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Butler D, Reyes DR. Heart-on-a-chip systems: disease modeling and drug screening applications. LAB ON A CHIP 2024; 24:1494-1528. [PMID: 38318723 DOI: 10.1039/d3lc00829k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2024]
Abstract
Cardiovascular disease (CVD) is the leading cause of death worldwide, casting a substantial economic footprint and burdening the global healthcare system. Historically, pre-clinical CVD modeling and therapeutic screening have been performed using animal models. Unfortunately, animal models oftentimes fail to adequately mimic human physiology, leading to a poor translation of therapeutics from pre-clinical trials to consumers. Even those that make it to market can be removed due to unforeseen side effects. As such, there exists a clinical, technological, and economical need for systems that faithfully capture human (patho)physiology for modeling CVD, assessing cardiotoxicity, and evaluating drug efficacy. Heart-on-a-chip (HoC) systems are a part of the broader organ-on-a-chip paradigm that leverages microfluidics, tissue engineering, microfabrication, electronics, and gene editing to create human-relevant models for studying disease, drug-induced side effects, and therapeutic efficacy. These compact systems can be capable of real-time measurements and on-demand characterization of tissue behavior and could revolutionize the drug development process. In this review, we highlight the key components that comprise a HoC system followed by a review of contemporary reports of their use in disease modeling, drug toxicity and efficacy assessment, and as part of multi-organ-on-a-chip platforms. We also discuss future perspectives and challenges facing the field, including a discussion on the role that standardization is expected to play in accelerating the widespread adoption of these platforms.
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Affiliation(s)
- Derrick Butler
- Microsystems and Nanotechnology Division, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA.
| | - Darwin R Reyes
- Microsystems and Nanotechnology Division, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA.
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2
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Abrasheva VO, Kovalenko SG, Slotvitsky M, Romanova SА, Aitova AA, Frolova S, Tsvelaya V, Syunyaev RA. Human sodium current voltage-dependence at physiological temperature measured by coupling a patch-clamp experiment to a mathematical model. J Physiol 2024; 602:633-661. [PMID: 38345560 DOI: 10.1113/jp285162] [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: 06/16/2023] [Accepted: 01/02/2024] [Indexed: 02/20/2024] Open
Abstract
Voltage-gated Na+ channels are crucial to action potential propagation in excitable tissues. Because of the high amplitude and rapid activation of the Na+ current, voltage-clamp measurements are very challenging and are usually performed at room temperature. In this study, we measured Na+ current voltage-dependence in stem cell-derived cardiomyocytes at physiological temperature. While the apparent activation and inactivation curves, measured as the dependence of current amplitude on voltage, fall within the range reported in previous studies, we identified a systematic error in our measurements. This error is caused by the deviation of the membrane potential from the command potential of the amplifier. We demonstrate that it is possible to account for this artifact using computer simulation of the patch-clamp experiment. We obtained surprising results through patch-clamp model optimization: a half-activation of -11.5 mV and a half-inactivation of -87 mV. Although the half-activation deviates from previous research, we demonstrate that this estimate reproduces the conduction velocity dependence on extracellular potassium concentration. KEY POINTS: Voltage-gated Na+ currents play a crucial role in excitable tissues including neurons, cardiac and skeletal muscle. Measurement of Na+ current is challenging because of its high amplitude and rapid kinetics, especially at physiological temperature. We have used the patch-clamp technique to measure human Na+ current voltage-dependence in human induced pluripotent stem cell-derived cardiomyocytes. The patch-clamp data were processed by optimization of the model accounting for voltage-clamp experiment artifacts, revealing a large difference between apparent parameters of Na+ current and the results of the optimization. We conclude that actual Na+ current activation is extremely depolarized in comparison to previous studies. The new Na+ current model provides a better understanding of action potential propagation; we demonstrate that it explains propagation in hyperkalaemic conditions.
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Affiliation(s)
| | - Sandaara G Kovalenko
- Moscow Institute of Physics and Technology, Moscow, Russia
- M. F. Vladimirsky Moscow Regional Research Clinical Institute, Moscow, Russia
- ITMO University, St Petersburg, Russia
| | - Mihail Slotvitsky
- Moscow Institute of Physics and Technology, Moscow, Russia
- M. F. Vladimirsky Moscow Regional Research Clinical Institute, Moscow, Russia
- ITMO University, St Petersburg, Russia
| | - Serafima А Romanova
- Moscow Institute of Physics and Technology, Moscow, Russia
- M. F. Vladimirsky Moscow Regional Research Clinical Institute, Moscow, Russia
| | - Aleria A Aitova
- Moscow Institute of Physics and Technology, Moscow, Russia
- M. F. Vladimirsky Moscow Regional Research Clinical Institute, Moscow, Russia
- ITMO University, St Petersburg, Russia
| | - Sheida Frolova
- Moscow Institute of Physics and Technology, Moscow, Russia
- M. F. Vladimirsky Moscow Regional Research Clinical Institute, Moscow, Russia
| | - Valeria Tsvelaya
- Moscow Institute of Physics and Technology, Moscow, Russia
- M. F. Vladimirsky Moscow Regional Research Clinical Institute, Moscow, Russia
- ITMO University, St Petersburg, Russia
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3
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Bukhari HA, Sánchez C, Laguna P, Potse M, Pueyo E. Differences in ventricular wall composition may explain inter-patient variability in the ECG response to variations in serum potassium and calcium. Front Physiol 2023; 14:1060919. [PMID: 37885805 PMCID: PMC10598848 DOI: 10.3389/fphys.2023.1060919] [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: 10/03/2022] [Accepted: 09/18/2023] [Indexed: 10/28/2023] Open
Abstract
Objective: Chronic kidney disease patients have a decreased ability to maintain normal electrolyte concentrations in their blood, which increases the risk for ventricular arrhythmias and sudden cardiac death. Non-invasive monitoring of serum potassium and calcium concentration, [K+] and [Ca2+], can help to prevent arrhythmias in these patients. Electrocardiogram (ECG) markers that significantly correlate with [K+] and [Ca2+] have been proposed, but these relations are highly variable between patients. We hypothesized that inter-individual differences in cell type distribution across the ventricular wall can help to explain this variability. Methods: A population of human heart-torso models were built with different proportions of endocardial, midmyocardial and epicardial cells. Propagation of ventricular electrical activity was described by a reaction-diffusion model, with modified Ten Tusscher-Panfilov dynamics. [K+] and [Ca2+] were varied individually and in combination. Twelve-lead ECGs were simulated and the width, amplitude and morphological variability of T waves and QRS complexes were quantified. Results were compared to measurements from 29 end-stage renal disease (ESRD) patients undergoing hemodialysis (HD). Results: Both simulations and patients data showed that most of the analyzed T wave and QRS complex markers correlated strongly with [K+] (absolute median Pearson correlation coefficients, r, ranging from 0.68 to 0.98) and [Ca2+] (ranging from 0.70 to 0.98). The same sign and similar magnitude of median r was observed in the simulations and the patients. Different cell type distributions in the ventricular wall led to variability in ECG markers that was accentuated at high [K+] and low [Ca2+], in agreement with the larger variability between patients measured at the onset of HD. The simulated ECG variability explained part of the measured inter-patient variability. Conclusion: Changes in ECG markers were similarly related to [K+] and [Ca2+] variations in our models and in the ESRD patients. The high inter-patient ECG variability may be explained by variations in cell type distribution across the ventricular wall, with high sensitivity to variations in the proportion of epicardial cells. Significance: Differences in ventricular wall composition help to explain inter-patient variability in ECG response to [K+] and [Ca2+]. This finding can be used to improve serum electrolyte monitoring in ESRD patients.
