1
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Fitts RH, Wang X, Kwok WM, Camara AKS. Cardiomyocyte Adaptation to Exercise: K+ Channels, Contractility and Ischemic Injury. Int J Sports Med 2024; 45:791-803. [PMID: 38648799 DOI: 10.1055/a-2296-7604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/25/2024]
Abstract
Cardiovascular disease is a leading cause of morbidity and mortality, and exercise-training (TRN) is known to reduce risk factors and protect the heart from ischemia and reperfusion injury. Though the cardioprotective effects of exercise are well-documented, underlying mechanisms are not well understood. This review highlights recent findings and focuses on cardiac factors with emphasis on K+ channel control of the action potential duration (APD), β-adrenergic and adenosine regulation of cardiomyocyte function, and mitochondrial Ca2+ regulation. TRN-induced prolongation and shortening of the APD at low and high activation rates, respectively, is discussed in the context of a reduced response of the sarcolemma delayed rectifier potassium channel (IK) and increased content and activation of the sarcolemma KATP channel. A proposed mechanism underlying the latter is presented, including the phosphatidylinositol-3kinase/protein kinase B pathway. TRN induced increases in cardiomyocyte contractility and the response to adrenergic agonists are discussed. The TRN-induced protection from reperfusion injury is highlighted by the increased content and activation of the sarcolemma KATP channel and the increased phosphorylated glycogen synthase kinase-3β, which aid in preventing mitochondrial Ca2+ overload and mitochondria-triggered apoptosis. Finally, a brief section is presented on the increased incidences of atrial fibrillation associated with age and in life-long exercisers.
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Affiliation(s)
- Robert H Fitts
- Biological Sciences, Marquette University, Milwaukee, United States
| | - Xinrui Wang
- Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, United States
- Cardiovascular Center, Medical College of Wisconsin, Milwaukee, United States
| | - Wai-Meng Kwok
- Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, United States
- Cardiovascular Center, Medical College of Wisconsin, Milwaukee, United States
- Anesthesiology, Medical College of Wisconsin, Milwaukee, United States
- Cancer Center, Medical College of Wisconsin, Milwaukee, United States
| | - Amadou K S Camara
- Cardiovascular Center, Medical College of Wisconsin, Milwaukee, United States
- Anesthesiology, Medical College of Wisconsin, Milwaukee, United States
- Cancer Center, Medical College of Wisconsin, Milwaukee, United States
- Physiology, Medical College of Wisconsin, Milwaukee, United States
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2
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Riebel LL, Wang ZJ, Martinez-Navarro H, Trovato C, Camps J, Berg LA, Zhou X, Doste R, Sachetto Oliveira R, Weber Dos Santos R, Biasetti J, Rodriguez B. In silico evaluation of cell therapy in acute versus chronic infarction: role of automaticity, heterogeneity and Purkinje in human. Sci Rep 2024; 14:21584. [PMID: 39284812 PMCID: PMC11405404 DOI: 10.1038/s41598-024-67951-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Accepted: 07/17/2024] [Indexed: 09/22/2024] Open
Abstract
Human-based modelling and simulation offer an ideal testbed for novel medical therapies to guide experimental and clinical studies. Myocardial infarction (MI) is a common cause of heart failure and mortality, for which novel therapies are urgently needed. Although cell therapy offers promise, electrophysiological heterogeneity raises pro-arrhythmic safety concerns, where underlying complex spatio-temporal dynamics cannot be investigated experimentally. Here, after demonstrating credibility of the modelling and simulation framework, we investigate cell therapy in acute versus chronic MI and the role of cell heterogeneity, scar size and the Purkinje system. Simulations agreed with experimental and clinical recordings from ionic to ECG dynamics in acute and chronic infarction. Following cell delivery, spontaneous beats were facilitated by heterogeneity in cell populations, chronic MI due to tissue depolarisation and slow sinus rhythm. Subsequent re-entrant arrhythmias occurred, in some instances with Purkinje involvement and their susceptibility was enhanced by impaired Purkinje-myocardium coupling, large scars and acute infarction. We conclude that homogeneity in injected ventricular-like cell populations minimises their spontaneous beating, which is enhanced by chronic MI, whereas a healthy Purkinje-myocardium coupling is key to prevent subsequent re-entrant arrhythmias, particularly for large scars.
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Affiliation(s)
| | | | | | - Cristian Trovato
- Department of Computer Science, University of Oxford, Oxford, UK
- Systems Medicine, Clinical Pharmacology & Safety Science, R&D, AstraZeneca, Cambridge, UK
| | - Julia Camps
- Department of Computer Science, University of Oxford, Oxford, UK
| | - Lucas Arantes Berg
- Department of Computer Science, University of Oxford, Oxford, UK
- Universidade Federal de Juiz de Fora, Juiz de Fora, Brazil
| | - Xin Zhou
- Department of Computer Science, University of Oxford, Oxford, UK
| | - Ruben Doste
- Department of Computer Science, University of Oxford, Oxford, UK
| | | | | | - Jacopo Biasetti
- Systems Medicine, Clinical Pharmacology & Safety Science, R&D, AstraZeneca, Gothenburg, Sweden
| | - Blanca Rodriguez
- Department of Computer Science, University of Oxford, Oxford, UK.
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3
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Dermul N, Dierckx H. Reconstruction of excitation waves from mechanical deformation using physics-informed neural networks. Sci Rep 2024; 14:16975. [PMID: 39043805 PMCID: PMC11266589 DOI: 10.1038/s41598-024-67597-3] [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: 01/30/2024] [Accepted: 07/12/2024] [Indexed: 07/25/2024] Open
Abstract
Non-invasive assessment of the electrical activation pattern can significantly contribute to the diagnosis and treatment of cardiac arrhythmias, due to faster and safer diagnosis, improved surgical planning and easier follow-up. One promising path is to measure the mechanical contraction via echocardiography and utilize this as an indirect way of measuring the original activation pattern. To solve this demanding inversion task, we make use of physics-informed neural networks, an upcoming methodology to solve forward and inverse physical problems governed by partial differential equations. In this study, synthetic data sets were created, consisting of 2D excitation waves coupled to an isotropic and linearly deforming elastic medium. We show that for both focal and spiral patterns, the underlying excitation waves can be reconstructed accurately. We test the robustness of the method against Gaussian noise, reduced spatial resolution and projected tri-planar data. In situations where the data quality is heavily reduced, we show how to improve the reconstruction by additional regularization on the wave speed. Our findings suggest that physics-informed neural networks hold the potential to solve sparse and noisy bio-mechanical inversion problems and may offer a pathway to non-invasive assessment of certain cardiac arrhythmias.
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Affiliation(s)
- Nathan Dermul
- Department of Mathematics, KU Leuven, 8500, Kortrijk, Belgium.
- iSi Health, Institute of Physics-based Modeling for In Silico Health, KU Leuven, 3000, Leuven, Belgium.
| | - Hans Dierckx
- Department of Mathematics, KU Leuven, 8500, Kortrijk, Belgium
- iSi Health, Institute of Physics-based Modeling for In Silico Health, KU Leuven, 3000, Leuven, Belgium
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4
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Li L. Toward Enabling Cardiac Digital Twins of Myocardial Infarction Using Deep Computational Models for Inverse Inference. IEEE TRANSACTIONS ON MEDICAL IMAGING 2024; 43:2466-2478. [PMID: 38373128 PMCID: PMC7616288 DOI: 10.1109/tmi.2024.3367409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/21/2024]
Abstract
Cardiac digital twins (CDTs) have the potential to offer individualized evaluation of cardiac function in a non-invasive manner, making them a promising approach for personalized diagnosis and treatment planning of myocardial infarction (MI). The inference of accurate myocardial tissue properties is crucial in creating a reliable CDT of MI. In this work, we investigate the feasibility of inferring myocardial tissue properties from the electrocardiogram (ECG) within a CDT platform. The platform integrates multi-modal data, such as cardiac MRI and ECG, to enhance the accuracy and reliability of the inferred tissue properties. We perform a sensitivity analysis based on computer simulations, systematically exploring the effects of infarct location, size, degree of transmurality, and electrical activity alteration on the simulated QRS complex of ECG, to establish the limits of the approach. We subsequently present a novel deep computational model, comprising a dual-branch variational autoencoder and an inference model, to infer infarct location and distribution from the simulated QRS. The proposed model achieves mean Dice scores of 0.457 ±0.317 and 0.302 ±0.273 for the inference of left ventricle scars and border zone, respectively. The sensitivity analysis enhances our understanding of the complex relationship between infarct characteristics and electrophysiological features. The in silico experimental results show that the model can effectively capture the relationship for the inverse inference, with promising potential for clinical application in the future. The code is available at https://github.com/lileitech/MI_inverse_inference.
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Affiliation(s)
- Lei Li
- Department of Engineering Science, Institute of Biomedical
Engineering, University of Oxford, OX3 7DQ,
Oxford, U.K.
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5
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Trayanova NA, Lyon A, Shade J, Heijman J. Computational modeling of cardiac electrophysiology and arrhythmogenesis: toward clinical translation. Physiol Rev 2024; 104:1265-1333. [PMID: 38153307 PMCID: PMC11381036 DOI: 10.1152/physrev.00017.2023] [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: 04/05/2023] [Revised: 12/19/2023] [Accepted: 12/21/2023] [Indexed: 12/29/2023] Open
Abstract
The complexity of cardiac electrophysiology, involving dynamic changes in numerous components across multiple spatial (from ion channel to organ) and temporal (from milliseconds to days) scales, makes an intuitive or empirical analysis of cardiac arrhythmogenesis challenging. Multiscale mechanistic computational models of cardiac electrophysiology provide precise control over individual parameters, and their reproducibility enables a thorough assessment of arrhythmia mechanisms. This review provides a comprehensive analysis of models of cardiac electrophysiology and arrhythmias, from the single cell to the organ level, and how they can be leveraged to better understand rhythm disorders in cardiac disease and to improve heart patient care. Key issues related to model development based on experimental data are discussed, and major families of human cardiomyocyte models and their applications are highlighted. An overview of organ-level computational modeling of cardiac electrophysiology and its clinical applications in personalized arrhythmia risk assessment and patient-specific therapy of atrial and ventricular arrhythmias is provided. The advancements presented here highlight how patient-specific computational models of the heart reconstructed from patient data have achieved success in predicting risk of sudden cardiac death and guiding optimal treatments of heart rhythm disorders. Finally, an outlook toward potential future advances, including the combination of mechanistic modeling and machine learning/artificial intelligence, is provided. As the field of cardiology is embarking on a journey toward precision medicine, personalized modeling of the heart is expected to become a key technology to guide pharmaceutical therapy, deployment of devices, and surgical interventions.
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Affiliation(s)
- Natalia A Trayanova
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland, United States
- Alliance for Cardiovascular Diagnostic and Treatment Innovation, Johns Hopkins University, Baltimore, Maryland, United States
| | - Aurore Lyon
- Department of Biomedical Engineering, CARIM School for Cardiovascular Diseases, Maastricht University, Maastricht, The Netherlands
- Division of Heart and Lungs, Department of Medical Physiology, University Medical Centre Utrecht, Utrecht, The Netherlands
| | - Julie Shade
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland, United States
- Alliance for Cardiovascular Diagnostic and Treatment Innovation, Johns Hopkins University, Baltimore, Maryland, United States
| | - Jordi Heijman
- Department of Cardiology, CARIM School for Cardiovascular Diseases, Maastricht University, Maastricht, The Netherlands
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6
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Li Q, Yan Z, Wang Z, Liang C, Wang X, Wu X, Wang W, Yuan Y, Wang K. A simulation study on the antiarrhythmic mechanisms of established agents in myocardial ischemia and infarction. PLoS Comput Biol 2024; 20:e1012244. [PMID: 38917196 PMCID: PMC11230589 DOI: 10.1371/journal.pcbi.1012244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Revised: 07/08/2024] [Accepted: 06/10/2024] [Indexed: 06/27/2024] Open
Abstract
Patients with myocardial ischemia and infarction are at increased risk of arrhythmias, which in turn, can exacerbate the overall risk of mortality. Despite the observed reduction in recurrent arrhythmias through antiarrhythmic drug therapy, the precise mechanisms underlying their effectiveness in treating ischemic heart disease remain unclear. Moreover, there is a lack of specialized drugs designed explicitly for the treatment of myocardial ischemic arrhythmia. This study employs an electrophysiological simulation approach to investigate the potential antiarrhythmic effects and underlying mechanisms of various pharmacological agents in the context of ischemia and myocardial infarction (MI). Based on physiological experimental data, computational models are developed to simulate the effects of a series of pharmacological agents (amiodarone, telmisartan, E-4031, chromanol 293B, and glibenclamide) on cellular electrophysiology and utilized to further evaluate their antiarrhythmic effectiveness during ischemia. On 2D and 3D tissues with multiple pathological conditions, the simulation results indicate that the antiarrhythmic effect of glibenclamide is primarily attributed to the suppression of efflux of potassium ion to facilitate the restitution of [K+]o, as opposed to recovery of IKATP during myocardial ischemia. This discovery implies that, during acute cardiac ischemia, pro-arrhythmogenic alterations in cardiac tissue's excitability and conduction properties are more significantly influenced by electrophysiological changes in the depolarization rate, as opposed to variations in the action potential duration (APD). These findings offer specific insights into potentially effective targets for investigating ischemic arrhythmias, providing significant guidance for clinical interventions in acute coronary syndrome.
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Affiliation(s)
- Qince Li
- School of Computer Science and Technology, Harbin Institute of Technology (HIT), Harbin, China
| | - Zheng Yan
- School of Computer Science and Technology, Harbin Institute of Technology (HIT), Harbin, China
| | - Zhen Wang
- Zibo Central Hospital, Zibo, Shandong, China
| | - Cuiping Liang
- Beijing Institute of Computer Technology and Applications, Beijing, China
| | - Xiqian Wang
- Zibo Central Hospital, Zibo, Shandong, China
| | - Xianghu Wu
- Zibo Central Hospital, Zibo, Shandong, China
| | - Wei Wang
- School of Computer Science and Technology, Harbin Institute of Technology (HIT), Harbin, China
| | - Yongfeng Yuan
- School of Computer Science and Technology, Harbin Institute of Technology (HIT), Harbin, China
| | - Kuanquan Wang
- School of Computer Science and Technology, Harbin Institute of Technology (HIT), Harbin, China
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7
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Camps J, Berg LA, Wang ZJ, Sebastian R, Riebel LL, Doste R, Zhou X, Sachetto R, Coleman J, Lawson B, Grau V, Burrage K, Bueno-Orovio A, Weber Dos Santos R, Rodriguez B. Digital twinning of the human ventricular activation sequence to Clinical 12-lead ECGs and magnetic resonance imaging using realistic Purkinje networks for in silico clinical trials. Med Image Anal 2024; 94:103108. [PMID: 38447244 DOI: 10.1016/j.media.2024.103108] [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: 06/23/2023] [Revised: 02/06/2024] [Accepted: 02/13/2024] [Indexed: 03/08/2024]
Abstract
Cardiac in silico clinical trials can virtually assess the safety and efficacy of therapies using human-based modelling and simulation. These technologies can provide mechanistic explanations for clinically observed pathological behaviour. Designing virtual cohorts for in silico trials requires exploiting clinical data to capture the physiological variability in the human population. The clinical characterisation of ventricular activation and the Purkinje network is challenging, especially non-invasively. Our study aims to present a novel digital twinning pipeline that can efficiently generate and integrate Purkinje networks into human multiscale biventricular models based on subject-specific clinical 12-lead electrocardiogram and magnetic resonance recordings. Essential novel features of the pipeline are the human-based Purkinje network generation method, personalisation considering ECG R wave progression as well as QRS morphology, and translation from reduced-order Eikonal models to equivalent biophysically-detailed monodomain ones. We demonstrate ECG simulations in line with clinical data with clinical image-based multiscale models with Purkinje in four control subjects and two hypertrophic cardiomyopathy patients (simulated and clinical QRS complexes with Pearson's correlation coefficients > 0.7). Our methods also considered possible differences in the density of Purkinje myocardial junctions in the Eikonal-based inference as regional conduction velocities. These differences translated into regional coupling effects between Purkinje and myocardial models in the monodomain formulation. In summary, we demonstrate a digital twin pipeline enabling simulations yielding clinically consistent ECGs with clinical CMR image-based biventricular multiscale models, including personalised Purkinje in healthy and cardiac disease conditions.
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Affiliation(s)
- Julia Camps
- University of Oxford, Oxford, United Kingdom.
| | | | | | | | | | - Ruben Doste
- University of Oxford, Oxford, United Kingdom
| | - Xin Zhou
- University of Oxford, Oxford, United Kingdom
| | - Rafael Sachetto
- Universidade Federal de São João del Rei, São João del Rei, MG, Brazil
| | | | - Brodie Lawson
- Queensland University of Technology, Brisbane, Australia
| | | | - Kevin Burrage
- University of Oxford, Oxford, United Kingdom; Queensland University of Technology, Brisbane, Australia
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8
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Coleman JA, Doste R, Beltrami M, Coppini R, Olivotto I, Raman B, Bueno-Orovio A. Electrophysiological mechanisms underlying T wave pseudonormalisation on stress ECGs in hypertrophic cardiomyopathy. Comput Biol Med 2024; 169:107829. [PMID: 38096763 DOI: 10.1016/j.compbiomed.2023.107829] [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: 08/23/2023] [Revised: 11/09/2023] [Accepted: 12/04/2023] [Indexed: 02/08/2024]
Abstract
BACKGROUND Pseudonormal T waves may be detected on stress electrocardiograms (ECGs) in hypertrophic cardiomyopathy (HCM). Either myocardial ischaemia or purely exercise-induced changes have been hypothesised to contribute to this phenomenon, but the precise electrophysiological mechanisms remain unknown. METHODS Computational models of human HCM ventricles (n = 20) with apical and asymmetric septal hypertrophy phenotypes with variable severities of repolarisation impairment were used to investigate the effects of acute myocardial ischaemia on ECGs with T wave inversions at baseline. Virtual 12-lead ECGs were derived from a total of 520 biventricular simulations, for cases with regionally ischaemic K+ accumulation in hypertrophied segments, global exercise-induced serum K+ increases, and/or increased pacing frequency, to analyse effects on ECG biomarkers including ST segments, T wave amplitudes, and QT intervals. RESULTS Regional ischaemic K+ accumulation had a greater impact on T wave pseudonormalisation than exercise-induced serum K+ increases, due to larger reductions in repolarisation gradients. Increases in serum K+ and pacing rate partially corrected T waves in some anatomical and electrophysiological phenotypes. T wave morphology was more sensitive than ST segment elevation to regional K+ increases, suggesting that T wave pseudonormalisation may sometimes be an early, or the only, ECG feature of myocardial ischaemia in HCM. CONCLUSIONS Ischaemia-induced T wave pseudonormalisation can occur on stress ECG testing in HCM before significant ST segment changes. Some anatomical and electrophysiological phenotypes may enable T wave pseudonormalisation due to exercise-induced increased serum K+ and pacing rate. Consideration of dynamic T wave abnormalities could improve the detection of myocardial ischaemia in HCM.
