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Bai J, Zhang C, Liang Y, Tavares A, Wang L. Impact of Combined Modulation of Two Potassium Ion Currents on Spiral Waves and Turbulent States in the Heart. ENTROPY (BASEL, SWITZERLAND) 2024; 26:446. [PMID: 38920457 PMCID: PMC11202854 DOI: 10.3390/e26060446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2024] [Revised: 05/23/2024] [Accepted: 05/24/2024] [Indexed: 06/27/2024]
Abstract
In the realm of cardiac research, the control of spiral waves and turbulent states has been a persistent focus for scholars. Among various avenues of investigation, the modulation of ion currents represents a crucial direction. It has been proved that the methods involving combined control of currents are superior to singular approaches. While previous studies have proposed some combination strategies, further reinforcement and supplementation are required, particularly in the context of controlling arrhythmias through the combined regulation of two potassium ion currents. This study employs the Luo-Rudy phase I cardiac model, modulating the maximum conductance of the time-dependent potassium current and the time-independent potassium current, to investigate the effects of this combined modulation on spiral waves and turbulent states. Numerical simulation results indicate that, compared to modulating a single current, combining reductions in the conductance of two potassium ion currents can rapidly control spiral waves and turbulent states in a short duration. This implies that employing blockers for both potassium ion currents concurrently represents a more efficient control strategy. The control outcomes of this study represent a novel and effective combination for antiarrhythmic interventions, offering potential avenues for new antiarrhythmic drug targets.
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Affiliation(s)
- Jing Bai
- School of Statistics and Data Science, Zhuhai College of Science and Technology, Zhuhai 519041, China; (J.B.); (C.Z.)
- Department of Industrial Electronics, University of Minho, 4800-058 Guimaraes, Portugal
| | - Chunfu Zhang
- School of Statistics and Data Science, Zhuhai College of Science and Technology, Zhuhai 519041, China; (J.B.); (C.Z.)
- Department of Industrial Electronics, University of Minho, 4800-058 Guimaraes, Portugal
| | - Yanchun Liang
- School of Computer Science, Zhuhai College of Science and Technology, Zhuhai 519041, China
| | - Adriano Tavares
- Department of Industrial Electronics, University of Minho, 4800-058 Guimaraes, Portugal
| | - Lidong Wang
- School of Statistics and Data Science, Zhuhai College of Science and Technology, Zhuhai 519041, China; (J.B.); (C.Z.)
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Punacha S, Berg S, Sebastian A, Krinski VI, Luther S, Shajahan TK. Spiral wave unpinning facilitated by wave emitting sites in cardiac monolayers. Proc Math Phys Eng Sci 2019; 475:20190420. [PMID: 31736652 DOI: 10.1098/rspa.2019.0420] [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: 07/04/2019] [Accepted: 09/23/2019] [Indexed: 11/12/2022] Open
Abstract
Rotating spiral waves of electrical activity in the heart can anchor to unexcitable tissue (an obstacle) and become stable pinned waves. A pinned rotating wave can be unpinned either by a local electrical stimulus applied close to the spiral core, or by an electric field pulse that excites the core of a pinned wave independently of its localization. The wave will be unpinned only when the pulse is delivered inside a narrow time interval called the unpinning window (UW) of the spiral. In experiments with cardiac monolayers, we found that other obstacles situated near the pinning centre of the spiral can facilitate unpinning. In numerical simulations, we found increasing or decreasing of the UW depending on the location, orientation and distance between the pinning centre and an obstacle. Our study indicates that multiple obstacles could contribute to unpinning in experiments with intact hearts.