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Affiliation(s)
- Hassaan A. Bukhari
- BSICoS Group, I3A Institute, University of Zaragoza, IIS Aragón, Zaragoza, Spain
- CIBER en Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Zaragoza, Spain
- Carmen Team, Inria Bordeaux—Sud-Ouest, Talence, France
- University of Bordeaux, IMB, UMR 5251, Talence, France
| | - Carlos Sánchez
- BSICoS Group, I3A Institute, University of Zaragoza, IIS Aragón, Zaragoza, Spain
- CIBER en Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Zaragoza, Spain
| | - Pablo Laguna
- BSICoS Group, I3A Institute, University of Zaragoza, IIS Aragón, Zaragoza, Spain
- CIBER en Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Zaragoza, Spain
| | - Mark Potse
- Carmen Team, Inria Bordeaux—Sud-Ouest, Talence, France
- University of Bordeaux, IMB, UMR 5251, Talence, France
- IHU Liryc, Electrophysiology and Heart Modeling Institute, Fondation Bordeaux Université, Bordeaux, France
| | - Esther Pueyo
- BSICoS Group, I3A Institute, University of Zaragoza, IIS Aragón, Zaragoza, Spain
- CIBER en Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Zaragoza, Spain
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Dileep D, Syed TA, Sloan TFW, Dhandapany PS, Siddiqi K, Sirajuddin M. Cardiomyocyte orientation recovery at micrometer scale reveals long-axis fiber continuum in heart walls. EMBO J 2023; 42:e113288. [PMID: 37671467 PMCID: PMC10548172 DOI: 10.15252/embj.2022113288] [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: 12/14/2022] [Revised: 08/01/2023] [Accepted: 08/06/2023] [Indexed: 09/07/2023] Open
Abstract
Coordinated cardiomyocyte contraction drives the mammalian heart to beat and circulate blood. No consensus model of cardiomyocyte geometrical arrangement exists, due to the limited spatial resolution of whole heart imaging methods and the piecemeal nature of studies based on histological sections. By combining microscopy and computer vision, we produced the first-ever three-dimensional cardiomyocyte orientation reconstruction across mouse ventricular walls at the micrometer scale, representing a gain of three orders of magnitude in spatial resolution. We recovered a cardiomyocyte arrangement aligned to the long-axis direction of the outer ventricular walls. This cellular network lies in a thin shell and forms a continuum with longitudinally arranged cardiomyocytes in the inner walls, with a complex geometry at the apex. Our reconstruction methods can be applied at fine spatial scales to further understanding of heart wall electrical function and mechanics, and set the stage for the study of micron-scale fiber remodeling in heart disease.
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Affiliation(s)
- Drisya Dileep
- Centre for Cardiovascular Biology and DiseaseInstitute for Stem Cell Science and Regenerative MedicineBengaluruIndia
- The University of Trans‐Disciplinary Health Sciences and Technology (TDU)BengaluruIndia
| | - Tabish A Syed
- School of Computer Science and Centre for Intelligent MachinesMcGill University, and MILA – Québec AI InstituteMontréalQCCanada
| | | | - Perundurai S Dhandapany
- Centre for Cardiovascular Biology and DiseaseInstitute for Stem Cell Science and Regenerative MedicineBengaluruIndia
| | - Kaleem Siddiqi
- School of Computer Science and Centre for Intelligent MachinesMcGill University, and MILA – Québec AI InstituteMontréalQCCanada
| | - Minhajuddin Sirajuddin
- Centre for Cardiovascular Biology and DiseaseInstitute for Stem Cell Science and Regenerative MedicineBengaluruIndia
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Dokuchaev A, Kursanov A, Balakina-Vikulova NA, Katsnelson LB, Solovyova O. The importance of mechanical conditions in the testing of excitation abnormalities in a population of electro-mechanical models of human ventricular cardiomyocytes. Front Physiol 2023; 14:1187956. [PMID: 37362439 PMCID: PMC10285544 DOI: 10.3389/fphys.2023.1187956] [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: 03/16/2023] [Accepted: 05/25/2023] [Indexed: 06/28/2023] Open
Abstract
Background: Populations of in silico electrophysiological models of human cardiomyocytes represent natural variability in cell activity and are thoroughly calibrated and validated using experimental data from the human heart. The models have been shown to predict the effects of drugs and their pro-arrhythmic risks. However, excitation and contraction are known to be tightly coupled in the myocardium, with mechanical loads and stretching affecting both mechanics and excitation through mechanisms of mechano-calcium-electrical feedback. However, these couplings are not currently a focus of populations of cell models. Aim: We investigated the role of cardiomyocyte mechanical activity under different mechanical conditions in the generation, calibration, and validation of a population of electro-mechanical models of human cardiomyocytes. Methods: To generate a population, we assumed 11 input parameters of ionic currents and calcium dynamics in our recently developed TP + M model as varying within a wide range. A History matching algorithm was used to generate a non-implausible parameter space by calibrating the action potential and calcium transient biomarkers against experimental data and rejecting models with excitation abnormalities. The population was further calibrated using experimental data on human myocardial force characteristics and mechanical tests involving variations in preload and afterload. Models that passed the mechanical tests were validated with additional experimental data, including the effects of drugs with high or low pro-arrhythmic risk. Results: More than 10% of the models calibrated on electrophysiological data failed mechanical tests and were rejected from the population due to excitation abnormalities at reduced preload or afterload for cell contraction. The final population of accepted models yielded action potential, calcium transient, and force/shortening outputs consistent with experimental data. In agreement with experimental and clinical data, the models demonstrated a high frequency of excitation abnormalities in simulations of Dofetilide action on the ionic currents, in contrast to Verapamil. However, Verapamil showed a high frequency of failed contractions at high concentrations. Conclusion: Our results highlight the importance of considering mechanoelectric coupling in silico cardiomyocyte models. Mechanical tests allow a more thorough assessment of the effects of interventions on cardiac function, including drug testing.