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Affiliation(s)
- James A Coleman
- Department of Computer Science, University of Oxford, Oxford, United Kingdom
| | - Ruben Doste
- Department of Computer Science, University of Oxford, Oxford, United Kingdom
| | - Matteo Beltrami
- Cardiomyopathy Unit, Careggi University Hospital, Florence, Italy
| | - Raffaele Coppini
- Department of NeuroFarBa, University of Florence, Florence, Italy
| | - Iacopo Olivotto
- Cardiomyopathy Unit, Careggi University Hospital, Florence, Italy; Meyer Children's Hospital IRCCS, Florence, Italy
| | - Betty Raman
- Oxford Centre for Clinical Magnetic Resonance Research (OCMR), Radcliffe Department of Medicine, Division of Cardiovascular Medicine, University of Oxford, Oxford, United Kingdom
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9
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Engelhardt E, Elzenheimer E, Hoffmann J, Meledeth C, Frey N, Schmidt G. Non-Invasive Electroanatomical Mapping: A State-Space Approach for Myocardial Current Density Estimation. Bioengineering (Basel) 2023; 10:1432. [PMID: 38136023 PMCID: PMC10741003 DOI: 10.3390/bioengineering10121432] [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: 11/12/2023] [Revised: 12/05/2023] [Accepted: 12/13/2023] [Indexed: 12/24/2023] Open
Abstract
Electroanatomical mapping is a method for creating a model of the electrophysiology of the human heart. Medical professionals routinely locate and ablate the site of origin of cardiac arrhythmias with invasive catheterization. Non-invasive localization takes the form of electrocardiographic (ECG) or magnetocardiographic (MCG) imaging, where the goal is to reconstruct the electrical activity of the human heart. Non-invasive alternatives to catheter electroanatomical mapping would reduce patients' risks and open new venues for treatment planning and prevention. This work introduces a new system state-based method for estimating the electrical activity of the human heart from MCG measurements. Our model enables arbitrary propagation paths and velocities. A Kalman filter optimally estimates the current densities under the given measurements and model parameters. In an outer optimization loop, these model parameters are then optimized via gradient descent. This paper aims to establish the foundation for future research by providing a detailed mathematical explanation of the algorithm. We demonstrate the feasibility of our method through a simplified one-layer simulation. Our results show that the algorithm can learn the propagation paths from the magnetic measurements. A threshold-based segmentation into healthy and pathological tissue yields a DICE score of 0.84, a recall of 0.77, and a precision of 0.93.
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Affiliation(s)
- Erik Engelhardt
- Department of Electrical Information Engineering, Faculty of Engineering, Kiel University, Kaiserstr. 2, 24143 Kiel, Germany; (E.E.); (E.E.)
| | - Eric Elzenheimer
- Department of Electrical Information Engineering, Faculty of Engineering, Kiel University, Kaiserstr. 2, 24143 Kiel, Germany; (E.E.); (E.E.)
| | - Johannes Hoffmann
- Department of Electrical Information Engineering, Faculty of Engineering, Kiel University, Kaiserstr. 2, 24143 Kiel, Germany; (E.E.); (E.E.)
| | - Christy Meledeth
- Internal Medicine 1—Cardiology and Internal Intensive Care Medicine, Med Campus III, Kepler University Hospital, Krankenhausstraße 9, 4021 Linz, Austria;
| | - Norbert Frey
- Department of Internal Medicine III (Cardiology, Angiology and Pneumonology), University Medical Center Heidelberg, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany;
| | - Gerhard Schmidt
- Department of Electrical Information Engineering, Faculty of Engineering, Kiel University, Kaiserstr. 2, 24143 Kiel, Germany; (E.E.); (E.E.)
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10
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Llopis-Lorente J, Baroudi S, Koloskoff K, Mora MT, Basset M, Romero L, Benito S, Dayan F, Saiz J, Trenor B. Combining pharmacokinetic and electrophysiological models for early prediction of drug-induced arrhythmogenicity. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2023; 242:107860. [PMID: 37844488 DOI: 10.1016/j.cmpb.2023.107860] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 09/28/2023] [Accepted: 10/10/2023] [Indexed: 10/18/2023]
Abstract
BACKGROUND AND OBJECTIVE In silico methods are gaining attention for predicting drug-induced Torsade de Pointes (TdP) in different stages of drug development. However, many computational models tended not to account for inter-individual response variability due to demographic covariates, such as sex, or physiologic covariates, such as renal function, which may be crucial when predicting TdP. This study aims to compare the effects of drugs in male and female populations with normal and impaired renal function using in silico methods. METHODS Pharmacokinetic models considering sex and renal function as covariates were implemented from data published in pharmacokinetic studies. Drug effects were simulated using an electrophysiologically calibrated population of cellular models of 300 males and 300 females. The population of models was built by modifying the endocardial action potential model published by O'Hara et al. (2011) according to the experimentally measured gene expression levels of 12 ion channels. RESULTS Fifteen pharmacokinetic models for CiPA drugs were implemented and validated in this study. Eight pharmacokinetic models included the effect of renal function and four the effect of sex. The mean difference in action potential duration (APD) between male and female populations was 24.9 ms (p<0.05). Our simulations indicated that women with impaired renal function were particularly susceptible to drug-induced arrhythmias, whereas healthy men were less prone to TdP. Differences between patient groups were more pronounced for high TdP-risk drugs. The proposed in silico tool also revealed that individuals with impaired renal function, electrophysiologically simulated with hyperkalemia (extracellular potassium concentration [K+]o = 7 mM) exhibited less pronounced APD prolongation than individuals with normal potassium levels. The pharmacokinetic/electrophysiological framework was used to determine the maximum safe dose of dofetilide in different patient groups. As a proof of concept, 3D simulations were also run for dofetilide obtaining QT prolongation in accordance with previously reported clinical values. CONCLUSIONS This study presents a novel methodology that combines pharmacokinetic and electrophysiological models to incorporate the effects of sex and renal function into in silico drug simulations and highlights their impact on TdP-risk assessment. Furthermore, it may also help inform maximum dose regimens that ensure TdP-related safety in a specific sub-population of patients.
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Affiliation(s)
- Jordi Llopis-Lorente
- Centro de Investigación e Innovación en Bioingeniería (Ci(2)B), Universitat Politècnica de València, camino de Vera, s/n, 46022, Valencia, Spain
| | | | | | - Maria Teresa Mora
- Centro de Investigación e Innovación en Bioingeniería (Ci(2)B), Universitat Politècnica de València, camino de Vera, s/n, 46022, Valencia, Spain
| | | | - Lucía Romero
- Centro de Investigación e Innovación en Bioingeniería (Ci(2)B), Universitat Politècnica de València, camino de Vera, s/n, 46022, Valencia, Spain
| | | | | | - Javier Saiz
- Centro de Investigación e Innovación en Bioingeniería (Ci(2)B), Universitat Politècnica de València, camino de Vera, s/n, 46022, Valencia, Spain
| | - Beatriz Trenor
- Centro de Investigación e Innovación en Bioingeniería (Ci(2)B), Universitat Politècnica de València, camino de Vera, s/n, 46022, Valencia, Spain.
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11
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García-Mendívil L, Pérez-Zabalza M, Oliver-Gelabert A, Vallejo-Gil JM, Fañanás-Mastral J, Vázquez-Sancho M, Bellido-Morales JA, Vaca-Núñez AS, Ballester-Cuenca C, Diez E, Ordovás L, Pueyo E. Interindividual Age-Independent Differences in Human CX43 Impact Ventricular Arrhythmic Risk. RESEARCH (WASHINGTON, D.C.) 2023; 6:0254. [PMID: 38023417 PMCID: PMC10650968 DOI: 10.34133/research.0254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/11/2023] [Accepted: 10/02/2023] [Indexed: 12/01/2023]
Abstract
Connexin 43 (CX43) is one of the major components of gap junctions, the structures responsible for the intercellular communication and transmission of the electrical impulse in the left ventricle. There is limited information on the histological changes of CX43 with age and their effect on electrophysiology, especially in humans. Here, we analyzed left ventricular biopsies from living donors starting at midlife to characterize age-related CX43 remodeling. We assessed its quantity, degree of lateralization, and spatial heterogeneity together with fibrotic deposition. We observed no significant age-related remodeling of CX43. Only spatial heterogeneity increased slightly with age, and this increase was better explained by biological age than by chronological age. Importantly, we found that CX43 features varied considerably among individuals in our population with no relevant relationship to age or fibrosis content, in contrast to animal species. We used our experimental results to feed computational models of human ventricular electrophysiology and to assess the effects of interindividual differences in specific features of CX43 and fibrosis on conduction velocity, action potential duration, and arrhythmogenicity. We found that larger amounts of fibrosis were associated with the highest arrhythmic risk, with this risk being increased when fibrosis deposition was combined with a reduction in CX43 amount and/or with an increase in CX43 spatial heterogeneity. These mechanisms underlying high arrhythmic risk in some individuals were not associated with age in our study population. In conclusion, our data rule out CX43 remodeling as an age-related arrhythmic substrate in the population beyond midlife, but highlight its potential as a proarrhythmic factor at the individual level, especially when combined with increased fibrosis.
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Affiliation(s)
- Laura García-Mendívil
- Biomedical Signal Interpretation and Computational Simulation group (BSICoS), Aragón Institute of Engineering Research,
University of Zaragoza, Zaragoza 50018, Spain
- BSICoS, Instituto de Investigación Sanitaria Aragón (IISA), Zaragoza 50018, Spain
| | - María Pérez-Zabalza
- Biomedical Signal Interpretation and Computational Simulation group (BSICoS), Aragón Institute of Engineering Research,
University of Zaragoza, Zaragoza 50018, Spain
- BSICoS, Instituto de Investigación Sanitaria Aragón (IISA), Zaragoza 50018, Spain
- Centro Universitario de la Defensa (CUD), Zaragoza 50090, Spain
| | - Antoni Oliver-Gelabert
- Biomedical Signal Interpretation and Computational Simulation group (BSICoS), Aragón Institute of Engineering Research,
University of Zaragoza, Zaragoza 50018, Spain
- BSICoS, Instituto de Investigación Sanitaria Aragón (IISA), Zaragoza 50018, Spain
| | - José María Vallejo-Gil
- Department of Cardiovascular Surgery,
University Hospital Miguel Servet, Zaragoza 50009, Spain
| | - Javier Fañanás-Mastral
- Department of Cardiovascular Surgery,
University Hospital Miguel Servet, Zaragoza 50009, Spain
| | - Manuel Vázquez-Sancho
- Department of Cardiovascular Surgery,
University Hospital Miguel Servet, Zaragoza 50009, Spain
| | | | | | - Carlos Ballester-Cuenca
- Department of Cardiovascular Surgery,
University Hospital Miguel Servet, Zaragoza 50009, Spain
| | - Emiliano Diez
- Institute of Experimental Medicine and Biology of Cuyo (IMBECU), CONICET, Mendoza 5500, Argentina
| | - Laura Ordovás
- Biomedical Signal Interpretation and Computational Simulation group (BSICoS), Aragón Institute of Engineering Research,
University of Zaragoza, Zaragoza 50018, Spain
- BSICoS, Instituto de Investigación Sanitaria Aragón (IISA), Zaragoza 50018, Spain
- Fundación Agencia Aragonesa para la Investigación y el Desarrollo (ARAID), Zaragoza 50018, Spain
| | - Esther Pueyo
- Biomedical Signal Interpretation and Computational Simulation group (BSICoS), Aragón Institute of Engineering Research,
University of Zaragoza, Zaragoza 50018, Spain
- BSICoS, Instituto de Investigación Sanitaria Aragón (IISA), Zaragoza 50018, Spain
- Biomedical Research Networking Center in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Zaragoza 50018, Spain
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12
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Tsumoto K, Shimamoto T, Aoji Y, Himeno Y, Kuda Y, Tanida M, Amano A, Kurata Y. Theoretical prediction of early afterdepolarization-evoked triggered activity formation initiating ventricular reentrant arrhythmias. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2023; 240:107722. [PMID: 37515880 DOI: 10.1016/j.cmpb.2023.107722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 07/02/2023] [Accepted: 07/14/2023] [Indexed: 07/31/2023]
Abstract
BACKGROUND AND OBJECTIVE Excessive prolongation of QT interval on ECGs in patients with congenital/acquired long QT syndrome and heart failure is a sign suggesting the development of early afterdepolarization (EAD), an abnormal repolarization in the action potential of ventricular cardiomyocytes. The development of EAD has been believed to be a trigger for fatal tachyarrhythmia, which can be a risk for sudden cardiac death. The role of EAD in triggering ventricular tachycardia (VT) remains unclear. The aim of this study was to elucidate the mechanism of EAD-induced triggered activity formation that leads to the VT such as Torsades de Pointes. METHODS We investigated the relationship between EAD and tachyarrhythmia initiation by constructing homogeneous myocardial sheet models consisting of the mid-myocardial cell version of a human ventricular myocyte model and performing simulations of excitation propagation. RESULTS A solitary island-like (clustering) occurrence of EADs in the homogeneous myocardial sheet could induce a focal excitation wave. However, reentrant excitation, an entity of tachyarrhythmia, was not able to be triggered regardless of the EAD cluster size when the focal excitation wave formed a repolarization potential difference boundary consisting of only a convex surface. The discontinuous distribution of multiple EAD clusters in the ventricular tissue formed a specific repolarization heterogeneity due to the repolarization potential difference, the shape of which depended on EAD cluster size and placed intervals. We found that the triggered activity was formed in such a manner that the repolarization potential difference boundary included a concave surface. CONCLUSIONS The formation of triggered activity that led to tachyarrhythmia required not only the occurrence of EAD onset-mediated focal excitation wave but also a repolarization heterogeneity-based specific repolarization potential difference boundary shape formed within the tissue.
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Affiliation(s)
- Kunichika Tsumoto
- Department of Physiology II, Kanazawa Medical University, Uchinada 920-0293, Japan.
| | - Takao Shimamoto
- Department of Bioinformatics, College of Life Sciences, Ritsumeikan University, Kusatsu 525-8577, Japan
| | - Yuma Aoji
- Department of Bioinformatics, College of Life Sciences, Ritsumeikan University, Kusatsu 525-8577, Japan
| | - Yukiko Himeno
- Department of Bioinformatics, College of Life Sciences, Ritsumeikan University, Kusatsu 525-8577, Japan
| | - Yuhichi Kuda
- Department of Physiology II, Kanazawa Medical University, Uchinada 920-0293, Japan
| | - Mamoru Tanida
- Department of Physiology II, Kanazawa Medical University, Uchinada 920-0293, Japan
| | - Akira Amano
- Department of Bioinformatics, College of Life Sciences, Ritsumeikan University, Kusatsu 525-8577, Japan
| | - Yasutaka Kurata
- Department of Physiology II, Kanazawa Medical University, Uchinada 920-0293, Japan.
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13
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Gillette K, Gsell MAF, Nagel C, Bender J, Winkler B, Williams SE, Bär M, Schäffter T, Dössel O, Plank G, Loewe A. MedalCare-XL: 16,900 healthy and pathological synthetic 12 lead ECGs from electrophysiological simulations. Sci Data 2023; 10:531. [PMID: 37553349 PMCID: PMC10409805 DOI: 10.1038/s41597-023-02416-4] [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: 03/29/2023] [Accepted: 07/25/2023] [Indexed: 08/10/2023] Open
Abstract
Mechanistic cardiac electrophysiology models allow for personalized simulations of the electrical activity in the heart and the ensuing electrocardiogram (ECG) on the body surface. As such, synthetic signals possess known ground truth labels of the underlying disease and can be employed for validation of machine learning ECG analysis tools in addition to clinical signals. Recently, synthetic ECGs were used to enrich sparse clinical data or even replace them completely during training leading to improved performance on real-world clinical test data. We thus generated a novel synthetic database comprising a total of 16,900 12 lead ECGs based on electrophysiological simulations equally distributed into healthy control and 7 pathology classes. The pathological case of myocardial infraction had 6 sub-classes. A comparison of extracted features between the virtual cohort and a publicly available clinical ECG database demonstrated that the synthetic signals represent clinical ECGs for healthy and pathological subpopulations with high fidelity. The ECG database is split into training, validation, and test folds for development and objective assessment of novel machine learning algorithms.