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Affiliation(s)
- Shreyas Punacha
- National Institute of Technology Karnataka, Surathkal, Mangalore 575025, India
| | - Sebastian Berg
- Max Planck Institute of Dynamics and Self Organization, Göttingen 37017, Germany
| | - Anupama Sebastian
- National Institute of Technology Karnataka, Surathkal, Mangalore 575025, India
| | - Valentin I Krinski
- Max Planck Institute of Dynamics and Self Organization, Göttingen 37017, Germany
| | - Stefan Luther
- Max Planck Institute of Dynamics and Self Organization, Göttingen 37017, Germany
| | - T K Shajahan
- National Institute of Technology Karnataka, Surathkal, Mangalore 575025, India.,Max Planck Institute of Dynamics and Self Organization, Göttingen 37017, Germany
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3
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Moreno A, Walton RD, Constantin M, Bernus O, Vigmond EJ, Bayer JD. Wide-area low-energy surface stimulation of large mammalian ventricular tissue. Sci Rep 2019; 9:15863. [PMID: 31676789 PMCID: PMC6825186 DOI: 10.1038/s41598-019-51364-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 09/30/2019] [Indexed: 11/09/2022] Open
Abstract
The epicardial and endocardial surfaces of the heart are attractive targets to administer antiarrhythmic electrotherapies. Electrically stimulating wide areas of the surfaces of small mammalian ventricles is straightforward given the relatively small scale of their myocardial dimensions compared to the tissue space constant and electrical field. However, it has yet to be proven for larger mammalian hearts with tissue properties and ventricular dimensions closer to humans. Our goal was to address the feasibility and impact of wide-area electrical stimulation on the ventricular surfaces of large mammalian hearts at different stimulus strengths. This was accomplished by placing long line electrodes on the ventricular surfaces of pig hearts that span wide areas, and activating them individually. Stimulus efficacy was assessed and compared between surfaces, and tissue viability was evaluated. Activation time was dependent on stimulation strength and location, achieving uniform linear stimulation at 9x threshold strength. Endocardial stimulation activated more tissue transmurally than epicardial stimulation, which could be considered a potential target for future cardiac electrotherapies. Overall, our results indicate that electrically stimulating wide areas of the ventricular surfaces of large mammals is achievable with line electrodes, minimal tissue damage, and energies under the human pain threshold (100 mJ).
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Affiliation(s)
- Angel Moreno
- IHU-LIRYC, Electrophysiology and Heart Modeling Institute, Fondation Bordeaux Université. Pessac, Bordeaux, France.,Centre National De La Recherche Scientifique, Institut de Mathématiques de Bordeaux, UMR5251, Bordeaux, France
| | - Richard D Walton
- IHU-LIRYC, Electrophysiology and Heart Modeling Institute, Fondation Bordeaux Université. Pessac, Bordeaux, France.,Centre de Recherche Cardio-Thoracique de Bordeaux, Université de Bordeaux, U1045, Bordeaux, France.,INSERM, Centre de recherche Cardio-Thoracique de Bordeaux, U1045, Bordeaux, France
| | - Marion Constantin
- IHU-LIRYC, Electrophysiology and Heart Modeling Institute, Fondation Bordeaux Université. Pessac, Bordeaux, France.,Centre de Recherche Cardio-Thoracique de Bordeaux, Université de Bordeaux, U1045, Bordeaux, France.,INSERM, Centre de recherche Cardio-Thoracique de Bordeaux, U1045, Bordeaux, France
| | - Olivier Bernus
- IHU-LIRYC, Electrophysiology and Heart Modeling Institute, Fondation Bordeaux Université. Pessac, Bordeaux, France.,Centre de Recherche Cardio-Thoracique de Bordeaux, Université de Bordeaux, U1045, Bordeaux, France.,INSERM, Centre de recherche Cardio-Thoracique de Bordeaux, U1045, Bordeaux, France
| | - Edward J Vigmond
- IHU-LIRYC, Electrophysiology and Heart Modeling Institute, Fondation Bordeaux Université. Pessac, Bordeaux, France.,Centre National De La Recherche Scientifique, Institut de Mathématiques de Bordeaux, UMR5251, Bordeaux, France
| | - Jason D Bayer
- IHU-LIRYC, Electrophysiology and Heart Modeling Institute, Fondation Bordeaux Université. Pessac, Bordeaux, France. .,Centre National De La Recherche Scientifique, Institut de Mathématiques de Bordeaux, UMR5251, Bordeaux, France. .,L'Institut de Rythmologie et Modélisation Cardiaque (LIRYC), Hôpital Xavier Arnozan, Avenue du Haut Lévêque, 33604, Pessac, France.
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Konakanchi D, de Jongh Curry AL, Dokos S. Effects of macroscopic heterogeneity on propagation in a computationally inexpensive 2D model of the heart. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2014; 2014:4320-4323. [PMID: 25570948 DOI: 10.1109/embc.2014.6944580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We have developed a computationally inexpensive, two-dimensional, bidomain model of the heart to demonstrate the effect of tissue heterogeneity on propagation of cardiac impulses generated by the sino-atrial node (SAN). The geometry consists of a thin sheet of cardiac tissue with designated areas that represent the SAN and atria. The SAN auto-generates continuous impulses that result in waves of normal propagation throughout the tissue. On the introduction of heterogeneous patches with low tissue conductivities, the rhythm of the waveform becomes irregular. The study suggests that simplified and computationally inexpensive models can be insightful tools to better understand the mechanisms that cause atrial fibrillation (AF) and hence more effective treatment methods.