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Affiliation(s)
- Arsenii Dokuchaev
- Laboratory of Mathematical Physiology, Institute of Immunology and Physiology, Ural Branch of Russian Academy of Sciences, Ekaterinburg, Russia
| | - Alexander Kursanov
- Laboratory of Mathematical Physiology, Institute of Immunology and Physiology, Ural Branch of Russian Academy of Sciences, Ekaterinburg, Russia
- Laboratory of Mathematical Modeling in Physiology and Medicine Based on Supercomputers, Ural Federal University, Ekaterinburg, Russia
| | - Nathalie A. Balakina-Vikulova
- Laboratory of Mathematical Physiology, Institute of Immunology and Physiology, Ural Branch of Russian Academy of Sciences, Ekaterinburg, Russia
- Laboratory of Mathematical Modeling in Physiology and Medicine Based on Supercomputers, Ural Federal University, Ekaterinburg, Russia
| | - Leonid B. Katsnelson
- Laboratory of Mathematical Physiology, Institute of Immunology and Physiology, Ural Branch of Russian Academy of Sciences, Ekaterinburg, Russia
- Laboratory of Mathematical Modeling in Physiology and Medicine Based on Supercomputers, Ural Federal University, Ekaterinburg, Russia
| | - Olga Solovyova
- Laboratory of Mathematical Physiology, Institute of Immunology and Physiology, Ural Branch of Russian Academy of Sciences, Ekaterinburg, Russia
- Laboratory of Mathematical Modeling in Physiology and Medicine Based on Supercomputers, Ural Federal University, Ekaterinburg, Russia
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Novel method of differentiating human induced pluripotent stem cells to mature cardiomyocytes via Sfrp2. Sci Rep 2023; 13:3920. [PMID: 36894665 PMCID: PMC9998650 DOI: 10.1038/s41598-023-31144-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Accepted: 03/07/2023] [Indexed: 03/11/2023] Open
Abstract
Current methods to generate cardiomyocytes from induced pluripotent stem cells (iPSc) utilize broad-spectrum pharmacological inhibitors. These methods give rise to cardiomyocytes which are typically immature. Since we have recently demonstrated that cardiomyogenesis in vitro and in vivo requires Sfrp2, we asked if Sfrp2 would drive differentiation of human iPSc into cardiomyocytes. Indeed, we found that Sfrp2 induced robust cardiac differentiation. Importantly, replacement of broad spectrum pharmacological inhibitors with Sfrp2 gave rise to mature cardiomyocytes as evidenced by their sarcomere structure, electrophysiological profiles, and ability to form gap junctions.
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7
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Kihlgren M, Almqvist C, Amankhani F, Jonasson L, Norman C, Perez M, Ebrahimi A, Gottfridsson C. The U-wave: A remaining enigma of the electrocardiogram. J Electrocardiol 2023; 79:13-20. [PMID: 36907158 DOI: 10.1016/j.jelectrocard.2023.03.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 02/24/2023] [Accepted: 03/01/2023] [Indexed: 03/07/2023]
Abstract
The U-wave's electrophysiological origin remains unknown and is subject to debate. It is rarely used for diagnosis in clinical practice. The aim of this study was to review new information regarding the U-wave. Further to present the proposed theories behind the U-wave's origin along with potential pathophysiologic and prognostic implications related to its presence, polarity and morphology. METHOD Literature searches were conducted to retrieve publications related to the electrocardiogram U-wave in the literature database Embase. RESULTS The review of the literature revealed the following major theories that will be discussed; late depolarisation, delayed or prolonged repolarisation, electro-mechanical stretch and IK1 dependent intrinsic potential differences in the terminal part of the action potential. Various pathologic conditions were found to correlate with the presence and properties of the U-wave, such as its amplitude and polarity. Abnormal U-waves can, for example, be observed in coronary artery disease with ongoing myocardial ischemia or infarction, ventricular hypertrophy, congenital heart disease, primary cardiomyopathy and valvular defects. Negative U-waves are highly specific for the presence of heart diseases. Concordantly negative T- and U-waves are especially associated with cardiac disease. Patients with negative U-waves tend to have higher blood pressure and history of hypertension, higher heart rate, cardiac disease and left ventricular hypertrophy compared to subjects with normal U-waves. Negative U-waves have been found to be associated with increased risk of all-cause mortality, cardiac death and cardiac hospitalisation in men. CONCLUSIONS The origin of the U-wave is still not established. U-wave diagnostics may reveal cardiac disorders and the cardiovascular prognosis. Including the U-wave characteristics in the clinical ECG assessment may be useful.