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Affiliation(s)
- Karli Gillette
- Gottfried Schatz Research Center: Division of Medical Physics and Biophysics, Medical University of Graz, Graz, Austria
- BioTechMed-Graz, Graz, Austria
| | - Matthias A F Gsell
- Gottfried Schatz Research Center: Division of Medical Physics and Biophysics, Medical University of Graz, Graz, Austria
| | - Claudia Nagel
- Institute of Biomedical Engineering, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
| | - Jule Bender
- Institute of Biomedical Engineering, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
| | - Benjamin Winkler
- Physikalisch-Technische Bundesanstalt, National Metrology Institute, Berlin, Germany
| | - Steven E Williams
- King's College London, London, United Kingdom
- University of Edinburgh, Edinburgh, United Kingdom
| | - Markus Bär
- Physikalisch-Technische Bundesanstalt, National Metrology Institute, Berlin, Germany
| | - Tobias Schäffter
- Physikalisch-Technische Bundesanstalt, National Metrology Institute, Berlin, Germany
- King's College London, London, United Kingdom
- Biomedical Engineering, Technische Universität Berlin, Einstein Centre Digital Future, Berlin, Germany
| | - Olaf Dössel
- Institute of Biomedical Engineering, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
| | - Gernot Plank
- Gottfried Schatz Research Center: Division of Medical Physics and Biophysics, Medical University of Graz, Graz, Austria.
- BioTechMed-Graz, Graz, Austria.
| | - Axel Loewe
- Institute of Biomedical Engineering, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany.
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14
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The role of β-adrenergic stimulation in QT interval adaptation to heart rate during stress test. PLoS One 2023; 18:e0280901. [PMID: 36701349 PMCID: PMC9879473 DOI: 10.1371/journal.pone.0280901] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2022] [Accepted: 01/10/2023] [Indexed: 01/27/2023] Open
Abstract
The adaptation lag of the QT interval after heart rate (HR) has been proposed as an arrhythmic risk marker. Most studies have quantified the QT adaptation lag in response to abrupt, step-like changes in HR induced by atrial pacing, in response to tilt test or during ambulatory recordings. Recent studies have introduced novel methods to quantify the QT adaptation lag to gradual, ramp-like HR changes in stress tests by evaluating the differences between the measured QT series and an estimated, memoryless QT series obtained from the instantaneous HR. These studies have observed the QT adaptation lag to progressively reduce when approaching the stress peak, with the underlying mechanisms being still unclear. This study analyzes the contribution of β-adrenergic stimulation to QT interval rate adaptation in response to gradual, ramp-like HR changes. We first quantify the QT adaptation lag in Coronary Artery Disease (CAD) patients undergoing stress test. To uncover the involved mechanisms, we use biophysically detailed computational models coupling descriptions of human ventricular electrophysiology and β-adrenergic signaling, from which we simulate ventricular action potentials and ECG signals. We characterize the adaptation of the simulated QT interval in response to the HR time series measured from each of the analyzed CAD patients. We show that, when the simulated ventricular tissue is subjected to a time-varying β-adrenergic stimulation pattern, with higher stimulation levels close to the stress peak, the simulated QT interval presents adaptation lags during exercise that are more similar to those measured from the patients than when subjected to constant β-adrenergic stimulation. During stress test recovery, constant and time-varying β-adrenergic stimulation patterns render similar adaptation lags, which are generally shorter than during exercise, in agreement with results from the patients. In conclusion, our findings support the role of time-varying β-adrenergic stimulation in contributing to QT interval adaptation to gradually increasing HR changes as those seen during the exercise phase of a stress test.
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15
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Ferrero JM, Gonzalez-Ascaso A, Matas JFR. The mechanisms of potassium loss in acute myocardial ischemia: New insights from computational simulations. Front Physiol 2023; 14:1074160. [PMID: 36923288 PMCID: PMC10009276 DOI: 10.3389/fphys.2023.1074160] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Accepted: 02/13/2023] [Indexed: 03/03/2023] Open
Abstract
Acute myocardial ischemia induces hyperkalemia (accumulation of extracellular potassium), a major perpetrator of lethal reentrant ventricular arrhythmias. Despite considerable experimental efforts to explain this pathology in the last decades, the intimate mechanisms behind hyperkalemia remain partially unknown. In order to investigate these mechanisms, we developed a novel computational model of acute myocardial ischemia which couples a) an electrophysiologically detailed human cardiomyocyte model that incorporates modifications to account for ischemia-induced changes in transmembrane currents, with b) a model of cardiac tissue and extracellular K + transport. The resulting model is able to reproduce and explain the triphasic time course of extracellular K + concentration within the ischemic zone, with values of [ K + ] o close to 14 mmol/L in the central ischemic zone after 30 min. In addition, the formation of a [ K + ] o border zone of approximately 1.2 cm 15 min after the onset of ischemia is predicted by the model. Our results indicate that the primary rising phase of [ K + ] o is mainly due to the imbalance between K + efflux, that increases slightly, and K + influx, that follows a reduction of the NaK pump activity by more than 50%. The onset of the plateau phase is caused by the appearance of electrical alternans (a novel mechanism identified by the model), which cause an abrupt reduction in the K + efflux. After the plateau, the secondary rising phase of [ K + ] o is caused by a subsequent imbalance between the K + influx, which continues to decrease slowly, and the K + efflux, which remains almost constant. Further, the study shows that the modulation of these mechanisms by the electrotonic coupling is the main responsible for the formation of the ischemic border zone in tissue, with K + transport playing only a minor role. Finally, the results of the model indicate that the injury current established between the healthy and the altered tissue is not sufficient to depolarize non-ischemic cells within the healthy tissue.
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Affiliation(s)
- Jose M Ferrero
- Centro de Investigacion e Innovacion en Bioingenieria, Universitat Politecnica de Valencia, Valencia, Spain
| | - Ana Gonzalez-Ascaso
- Centro de Investigacion e Innovacion en Bioingenieria, Universitat Politecnica de Valencia, Valencia, Spain.,Dipartimento di Chimica, Materiali e Ingegneria Chimica "Giulio Natta", Politecnico di Milano, Milan, Italy
| | - Jose F Rodriguez Matas
- Dipartimento di Chimica, Materiali e Ingegneria Chimica "Giulio Natta", Politecnico di Milano, Milan, Italy
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16
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Li Y, Wan R, Liu J, Liu W, Ma L, Zhang H. In silico mechanisms of arsenic trioxide-induced cardiotoxicity. Front Physiol 2022; 13:1004605. [PMID: 36589437 PMCID: PMC9798418 DOI: 10.3389/fphys.2022.1004605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Accepted: 11/28/2022] [Indexed: 12/23/2022] Open
Abstract
It has been found that arsenic trioxide (ATO) is effective in treating acute promyelocytic leukemia (APL). However, long QT syndrome was reported in patients receiving therapy using ATO, which even led to sudden cardiac death. The underlying mechanisms of ATO-induced cardiotoxicity have been investigated in some biological experiments, showing that ATO affects human ether-à-go-go-related gene (hERG) channels, coding rapid delayed rectifier potassium current (I Kr ), as well as L-type calcium (I CaL ) channels. Nevertheless, the mechanism by which these channel reconstitutions induced the arrhythmia in ventricular tissue remains unsolved. In this study, a mathematical model was developed to simulate the effect of ATO on ventricular electrical excitation at cellular and tissue levels by considering ATO's effects on I Kr and I CaL . The ATO-dose-dependent pore block model was incorporated into the I Kr model, and the enhanced degree of ATO to I CaL was based on experimental data. Simulation results indicated that ATO extended the action potential duration of three types of ventricular myocytes (VMs), including endocardial cells (ENDO), midmyocardial cells (MCELL), and epicardial cells (EPI), and exacerbated the heterogeneity among them. ATO could also induce alternans in all three kinds of VMs. In a cable model of the intramural ventricular strand, the effects of ATO are reflected in a prolonged QT interval of simulated pseudo-ECG and a wide vulnerable window, thus increasing the possibility of spiral wave formation in ventricular tissue. In addition to showing that ATO prolonged QT, we revealed that the heterogeneity caused by ATO is also an essential hazard factor. Based on this, a pharmacological intervention of ATO toxicity by resveratrol was undertaken. This study provides a further understanding of ATO-induced cardiotoxicity, which may help to improve the treatment for APL patients.
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Affiliation(s)
- Yacong Li
- Beijing Academy of Artificial Intelligence, Beijing, China
| | - Runlan Wan
- Department of Oncology, The Affiliated Hospital of Southwest Medical University, Luzhou, China
| | - Jun Liu
- School of Computer Science and Technology, Harbin Institute of Technology, Harbin, China,Key Laboratory of Medical Electrophysiology, Ministry of Education & Medical Electrophysiological Key Laboratory of Sichuan Province, Institute of Cardiovascular Research, Southwest Medical University, Luzhou, China,*Correspondence: Jun Liu, ; Weichao Liu, ; Henggui Zhang,
| | - Weichao Liu
- Key Laboratory of Medical Electrophysiology, Ministry of Education & Medical Electrophysiological Key Laboratory of Sichuan Province, Institute of Cardiovascular Research, Southwest Medical University, Luzhou, China,*Correspondence: Jun Liu, ; Weichao Liu, ; Henggui Zhang,
| | - Lei Ma
- Beijing Academy of Artificial Intelligence, Beijing, China,National Biomedical Imaging Center, Peking University, Beijing, China
| | - Henggui Zhang
- Biological Physics Group, School of Physics and Astronomy, The University of Manchester, Manchester, United Kingdom,*Correspondence: Jun Liu, ; Weichao Liu, ; Henggui Zhang,
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17
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Strocchi M, Wijesuriya N, Elliott MK, Gillette K, Neic A, Mehta V, Vigmond EJ, Plank G, Rinaldi CA, Niederer SA. Leadless biventricular left bundle and endocardial lateral wall pacing versus left bundle only pacing in left bundle branch block patients. Front Physiol 2022; 13:1049214. [PMID: 36589454 PMCID: PMC9794756 DOI: 10.3389/fphys.2022.1049214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Accepted: 11/28/2022] [Indexed: 12/15/2022] Open
Abstract
Biventricular endocardial (BIV-endo) pacing and left bundle pacing (LBP) are novel delivery methods for cardiac resynchronization therapy (CRT). Both pacing methods can be delivered through leadless pacing, to avoid risks associated with endocardial or transvenous leads. We used computational modelling to quantify synchrony induced by BIV-endo pacing and LBP through a leadless pacing system, and to investigate how the right-left ventricle (RV-LV) delay, RV lead location and type of left bundle capture affect response. We simulated ventricular activation on twenty-four four-chamber heart meshes inclusive of His-Purkinje networks with left bundle branch block (LBBB). Leadless biventricular (BIV) pacing was simulated by adding an RV apical stimulus and an LV lateral wall stimulus (BIV-endo lateral) or targeting the left bundle (BIV-LBP), with an RV-LV delay set to 5 ms. To test effect of prolonged RV-LV delays and RV pacing location, the RV-LV delay was increased to 35 ms and/or the RV stimulus was moved to the RV septum. BIV-endo lateral pacing was less sensitive to increased RV-LV delays, while RV septal pacing worsened response compared to RV apical pacing, especially for long RV-LV delays. To investigate how left bundle capture affects response, we computed 90% BIV activation times (BIVAT-90) during BIV-LBP with selective and non-selective capture, and left bundle branch area pacing (LBBAP), simulated by pacing 1 cm below the left bundle. Non-selective LBP was comparable to selective LBP. LBBAP was worse than selective LBP (BIVAT-90: 54.2 ± 5.7 ms vs. 62.7 ± 6.5, p < 0.01), but it still significantly reduced activation times from baseline. Finally, we compared leadless LBP with RV pacing against optimal LBP delivery through a standard lead system by simulating BIV-LBP and selective LBP alone with and without optimized atrioventricular delay (AVD). Although LBP alone with optimized AVD was better than BIV-LBP, when AVD optimization was not possible BIV-LBP outperformed LBP alone, because the RV pacing stimulus shortened RV activation (BIVAT-90: 54.2 ± 5.7 ms vs. 66.9 ± 5.1 ms, p < 0.01). BIV-endo lateral pacing or LBP delivered through a leadless system could potentially become an alternative to standard CRT. RV-LV delay, RV lead location and type of left bundle capture affect leadless pacing efficacy and should be considered in future trial designs.
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Affiliation(s)
- Marina Strocchi
- School of Biomedical Engineering and Imaging Sciences, King’s College London, London, United Kingdom
| | - Nadeev Wijesuriya
- School of Biomedical Engineering and Imaging Sciences, King’s College London, London, United Kingdom
- Guy’s and St Thomas’ NHS Foundation Trust, London, United Kingdom
| | - Mark K. Elliott
- School of Biomedical Engineering and Imaging Sciences, King’s College London, London, United Kingdom
- Guy’s and St Thomas’ NHS Foundation Trust, London, United Kingdom
| | - Karli Gillette
- BioTechMed-Graz, Graz, Austria
- Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria
| | | | - Vishal Mehta
- School of Biomedical Engineering and Imaging Sciences, King’s College London, London, United Kingdom
- Guy’s and St Thomas’ NHS Foundation Trust, London, United Kingdom
| | - Edward J. Vigmond
- University of Bordeaux, CNRS, Bordeaux, France
- IHU Liryc, Bordeaux, France
| | - Gernot Plank
- BioTechMed-Graz, Graz, Austria
- Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria
| | - Christopher A. Rinaldi
- School of Biomedical Engineering and Imaging Sciences, King’s College London, London, United Kingdom
- Guy’s and St Thomas’ NHS Foundation Trust, London, United Kingdom
| | - Steven A. Niederer
- School of Biomedical Engineering and Imaging Sciences, King’s College London, London, United Kingdom
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18
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Jiang H, Zhang S, Lu W, Yang F, Bi X, Ma W, Wei Z. In silico assessment of pharmacotherapy for carbon monoxide induced arrhythmias in healthy and failing human hearts. Front Physiol 2022; 13:1018299. [DOI: 10.3389/fphys.2022.1018299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2022] [Accepted: 11/16/2022] [Indexed: 11/17/2022] Open
Abstract
Background: Carbon monoxide (CO) is gaining increased attention in air pollution-induced arrhythmias. The severe cardiotoxic consequences of CO urgently require effective pharmacotherapy to treat it. However, existing evidence demonstrates that CO can induce arrhythmias by directly affecting multiple ion channels, which is a pathway distinct from heart ischemia and has received less concern in clinical treatment.Objective: To evaluate the efficacy of some common clinical antiarrhythmic drugs for CO-induced arrhythmias, and to propose a potential pharmacotherapy for CO-induced arrhythmias through the virtual pathological cell and tissue models.Methods: Two pathological models describing CO effects on healthy and failing hearts were constructed as control baseline models. After this, we first assessed the efficacy of some common antiarrhythmic drugs like ranolazine, amiodarone, nifedipine, etc., by incorporating their ion channel-level effects into the cell model. Cellular biomarkers like action potential duration and tissue-level biomarkers such as the QT interval from pseudo-ECGs were obtained to assess the drug efficacy. In addition, we also evaluated multiple specific IKr activators in a similar way to multi-channel blocking drugs, as the IKr activator showed great potency in dealing with CO-induced pathological changes.Results: Simulation results showed that the tested seven antiarrhythmic drugs failed to rescue the heart from CO-induced arrhythmias in terms of the action potential and the ECG manifestation. Some of them even worsened the condition of arrhythmogenesis. In contrast, IKr activators like HW-0168 effectively alleviated the proarrhythmic effects of CO.Conclusion: Current antiarrhythmic drugs including the ranolazine suggested in previous studies did not achieve therapeutic effects for the cardiotoxicity of CO, and we showed that the specific IKr activator is a promising pharmacotherapy for the treatment of CO-induced arrhythmias.
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19
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Zhang S, Lu W, Yang F, Li Z, Wang S, Jiang M, Wang X, Wei Z. Computational analysis of arrhythmogenesis in KCNH2 T618I mutation-associated short QT syndrome and the pharmacological effects of quinidine and sotalol. NPJ Syst Biol Appl 2022; 8:43. [PMID: 36333337 PMCID: PMC9636227 DOI: 10.1038/s41540-022-00254-5] [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: 06/13/2022] [Accepted: 10/18/2022] [Indexed: 11/06/2022] Open
Abstract
Short QT syndrome (SQTS) is a rare but dangerous genetic disease. In this research, we conducted a comprehensive in silico investigation into the arrhythmogenesis in KCNH2 T618I-associated SQTS using a multi-scale human ventricle model. A Markov chain model of IKr was developed firstly to reproduce the experimental observations. It was then incorporated into cell, tissue, and organ models to explore how the mutation provided substrates for ventricular arrhythmias. Using this T618I Markov model, we explicitly revealed the subcellular level functional alterations by T618I mutation, particularly the changes of ion channel states that are difficult to demonstrate in wet experiments. The following tissue and organ models also successfully reproduced the changed dynamics of reentrant spiral waves and impaired rate adaptions in hearts of T618I mutation. In terms of pharmacotherapy, we replicated the different effects of a drug under various conditions using identical mathematical descriptions for drugs. This study not only simulated the actions of an effective drug (quinidine) at various physiological levels, but also elucidated why the IKr inhibitor sotalol failed in SQT1 patients through profoundly analyzing its mutation-dependent actions.
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Affiliation(s)
- Shugang Zhang
- College of Computer Science and Technology, Ocean University of China, Qingdao, 266100, China
| | - Weigang Lu
- Department of Educational Technology, Ocean University of China, Qingdao, 266100, China.
