-52. Epub 2014 Dec 22.

Laboratory of Cardiac Physiology, Institute of Physiology, Komi Science Center, Ural Branch, Russian Academy of Sciences, 50 Pervomayskaya Street, 167982 Syktyvkar, Russia., First Department of Internal Diseases of Komi Branch of Kirov State Medical Academy, 11 Babushkin Street, Syktyvkar 167000, Russia., Department of Physiology, Medical Institute of Syktyvkar State University, 11 Babushkin Street, Syktyvkar 167000, Russia.

The objective of the study was to investigate the role of electrical remodeling of the ventricular myocardium in hemodynamic impairment and the development of arrhythmogenic substrate. Experiments were conducted with 11 healthy and 12 diabetic (alloxan model, 4 weeks) rabbits. Left ventricular pressure was monitored and unipolar electrograms were recorded from 64 epicardial leads. Aortic banding was used to provoke arrhythmia. The diabetic rabbits had prolonged QTc, with activation-recovery intervals (surrogates for repolarization durations) being relatively short on the left ventricular base and long on the anterior apical portions of both ventricles (P < 0.05). In the diabetic rabbits, a negative correlation (-0.726 to -0.817) was observed between dP/dt(max), dP/dt(min), and repolarization dispersions. Under conditions of systolic overload (5 min), tachyarrhythmias were equally rare and the QTc and activation-recovery intervals were shortened in both groups (P < 0.05), whereas QRS was prolonged in the diabetic rabbits only. The repolarization shortening was more pronounced on the apex, which led to the development of apicobasal and interventricular end of repolarization gradients in the healthy animals, and to the flattening of the repolarization profile in the diabetic group. Thus, the diabetes-related pattern of ventricular repolarization was associated with inotropic and lusitropic impairment of the cardiac pump function.
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http://dx.doi.org/10.1139/cjpp-2014-0293DOI Listing
April 2015

Effects of echinochrome on ventricular repolarization in acute ischemia.

J Electrocardiol 2015 Mar-Apr;48(2):181-6. Epub 2015 Jan 8.

Laboratory of Cardiac Physiology, Institute of Physiology, Komi Science Centre, Ural Branch, Russian Academy of Sciences, 50, Pervomayskaya St, Syktyvkar, Russian Federation; Department of Physiology, Medical Institute of Syktyvkar State University, 11, Babushkin St, Syktyvkar, Russian Federation.

Background: Myocardial ischemic electrophysiological alterations are associated with the generation of reactive oxygen species. However, electrophysiological effects of antioxidants are unclear. Our objective was to determine the effects of the antioxidant echinochrome on ventricular repolarization in a feline model of 30-min ischemia.

Methods And Results: Activation-recovery intervals were measured from 64 ventricular electrograms recorded before and during the LAD ligation in untreated animals (controls, n=5) and animals given echinochrome (1mg/kg, n=5 and 2mg/kg, n=7). In controls, ischemia resulted in the increase of repolarization dispersion, QTc and Tpeak-Tend intervals and precordial T wave amplitude dispersion. Echinochrome attenuated the ischemic increase of repolarization dispersion. The increased dose of echinochrome abolished the ischemic ECG repolarization changes but did not modify the incidence of ventricular arrhythmias.

Conclusion: Echinochrome modified ischemic alterations of repolarization dispersion that were associated with the changes of the body surface T wave amplitude dispersion and Tpeak-Tend interval.
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http://dx.doi.org/10.1016/j.jelectrocard.2015.01.003DOI Listing
November 2015

What does the T(peak)-T(end) interval reflect? An experimental and model study.

J Electrocardiol 2013 Jul-Aug;46(4):296.e1-8. Epub 2013 Mar 6.

Laboratory of Cardiac Physiology, Institute of Physiology, Komi Science Center, Ural Branch, Russian Academy of Sciences, 50, Pervomayskaya st, Syktyvkar, Russia.

Background: It is unclear whether the Tpeak-Tend interval is an index of the transmural or the total dispersion of repolarization.

Methods: We examined the Tpeak-Tend interval using a computer model of the rabbit heart ventricles based on experimentally measured transmural, apicobasal, and interventricular gradients of action potential duration.

Results: Experimentally measured activation-recovery intervals increased from apex to base, from the left ventricle to the right ventricle, and in the apical portion of the left ventricle from epicardium to endocardium and from the right side of septum to the left side. The simulated Tpeak corresponded to the earliest end of repolarization, whereas the Tend corresponded to the latest end of repolarization. The different components of the global repolarization dispersion were discerned by simulation.

Conclusions: The Tpeak-Tend interval corresponds to the global dispersion of repolarization with distinct contributions of the apicobasal and transmural action potential duration gradients and apicobasal difference in activation times.
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http://dx.doi.org/10.1016/j.jelectrocard.2013.02.001DOI Listing
January 2014

Load-induced changes in ventricular repolarization: evidence of autonomic modulation.

Can J Physiol Pharmacol 2011 Dec 24;89(12):935-44. Epub 2011 Nov 24.

a Laboratory of Cardiac Physiology, Institute of Physiology, Komi Science Center, Ural Branch, Russian Academy of Sciences, 50 Pervomayskaya Street, Syktyvkar, 167982 Russia.

Augmented hemodynamic load increases the risk of arrhythmogenesis by modulating cardiac repolarization duration. We hypothesized that the intervention on the autonomic tone may affect the load-dependent changes in ventricular repolarization. Activation-recovery intervals were measured in unipolar electrograms simultaneously recorded from 64 ventricular epicardial leads, in a total of 26 chinchilla rabbits in resting conditions, and after 1 and 10 min of aortic stenosis. Eleven animals were given atropine and propranolol before the loading. The short-term stenosis decreased the activation-recovery intervals in the right ventricle, whereas the prolonged overload increased the repolarization duration in both ventricles. The treatment with the β-adrenergic and M-cholinergic blockers prolonged the activation-recovery intervals, especially at the left ventricle, attenuating the apicobasal and interventricular gradients of repolarization duration seen in the baseline state. Further ventricular loading shortened the repolarization duration in both ventricles in animals with autonomic blockade. Thus, the autonomic tone was shown to be essential for the development of repolarization heterogeneity across the ventricles. The autonomic blockade transformed the biphasic changes of activation-recovery intervals into their monophasic shortening at aortic stenosis.
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http://dx.doi.org/10.1139/y11-098DOI Listing
December 2011

Effect of the left ventricular overload on epicardial repolarization in the rabbit.

Anadolu Kardiyol Derg 2007 Jul;7 Suppl 1:93-4

Institute of Physiology, Komi Science Center, Ural Division, Russian Academy of Sciences, Syktyvkar, Komi, Russia.

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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July 2007
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