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Affiliation(s)
- Moa Kihlgren
- Cardiovascular Safety Center of Excellence and Safety Knowledge Groups, Global Patient Safety, Oncology R&D, AstraZeneca Gothenburg, Sweden.
| | - Christina Almqvist
- Cardiovascular Safety Center of Excellence and Safety Knowledge Groups, Global Patient Safety, Oncology R&D, AstraZeneca Gothenburg, Sweden.
| | - Fereydoun Amankhani
- Cardiovascular Safety Center of Excellence and Safety Knowledge Groups, Global Patient Safety, Oncology R&D, AstraZeneca Gothenburg, Sweden.
| | - Linda Jonasson
- Cardiovascular Safety Center of Excellence and Safety Knowledge Groups, Global Patient Safety, Oncology R&D, AstraZeneca Gothenburg, Sweden.
| | - Cecilia Norman
- Cardiovascular Safety Center of Excellence and Safety Knowledge Groups, Global Patient Safety, Oncology R&D, AstraZeneca Gothenburg, Sweden.
| | - Marcos Perez
- Cardiovascular Safety Center of Excellence and Safety Knowledge Groups, Global Patient Safety, Oncology R&D, AstraZeneca Gothenburg, Sweden.
| | - Ahmad Ebrahimi
- Cardiovascular Safety Center of Excellence and Safety Knowledge Groups, Global Patient Safety, Oncology R&D, AstraZeneca Gothenburg, Sweden.
| | - Christer Gottfridsson
- Cardiovascular Safety Center of Excellence and Safety Knowledge Groups, Global Patient Safety, Oncology R&D, AstraZeneca Gothenburg, Sweden.
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Asfaw TN, Bondarenko VE. A compartmentalized mathematical model of the β 1- and β 2-adrenergic signaling systems in ventricular myocytes from mouse in heart failure. Am J Physiol Cell Physiol 2023; 324:C263-C291. [PMID: 36468844 DOI: 10.1152/ajpcell.00366.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Mouse models of heart failure are extensively used to research human cardiovascular diseases. In particular, one of the most common is the mouse model of heart failure resulting from transverse aortic constriction (TAC). Despite this, there are no comprehensive compartmentalized mathematical models that describe the complex behavior of the action potential, [Ca2+]i transients, and their regulation by β1- and β2-adrenergic signaling systems in failing mouse myocytes. In this paper, we develop a novel compartmentalized mathematical model of failing mouse ventricular myocytes after TAC procedure. The model describes well the cell geometry, action potentials, [Ca2+]i transients, and β1- and β2-adrenergic signaling in the failing cells. Simulation results obtained with the failing cell model are compared with those from the normal ventricular myocytes. Exploration of the model reveals the sarcoplasmic reticulum Ca2+ load mechanisms in failing ventricular myocytes. We also show a larger susceptibility of the failing myocytes to early and delayed afterdepolarizations and to a proarrhythmic behavior of Ca2+ dynamics upon stimulation with isoproterenol. The mechanisms of the proarrhythmic behavior suppression are investigated and sensitivity analysis is performed. The developed model can explain the existing experimental data on failing mouse ventricular myocytes and make experimentally testable predictions of a failing myocyte's behavior.
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Affiliation(s)
- Tesfaye Negash Asfaw
- Department of Mathematics and Statistics, Georgia State University, Atlanta, Georgia
| | - Vladimir E Bondarenko
- Department of Mathematics and Statistics, Georgia State University, Atlanta, Georgia.,Neuroscience Institute, Georgia State University, Atlanta, Georgia
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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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10
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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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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. [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] [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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Biasi N, Seghetti P, Tognetti A. A transmurally heterogeneous model of the ventricular tissue and its application for simulation of Brugada Syndrome. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2022; 2022:3951-3954. [PMID: 36086131 DOI: 10.1109/embc48229.2022.9871482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
We present a transmurally heterogeneous phe-nomenological model of ventricular tissue that is designed to reproduce the most important features of action potential prop-agation of endocardial, midmyocardial, and epicardial tissue. Our model consists of only 3 variables and 20 parameters. Therefore, it is highly computational efficient and easy to fit to experimental data. We exploited our myocyte model to simulate action potential propagation in a 3D slab of cardiac tissue both in healthy conditions and in presence of Brugada syndrome. The results show that our model can accurately reproduce the transmural heterogeneity of the ventricular wall and the main characteristics of electrocardiographic pattern both in healthy and pathological conditions.
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13
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O' Brien S, Holmes AP, Johnson DM, Kabir SN, O' Shea C, O' Reilly M, Avezzu A, Reyat JS, Hall AW, Apicella C, Ellinor PT, Niederer S, Tucker NR, Fabritz L, Kirchhof P, Pavlovic D. Increased atrial effectiveness of flecainide conferred by altered biophysical properties of sodium channels. J Mol Cell Cardiol 2022; 166:23-35. [PMID: 35114252 DOI: 10.1016/j.yjmcc.2022.01.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Revised: 01/13/2022] [Accepted: 01/26/2022] [Indexed: 11/25/2022]
Abstract
Atrial fibrillation (AF) affects over 1% of the population and is a leading cause of stroke and heart failure in the elderly. A feared side effect of sodium channel blocker therapy, ventricular pro-arrhythmia, appears to be relatively rare in patients with AF. The biophysical reasons for this relative safety of sodium blockers are not known. Our data demonstrates intrinsic differences between atrial and ventricular cardiac voltage-gated sodium currents (INa), leading to reduced maximum upstroke velocity of action potential and slower conduction, in left atria compared to ventricle. Reduced atrial INa is only detected at physiological membrane potentials and is driven by alterations in sodium channel biophysical properties and not by NaV1.5 protein expression. Flecainide displayed greater inhibition of atrial INa, greater reduction of maximum upstroke velocity of action potential, and slowed conduction in atrial cells and tissue. Our work highlights differences in biophysical properties of sodium channels in left atria and ventricles and their response to flecainide. These differences can explain the relative safety of sodium channel blocker therapy in patients with atrial fibrillation.