- Biological Physics Group, School of Physics and Astronomy, The University of Manchester, Manchester, M13 9PL, UK.
| | - Fei Yang
- School of Mechanical, Electrical, and Information Engineering, Shandong University, Weihai, 264200, China
| | - Zhen Li
- College of Computer Science and Technology, Qingdao University, Qingdao, 266071, China
| | - Shuang Wang
- College of Computer Science and Technology, China University of Petroleum (East China), Qingdao, 266580, China
| | - Mingjian Jiang
- School of Information and Control Engineering, Qingdao University of Technology, Qingdao, 266033, China
| | | | - Zhiqiang Wei
- College of Computer Science and Technology, Ocean University of China, Qingdao, 266100, China
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20
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Monasterio V, Pueyo E, Rodríguez-Matas JF, Carro J. Cardiac cells stimulated with an axial current-like waveform reproduce electrophysiological properties of tissue fibers. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2022; 226:107121. [PMID: 36156439 DOI: 10.1016/j.cmpb.2022.107121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Revised: 09/01/2022] [Accepted: 09/07/2022] [Indexed: 06/16/2023]
Abstract
BACKGROUND AND OBJECTIVE In silico electrophysiological models are generally validated by comparing simulated results with experimental data. When dealing with single-cell and tissue scales simultaneously, as occurs frequently during model development and calibration, the effects of inter-cellular coupling should be considered to ensure the trustworthiness of model predictions. The hypothesis of this paper is that the cell-tissue mismatch can be reduced by incorporating the effects of conduction into the single-cell stimulation current. METHODS Five different stimulation waveforms were applied to the human ventricular O'Hara-Rudy cell model. The waveforms included the commonly used monophasic and biphasic (symmetric and asymmetric) pulses, a triangular waveform and a newly proposed asymmetric waveform (stimulation A) that resembles the transmembrane current associated with AP conduction in tissue. A comparison between single-cell and fiber simulated results was established by computing the relative difference between the values of AP-derived properties at different scales, and by evaluating the differences in the contributions of ionic conductances to each evaluated property. As a proof of the benefit, we investigated multi-scale differences in the simulation of the effects induced by dofetilide, a selective IKr blocker with high torsadogenic risk, on ventricular repolarization at different pacing rates. RESULTS Out of the five tested stimulation waveforms, stimulation A produced the closest correspondence between cell and tissue simulations in terms of AP properties at steady-state and under dynamic pacing and of ionic contributors to those AP properties. Also, stimulation A reproduced the effects of dofetilide better than the other alternative waveforms, mirroring the 'beat-skipping' behavior observed at fast pacing rates in experiments with human tissue. CONCLUSIONS The proposed stimulation current waveform accounts for inter-cellular coupling effects by mimicking cell excitation during AP conduction. The proposed waveform improves the correspondence between simulation scales, which could improve the trustworthiness of single-cell simulations without adding computational cost.
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Affiliation(s)
| | - Esther Pueyo
- Aragón Institute for Engineering Research, University of Zaragoza, IIS Aragón, Zaragoza, Spain; CIBER in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Spain
| | - José Félix Rodríguez-Matas
- LaBS, Department of Chemistry, Materials and Chemical Engineering "Giulio Natta", Politecnico di Milano, Italy
| | - Jesús Carro
- Universidad San Jorge, Villanueva de Gállego, Spain
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21
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Gillette K, Gsell MAF, Strocchi M, Grandits T, Neic A, Manninger M, Scherr D, Roney CH, Prassl AJ, Augustin CM, Vigmond EJ, Plank G. A personalized real-time virtual model of whole heart electrophysiology. Front Physiol 2022; 13:907190. [PMID: 36213235 PMCID: PMC9539798 DOI: 10.3389/fphys.2022.907190] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 08/15/2022] [Indexed: 01/12/2023] Open
Abstract
Computer models capable of representing the intrinsic personal electrophysiology (EP) of the heart in silico are termed virtual heart technologies. When anatomy and EP are tailored to individual patients within the model, such technologies are promising clinical and industrial tools. Regardless of their vast potential, few virtual technologies simulating the entire organ-scale EP of all four-chambers of the heart have been reported and widespread clinical use is limited due to high computational costs and difficulty in validation. We thus report on the development of a novel virtual technology representing the electrophysiology of all four-chambers of the heart aiming to overcome these limitations. In our previous work, a model of ventricular EP embedded in a torso was constructed from clinical magnetic resonance image (MRI) data and personalized according to the measured 12 lead electrocardiogram (ECG) of a single subject under normal sinus rhythm. This model is then expanded upon to include whole heart EP and a detailed representation of the His-Purkinje system (HPS). To test the capacities of the personalized virtual heart technology to replicate standard clinical morphological ECG features under such conditions, bundle branch blocks within both the right and the left ventricles under two different conduction velocity settings are modeled alongside sinus rhythm. To ensure clinical viability, model generation was completely automated and simulations were performed using an efficient real-time cardiac EP simulator. Close correspondence between the measured and simulated 12 lead ECG was observed under normal sinus conditions and all simulated bundle branch blocks manifested relevant clinical morphological features.
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Affiliation(s)
- Karli Gillette
- Gottfried Schatz Research Center—Biophysics, Medical University of Graz, Graz, Austria
- BioTechMed-Graz, Graz, Austria
| | - Matthias A. F. Gsell
- Gottfried Schatz Research Center—Biophysics, Medical University of Graz, Graz, Austria
- NAWI Graz, Institute of Mathematics and Scientific Computing, University of Graz, Graz, Austria
| | | | - Thomas Grandits
- Gottfried Schatz Research Center—Biophysics, Medical University of Graz, Graz, Austria
- NAWI Graz, Institute of Mathematics and Scientific Computing, University of Graz, Graz, Austria
| | | | - Martin Manninger
- Division of Cardiology, Department of Internal Medicine, Medical University of Graz, Graz, Austria
| | - Daniel Scherr
- Division of Cardiology, Department of Internal Medicine, Medical University of Graz, Graz, Austria
| | | | - Anton J. Prassl
- Gottfried Schatz Research Center—Biophysics, Medical University of Graz, Graz, Austria
- BioTechMed-Graz, Graz, Austria
| | - Christoph M. Augustin
- Gottfried Schatz Research Center—Biophysics, Medical University of Graz, Graz, Austria
- BioTechMed-Graz, Graz, Austria
| | | | - Gernot Plank
- Gottfried Schatz Research Center—Biophysics, Medical University of Graz, Graz, Austria
- BioTechMed-Graz, Graz, Austria
- *Correspondence: Gernot Plank,
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22
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Abstract
The global burden caused by cardiovascular disease is substantial, with heart disease representing the most common cause of death around the world. There remains a need to develop better mechanistic models of cardiac function in order to combat this health concern. Heart rhythm disorders, or arrhythmias, are one particular type of disease which has been amenable to quantitative investigation. Here we review the application of quantitative methodologies to explore dynamical questions pertaining to arrhythmias. We begin by describing single-cell models of cardiac myocytes, from which two and three dimensional models can be constructed. Special focus is placed on results relating to pattern formation across these spatially-distributed systems, especially the formation of spiral waves of activation. Next, we discuss mechanisms which can lead to the initiation of arrhythmias, focusing on the dynamical state of spatially discordant alternans, and outline proposed mechanisms perpetuating arrhythmias such as fibrillation. We then review experimental and clinical results related to the spatio-temporal mapping of heart rhythm disorders. Finally, we describe treatment options for heart rhythm disorders and demonstrate how statistical physics tools can provide insights into the dynamics of heart rhythm disorders.
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Affiliation(s)
- Wouter-Jan Rappel
- Department of Physics, University of California San Diego, La Jolla, CA 92037
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23
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Yoneda K, Kanada R, Okada JI, Watanabe M, Sugiura S, Hisada T, Washio T. A thermodynamically consistent monte carlo cross-bridge model with a trapping mechanism reveals the role of stretch activation in heart pumping. Front Physiol 2022; 13:855303. [PMID: 36160842 PMCID: PMC9498833 DOI: 10.3389/fphys.2022.855303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2022] [Accepted: 07/18/2022] [Indexed: 11/24/2022] Open
Abstract
Changes in intracellular calcium concentrations regulate heart beats. However, the decline in the left ventricular pressure during early diastole is much sharper than that of the Ca2+ transient, resulting in a rapid supply of blood to the left ventricle during the diastole. At the tissue level, cardiac muscles have a distinct characteristic, known as stretch activation, similar to the function of insect flight muscles. Stretch activation, which is a delayed increase in force following a rapid muscle length increase, has been thought to be related to autonomous control in these muscles. In this numerical simulation study, we introduced a molecular mechanism of stretch activation and investigated the role of this mechanism in the pumping function of the heart, using the previously developed coupling multiple-step active stiffness integration scheme for a Monte Carlo (MC) cross-bridge model and a bi-ventricular finite element model. In the MC cross-bridge model, we introduced a mechanism for trapping the myosin molecule in its post-power stroke state. We then determined the rate constants of transitions for trapping and escaping in a thermodynamically consistent manner. Based on our numerical analysis, we draw the following conclusions regarding the stretch activation mechanism: (i) the delayed force becomes larger than the original isometric force because the population of trapped myosin molecules and their average force increase after stretching; (ii) the delayed force has a duration of more than a few seconds owing to a fairly small rate constant of escape from the trapped state. For the role of stretch activation in heart pumping, we draw the following conclusions: (iii) for the regions in which the contraction force decreases earlier than the neighboring region in the end-systole phase, the trapped myosin molecules prevent further lengthening of the myocytes, which then prevents further shortening of neighboring myocytes; (iv) as a result, the contraction forces are sustained longer, resulting in a larger blood ejection, and their degeneration is synchronized.
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Affiliation(s)
- Kazunori Yoneda
- Section Solutions Division, Healthcare Solutions Development Unit, Fujitsu Japan Limited, Shiodome City Center, Tokyo, Japan
| | - Ryo Kanada
- RIKEN Center for Computational Science HPC- and AI-driven Drug Development Platform Division, AI-driven Drug Discovery Collaborative Unit, Kobe, Japan
| | - Jun-ichi Okada
- UT-Heart Inc., Kashiwanoha Campus Satellite, Kashiwa, Japan
- Graduate School of Frontier Sciences, University of Tokyo, Kashiwanoha Campus Satellite, Kashiwa, Japan
| | - Masahiro Watanabe
- Section Solutions Division, Healthcare Solutions Development Unit, Fujitsu Japan Limited, Shiodome City Center, Tokyo, Japan
| | - Seiryo Sugiura
- UT-Heart Inc., Kashiwanoha Campus Satellite, Kashiwa, Japan
| | | | - Takumi Washio
- UT-Heart Inc., Kashiwanoha Campus Satellite, Kashiwa, Japan
- Graduate School of Frontier Sciences, University of Tokyo, Kashiwanoha Campus Satellite, Kashiwa, Japan
- *Correspondence: Takumi Washio,
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24
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Barone A, Grieco D, Gizzi A, Molinari L, Zaltieri M, Massaroni C, Loppini A, Schena E, Bressi E, de Ruvo E, Caló L, Filippi S. A Simulation Study of the Effects of His Bundle Pacing in Left Bundle Branch Block. Med Eng Phys 2022; 107:103847. [DOI: 10.1016/j.medengphy.2022.103847] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 04/30/2022] [Accepted: 07/09/2022] [Indexed: 11/28/2022]
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25
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Bi X, Zhang S, Jiang H, Ma W, Li Y, Lu W, Yang F, Wei Z. Mechanistic Insights Into Inflammation-Induced Arrhythmias: A Simulation Study. Front Physiol 2022; 13:843292. [PMID: 35711306 PMCID: PMC9196871 DOI: 10.3389/fphys.2022.843292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2021] [Accepted: 04/25/2022] [Indexed: 11/29/2022] Open
Abstract
Cardiovascular diseases are the primary cause of death of humans, and among these, ventricular arrhythmias are the most common cause of death. There is plausible evidence implicating inflammation in the etiology of ventricular fibrillation (VF). In the case of systemic inflammation caused by an overactive immune response, the induced inflammatory cytokines directly affect the function of ion channels in cardiomyocytes, leading to a prolonged action potential duration (APD). However, the mechanistic links between inflammatory cytokine-induced molecular and cellular influences and inflammation-associated ventricular arrhythmias need to be elucidated. The present study aimed to determine the potential impact of systemic inflammation on ventricular electrophysiology by means of multiscale virtual heart models. The experimental data on the ionic current of three major cytokines [i.e., tumor necrosis factor-α (TNF-α), interleukin-1 (IL-1β), and interleukin-6 (IL-6)] were incorporated into the cell model, and the effects of each cytokine and their combined effect on the cell action potential (AP) were evaluated. Moreover, the integral effect of these cytokines on the conduction of excitation waves was also investigated in a tissue model. The simulation results suggested that inflammatory cytokines significantly prolonged APD, enhanced the transmural and regional repolarization heterogeneities that predispose to arrhythmias, and reduced the adaptability of ventricular tissue to fast heart rates. In addition, simulated pseudo-ECGs showed a prolonged QT interval—a manifestation consistent with clinical observations. In summary, the present study provides new insights into ventricular arrhythmias associated with inflammation.
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Affiliation(s)
- Xiangpeng Bi
- College of Computer Science and Technology, Ocean University of China, Qingdao, China
| | - Shugang Zhang
- College of Computer Science and Technology, Ocean University of China, Qingdao, China
| | - Huasen Jiang
- College of Computer Science and Technology, Ocean University of China, Qingdao, China
| | - Wenjian Ma
- College of Computer Science and Technology, Ocean University of China, Qingdao, China
| | - Yuanfei Li
- College of Computer Science and Technology, Ocean University of China, Qingdao, China
| | - Weigang Lu
- Department of Educational Technology, Ocean University of China, Qingdao, China
| | - Fei Yang
- School of Mechanical, Electrical and Information Engineering, Shandong University, Weihai, China
| | - Zhiqiang Wei
- College of Computer Science and Technology, Ocean University of China, Qingdao, China
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26
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Liang C, Li Q, Wang K, Du Y, Wang W, Zhang H. Mechanisms of ventricular arrhythmias elicited by coexistence of multiple electrophysiological remodeling in ischemia: A simulation study. PLoS Comput Biol 2022; 18:e1009388. [PMID: 35476614 PMCID: PMC9045648 DOI: 10.1371/journal.pcbi.1009388] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Accepted: 02/18/2022] [Indexed: 11/18/2022] Open
Abstract
Myocardial ischemia, injury and infarction (MI) are the three stages of acute coronary syndrome (ACS). In the past two decades, a great number of studies focused on myocardial ischemia and MI individually, and showed that the occurrence of reentrant arrhythmias is often associated with myocardial ischemia or MI. However, arrhythmogenic mechanisms in the tissue with various degrees of remodeling in the ischemic heart have not been fully understood. In this study, biophysical detailed single-cell models of ischemia 1a, 1b, and MI were developed to mimic the electrophysiological remodeling at different stages of ACS. 2D tissue models with different distributions of ischemia and MI areas were constructed to investigate the mechanisms of the initiation of reentrant waves during the progression of ischemia. Simulation results in 2D tissues showed that the vulnerable windows (VWs) in simultaneous presence of multiple ischemic conditions were associated with the dynamics of wave propagation in the tissues with each single pathological condition. In the tissue with multiple pathological conditions, reentrant waves were mainly induced by two different mechanisms: one is the heterogeneity along the excitation wavefront, especially the abrupt variation in conduction velocity (CV) across the border of ischemia 1b and MI, and the other is the decreased safe factor (SF) for conduction at the edge of the tissue in MI region which is attributed to the increased excitation threshold of MI region. Finally, the reentrant wave was observed in a 3D model with a scar reconstructed from MRI images of a MI patient. These comprehensive findings provide novel insights for understanding the arrhythmic risk during the progression of myocardial ischemia and highlight the importance of the multiple pathological stages in designing medical therapies for arrhythmias in ischemia.
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Affiliation(s)
- Cuiping Liang
- School of Computer Science and Technology, Harbin Institute of Technology (HIT), Harbin, China
| | - Qince Li
- School of Computer Science and Technology, Harbin Institute of Technology (HIT), Harbin, China
- Peng Cheng Laboratory, Shenzhen, China
- * E-mail:
| | - Kuanquan Wang
- School of Computer Science and Technology, Harbin Institute of Technology (HIT), Harbin, China
| | - Yimei Du
- Wuhan Union Hospital, Tongji Medical College of Huazhong University of Science and Technology, Wuhan, China
| | - Wei Wang
- School of Computer Science and Technology, Harbin Institute of Technology (HIT), Harbin, China
| | - Henggui Zhang
- Peng Cheng Laboratory, Shenzhen, China
- School of Physics and Astronomy, The University of Manchester, Manchester, United Kingdom
- Key Laboratory of Medical Electrophysiology of Ministry of Education and Medical Electrophysiological Key Laboratory of Sichuan Province, Institute of Cardiovascular Research, Southwest Medical University, Luzhou, China
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27
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Pargaei M, Kumar BVR, Pavarino LF, Scacchi S. Cardiac electro-mechanical activity in a deforming human cardiac tissue: modeling, existence-uniqueness, finite element computation and application to multiple ischemic disease. J Math Biol 2022; 84:17. [PMID: 35142929 DOI: 10.1007/s00285-022-01717-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 12/11/2021] [Accepted: 01/10/2022] [Indexed: 11/24/2022]
Abstract
In this study, the cardiac electro-mechanical model in a deforming domain is taken with the addition of mechanical feedback and stretch-activated channel current coupled with the ten Tusscher human ventricular cell level model that results in a coupled PDE-ODE system. The existence and uniqueness of such a coupled system in a deforming domain is proved. At first, the existence of a solution is proved in the deformed domain. The local existence of the solution is proved using the regularization and the Faedo-Galerkin technique. Then, the global existence is proved using the energy estimates in appropriate Banach spaces, Gronwall lemma, and the compactness procedure. The existence of the solution in an undeformed domain is proved using the lower semi-continuity of the norms. Uniqueness is proved using Young's inequality, Gronwall lemma, and the Cauchy-Schwartz inequality. For the application purpose, this model is applied to understand the electro-mechanical activity in ischemic cardiac tissue. It also takes care of the development of active tension, conductive, convective, and ionic feedback. The Second Piola-Kirchoff stress tensor arising in Lagrangian mapping between reference and moving frames is taken as a combination of active, passive, and volumetric components. We investigated the effect of varying strength of hyperkalemia and hypoxia, in the ischemic subregions of human cardiac tissue with local multiple ischemic subregions, on the electro-mechanical activity of healthy and ischemic zones. This system is solved numerically using the [Formula: see text] finite element method in space and the implicit-explicit Euler method in time. Discontinuities arising with the modeled multiple ischemic regions are treated to the desired order of accuracy by a simple regularization technique using the interpolating polynomials. We examined the cardiac electro-mechanical activity for several cases in multiple hyperkalemic and hypoxic human cardiac tissue. We concluded that local multiple ischemic subregions severely affect the cardiac electro-mechanical activity more, in terms of action potential (v) and mechanical parameters, intracellular calcium ion concentration [Formula: see text], active tension ([Formula: see text]), stretch ([Formula: see text]) and stretch rate ([Formula: see text]), of a healthy cell in its vicinity, compared to a single Hyperkalemic or Hypoxic subregion. The four moderate hypoxically generated ischemic subregions affect the waveform of the stretch along the fiber and the stretch rate more than a single severe ischemic subregion.