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Jiménez ZA, Zhang Z, Steinbock O. Electric-field-controlled unpinning of scroll waves. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2013; 88:052918. [PMID: 24329342 DOI: 10.1103/physreve.88.052918] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2013] [Indexed: 06/03/2023]
Abstract
Three-dimensional excitation vortices exist in systems such as chemical reactions and the human heart. Their one-dimensional rotation backbone can pin to unexcitable heterogeneities, which greatly affect the structure, dynamics, and lifetime of the vortex. In experiments with the Belousov-Zhabotinsky reaction, we demonstrate vortex unpinning from a pair of inert and impermeable spheres using externally applied electric fields. Unpinning occurs abruptly but is preceded by a slow reorientation and deformation of the initially circular vortex loop. Our experimental findings are reproduced by numerical simulations of an excitable reaction-diffusion-advection model.
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Affiliation(s)
- Zulma A Jiménez
- Florida State University, Department of Chemistry and Biochemistry, Tallahassee, Florida 32306-4390, USA
| | - Zhihui Zhang
- Florida State University, Department of Chemistry and Biochemistry, Tallahassee, Florida 32306-4390, USA
| | - Oliver Steinbock
- Florida State University, Department of Chemistry and Biochemistry, Tallahassee, Florida 32306-4390, USA
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Huang X, Liu X, Zheng L, Mi Y, Qian Y. Effects of pacing magnitudes and forms on bistability width in a modeled ventricular tissue. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2013; 88:012711. [PMID: 23944495 DOI: 10.1103/physreve.88.012711] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2013] [Revised: 06/16/2013] [Indexed: 06/02/2023]
Abstract
Bistability in periodically paced cardiac tissue is relevant to cardiac arrhythmias and its control. In the present paper, one-dimensional tissue of the phase I Luo-Rudy model is numerically investigated. The effects of various parameters of pacing signals on bistability width are studied. The following conclusions are obtained: (i) Pacing can be classified into two types: pulsatile and sinusoidal types. Pulsatile pacing reduces bistability width as its magnitude is increased. Sinusoidal pacing increases the width as its amplitude is increased. (ii) In a pacing period the hyperpolarizing part plays a more important role than the depolarizing part. Variations of the hyperpolarizing ratio in a period evidently change the width of bistability and its variation tendency. (iii) A dynamical mechanism is proposed to qualitatively explain the phenomena, which reveals the reason for the different effects of pulsatile and sinusoidal pacing on bistability. The methods for changing bistability width by external pacing may help control arrhythmias in cardiology.
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Affiliation(s)
- Xiaodong Huang
- Department of Physics, South China University of Technology, Guangzhou 510640, China.
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Hörning M. Termination of pinned vortices by high-frequency wave trains in heartlike excitable media with anisotropic fiber orientation. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2012; 86:031912. [PMID: 23030949 DOI: 10.1103/physreve.86.031912] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2012] [Revised: 07/22/2012] [Indexed: 06/01/2023]
Abstract
A variety of chemical and biological nonlinear excitable media, including heart tissue, exhibit vortices (spiral waves) that can anchor to nonexcitable obstacles. Such anchored vortices can be terminated by the application of high-frequency wave trains, as shown previously in isotropic excitable media. In this study, we examined the basic dependencies of the conduction velocities of planar waves and waves around curved obstacles as a function of anisotropy through numerical simulations of excitable media that mimic the fiber orientation in a real heart. We also investigated the unpinning of anchored spiral waves by high-frequency wave trains in an anisotropic excitable medium. Unlike the findings regarding the termination of spiral waves in isotropic excitable systems, we found a nonmonotonic relationship between the maximum unpinning period and the obstacle radius depending on the fiber orientation, where the formation of unwanted secondary pinned vortices or chaotic waves is seen over a wide range of parameters.
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Affiliation(s)
- Marcel Hörning
- Department of Physics, Graduate School of Science, Kyoto University, Japan.
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