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Affiliation(s)
- Sian O' Brien
- Institute of Cardiovascular Science, University of Birmingham, Birmingham, UK
| | - Andrew P Holmes
- Institute of Cardiovascular Science, University of Birmingham, Birmingham, UK; School of Biomedical Sciences, Institute of Clinical Sciences, University of Birmingham, Birmingham, UK
| | - Daniel M Johnson
- Institute of Cardiovascular Science, University of Birmingham, Birmingham, UK; School of Life, Health and Chemical Sciences, The Open University, Walton Hall, Milton Keynes, UK
| | - S Nashitha Kabir
- Institute of Cardiovascular Science, University of Birmingham, Birmingham, UK
| | - Christopher O' Shea
- Institute of Cardiovascular Science, University of Birmingham, Birmingham, UK
| | - Molly O' Reilly
- Institute of Cardiovascular Science, University of Birmingham, Birmingham, UK
| | - Adelisa Avezzu
- School of Biomedical Engineering & Imaging Sciences, Kings' College London, London, UK
| | - Jasmeet S Reyat
- Institute of Cardiovascular Science, University of Birmingham, Birmingham, UK
| | - Amelia W Hall
- Cardiovascular Research Center, Massachusetts General Hospital, Boston, MA 02129, USA; Cardiovascular Disease Initiative, The Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Clara Apicella
- Institute of Cardiovascular Science, University of Birmingham, Birmingham, UK
| | - Patrick T Ellinor
- Cardiovascular Research Center, Massachusetts General Hospital, Boston, MA 02129, USA; Cardiovascular Disease Initiative, The Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Steven Niederer
- School of Biomedical Engineering & Imaging Sciences, Kings' College London, London, UK
| | - Nathan R Tucker
- Cardiovascular Research Center, Massachusetts General Hospital, Boston, MA 02129, USA; Cardiovascular Disease Initiative, The Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Masonic Medical Research Institute, Utica, NY, 13501, USA
| | - Larissa Fabritz
- Institute of Cardiovascular Science, University of Birmingham, Birmingham, UK; University Center of Cardiovascular Science, University Heart and Vascular Center UKE, Hamburg, Germany; Department of Cardiology, University Heart and Vascular Center UKE, Hamburg, Germany; German Center for Cardiovascular Research (DZHK), Partner Site Hamburg/Kiel/Lübeck, Germany
| | - Paulus Kirchhof
- Institute of Cardiovascular Science, University of Birmingham, Birmingham, UK; Department of Cardiology, University Heart and Vascular Center UKE, Hamburg, Germany; German Center for Cardiovascular Research (DZHK), Partner Site Hamburg/Kiel/Lübeck, Germany
| | - Davor Pavlovic
- Institute of Cardiovascular Science, University of Birmingham, Birmingham, UK.
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14
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Floy ME, Shabnam F, Simmons AD, Bhute VJ, Jin G, Friedrich WA, Steinberg AB, Palecek SP. Advances in Manufacturing Cardiomyocytes from Human Pluripotent Stem Cells. Annu Rev Chem Biomol Eng 2022; 13:255-278. [PMID: 35320695 DOI: 10.1146/annurev-chembioeng-092120-033922] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The emergence of human pluripotent stem cell (hPSC) technology over the past two decades has provided a source of normal and diseased human cells for a wide variety of in vitro and in vivo applications. Notably, hPSC-derived cardiomyocytes (hPSC-CMs) are widely used to model human heart development and disease and are in clinical trials for treating heart disease. The success of hPSC-CMs in these applications requires robust, scalable approaches to manufacture large numbers of safe and potent cells. Although significant advances have been made over the past decade in improving the purity and yield of hPSC-CMs and scaling the differentiation process from 2D to 3D, efforts to induce maturation phenotypes during manufacturing have been slow. Process monitoring and closed-loop manufacturing strategies are just being developed. We discuss recent advances in hPSC-CM manufacturing, including differentiation process development and scaling and downstream processes as well as separation and stabilization. Expected final online publication date for the Annual Review of Chemical and Biomolecular Engineering, Volume 13 is October 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Martha E Floy
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, Wisconsin, USA; , , , , ,
| | - Fathima Shabnam
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, Wisconsin, USA; , , , , ,
| | - Aaron D Simmons
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, Wisconsin, USA; , , , , ,
| | - Vijesh J Bhute
- Department of Medical Genetics, University of Wisconsin-Madison, Madison, Wisconsin, USA; , .,Department of Chemical Engineering, Imperial College London, London, United Kingdom
| | - Gyuhyung Jin
- Department of Chemical Engineering, Purdue University, West Lafayette, Indiana, USA;
| | - Will A Friedrich
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, Wisconsin, USA; , , , , ,
| | - Alexandra B Steinberg
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, Wisconsin, USA; , , , , ,
| | - Sean P Palecek
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, Wisconsin, USA; , , , , ,
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15
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Human Induced Pluripotent Stem Cell as a Disease Modeling and Drug Development Platform-A Cardiac Perspective. Cells 2021; 10:cells10123483. [PMID: 34943991 PMCID: PMC8699880 DOI: 10.3390/cells10123483] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 12/03/2021] [Accepted: 12/06/2021] [Indexed: 02/07/2023] Open
Abstract
A comprehensive understanding of the pathophysiology and cellular responses to drugs in human heart disease is limited by species differences between humans and experimental animals. In addition, isolation of human cardiomyocytes (CMs) is complicated because cells obtained by biopsy do not proliferate to provide sufficient numbers of cells for preclinical studies in vitro. Interestingly, the discovery of human-induced pluripotent stem cell (hiPSC) has opened up the possibility of generating and studying heart disease in a culture dish. The combination of reprogramming and genome editing technologies to generate a broad spectrum of human heart diseases in vitro offers a great opportunity to elucidate gene function and mechanisms. However, to exploit the potential applications of hiPSC-derived-CMs for drug testing and studying adult-onset cardiac disease, a full functional characterization of maturation and metabolic traits is required. In this review, we focus on methods to reprogram somatic cells into hiPSC and the solutions for overcome immaturity of the hiPSC-derived-CMs to mimic the structure and physiological properties of the adult human CMs to accurately model disease and test drug safety. Finally, we discuss how to improve the culture, differentiation, and purification of CMs to obtain sufficient numbers of desired types of hiPSC-derived-CMs for disease modeling and drug development platform.