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Affiliation(s)
- Meena Pargaei
- Department of Mathematics and Statistics, Indian Institute of Technology, Kanpur, India.,Govt. Post Graduate College, Champawat, Uttarakhand, India
| | - B V Rathish Kumar
- Department of Mathematics and Statistics, Indian Institute of Technology, Kanpur, India
| | - Luca F Pavarino
- Department of Mathematics, University of Pavia, Pavia, Italy
| | - Simone Scacchi
- Department of Mathematics, University of Milan, Milan, Italy
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28
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Jiang H, Zhang S, Bi X, Ma W, Wei Z. Proarrhythmic effects of carbon monoxide in human ventricular tissue: insights from computational modeling. Comput Biol Med 2022; 140:105066. [PMID: 34839185 DOI: 10.1016/j.compbiomed.2021.105066] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Revised: 11/20/2021] [Accepted: 11/21/2021] [Indexed: 11/03/2022]
Abstract
Epidemiological studies have demonstrated that ambient air pollution has been closely associated with cardiovascular diseases. Carbon monoxide (CO) is a common ambient air pollutant that can cause adverse effects on the heart. CO is known to cause tissue ischemia, resulting in ventricular arrhythmias. However, accumulating biological studies showed that CO could exert effects on multiple cardiac ionic channels under normoxic conditions, which might indicate new proarrhythmic mechanisms other than ischemia-mediated electrophysiology changes. In this work, we evaluated the functional impacts of CO on human ventricles using a multi-scale model of human ventricular tissue. Experimental data regarding the effects of CO on different ion channels were incorporated into the cell model to explore the alterations of ventricular electrophysiology. Simulation results suggested that CO significantly prolonged the duration of ventricular action potentials, enhanced the transmural dispersion of repolarization, and reduced the adaptability of ventricular tissue to fast heart rates. In addition, simulated pseudo-ECGs showed consistent manifestations with the clinical observation that CO caused an apparent QT interval prolongation and T-wave widening, indicating that CO affected the heart's abnormal ventricular repolarization.
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Affiliation(s)
- Huasen Jiang
- College of Computer Science and Technology, Ocean University of China, Qingdao, 266100, China
| | - Shugang Zhang
- College of Computer Science and Technology, Ocean University of China, Qingdao, 266100, China.
| | - Xiangpeng Bi
- College of Computer Science and Technology, Ocean University of China, Qingdao, 266100, China
| | - Wenjian Ma
- College of Computer Science and Technology, Ocean University of China, Qingdao, 266100, China
| | - Zhiqiang Wei
- College of Computer Science and Technology, Ocean University of China, Qingdao, 266100, China
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29
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Gillette K, Gsell MAF, Bouyssier J, Prassl AJ, Neic A, Vigmond EJ, Plank G. Automated Framework for the Inclusion of a His-Purkinje System in Cardiac Digital Twins of Ventricular Electrophysiology. Ann Biomed Eng 2021; 49:3143-3153. [PMID: 34431016 PMCID: PMC8671274 DOI: 10.1007/s10439-021-02825-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Accepted: 06/26/2021] [Indexed: 11/28/2022]
Abstract
Personalized models of cardiac electrophysiology (EP) that match clinical observation with high fidelity, referred to as cardiac digital twins (CDTs), show promise as a tool for tailoring cardiac precision therapies. Building CDTs of cardiac EP relies on the ability of models to replicate the ventricular activation sequence under a broad range of conditions. Of pivotal importance is the His-Purkinje system (HPS) within the ventricles. Workflows for the generation and incorporation of HPS models are needed for use in cardiac digital twinning pipelines that aim to minimize the misfit between model predictions and clinical data such as the 12 lead electrocardiogram (ECG). We thus develop an automated two stage approach for HPS personalization. A fascicular-based model is first introduced that modulates the endocardial Purkinje network. Only emergent features of sites of earliest activation within the ventricular myocardium and a fast-conducting sub-endocardial layer are accounted for. It is then replaced by a topologically realistic Purkinje-based representation of the HPS. Feasibility of the approach is demonstrated. Equivalence between both HPS model representations is investigated by comparing activation patterns and 12 lead ECGs under both sinus rhythm and right-ventricular apical pacing. Predominant ECG morphology is preserved by both HPS models under sinus conditions, but elucidates differences during pacing.
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Affiliation(s)
- Karli Gillette
- Gottfried Schatz Research Center Biophysics, Medical University of Graz, Graz, Austria
- BioTechMed-Graz, Graz, Austria
| | - Matthias A F Gsell
- Gottfried Schatz Research Center Biophysics, Medical University of Graz, Graz, Austria
| | - Julien Bouyssier
- IHU Liryc, Electrophysiology and Heart Modeling Institute, Fondation Bordeaux Université, Pessac-Bordeaux, France
| | - Anton J Prassl
- Gottfried Schatz Research Center Biophysics, Medical University of Graz, Graz, Austria
| | | | - Edward J Vigmond
- IHU Liryc, Electrophysiology and Heart Modeling Institute, Fondation Bordeaux Université, Pessac-Bordeaux, France
| | - Gernot Plank
- Gottfried Schatz Research Center Biophysics, Medical University of Graz, Graz, Austria.
- BioTechMed-Graz, Graz, Austria.
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30
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Analysis of vulnerability to reentry in acute myocardial ischemia using a realistic human heart model. Comput Biol Med 2021; 141:105038. [PMID: 34836624 DOI: 10.1016/j.compbiomed.2021.105038] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Revised: 10/25/2021] [Accepted: 11/12/2021] [Indexed: 11/21/2022]
Abstract
Electrophysiological alterations of the myocardium caused by acute ischemia constitute a pro-arrhythmic substrate for the generation of potentially lethal arrhythmias. Experimental evidence has shown that the main components of acute ischemia that induce these electrophysiological alterations are hyperkalemia, hypoxia (or anoxia in complete artery occlusion), and acidosis. However, the influence of each ischemic component on the likelihood of reentry is not completely established. Moreover, the role of the His-Purkinje system (HPS) in the initiation and maintenance of arrhythmias is not completely understood. In the present work, we investigate how the three components of ischemia affect the vulnerable window (VW) for reentry using computational simulations. In addition, we analyze the role of the HPS on arrhythmogenesis. A 3D biventricular/torso human model that includes a realistic geometry of the central and border ischemic zones with one of the most electrophysiologically detailed model of ischemia to date, as well as a realistic cardiac conduction system, were used to assess the VW for reentry. Four scenarios of ischemic severity corresponding to different minutes after coronary artery occlusion were simulated. Our results suggest that ischemic severity plays an important role in the generation of reentries. Indeed, this is the first 3D simulation study to show that ventricular arrhythmias could be generated under moderate ischemic conditions, but not in mild and severe ischemia. Moreover, our results show that anoxia is the ischemic component with the most significant effect on the width of the VW. Thus, a change in the level of anoxia from moderate to severe leads to a greater increment in the VW (40 ms), in comparison with the increment of 20 ms and 35 ms produced by the individual change in the level of hyperkalemia and acidosis, respectively. Finally, the HPS was a necessary element for the generation of approximately 17% of reentries obtained. The retrograde conduction from the myocardium to HPS in the ischemic region, conduction blocks in discrete sections of the HPS, and the degree of ischemia affecting Purkinje cells, are suggested as mechanisms that favor the generation of ventricular arrhythmias.
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31
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Biasi N, Tognetti A. A computationally efficient dynamic model of human epicardial tissue. PLoS One 2021; 16:e0259066. [PMID: 34699557 PMCID: PMC8547700 DOI: 10.1371/journal.pone.0259066] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Accepted: 10/11/2021] [Indexed: 11/29/2022] Open
Abstract
We present a new phenomenological model of human ventricular epicardial cells and we test its reentry dynamics. The model is derived from the Rogers-McCulloch formulation of the FitzHugh-Nagumo equations and represents the total ionic current divided into three contributions corresponding to the excitatory, recovery and transient outward currents. Our model reproduces the main characteristics of human epicardial tissue, including action potential amplitude and morphology, upstroke velocity, and action potential duration and conduction velocity restitution curves. The reentry dynamics is stable, and the dominant period is about 270 ms, which is comparable to clinical values. The proposed model is the first phenomenological model able to accurately resemble human experimental data by using only 3 state variables and 17 parameters. Indeed, it is more computationally efficient than existing models (i.e., almost two times faster than the minimal ventricular model). Beyond the computational efficiency, the low number of parameters facilitates the process of fitting the model to the experimental data.
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Affiliation(s)
- Niccoló Biasi
- Department of Information Engineering, University of Pisa, Pisa, Italy
| | - Alessandro Tognetti
- Department of Information Engineering, University of Pisa, Pisa, Italy.,Research Centre "E. Piaggio", University of Pisa, Pisa, Italy
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32
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Sankarankutty AC, Greiner J, Bragard J, Visker JR, Shankar TS, Kyriakopoulos CP, Drakos SG, Sachse FB. Etiology-Specific Remodeling in Ventricular Tissue of Heart Failure Patients and Its Implications for Computational Modeling of Electrical Conduction. Front Physiol 2021; 12:730933. [PMID: 34675817 PMCID: PMC8523803 DOI: 10.3389/fphys.2021.730933] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Accepted: 09/07/2021] [Indexed: 11/13/2022] Open
Abstract
With an estimated 64.3 million cases worldwide, heart failure (HF) imposes an enormous burden on healthcare systems. Sudden death from arrhythmia is the major cause of mortality in HF patients. Computational modeling of the failing heart provides insights into mechanisms of arrhythmogenesis, risk stratification of patients, and clinical treatment. However, the lack of a clinically informed approach to model cardiac tissues in HF hinders progress in developing patient-specific strategies. Here, we provide a microscopy-based foundation for modeling conduction in HF tissues. We acquired 2D images of left ventricular tissues from HF patients (n = 16) and donors (n = 5). The composition and heterogeneity of fibrosis were quantified at a sub-micrometer resolution over an area of 1 mm2. From the images, we constructed computational bidomain models of tissue electrophysiology. We computed local upstroke velocities of the membrane voltage and anisotropic conduction velocities (CV). The non-myocyte volume fraction was higher in HF than donors (39.68 ± 14.23 vs. 22.09 ± 2.72%, p < 0.01), and higher in ischemic (IC) than nonischemic (NIC) cardiomyopathy (47.2 ± 16.18 vs. 32.16 ± 6.55%, p < 0.05). The heterogeneity of fibrosis within each subject was highest for IC (27.1 ± 6.03%) and lowest for donors (7.47 ± 1.37%) with NIC (15.69 ± 5.76%) in between. K-means clustering of this heterogeneity discriminated IC and NIC with an accuracy of 81.25%. The heterogeneity in CV increased from donor to NIC to IC tissues. CV decreased with increasing fibrosis for longitudinal (R 2 = 0.28, p < 0.05) and transverse conduction (R 2 = 0.46, p < 0.01). The tilt angle of the CV vectors increased 2.1° for longitudinal and 0.91° for transverse conduction per 1% increase in fibrosis. Our study suggests that conduction fundamentally differs in the two etiologies due to the characteristics of fibrosis. Our study highlights the importance of the etiology-specific modeling of HF tissues and integration of medical history into electrophysiology models for personalized risk stratification and treatment planning.
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Affiliation(s)
- Aparna C Sankarankutty
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, UT, United States.,Department of Biomedical Engineering, University of Utah, Salt Lake City, UT, United States
| | - Joachim Greiner
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg⋅Bad Krozingen, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Jean Bragard
- Department of Physics and Applied Mathematics, School of Sciences, University of Navarra, Pamplona, Spain
| | - Joseph R Visker
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, UT, United States.,Division of Cardiovascular Medicine, University of Utah School of Medicine, Salt Lake City, UT, United States
| | - Thirupura S Shankar
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, UT, United States.,Department of Biomedical Engineering, University of Utah, Salt Lake City, UT, United States
| | - Christos P Kyriakopoulos
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, UT, United States.,Division of Cardiovascular Medicine, University of Utah School of Medicine, Salt Lake City, UT, United States
| | - Stavros G Drakos
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, UT, United States.,Department of Biomedical Engineering, University of Utah, Salt Lake City, UT, United States.,Division of Cardiovascular Medicine, University of Utah School of Medicine, Salt Lake City, UT, United States
| | - Frank B Sachse
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, UT, United States.,Department of Biomedical Engineering, University of Utah, Salt Lake City, UT, United States
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33
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Dasí A, Hernández-Romero I, Gomez JF, Climent AM, Ferrero JM, Trenor B. Analysis of the response of human iPSC-derived cardiomyocyte tissue to I CaL block. A combined in vitro and in silico approach. Comput Biol Med 2021; 137:104796. [PMID: 34461502 DOI: 10.1016/j.compbiomed.2021.104796] [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: 03/07/2021] [Revised: 08/02/2021] [Accepted: 08/22/2021] [Indexed: 11/19/2022]
Abstract
The high incidence of cardiac arrythmias underlines the need for the assessment of pharmacological therapies. In this field of drug efficacy, as in the field of drug safety highlighted by the Comprehensive in Vitro Proarrhythmia Assay initiative, new pillars for research have become crucial: firstly, the integration of in-silico experiments, and secondly the evaluation of fully integrated biological systems, such as human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs). In this study, we therefore aimed to combine in-vitro experiments and in-silico simulations to evaluate the antiarrhythmic effect of L-type calcium current (ICaL) block in hiPSC-CMs. For this, hiPSC-CM preparations were cultured and an equivalent virtual tissue was modeled. Re-entry patterns of electrical activation were induced and several biomarkers were obtained before and after ICaL block. The virtual hiPSC-CM simulations were also reproduced using a tissue composed of adult ventricular cardiomyocytes (hAdultV-CMs). The analysis of phases, currents and safety factor for propagation showed an increased size of the re-entry core when ICaL was blocked as a result of depressed cellular excitability. The bigger wavefront curvature yielded reductions of 12.2%, 6.9%, and 4.2% in the frequency of the re-entry for hiPSC-CM cultures, virtual hiPSC-CM, and hAdultV-CM tissues, respectively. Furthermore, ICaL block led to a 47.8% shortening of the vulnerable window for re-entry in the virtual hiPSC-CM tissue and to re-entry vanishment in hAdultV-CM tissue. The consistent behavior between in-vitro and in-silico hiPSC-CMs and between in-silico hiPSC-CMs and hAdultV-CMs evidences that virtual hiPSC-CM tissues are suitable for assessing cardiac efficacy, as done in the present study through the analysis of ICaL block.
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Affiliation(s)
- Albert Dasí
- Centro de Investigación e Innovación en Bioingeniería, Ci2B, Universitat Politècnica de València, Valencia, Spain
| | - Ismael Hernández-Romero
- Department of Signal Theory and Communications and Telematics Systems and Computing, Rey Juan Carlos University, Fuenlabrada, Spain
| | - Juan F Gomez
- Centro de Investigación e Innovación en Bioingeniería, Ci2B, Universitat Politècnica de València, Valencia, Spain; Valencian International University, Valencia, Spain
| | - Andreu M Climent
- Instituto ITACA, Universitat Politècnica de València, Valencia, Spain
| | - Jose M Ferrero
- Centro de Investigación e Innovación en Bioingeniería, Ci2B, Universitat Politècnica de València, Valencia, Spain
| | - Beatriz Trenor
- Centro de Investigación e Innovación en Bioingeniería, Ci2B, Universitat Politècnica de València, Valencia, Spain.
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34
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Yoneda K, Okada JI, Watanabe M, Sugiura S, Hisada T, Washio T. A Multiple Step Active Stiffness Integration Scheme to Couple a Stochastic Cross-Bridge Model and Continuum Mechanics for Uses in Both Basic Research and Clinical Applications of Heart Simulation. Front Physiol 2021; 12:712816. [PMID: 34483965 PMCID: PMC8414591 DOI: 10.3389/fphys.2021.712816] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Accepted: 07/06/2021] [Indexed: 11/25/2022] Open
Abstract
In a multiscale simulation of a beating heart, the very large difference in the time scales between rapid stochastic conformational changes of contractile proteins and deterministic macroscopic outcomes, such as the ventricular pressure and volume, have hampered the implementation of an efficient coupling algorithm for the two scales. Furthermore, the consideration of dynamic changes of muscle stiffness caused by the cross-bridge activity of motor proteins have not been well established in continuum mechanics. To overcome these issues, we propose a multiple time step scheme called the multiple step active stiffness integration scheme (MusAsi) for the coupling of Monte Carlo (MC) multiple steps and an implicit finite element (FE) time integration step. The method focuses on the active tension stiffness matrix, where the active tension derivatives concerning the current displacements in the FE model are correctly integrated into the total stiffness matrix to avoid instability. A sensitivity analysis of the number of samples used in the MC model and the combination of time step sizes confirmed the accuracy and robustness of MusAsi, and we concluded that the combination of a 1.25 ms FE time step and 0.005 ms MC multiple steps using a few hundred motor proteins in each finite element was appropriate in the tradeoff between accuracy and computational time. Furthermore, for a biventricular FE model consisting of 45,000 tetrahedral elements, one heartbeat could be computed within 1.5 h using 320 cores of a conventional parallel computer system. These results support the practicality of MusAsi for uses in both the basic research of the relationship between molecular mechanisms and cardiac outputs, and clinical applications of perioperative prediction.