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16
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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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17
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Uzelac I, Kaboudian A, Iravanian S, Siles-Paredes JG, Gumbart JC, Ashikaga H, Bhatia N, Gilmour RF, Cherry EM, Fenton FH. Quantifying arrhythmic long QT effects of hydroxychloroquine and azithromycin with whole-heart optical mapping and simulations. Heart Rhythm O2 2021; 2:394-404. [PMID: 34430945 PMCID: PMC8369304 DOI: 10.1016/j.hroo.2021.06.008] [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] [Indexed: 12/13/2022] Open
Abstract
Background In March 2020, hydroxychloroquine (HCQ) alone or combined with azithromycin (AZM) was authorized as a treatment for COVID-19 in many countries. The therapy proved ineffective with long QT and deadly cardiac arrhythmia risks, illustrating challenges to determine the new safety profile of repurposed drugs. Objective To investigate proarrhythmic effects and mechanism of HCQ and AZM (combined and alone) with high doses of HCQ as in the COVID-19 clinical trials. Methods Proarrhythmic effects of HCQ and AZM are quantified using optical mapping with voltage-sensitive dyes in ex vivo Langendorff-perfused guinea pig (GP) hearts and with numerical simulations of a GP Luo-Rudy and a human O’Hara-Virag-Varro-Rudy models, for Epi, Endo, and M cells, in cell and tissue, incorporating the drug’s effect on cell membrane ionic currents. Results Experimentally, HCQ alone and combined with AZM leads to long QT intervals by prolonging the action potential duration and increased spatial dispersion of action potential (AP) repolarization across the heart, leading to proarrhythmic discordant alternans. AZM alone had a lesser arrhythmic effect with less triangulation of the AP shape. Mathematical cardiac models fail to reproduce most of the arrhythmic effects observed experimentally. Conclusions During public health crises, the risks and benefits of new and repurposed drugs could be better assessed with alternative experimental and computational approaches to identify proarrhythmic mechanisms. Optical mapping is an effective framework suitable to investigate the drug’s adverse effects on cardiac cell membrane ionic channels at the cellular level and arrhythmia mechanisms at the tissue and whole-organ level.
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Affiliation(s)
- Ilija Uzelac
- School of Physics, Georgia Institute of Technology, Atlanta, Georgia
| | - Abouzar Kaboudian
- School of Physics, Georgia Institute of Technology, Atlanta, Georgia
| | - Shahriar Iravanian
- Division of Cardiology, Section of Electrophysiology, Emory University Hospital, Atlanta, Georgia
| | | | - James C Gumbart
- School of Physics, Georgia Institute of Technology, Atlanta, Georgia
| | - Hiroshi Ashikaga
- Cardiac Arrhythmia Service, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Neal Bhatia
- Division of Cardiology, Section of Electrophysiology, Emory University Hospital, Atlanta, Georgia
| | - Robert F Gilmour
- Biomedical Sciences, University of Prince Edward Island, Charlottetown, Canada
| | - Elizabeth M Cherry
- School of Computational Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia
| | - Flavio H Fenton
- School of Physics, Georgia Institute of Technology, Atlanta, Georgia
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18
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Peirlinck M, Sahli Costabal F, Kuhl E. Sex Differences in Drug-Induced Arrhythmogenesis. Front Physiol 2021; 12:708435. [PMID: 34489728 PMCID: PMC8417068 DOI: 10.3389/fphys.2021.708435] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Accepted: 07/14/2021] [Indexed: 12/25/2022] Open
Abstract
The electrical activity in the heart varies significantly between men and women and results in a sex-specific response to drugs. Recent evidence suggests that women are more than twice as likely as men to develop drug-induced arrhythmia with potentially fatal consequences. Yet, the sex-specific differences in drug-induced arrhythmogenesis remain poorly understood. Here we integrate multiscale modeling and machine learning to gain mechanistic insight into the sex-specific origin of drug-induced cardiac arrhythmia at differing drug concentrations. To quantify critical drug concentrations in male and female hearts, we identify the most important ion channels that trigger male and female arrhythmogenesis, and create and train a sex-specific multi-fidelity arrhythmogenic risk classifier. Our study reveals that sex differences in ion channel activity, tissue conductivity, and heart dimensions trigger longer QT-intervals in women than in men. We quantify the critical drug concentration for dofetilide, a high risk drug, to be seven times lower for women than for men. Our results emphasize the importance of including sex as an independent biological variable in risk assessment during drug development. Acknowledging and understanding sex differences in drug safety evaluation is critical when developing novel therapeutic treatments on a personalized basis. The general trends of this study have significant implications on the development of safe and efficacious new drugs and the prescription of existing drugs in combination with other drugs.
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Affiliation(s)
- Mathias Peirlinck
- Department of Mechanical Engineering, Stanford University, Stanford, CA, United States
| | - Francisco Sahli Costabal
- Department of Mechanical and Metallurgical Engineering, School of Engineering, Pontificia Universidad Católica de Chile, Santiago, Chile
- Institute for Biological and Medical Engineering, Schools of Engineering, Medicine and Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile
- Millennium Nucleus for Cardiovascular Magnetic Resonance, Santiago, Chile
| | - Ellen Kuhl
- Department of Mechanical Engineering, Stanford University, Stanford, CA, United States
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19
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Ellermann C, Wolfes J, Eckardt L, Frommeyer G. Role of the rabbit whole-heart model for electrophysiologic safety pharmacology of non-cardiovascular drugs. Europace 2021; 23:828-836. [PMID: 33200170 DOI: 10.1093/europace/euaa288] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Accepted: 08/27/2020] [Indexed: 11/13/2022] Open
Abstract
Plenty of non-cardiovascular drugs alter cardiac electrophysiology and may ultimately lead to life-threatening arrhythmias. In clinical practice, measuring the QT interval as a marker for the repolarization period is the most common tool to assess the electrophysiologic safety of drugs. However, the sole measurement of the QT interval may be insufficient to determine the proarrhythmic risk of non-cardiovascular agents. Several other markers are considered in pre-clinical safety testing to determine potential harm on cardiac electrophysiology. Besides measuring typical electrophysiologic parameters such as repolarization duration, whole-heart models allow the determination of potential predictors for proarrhythmia. Spatial and temporal heterogeneity as well as changes of shape of the action potential can be easily assessed. In addition, provocation manoeuvers (either by electrolyte imbalances or programmed pacing protocols) may induce sustained arrhythmias and thereby determine ventricular vulnerability to arrhythmias. Compared with the human heart, the rabbit heart possesses a similar distribution of ion currents that govern cardiac repolarization, resulting in a rectangular action potential configuration in both species. In addition, similar biophysical properties of rabbit and human cardiac ion channels lead to a comparable pharmacologic response in human and rabbit hearts. Of note, arrhythmia patterns resemble in both species due to the similar effective size of human and rabbit hearts. Thus, the rabbit heart is particularly suitable for testing the electrophysiologic safety of drugs. Several experimental setups have been developed for studying cardiac electrophysiology in rabbits, ranging from single cell to tissue preparations, whole-heart setups, and in vivo models.