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Affiliation(s)
- Kazunori Yoneda
- Section Solutions Division, Healthcare Solutions Development Unit, Fujitsu Japan Ltd., Tokyo, Japan
| | - Jun-ichi Okada
- UT-Heart Inc., Kashiwa, Japan
- Future Center Initiative, University of Tokyo, Kashiwa, Japan
| | - Masahiro Watanabe
- Section Solutions Division, Healthcare Solutions Development Unit, Fujitsu Japan Ltd., Tokyo, Japan
| | | | | | - Takumi Washio
- UT-Heart Inc., Kashiwa, Japan
- Future Center Initiative, University of Tokyo, Kashiwa, Japan
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35
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Maturation strategies and limitations of induced pluripotent stem cell-derived cardiomyocytes. Biosci Rep 2021; 41:226678. [PMID: 33057659 PMCID: PMC8209171 DOI: 10.1042/bsr20200833] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Revised: 10/06/2020] [Accepted: 10/12/2020] [Indexed: 12/14/2022] Open
Abstract
Induced pluripotent stem cells (iPSCs) have the ability to differentiate into cardiomyocytes (CMs). They are not only widely used in cardiac pharmacology screening, human heart disease modeling, and cell transplantation-based treatments, but also the most promising source of CMs for experimental and clinical applications. However, their use is largely restricted by the immature phenotype of structure and function, which is similar to embryonic or fetal CMs and has certain differences from adult CMs. In order to overcome this critical issue, many studies have explored and revealed new strategies to induce the maturity of iPSC-CMs. Therefore, this article aims to review recent induction methods of mature iPSC-CMs, related mechanisms, and limitations.
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36
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Lin CY, Chung FP, Lin YJ, Chang SL, Lo LW, Hu YF, Tuan TC, Chao TF, Liao JN, Chang TY, Kuo L, Wu CI, Liu CM, Liu SH, Cheng WH, Lugtu IC, Te ALD, Huang TC, Lee PT, Vicera JJB, Chen SA. Clinical significance of J waves with respect to substrate characteristics and ablation outcomes in patients with arrhythmogenic right ventricular cardiomyopathy. Europace 2021; 23:1418-1427. [PMID: 33734367 DOI: 10.1093/europace/euab060] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Accepted: 02/24/2021] [Indexed: 11/13/2022] Open
Abstract
AIMS J-wave syndrome in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC) has been linked to an increased risk of ventricular arrhythmia. We investigated the significance of J waves with respect to substrate manifestations and ablation outcomes in patients with ARVC. METHODS AND RESULTS Forty-five patients with ARVC undergoing endocardial/epicardial mapping/ablation were studied. Patients were classified into two groups: 13 (28.9%) and 32 (71.1%) patients with and without J waves, respectively. The baseline characteristics, electrophysiological features, ventricular substrate, and recurrent ventricular tachycardia/fibrillation (VT/VF) were compared. Among the 13 patients with J waves, only the inferior J wave was observed. More ARVC patients with J waves fulfilled the major criteria of ventricular arrhythmias (76.9% vs. 21.9%, P = 0.003). Similar endocardial and epicardial substrate characteristics were observed between the two groups. However, patients with J waves had longer epicardial total activation time than those without (224.7 ± 29.9 vs. 200.8 ± 21.9 ms, P = 0.005). Concordance of latest endo/epicardial activation sites was observed in 29 (90.6%) patients without J waves and in none among those with J waves (P < 0.001). Complete elimination of endocardial/epicardial abnormal potentials resulted in the disappearance of the J wave in 8 of 13 (61.5%) patients. The VT/VF recurrences were not different between ARVC patients with and without J waves. CONCLUSION The presence of J waves was associated with the discordance of endocardial/epicardial activation pattern in terms of transmural depolarization discrepancy in patients with ARVC.
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Affiliation(s)
- Chin-Yu Lin
- Division of Cardiology, Department of Medicine, Heart Rhythm Center, Taipei Veterans General Hospital, No. 201, Section 2, Shih-Pai Road, Taipei, Taiwan.,Department of Medicine, National Yang Ming Chiao Tung University, School of Medicine, Taipei, Taiwan
| | - Fa-Po Chung
- Division of Cardiology, Department of Medicine, Heart Rhythm Center, Taipei Veterans General Hospital, No. 201, Section 2, Shih-Pai Road, Taipei, Taiwan.,Department of Medicine, National Yang Ming Chiao Tung University, School of Medicine, Taipei, Taiwan
| | - Yenn-Jiang Lin
- Division of Cardiology, Department of Medicine, Heart Rhythm Center, Taipei Veterans General Hospital, No. 201, Section 2, Shih-Pai Road, Taipei, Taiwan.,Department of Medicine, National Yang Ming Chiao Tung University, School of Medicine, Taipei, Taiwan
| | - Shih-Lin Chang
- Division of Cardiology, Department of Medicine, Heart Rhythm Center, Taipei Veterans General Hospital, No. 201, Section 2, Shih-Pai Road, Taipei, Taiwan.,Department of Medicine, National Yang Ming Chiao Tung University, School of Medicine, Taipei, Taiwan
| | - Li-Wei Lo
- Division of Cardiology, Department of Medicine, Heart Rhythm Center, Taipei Veterans General Hospital, No. 201, Section 2, Shih-Pai Road, Taipei, Taiwan.,Department of Medicine, National Yang Ming Chiao Tung University, School of Medicine, Taipei, Taiwan
| | - Yu-Feng Hu
- Division of Cardiology, Department of Medicine, Heart Rhythm Center, Taipei Veterans General Hospital, No. 201, Section 2, Shih-Pai Road, Taipei, Taiwan.,Department of Medicine, National Yang Ming Chiao Tung University, School of Medicine, Taipei, Taiwan
| | - Ta-Chuan Tuan
- Division of Cardiology, Department of Medicine, Heart Rhythm Center, Taipei Veterans General Hospital, No. 201, Section 2, Shih-Pai Road, Taipei, Taiwan.,Department of Medicine, National Yang Ming Chiao Tung University, School of Medicine, Taipei, Taiwan
| | - Tze-Fan Chao
- Division of Cardiology, Department of Medicine, Heart Rhythm Center, Taipei Veterans General Hospital, No. 201, Section 2, Shih-Pai Road, Taipei, Taiwan.,Department of Medicine, National Yang Ming Chiao Tung University, School of Medicine, Taipei, Taiwan
| | - Jo-Nan Liao
- Division of Cardiology, Department of Medicine, Heart Rhythm Center, Taipei Veterans General Hospital, No. 201, Section 2, Shih-Pai Road, Taipei, Taiwan.,Department of Medicine, National Yang Ming Chiao Tung University, School of Medicine, Taipei, Taiwan
| | - Ting-Yung Chang
- Division of Cardiology, Department of Medicine, Heart Rhythm Center, Taipei Veterans General Hospital, No. 201, Section 2, Shih-Pai Road, Taipei, Taiwan.,Department of Medicine, National Yang Ming Chiao Tung University, School of Medicine, Taipei, Taiwan
| | - Ling Kuo
- Division of Cardiology, Department of Medicine, Heart Rhythm Center, Taipei Veterans General Hospital, No. 201, Section 2, Shih-Pai Road, Taipei, Taiwan.,Department of Medicine, National Yang Ming Chiao Tung University, School of Medicine, Taipei, Taiwan
| | - Cheng-I Wu
- Division of Cardiology, Department of Medicine, Heart Rhythm Center, Taipei Veterans General Hospital, No. 201, Section 2, Shih-Pai Road, Taipei, Taiwan.,Department of Medicine, National Yang Ming Chiao Tung University, School of Medicine, Taipei, Taiwan
| | - Chih-Min Liu
- Division of Cardiology, Department of Medicine, Heart Rhythm Center, Taipei Veterans General Hospital, No. 201, Section 2, Shih-Pai Road, Taipei, Taiwan.,Department of Medicine, National Yang Ming Chiao Tung University, School of Medicine, Taipei, Taiwan
| | - Shin-Huei Liu
- Division of Cardiology, Department of Medicine, Heart Rhythm Center, Taipei Veterans General Hospital, No. 201, Section 2, Shih-Pai Road, Taipei, Taiwan.,Department of Medicine, National Yang Ming Chiao Tung University, School of Medicine, Taipei, Taiwan
| | - Wen-Han Cheng
- Division of Cardiology, Department of Medicine, Heart Rhythm Center, Taipei Veterans General Hospital, No. 201, Section 2, Shih-Pai Road, Taipei, Taiwan.,Department of Medicine, National Yang Ming Chiao Tung University, School of Medicine, Taipei, Taiwan
| | - Isaiah C Lugtu
- Division of Cardiology, Department of Medicine, Heart Rhythm Center, Taipei Veterans General Hospital, No. 201, Section 2, Shih-Pai Road, Taipei, Taiwan
| | - Abigail Louise D Te
- Division of Cardiology, Department of Medicine, Heart Rhythm Center, Taipei Veterans General Hospital, No. 201, Section 2, Shih-Pai Road, Taipei, Taiwan
| | - Ting-Chun Huang
- Division of Cardiology, Department of Medicine, Heart Rhythm Center, Taipei Veterans General Hospital, No. 201, Section 2, Shih-Pai Road, Taipei, Taiwan
| | - Po-Tseng Lee
- Division of Cardiology, Department of Medicine, Heart Rhythm Center, Taipei Veterans General Hospital, No. 201, Section 2, Shih-Pai Road, Taipei, Taiwan
| | - Jennifer Jeanne B Vicera
- Division of Cardiology, Department of Medicine, Heart Rhythm Center, Taipei Veterans General Hospital, No. 201, Section 2, Shih-Pai Road, Taipei, Taiwan
| | - Shih-Ann Chen
- Division of Cardiology, Department of Medicine, Heart Rhythm Center, Taipei Veterans General Hospital, No. 201, Section 2, Shih-Pai Road, Taipei, Taiwan.,Department of Medicine, National Yang Ming Chiao Tung University, School of Medicine, Taipei, Taiwan.,Cardiovascular Center, Taichung Veterans General Hospital, Taichung, Taiwan
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37
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Querdel E, Reinsch M, Castro L, Köse D, Bähr A, Reich S, Geertz B, Ulmer B, Schulze M, Lemoine MD, Krause T, Lemme M, Sani J, Shibamiya A, Stüdemann T, Köhne M, Bibra CV, Hornaschewitz N, Pecha S, Nejahsie Y, Mannhardt I, Christ T, Reichenspurner H, Hansen A, Klymiuk N, Krane M, Kupatt C, Eschenhagen T, Weinberger F. Human Engineered Heart Tissue Patches Remuscularize the Injured Heart in a Dose-Dependent Manner. Circulation 2021; 143:1991-2006. [PMID: 33648345 PMCID: PMC8126500 DOI: 10.1161/circulationaha.120.047904] [Citation(s) in RCA: 60] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Supplemental Digital Content is available in the text. Human engineered heart tissue (EHT) transplantation represents a potential regenerative strategy for patients with heart failure and has been successful in preclinical models. Clinical application requires upscaling, adaptation to good manufacturing practices, and determination of the effective dose.
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Affiliation(s)
- Eva Querdel
- Department of Experimental Pharmacology and Toxicology (E.Q., M.R., D.K., S.R., B.G., B.U., M.S., T.K., M.L., J.S., A.S., T.S., C.v.B., Y.N., I.M., T.C., A.H., T.E., F.W.), University Medical Center, Hamburg-Eppendorf, Germany.,German Centre for Cardiovascular Research (DZHK), partner site Hamburg/Kiel/Lübeck (E.Q., M.R., L.C., D.K., B.U., M.S., M.D.L., T.K., M.L., J.S., A.S., T.S., M. Köhne, C.v.B., S.P., I.M., T.C., H.R., A.H., T.E., F.W.)
| | - Marina Reinsch
- Department of Experimental Pharmacology and Toxicology (E.Q., M.R., D.K., S.R., B.G., B.U., M.S., T.K., M.L., J.S., A.S., T.S., C.v.B., Y.N., I.M., T.C., A.H., T.E., F.W.), University Medical Center, Hamburg-Eppendorf, Germany.,German Centre for Cardiovascular Research (DZHK), partner site Hamburg/Kiel/Lübeck (E.Q., M.R., L.C., D.K., B.U., M.S., M.D.L., T.K., M.L., J.S., A.S., T.S., M. Köhne, C.v.B., S.P., I.M., T.C., H.R., A.H., T.E., F.W.)
| | - Liesa Castro
- Department of Cardiovascular Surgery, University Heart Center (L.C., S.P., H.R.), University Medical Center, Hamburg-Eppendorf, Germany.,German Centre for Cardiovascular Research (DZHK), partner site Hamburg/Kiel/Lübeck (E.Q., M.R., L.C., D.K., B.U., M.S., M.D.L., T.K., M.L., J.S., A.S., T.S., M. Köhne, C.v.B., S.P., I.M., T.C., H.R., A.H., T.E., F.W.).,Now with Department of Cardiology and Intensive Care Medicine, University Hospital Schleswig-Holstein, Campus Lübeck, Germany (L.C.)
| | - Deniz Köse
- Department of Experimental Pharmacology and Toxicology (E.Q., M.R., D.K., S.R., B.G., B.U., M.S., T.K., M.L., J.S., A.S., T.S., C.v.B., Y.N., I.M., T.C., A.H., T.E., F.W.), University Medical Center, Hamburg-Eppendorf, Germany.,German Centre for Cardiovascular Research (DZHK), partner site Hamburg/Kiel/Lübeck (E.Q., M.R., L.C., D.K., B.U., M.S., M.D.L., T.K., M.L., J.S., A.S., T.S., M. Köhne, C.v.B., S.P., I.M., T.C., H.R., A.H., T.E., F.W.)
| | - Andrea Bähr
- I. Medizinische Klinik & Poliklinik, University Clinic Rechts der Isar (A.B., N.H., N.K., C.K.), Technical University Munich, Germany.,DZHK (German Centre for Cardiovascular Research), partner site Munich Heart Alliance Munich (A.B., N.H., N.K., C.K.).,Center for Innovative Medical Models, LMU Munich, Oberschleissheim, Germany (A.B., N.K.)
| | - Svenja Reich
- Department of Experimental Pharmacology and Toxicology (E.Q., M.R., D.K., S.R., B.G., B.U., M.S., T.K., M.L., J.S., A.S., T.S., C.v.B., Y.N., I.M., T.C., A.H., T.E., F.W.), University Medical Center, Hamburg-Eppendorf, Germany
| | - Birgit Geertz
- Department of Experimental Pharmacology and Toxicology (E.Q., M.R., D.K., S.R., B.G., B.U., M.S., T.K., M.L., J.S., A.S., T.S., C.v.B., Y.N., I.M., T.C., A.H., T.E., F.W.), University Medical Center, Hamburg-Eppendorf, Germany
| | - Bärbel Ulmer
- Department of Experimental Pharmacology and Toxicology (E.Q., M.R., D.K., S.R., B.G., B.U., M.S., T.K., M.L., J.S., A.S., T.S., C.v.B., Y.N., I.M., T.C., A.H., T.E., F.W.), University Medical Center, Hamburg-Eppendorf, Germany.,German Centre for Cardiovascular Research (DZHK), partner site Hamburg/Kiel/Lübeck (E.Q., M.R., L.C., D.K., B.U., M.S., M.D.L., T.K., M.L., J.S., A.S., T.S., M. Köhne, C.v.B., S.P., I.M., T.C., H.R., A.H., T.E., F.W.)
| | - Mirja Schulze
- Department of Experimental Pharmacology and Toxicology (E.Q., M.R., D.K., S.R., B.G., B.U., M.S., T.K., M.L., J.S., A.S., T.S., C.v.B., Y.N., I.M., T.C., A.H., T.E., F.W.), University Medical Center, Hamburg-Eppendorf, Germany.,German Centre for Cardiovascular Research (DZHK), partner site Hamburg/Kiel/Lübeck (E.Q., M.R., L.C., D.K., B.U., M.S., M.D.L., T.K., M.L., J.S., A.S., T.S., M. Köhne, C.v.B., S.P., I.M., T.C., H.R., A.H., T.E., F.W.)
| | - Marc D Lemoine
- German Centre for Cardiovascular Research (DZHK), partner site Hamburg/Kiel/Lübeck (E.Q., M.R., L.C., D.K., B.U., M.S., M.D.L., T.K., M.L., J.S., A.S., T.S., M. Köhne, C.v.B., S.P., I.M., T.C., H.R., A.H., T.E., F.W.).,Department of Cardiology-Electrophysiology (M.D.L.), University Heart Center, Hamburg, Germany
| | - Tobias Krause
- Department of Experimental Pharmacology and Toxicology (E.Q., M.R., D.K., S.R., B.G., B.U., M.S., T.K., M.L., J.S., A.S., T.S., C.v.B., Y.N., I.M., T.C., A.H., T.E., F.W.), University Medical Center, Hamburg-Eppendorf, Germany.,German Centre for Cardiovascular Research (DZHK), partner site Hamburg/Kiel/Lübeck (E.Q., M.R., L.C., D.K., B.U., M.S., M.D.L., T.K., M.L., J.S., A.S., T.S., M. Köhne, C.v.B., S.P., I.M., T.C., H.R., A.H., T.E., F.W.)
| | - Marta Lemme
- Department of Experimental Pharmacology and Toxicology (E.Q., M.R., D.K., S.R., B.G., B.U., M.S., T.K., M.L., J.S., A.S., T.S., C.v.B., Y.N., I.M., T.C., A.H., T.E., F.W.), University Medical Center, Hamburg-Eppendorf, Germany.,German Centre for Cardiovascular Research (DZHK), partner site Hamburg/Kiel/Lübeck (E.Q., M.R., L.C., D.K., B.U., M.S., M.D.L., T.K., M.L., J.S., A.S., T.S., M. Köhne, C.v.B., S.P., I.M., T.C., H.R., A.H., T.E., F.W.)
| | - Jascha Sani
- Department of Experimental Pharmacology and Toxicology (E.Q., M.R., D.K., S.R., B.G., B.U., M.S., T.K., M.L., J.S., A.S., T.S., C.v.B., Y.N., I.M., T.C., A.H., T.E., F.W.), University Medical Center, Hamburg-Eppendorf, Germany.,German Centre for Cardiovascular Research (DZHK), partner site Hamburg/Kiel/Lübeck (E.Q., M.R., L.C., D.K., B.U., M.S., M.D.L., T.K., M.L., J.S., A.S., T.S., M. Köhne, C.v.B., S.P., I.M., T.C., H.R., A.H., T.E., F.W.)
| | - Aya Shibamiya
- Department of Experimental Pharmacology and Toxicology (E.Q., M.R., D.K., S.R., B.G., B.U., M.S., T.K., M.L., J.S., A.S., T.S., C.v.B., Y.N., I.M., T.C., A.H., T.E., F.W.), University Medical Center, Hamburg-Eppendorf, Germany.,German Centre for Cardiovascular Research (DZHK), partner site Hamburg/Kiel/Lübeck (E.Q., M.R., L.C., D.K., B.U., M.S., M.D.L., T.K., M.L., J.S., A.S., T.S., M. Köhne, C.v.B., S.P., I.M., T.C., H.R., A.H., T.E., F.W.)
| | - Tim Stüdemann
- Department of Experimental Pharmacology and Toxicology (E.Q., M.R., D.K., S.R., B.G., B.U., M.S., T.K., M.L., J.S., A.S., T.S., C.v.B., Y.N., I.M., T.C., A.H., T.E., F.W.), University Medical Center, Hamburg-Eppendorf, Germany.,German Centre for Cardiovascular Research (DZHK), partner site Hamburg/Kiel/Lübeck (E.Q., M.R., L.C., D.K., B.U., M.S., M.D.L., T.K., M.L., J.S., A.S., T.S., M. Köhne, C.v.B., S.P., I.M., T.C., H.R., A.H., T.E., F.W.)
| | - Maria Köhne
- German Centre for Cardiovascular Research (DZHK), partner site Hamburg/Kiel/Lübeck (E.Q., M.R., L.C., D.K., B.U., M.S., M.D.L., T.K., M.L., J.S., A.S., T.S., M. Köhne, C.v.B., S.P., I.M., T.C., H.R., A.H., T.E., F.W.).,Department of Pediatric Cardiac Surgery (M. Köhne), University Heart Center, Hamburg, Germany
| | - Constantin von Bibra
- Department of Experimental Pharmacology and Toxicology (E.Q., M.R., D.K., S.R., B.G., B.U., M.S., T.K., M.L., J.S., A.S., T.S., C.v.B., Y.N., I.M., T.C., A.H., T.E., F.W.), University Medical Center, Hamburg-Eppendorf, Germany.,German Centre for Cardiovascular Research (DZHK), partner site Hamburg/Kiel/Lübeck (E.Q., M.R., L.C., D.K., B.U., M.S., M.D.L., T.K., M.L., J.S., A.S., T.S., M. Köhne, C.v.B., S.P., I.M., T.C., H.R., A.H., T.E., F.W.)
| | - Nadja Hornaschewitz
- I. Medizinische Klinik & Poliklinik, University Clinic Rechts der Isar (A.B., N.H., N.K., C.K.), Technical University Munich, Germany.,DZHK (German Centre for Cardiovascular Research), partner site Munich Heart Alliance Munich (A.B., N.H., N.K., C.K.)
| | - Simon Pecha
- Department of Cardiovascular Surgery, University Heart Center (L.C., S.P., H.R.), University Medical Center, Hamburg-Eppendorf, Germany.,German Centre for Cardiovascular Research (DZHK), partner site Hamburg/Kiel/Lübeck (E.Q., M.R., L.C., D.K., B.U., M.S., M.D.L., T.K., M.L., J.S., A.S., T.S., M. Köhne, C.v.B., S.P., I.M., T.C., H.R., A.H., T.E., F.W.)
| | - Yusuf Nejahsie
- Department of Experimental Pharmacology and Toxicology (E.Q., M.R., D.K., S.R., B.G., B.U., M.S., T.K., M.L., J.S., A.S., T.S., C.v.B., Y.N., I.M., T.C., A.H., T.E., F.W.), University Medical Center, Hamburg-Eppendorf, Germany
| | - Ingra Mannhardt
- Department of Experimental Pharmacology and Toxicology (E.Q., M.R., D.K., S.R., B.G., B.U., M.S., T.K., M.L., J.S., A.S., T.S., C.v.B., Y.N., I.M., T.C., A.H., T.E., F.W.), University Medical Center, Hamburg-Eppendorf, Germany.,German Centre for Cardiovascular Research (DZHK), partner site Hamburg/Kiel/Lübeck (E.Q., M.R., L.C., D.K., B.U., M.S., M.D.L., T.K., M.L., J.S., A.S., T.S., M. Köhne, C.v.B., S.P., I.M., T.C., H.R., A.H., T.E., F.W.)
| | - Torsten Christ
- Department of Experimental Pharmacology and Toxicology (E.Q., M.R., D.K., S.R., B.G., B.U., M.S., T.K., M.L., J.S., A.S., T.S., C.v.B., Y.N., I.M., T.C., A.H., T.E., F.W.), University Medical Center, Hamburg-Eppendorf, Germany.,German Centre for Cardiovascular Research (DZHK), partner site Hamburg/Kiel/Lübeck (E.Q., M.R., L.C., D.K., B.U., M.S., M.D.L., T.K., M.L., J.S., A.S., T.S., M. Köhne, C.v.B., S.P., I.M., T.C., H.R., A.H., T.E., F.W.)
| | - Hermann Reichenspurner
- Department of Cardiovascular Surgery, University Heart Center (L.C., S.P., H.R.), University Medical Center, Hamburg-Eppendorf, Germany.,German Centre for Cardiovascular Research (DZHK), partner site Hamburg/Kiel/Lübeck (E.Q., M.R., L.C., D.K., B.U., M.S., M.D.L., T.K., M.L., J.S., A.S., T.S., M. Köhne, C.v.B., S.P., I.M., T.C., H.R., A.H., T.E., F.W.)
| | - Arne Hansen
- Department of Experimental Pharmacology and Toxicology (E.Q., M.R., D.K., S.R., B.G., B.U., M.S., T.K., M.L., J.S., A.S., T.S., C.v.B., Y.N., I.M., T.C., A.H., T.E., F.W.), University Medical Center, Hamburg-Eppendorf, Germany.,German Centre for Cardiovascular Research (DZHK), partner site Hamburg/Kiel/Lübeck (E.Q., M.R., L.C., D.K., B.U., M.S., M.D.L., T.K., M.L., J.S., A.S., T.S., M. Köhne, C.v.B., S.P., I.M., T.C., H.R., A.H., T.E., F.W.)
| | - Nikolai Klymiuk
- I. Medizinische Klinik & Poliklinik, University Clinic Rechts der Isar (A.B., N.H., N.K., C.K.), Technical University Munich, Germany.,DZHK (German Centre for Cardiovascular Research), partner site Munich Heart Alliance Munich (A.B., N.H., N.K., C.K.).,Center for Innovative Medical Models, LMU Munich, Oberschleissheim, Germany (A.B., N.K.)
| | - M Krane
- Department of Cardiovascular Surgery, German Heart Centre Munich (M. Krane), Technical University Munich, Germany.,INSURE (Institute for Translational Cardiac Surgery), Cardiovascular Surgery, Munich, Germany (M. Krane)
| | - C Kupatt
- I. Medizinische Klinik & Poliklinik, University Clinic Rechts der Isar (A.B., N.H., N.K., C.K.), Technical University Munich, Germany.,DZHK (German Centre for Cardiovascular Research), partner site Munich Heart Alliance Munich (A.B., N.H., N.K., C.K.)
| | - Thomas Eschenhagen
- Department of Experimental Pharmacology and Toxicology (E.Q., M.R., D.K., S.R., B.G., B.U., M.S., T.K., M.L., J.S., A.S., T.S., C.v.B., Y.N., I.M., T.C., A.H., T.E., F.W.), University Medical Center, Hamburg-Eppendorf, Germany.,German Centre for Cardiovascular Research (DZHK), partner site Hamburg/Kiel/Lübeck (E.Q., M.R., L.C., D.K., B.U., M.S., M.D.L., T.K., M.L., J.S., A.S., T.S., M. Köhne, C.v.B., S.P., I.M., T.C., H.R., A.H., T.E., F.W.)
| | - Florian Weinberger
- Department of Experimental Pharmacology and Toxicology (E.Q., M.R., D.K., S.R., B.G., B.U., M.S., T.K., M.L., J.S., A.S., T.S., C.v.B., Y.N., I.M., T.C., A.H., T.E., F.W.), University Medical Center, Hamburg-Eppendorf, Germany.,German Centre for Cardiovascular Research (DZHK), partner site Hamburg/Kiel/Lübeck (E.Q., M.R., L.C., D.K., B.U., M.S., M.D.L., T.K., M.L., J.S., A.S., T.S., M. Köhne, C.v.B., S.P., I.M., T.C., H.R., A.H., T.E., F.W.)
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38
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Modeling and Analysis of Cardiac Hybrid Cellular Automata via GPU-Accelerated Monte Carlo Simulation. MATHEMATICS 2021. [DOI: 10.3390/math9020164] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The heart consists of a complex network of billions of cells. Under physiological conditions, cardiac cells propagate electrical signals in space, generating the heartbeat in a synchronous and coordinated manner. When such a synchronization fails, life-threatening events can arise. The inherent complexity of the underlying nonlinear dynamics and the large number of biological components involved make the modeling and the analysis of electrophysiological properties in cardiac tissue still an open challenge. We consider here a Hybrid Cellular Automata (HCA) approach modeling the cardiac cell-cell membrane resistance with a free variable. We show that the modeling approach can reproduce important and complex spatiotemporal properties paving the ground for promising future applications. We show how GPU-based technology can considerably accelerate the simulation and the analysis. Furthermore, we study the cardiac behavior within a unidimensional domain considering inhomogeneous resistance and we perform a Monte Carlo analysis to evaluate our approach.
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39
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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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40
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Wan Ab Naim WN, Mokhtarudin MJM, Lim E, Chan BT, Ahmad Bakir A, Nik Mohamed NA. The study of border zone formation in ischemic heart using electro-chemical coupled computational model. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2020; 36:e3398. [PMID: 32857480 DOI: 10.1002/cnm.3398] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 08/22/2020] [Accepted: 08/24/2020] [Indexed: 06/11/2023]
Abstract
Myocardial infarction (MI) is the most common cause of a heart failure, which occurs due to myocardial ischemia leading to left ventricular (LV) remodeling. LV remodeling particularly occurs at the ischemic area and the region surrounds it, known as the border zone. The role of the border zone in initiating LV remodeling process urges the investigation on the correlation between early border zone changes and remodeling outcome. Thus, this study aims to simulate a preliminary conceptual work of the border zone formation and evolution during onset of MI and its effect towards early LV remodeling processes by incorporating the oxygen concentration effect on the electrophysiology of an idealized three-dimensional LV through electro-chemical coupled mathematical model. The simulation result shows that the region of border zone, represented by the distribution of electrical conductivities, keeps expanding over time. Based on this result, the border zone is also proposed to consist of three sub-regions, namely mildly, moderately, and seriously impaired conductivity regions, which each region categorized depending on its electrical conductivities. This division could be used as a biomarker for classification of reversible and irreversible myocardial injury and will help to identify the different risks for the survival of patient. Larger ischemic size and complete occlusion of the coronary artery can be associated with an increased risk of developing irreversible injury, in particular if the reperfusion treatment is delayed. Increased irreversible injury area can be related with cardiovascular events and will further deteriorate the LV function over time.
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Affiliation(s)
- Wan N Wan Ab Naim
- Faculty of Mechanical and Automotive Engineering Technology, University Malaysia Pahang, Pekan, Malaysia
| | - Mohd J Mohamed Mokhtarudin
- Department of Mechanical Engineering, College of Engineering, University Malaysia Pahang, Kuantan, Malaysia
| | - Einly Lim
- Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, Kuala Lumpur, Malaysia
| | - Bee T Chan
- Department of Mechanical, Materials and Manufacturing Engineering, Faculty of Science and Engineering, University of Nottingham, Semenyih, Malaysia
| | - Azam Ahmad Bakir
- University of Southampton Malaysia Campus, Iskandar Puteri, Malaysia
| | - Nik A Nik Mohamed
- Faculty of Mechanical and Automotive Engineering Technology, University Malaysia Pahang, Pekan, Malaysia
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41
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His-bundle and left bundle pacing with optimized atrioventricular delay achieve superior electrical synchrony over endocardial and epicardial pacing in left bundle branch block patients. Heart Rhythm 2020; 17:1922-1929. [DOI: 10.1016/j.hrthm.2020.06.028] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 06/16/2020] [Accepted: 06/22/2020] [Indexed: 02/05/2023]
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42
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Wan Ab Naim WN, Mohamed Mokhtarudin MJ, Chan BT, Lim E, Ahmad Bakir A, Nik Mohamed NA. The study of myocardial ischemia-reperfusion treatment through computational modelling. J Theor Biol 2020; 509:110527. [PMID: 33096094 DOI: 10.1016/j.jtbi.2020.110527] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 09/25/2020] [Accepted: 10/15/2020] [Indexed: 10/23/2022]
Abstract
Reperfusion of the blood flow to ischemic myocardium is the standard treatment for patients suffering myocardial infarction. However, the reperfusion itself can also induce myocardial injury, in which the actual mechanism and its risk factors remain unclear. This work aims to study the mechanism of ischemia-reperfusion treatment using a three-dimensional (3D) oxygen diffusion model. An electrical model is then coupled to an oxygen model to identify the possible region of myocardial damage. Our findings show that the value of oxygen exceeds its optimum (>1.0) at the ischemic area during early reperfusion period. This complication was exacerbated in a longer ischemic period. While a longer reperfusion time causes a continuous excessive oxygen supply to the ischemic area throughout the reperfusion time. This work also suggests the use of less than 0.8 of initial oxygen concentration in the reperfusion treatment to prevent undesired upsurge at the early reperfusion period and further myocardial injury. We also found the region at risk for myocardial injury is confined in the ischemic vicinity revealed by its electrical conductivity impairment. Although there is a risk that reperfusion leads to myocardial injury for excessive oxygen accumulation, the reperfusion treatment is helpful in reducing the infarct size.
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Affiliation(s)
- Wan Naimah Wan Ab Naim
- Faculty of Mechanical and Automotive Engineering Technology, University Malaysia Pahang, 26600 Pekan, Pahang, Malaysia
| | - Mohd Jamil Mohamed Mokhtarudin
- Department of Mechanical Engineering, College of Engineering, University Malaysia Pahang, Lebuhraya Tun Razak, 26300 Gambang, Kuantan, Pahang, Malaysia.
| | - Bee Ting Chan
- Department of Mechanical, Materials and Manufacturing Engineering, Faculty of Science and Engineering, University of Nottingham, 43500 Selangor, Malaysia
| | - Einly Lim
- Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Azam Ahmad Bakir
- University of Southampton Malaysia Campus, No 3, Persiaran Canselor 1, Kota Ilmu Educity, 79200 Iskandar Puteri, Johor, Malaysia
| | - Nik Abdullah Nik Mohamed
- Faculty of Mechanical and Automotive Engineering Technology, University Malaysia Pahang, 26600 Pekan, Pahang, Malaysia
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43
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Ferraro E, Pozhidaeva L, Pitcher DS, Mansfield C, Koh JHB, Williamson C, Aslanidi O, Gorelik J, Ng FS. Prolonged ursodeoxycholic acid administration reduces acute ischaemia-induced arrhythmias in adult rat hearts. Sci Rep 2020; 10:15284. [PMID: 32943714 PMCID: PMC7499428 DOI: 10.1038/s41598-020-72016-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 08/07/2020] [Indexed: 12/13/2022] Open
Abstract
Acute myocardial ischaemia and reperfusion (I-R) are major causes of ventricular arrhythmias in patients with a history of coronary artery disease. Ursodeoxycholic acid (UDCA) has previously been shown to be antiarrhythmic in fetal hearts. This study was performed to investigate if UDCA protects against ischaemia-induced and reperfusion-induced arrhythmias in the adult myocardium, and compares the effect of acute (perfusion only) versus prolonged (2 weeks pre-treatment plus perfusion) UDCA administration. Langendorff-perfused adult Sprague-Dawley rat hearts were subjected to acute regional ischaemia by ligation of the left anterior descending artery (10 min), followed by reperfusion (2 min), and arrhythmia incidence quantified. Prolonged UDCA administration reduced the incidence of acute ischaemia-induced arrhythmias (p = 0.028), with a reduction in number of ventricular ectopic beats during the ischaemic phase compared with acute treatment (10 ± 3 vs 58 ± 15, p = 0.036). No antiarrhythmic effect was observed in the acute UDCA administration group. Neither acute nor prolonged UDCA treatment altered the incidence of reperfusion arrhythmias. The antiarrhythmic effect of UDCA may be partially mediated by an increase in cardiac wavelength, due to the attenuation of conduction velocity slowing (p = 0.03), and the preservation of Connexin43 phosphorylation during acute ischaemia (p = 0.0027). The potential antiarrhythmic effects of prolonged UDCA administration merit further investigation.