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Affiliation(s)
- Christian Ellermann
- Department of Cardiology II (Electrophysiology), University Hospital Münster, Albert-Schweitzer-Campus 1, Münster D-48149, Germany
| | - Julian Wolfes
- Department of Cardiology II (Electrophysiology), University Hospital Münster, Albert-Schweitzer-Campus 1, Münster D-48149, Germany
| | - Lars Eckardt
- Department of Cardiology II (Electrophysiology), University Hospital Münster, Albert-Schweitzer-Campus 1, Münster D-48149, Germany
| | - Gerrit Frommeyer
- Department of Cardiology II (Electrophysiology), University Hospital Münster, Albert-Schweitzer-Campus 1, Münster D-48149, Germany
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20
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Canine Myocytes Represent a Good Model for Human Ventricular Cells Regarding Their Electrophysiological Properties. Pharmaceuticals (Basel) 2021; 14:ph14080748. [PMID: 34451845 PMCID: PMC8398821 DOI: 10.3390/ph14080748] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 07/18/2021] [Accepted: 07/20/2021] [Indexed: 12/19/2022] Open
Abstract
Due to the limited availability of healthy human ventricular tissues, the most suitable animal model has to be applied for electrophysiological and pharmacological studies. This can be best identified by studying the properties of ion currents shaping the action potential in the frequently used laboratory animals, such as dogs, rabbits, guinea pigs, or rats, and comparing them to those of human cardiomyocytes. The authors of this article with the experience of three decades of electrophysiological studies, performed in mammalian and human ventricular tissues and isolated cardiomyocytes, summarize their results obtained regarding the major canine and human cardiac ion currents. Accordingly, L-type Ca2+ current (ICa), late Na+ current (INa-late), rapid and slow components of the delayed rectifier K+ current (IKr and IKs, respectively), inward rectifier K+ current (IK1), transient outward K+ current (Ito1), and Na+/Ca2+ exchange current (INCX) were characterized and compared. Importantly, many of these measurements were performed using the action potential voltage clamp technique allowing for visualization of the actual current profiles flowing during the ventricular action potential. Densities and shapes of these ion currents, as well as the action potential configuration, were similar in human and canine ventricular cells, except for the density of IK1 and the recovery kinetics of Ito. IK1 displayed a largely four-fold larger density in canine than human myocytes, and Ito recovery from inactivation displayed a somewhat different time course in the two species. On the basis of these results, it is concluded that canine ventricular cells represent a reasonably good model for human myocytes for electrophysiological studies, however, it must be borne in mind that due to their stronger IK1, the repolarization reserve is more pronounced in canine cells, and moderate differences in the frequency-dependent repolarization patterns can also be anticipated.
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21
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Maturation of human pluripotent stem cell derived cardiomyocytes in vitro and in vivo. Semin Cell Dev Biol 2021; 118:163-171. [PMID: 34053865 DOI: 10.1016/j.semcdb.2021.05.022] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 05/15/2021] [Accepted: 05/17/2021] [Indexed: 01/15/2023]
Abstract
Human pluripotent stem cell derived cardiomyocytes (hPSC-CMs) represent an inexhaustible cell source for in vitro disease modeling, drug discovery and toxicity screening, and potential therapeutic applications. However, currently available differentiation protocols yield populations of hPSC-CMs with an immature phenotype similar to cardiomyocytes in the early fetal heart. In this review, we consider the developmental processes and signaling cues involved in normal human cardiac maturation, as well as how these insights might be applied to the specific maturation of hPSC-CMs. We summarize the state-of-the-art and relative merits of reported hPSC-CM maturation strategies including prolonged duration in culture, metabolic manipulation, treatment with soluble or substrate-based cues, and tissue engineering approaches. Finally, we review the evidence that hPSC-CMs mature after implantation in injured hearts as such in vivo remodeling will likely affect the safety and efficacy of a potential hPSC-based cardiac therapy.
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22
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Michalek P, Hatahet SB, Svetlosak M, Margitfalvi P, Waczulikova I, Trnovec S, Böhm A, Benacka O, Hatala R. No Association Between T-peak to T-end Interval on the Resting ECG and Long-Term Incidence of Ventricular Arrhythmias Triggering ICD Interventions. Front Physiol 2020; 11:1115. [PMID: 32982802 PMCID: PMC7488192 DOI: 10.3389/fphys.2020.01115] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 08/11/2020] [Indexed: 11/15/2022] Open
Abstract
Background and Objectives Potential of using the T-peak to T-end (TpTe) interval as an electrocardiographic parameter reflecting the transmural dispersion of ventricular repolarization (TDR) to identify patients (pts.) with higher risk of malignant ventricular arrhythmias (MVA) for better selection of candidates for implantable cardioverter-defibrillator (ICD) in primary prevention (PP) of sudden cardiac death (SCD) remains controversial. The primary objective of this study was to investigate the relationship between the TpTe interval in patient’s preimplantation resting 12-lead electrocardiogram (ECG) and the incidence of MVA resulting in appropriate ICD intervention (AI). The secondary objective was to assess its relationship to overall mortality. Methods A total of 243 consecutive pts. with severe left ventricular (LV) systolic dysfunction after myocardial infarction (MI) with a single-chamber ICD for PP of SCD from one implantation center were included. Excluded were all pts. with any other disease that could interfere with the indication of ICD implantation. Primarily investigated intervals were measured manually in accordance with accepted methodology. Data on ICD interventions were acquired from device interrogation during regular outpatient visits. Survival data were collected from the databases of health insurance and regulatory authorities. Results We did not find a significant relationship between the duration of the TpTe interval and the incidence of MVA (71.5 ms in pts. with MVA vs. 70 ms in pts. without MVA; p = 0.408). Similar results were obtained for the corrected TpTe interval (TpTec) and the ratio of TpTe to QT interval (76.3 ms vs. 76.5 ms; p = 0.539 and 0.178 vs. 0.181; p = 0.547, respectively). There was also no significant difference between the duration of TpTe, TpTec and TpTe/QT ratio in pts. groups by overall mortality (71.5 ms in the deceased group vs. 70 ms in the survivors group; HR 1.01; 95% CI, 0.99–1.02; p = 0.715, 76.3 ms vs. 76.5 ms; HR 1.01; 95% CI, 0.99–1.02; p = 0.208 and 0.178 vs. 0.186; p = 0.116, respectively). Conclusion This study suggests no significant association of overall or MVA-free survival with ECG parameters reflecting TDR (TpTe, TpTec) in patients with systolic dysfunction after MI and ICD implanted for primary prevention.