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Affiliation(s)
- Elisa Ferraro
- National Heart and Lung Institute, Imperial College London, London, UK
| | - Lidia Pozhidaeva
- School of Biomedical Engineering and Imaging Science, King's College London, London, UK
| | - David S Pitcher
- National Heart and Lung Institute, Imperial College London, London, UK
| | | | - Jia Han Benjamin Koh
- School of Biomedical Engineering and Imaging Science, King's College London, London, UK
| | | | - Oleg Aslanidi
- School of Biomedical Engineering and Imaging Science, King's College London, London, UK
| | - Julia Gorelik
- National Heart and Lung Institute, Imperial College London, London, UK.
| | - Fu Siong Ng
- National Heart and Lung Institute, Imperial College London, London, UK.
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44
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Washio T, Sugiura S, Okada JI, Hisada T. Using Systolic Local Mechanical Load to Predict Fiber Orientation in Ventricles. Front Physiol 2020; 11:467. [PMID: 32581822 PMCID: PMC7295989 DOI: 10.3389/fphys.2020.00467] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Accepted: 04/16/2020] [Indexed: 11/25/2022] Open
Abstract
A simple rule adopted for myofiber reorientation in the ventricles is pursued by taking the microscopic branching network of myocytes into account. The macroscopic active tension generated on the microscopic branching structure is modeled by a multidirectional active stress tensor, which is defined as a function of the strains in the branching directions. In our reorientation algorithm, the principal direction of the branching network is updated so that it turns in the direction of greater active tension in the isovolumetric systole. Updates are performed step-by-step after the mechanical equilibrium has been attained with the current fiber structure. Starting from a nearly flat distribution of the principal fiber orientation along the circumferential direction, the reoriented fiber helix angles range from 70 to 40° at epicardium and from 60 to 80° at endocardium, in agreement with experimental observations. The helical ventricular myocardial band of Torrent-Guasp’s model and the apical spiral structure of Rushmer’s model are also reconstructed by our algorithm. Applying our algorithm to the infarcted ventricle model, the fiber structure near the infarcted site is remodeled so that the helix angle becomes steeper with respect to the circumferential direction near the epicardial surface. Based on our numerical analysis, we draw the following conclusions. (i) The multidirectional active tension based on the microscopic branching network is potentially used to seek tighter connection with neighboring aggregates. (ii) The thickening and thinning transitions in response to active tension in each myocyte allow the macroscopic principal fiber orientation of the microscopic branching network to move toward the direction of greater active tension. (iii) The force–velocity relationship is the key factor in transferring the fiber shortening strain to the magnitude of active tensions used in the myofiber reorientation. (iv) The algorithm naturally leads to homogeneity in the macroscopic active tension and the fiber shortening strain, and results in near-optimal pumping performance. (v) However, the reorientation mechanism may degrade the pumping performance if there is severely inhomogeneous contractility resulting from infarction. Our goal is to provide a tool to predict the fiber architecture of various heart disease patients for numerical simulations of their treatment plans.
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Affiliation(s)
- Takumi Washio
- UT-Heart Inc., Kashiwanoha Campus Satellite, Kashiwa, Japan.,Future Center Initiative, Kashiwanoha Campus Satellite, University of Tokyo, Kashiwa, Japan
| | - Seiryo Sugiura
- UT-Heart Inc., Kashiwanoha Campus Satellite, Kashiwa, Japan
| | - Jun-Ichi Okada
- UT-Heart Inc., Kashiwanoha Campus Satellite, Kashiwa, Japan.,Future Center Initiative, Kashiwanoha Campus Satellite, University of Tokyo, Kashiwa, Japan
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45
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Strocchi M, Augustin CM, Gsell MAF, Karabelas E, Neic A, Gillette K, Razeghi O, Prassl AJ, Vigmond EJ, Behar JM, Gould J, Sidhu B, Rinaldi CA, Bishop MJ, Plank G, Niederer SA. A publicly available virtual cohort of four-chamber heart meshes for cardiac electro-mechanics simulations. PLoS One 2020; 15:e0235145. [PMID: 32589679 PMCID: PMC7319311 DOI: 10.1371/journal.pone.0235145] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Accepted: 06/09/2020] [Indexed: 12/12/2022] Open
Abstract
Computational models of the heart are increasingly being used in the development of devices, patient diagnosis and therapy guidance. While software techniques have been developed for simulating single hearts, there remain significant challenges in simulating cohorts of virtual hearts from multiple patients. To facilitate the development of new simulation and model analysis techniques by groups without direct access to medical data, image analysis techniques and meshing tools, we have created the first publicly available virtual cohort of twenty-four four-chamber hearts. Our cohort was built from heart failure patients, age 67±14 years. We segmented four-chamber heart geometries from end-diastolic (ED) CT images and generated linear tetrahedral meshes with an average edge length of 1.1±0.2mm. Ventricular fibres were added in the ventricles with a rule-based method with an orientation of -60° and 80° at the epicardium and endocardium, respectively. We additionally refined the meshes to an average edge length of 0.39±0.10mm to show that all given meshes can be resampled to achieve an arbitrary desired resolution. We ran simulations for ventricular electrical activation and free mechanical contraction on all 1.1mm-resolution meshes to ensure that our meshes are suitable for electro-mechanical simulations. Simulations for electrical activation resulted in a total activation time of 149±16ms. Free mechanical contractions gave an average left ventricular (LV) and right ventricular (RV) ejection fraction (EF) of 35±1% and 30±2%, respectively, and a LV and RV stroke volume (SV) of 95±28mL and 65±11mL, respectively. By making the cohort publicly available, we hope to facilitate large cohort computational studies and to promote the development of cardiac computational electro-mechanics for clinical applications.
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Affiliation(s)
- Marina Strocchi
- School of Biomedical Engineering and Imaging Sciences, King’s College London, London, City of London, United Kingdom
| | | | | | - Elias Karabelas
- School of Biomedical Engineering and Imaging Sciences, King’s College London, London, City of London, United Kingdom
| | | | - Karli Gillette
- Institute of Biophysics, Medical University of Graz, Graz, Steiermark, Austria
| | - Orod Razeghi
- School of Biomedical Engineering and Imaging Sciences, King’s College London, London, City of London, United Kingdom
| | - Anton J. Prassl
- Institute of Biophysics, Medical University of Graz, Graz, Steiermark, Austria
| | - Edward J. Vigmond
- IHU Liryc, Electrophysiology and Heart Modeling Institute, fondation Bordeaux Université, F-33600 Pessac- Bordeaux, France
- University of Bordeaux, IMB, UMR 5251, F-33400 Talence, France
| | - Jonathan M. Behar
- School of Biomedical Engineering and Imaging Sciences, King’s College London, London, City of London, United Kingdom
- Guy’s and St Thomas’ NHS Foundation Trust, London, City of London, United Kingdom
| | - Justin Gould
- School of Biomedical Engineering and Imaging Sciences, King’s College London, London, City of London, United Kingdom
- Guy’s and St Thomas’ NHS Foundation Trust, London, City of London, United Kingdom
| | - Baldeep Sidhu
- School of Biomedical Engineering and Imaging Sciences, King’s College London, London, City of London, United Kingdom
- Guy’s and St Thomas’ NHS Foundation Trust, London, City of London, United Kingdom
| | - Christopher A. Rinaldi
- School of Biomedical Engineering and Imaging Sciences, King’s College London, London, City of London, United Kingdom
- Guy’s and St Thomas’ NHS Foundation Trust, London, City of London, United Kingdom
| | - Martin J. Bishop
- School of Biomedical Engineering and Imaging Sciences, King’s College London, London, City of London, United Kingdom
| | - Gernot Plank
- Institute of Biophysics, Medical University of Graz, Graz, Steiermark, Austria
| | - Steven A. Niederer
- School of Biomedical Engineering and Imaging Sciences, King’s College London, London, City of London, United Kingdom
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46
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Impact of Decreased Transmural Conduction Velocity on the Function of the Human Left Ventricle: A Simulation Study. BIOMED RESEARCH INTERNATIONAL 2020; 2020:2867865. [PMID: 32337235 PMCID: PMC7160730 DOI: 10.1155/2020/2867865] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 02/14/2020] [Accepted: 02/24/2020] [Indexed: 11/17/2022]
Abstract
This study investigates the impact of reduced transmural conduction velocity (TCV) on output parameters of the human heart. In a healthy heart, the TCV contributes to synchronization of the onset of contraction in individual layers of the left ventricle (LV). However, it is unclear whether the clinically observed decrease of TCV contributes significantly to a reduction of LV contractility. The applied three-dimensional finite element model of isovolumic contraction of the human LV incorporates transmural gradients in electromechanical delay and myocyte shortening velocity and evaluates the impact of TCV reduction on pressure rise (namely, (dP/dt)max) and on isovolumic contraction duration (IVCD) in a healthy LV. The model outputs are further exploited in the lumped “Windkessel” model of the human cardiovascular system (based on electrohydrodynamic analogy of respective differential equations) to simulate the impact of changes of (dP/dt)max and IVCD on chosen systemic parameters (ejection fraction, LV power, cardiac output, and blood pressure). The simulations have shown that a 50% decrease in TCV prolongs substantially the isovolumic contraction, decelerates slightly the LV pressure rise, increases the LV energy consumption, and reduces the LV power. These negative effects increase progressively with further reduction of TCV. In conclusion, these results suggest that the pumping efficacy of the human LV decreases with lower TCV due to a higher energy consumption and lower LV power. Although the changes induced by the clinically relevant reduction of TCV are not critical for a healthy heart, they may represent an important factor limiting the heart function under disease conditions.
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47
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Comparison of Electromechanical Delay during Ventricular Tachycardia and Fibrillation under Different Conductivity Conditions Using Computational Modeling. COMPUTATIONAL AND MATHEMATICAL METHODS IN MEDICINE 2020; 2020:9501985. [PMID: 32300375 PMCID: PMC7146094 DOI: 10.1155/2020/9501985] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Accepted: 02/25/2020] [Indexed: 01/27/2023]
Abstract
Electromechanical delay (EMD) is the time interval between local myocyte depolarization and the onset of myofiber shortening. Previously, researchers measured EMD during sinus rhythm and ectopic pacing in normal and heart failure conditions. However, to our knowledge, there are no reports regarding EMD during another type of rhythms or arrhythmia. The goal of this study was to quantify EMD during sinus rhythm, tachycardia, and ventricular fibrillation conditions. We hypothesized that EMD under sinus rhythm is longer due to isovolumetric contraction which is imprecise during arrhythmia. We used a realistic model of 3D electromechanical ventricles. During sinus rhythm, EMD was measured in the last cycle of cardiac systole under steady conditions. EMD under tachycardia and fibrillation conditions was measured during the entire simulation, resulting in multiple EMD values. We assessed EMD for the following 3 conduction velocities (CVs): 31 cm/s, 51 cm/s, and 69 cm/s. The average EMD during fibrillation condition was the shortest corresponding to 53.45 ms, 55.07 ms, and 50.77 ms, for the CVs of 31 cm/s, 51 cm/s, and 69 cm/s, respectively. The average EMD during tachycardia was 58.61 ms, 58.33 ms, and 52.50 ms for the three CVs. Under sinus rhythm with action potential duration restitution (APDR) slope 0.7, the average EMD was 66.35 ms, 66.41 ms, and 66.60 ms in line with the three CVs. This result supports our hypothesis that EMD under sinus rhythm is longer than that under tachyarrhythmia conditions. In conclusion, this study observed and quantified EMD under tachycardia and ventricular fibrillation conditions. This simulation study has widened our understanding of EMD in 3D ventricles under chaotic conditions.
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Tomek J, Bueno-Orovio A, Passini E, Zhou X, Minchole A, Britton O, Bartolucci C, Severi S, Shrier A, Virag L, Varro A, Rodriguez B. Development, calibration, and validation of a novel human ventricular myocyte model in health, disease, and drug block. eLife 2019; 8:48890. [PMID: 31868580 PMCID: PMC6970534 DOI: 10.7554/elife.48890] [Citation(s) in RCA: 100] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Accepted: 12/18/2019] [Indexed: 12/19/2022] Open
Abstract
Human-based modelling and simulations are becoming ubiquitous in biomedical science due to their ability to augment experimental and clinical investigations. Cardiac electrophysiology is one of the most advanced areas, with cardiac modelling and simulation being considered for virtual testing of pharmacological therapies and medical devices. Current models present inconsistencies with experimental data, which limit further progress. In this study, we present the design, development, calibration and independent validation of a human-based ventricular model (ToR-ORd) for simulations of electrophysiology and excitation-contraction coupling, from ionic to whole-organ dynamics, including the electrocardiogram. Validation based on substantial multiscale simulations supports the credibility of the ToR-ORd model under healthy and key disease conditions, as well as drug blockade. In addition, the process uncovers new theoretical insights into the biophysical properties of the L-type calcium current, which are critical for sodium and calcium dynamics. These insights enable the reformulation of L-type calcium current, as well as replacement of the hERG current model.
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Affiliation(s)
- Jakub Tomek
- Department of Computer Science, British Heart Foundation Centre of Research Excellence, University of Oxford, Oxford, United Kingdom
| | - Alfonso Bueno-Orovio
- Department of Computer Science, British Heart Foundation Centre of Research Excellence, University of Oxford, Oxford, United Kingdom
| | - Elisa Passini
- Department of Computer Science, British Heart Foundation Centre of Research Excellence, University of Oxford, Oxford, United Kingdom
| | - Xin Zhou
- Department of Computer Science, British Heart Foundation Centre of Research Excellence, University of Oxford, Oxford, United Kingdom
| | - Ana Minchole
- Department of Computer Science, British Heart Foundation Centre of Research Excellence, University of Oxford, Oxford, United Kingdom
| | - Oliver Britton
- Department of Computer Science, British Heart Foundation Centre of Research Excellence, University of Oxford, Oxford, United Kingdom
| | - Chiara Bartolucci
- Department of Electrical, Electronic, and Information Engineering "Guglielmo Marconi", University of Bologna, Bologna, Italy
| | - Stefano Severi
- Department of Electrical, Electronic, and Information Engineering "Guglielmo Marconi", University of Bologna, Bologna, Italy
| | - Alvin Shrier
- Department of Physiology, McGill University, Montreal, Canada
| | - Laszlo Virag
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Szeged, Szeged, Hungary
| | - Andras Varro
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Szeged, Szeged, Hungary
| | - Blanca Rodriguez
- Department of Computer Science, British Heart Foundation Centre of Research Excellence, University of Oxford, Oxford, United Kingdom
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High arrhythmic risk in antero-septal acute myocardial ischemia is explained by increased transmural reentry occurrence. Sci Rep 2019; 9:16803. [PMID: 31728039 PMCID: PMC6856379 DOI: 10.1038/s41598-019-53221-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Accepted: 10/24/2019] [Indexed: 12/16/2022] Open
Abstract
Acute myocardial ischemia is a precursor of sudden arrhythmic death. Variability in its manifestation hampers understanding of arrhythmia mechanisms and challenges risk stratification. Our aim is to unravel the mechanisms underlying how size, transmural extent and location of ischemia determine arrhythmia vulnerability and ECG alterations. High performance computing simulations using a human torso/biventricular biophysically-detailed model were conducted to quantify the impact of varying ischemic region properties, including location (LAD/LCX occlusion), transmural/subendocardial ischemia, size, and normal/slow myocardial propagation. ECG biomarkers and vulnerability window for reentry were computed in over 400 simulations for 18 cases evaluated. Two distinct mechanisms explained larger vulnerability to reentry in transmural versus subendocardial ischemia. Macro-reentry around the ischemic region was the primary mechanism increasing arrhythmic risk in transmural versus subendocardial ischemia, for both LAD and LCX occlusion. Transmural micro-reentry at the ischemic border zone explained arrhythmic vulnerability in subendocardial ischemia, especially in LAD occlusion, as reentries were favoured by the ischemic region intersecting the septo-apical region. ST elevation reflected ischemic extent in transmural ischemia for LCX and LAD occlusion but not in subendocardial ischemia (associated with mild ST depression). The technology and results presented can inform safety and efficacy evaluation of anti-arrhythmic therapy in acute myocardial ischemia.
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Factors Promoting Conduction Slowing as Substrates for Block and Reentry in Infarcted Hearts. Biophys J 2019; 117:2361-2374. [PMID: 31521328 PMCID: PMC6990374 DOI: 10.1016/j.bpj.2019.08.008] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Revised: 07/03/2019] [Accepted: 08/05/2019] [Indexed: 01/11/2023] Open
Abstract
The development of effective and safe therapies for scar-related ventricular tachycardias requires a detailed understanding of the mechanisms underlying the conduction block that initiates electrical re-entries associated with these arrhythmias. Conduction block has been often associated with electrophysiological changes that prolong action potential duration (APD) within the border zone (BZ) of chronically infarcted hearts. However, experimental evidence suggests that remodeling processes promoting conduction slowing as opposed to APD prolongation mark the chronic phase. In this context, the substrate for the initial block at the mouth of an isthmus/diastolic channel leading to ventricular tachycardia is unclear. The goal of this study was to determine whether electrophysiological parameters associated with conduction slowing can cause block and re-entry in the BZ. In silico experiments were conducted on two-dimensional idealized infarct tissue as well as on a cohort of postinfarction porcine left ventricular models constructed from ex vivo magnetic resonance imaging scans. Functional conduction slowing in the BZ was modeled by reducing sodium current density, whereas structural conduction slowing was represented by decreasing tissue conductivity and including fibrosis. The arrhythmogenic potential of APD prolongation was also tested as a basis for comparison. Within all models, the combination of reduced sodium current with structural remodeling more often degenerated into re-entry and, if so, was more likely to be sustained for more cycles. Although re-entries were also detected in experiments with prolonged APD, they were often not sustained because of the subsequent block caused by long-lasting repolarization. Functional and structural conditions associated with slow conduction rather than APD prolongation form a potent substrate for arrhythmogenesis at the isthmus/BZ of chronically infarcted hearts. Reduced excitability led to block while slow conduction shortened the wavelength of propagation, facilitating the sustenance of re-entries. These findings provide important insights for models of patient-specific risk stratification and therapy planning.
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