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Affiliation(s)
- Peter Michalek
- Faculty of Medicine, Comenius University in Bratislava, Bratislava, Slovakia
| | | | - Martin Svetlosak
- Department of Arrhythmias and Cardiac Pacing, The National Institute of Cardiovascular Diseases, Bratislava, Slovakia
| | - Peter Margitfalvi
- Department of Arrhythmias and Cardiac Pacing, The National Institute of Cardiovascular Diseases, Bratislava, Slovakia
| | - Iveta Waczulikova
- Faculty of Mathematics, Physics and Informatics, Comenius University in Bratislava, Bratislava, Slovakia
| | - Sebastian Trnovec
- Faculty of Medicine, Comenius University in Bratislava, Bratislava, Slovakia
| | - Allan Böhm
- Faculty of Medicine, Slovak Medical University in Bratislava, Bratislava, Slovakia.,Department of Acute Cardiology, The National Institute of Cardiovascular Diseases, Bratislava, Slovakia
| | - Ondrej Benacka
- Faculty of Medicine, Comenius University in Bratislava, Bratislava, Slovakia.,Department of Arrhythmias and Cardiac Pacing, The National Institute of Cardiovascular Diseases, Bratislava, Slovakia
| | - Robert Hatala
- Faculty of Medicine, Slovak Medical University in Bratislava, Bratislava, Slovakia.,Department of Arrhythmias and Cardiac Pacing, The National Institute of Cardiovascular Diseases, Bratislava, Slovakia
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23
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Simulating Notch-Dome Morphology of Action Potential of Ventricular Cell: How the Speeds of Positive and Negative Feedbacks on Transmembrane Voltage Can Influence the Health of a Cell? BIOMED RESEARCH INTERNATIONAL 2020; 2020:5169241. [PMID: 32953882 PMCID: PMC7487097 DOI: 10.1155/2020/5169241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Revised: 03/23/2020] [Accepted: 07/18/2020] [Indexed: 11/24/2022]
Abstract
Ventricular action potential is well-known because of its plateau phase with a spike-notch-dome morphology. As such, the morphology of action potential is necessary for ensuring a correct heart functioning. Any distraction from normal notch-dome morphology may trigger a circus movement reentry in the form of lethal ventricular fibrillation. When the epicardial action potential dome propagates from a site where it is maintained to regions where it has been lost, it gives rise to the proposed mechanism for the Brugada syndrome. Despite the impact of notch-dome dynamics on the heart function, no independent and explicit research has been performed on the simulation of notch-dome dynamics and morphology. In this paper, using a novel mathematical approach, a three-state variable model is proposed; we show that our proposed model not only can simulate morphology of action potential of ventricular cells but also can propose a biological reasonable tool for controlling of the morphology of action potential spike-notch-dome. We show that the processes of activation and inactivation of ionic gating variables (as positive or negative feedbacks on the voltage of cell membrane) and the ratio of their speeds (time constants) can be treated as a reasonable biological tool for simulating ventricular cell notch-dome. This finding may led to a new insight to the quantification of the health of a ventricular cell and may also propose a new drug therapy strategy for cardiac diseases.
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24
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Bartolucci C, Passini E, Hyttinen J, Paci M, Severi S. Simulation of the Effects of Extracellular Calcium Changes Leads to a Novel Computational Model of Human Ventricular Action Potential With a Revised Calcium Handling. Front Physiol 2020; 11:314. [PMID: 32351400 PMCID: PMC7174690 DOI: 10.3389/fphys.2020.00314] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Accepted: 03/19/2020] [Indexed: 01/13/2023] Open
Abstract
The importance of electrolyte concentrations for cardiac function is well established. Electrolyte variations can lead to arrhythmias onset, due to their important role in the action potential (AP) genesis and in maintaining cell homeostasis. However, most of the human AP computer models available in literature were developed with constant electrolyte concentrations, and fail to simulate physiological changes induced by electrolyte variations. This is especially true for Ca2+, even in the O'Hara-Rudy model (ORd), one of the most widely used models in cardiac electrophysiology. Therefore, the present work develops a new human ventricular model (BPS2020), based on ORd, able to simulate the inverse dependence of AP duration (APD) on extracellular Ca2+ concentration ([Ca2+]o), and APD rate dependence at 4 mM extracellular K+. The main changes needed with respect to ORd are: (i) an increased sensitivity of L-type Ca2+ current inactivation to [Ca2+]o; (ii) a single compartment description of the sarcoplasmic reticulum; iii) the replacement of Ca2+ release. BPS2020 is able to simulate the physiological APD-[Ca2+]o relationship, while also retaining the well-reproduced properties of ORd (APD rate dependence, restitution, accommodation and current block effects). We also used BPS2020 to generate an experimentally-calibrated population of models to investigate: (i) the occurrence of repolarization abnormalities in response to hERG current block; (ii) the rate adaptation variability; (iii) the occurrence of alternans and delayed after-depolarizations at fast pacing. Our results indicate that we successfully developed an improved version of ORd, which can be used to investigate electrophysiological changes and pro-arrhythmic abnormalities induced by electrolyte variations and current block at multiple rates and at the population level.
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Affiliation(s)
- Chiara Bartolucci
- Computational Physiopathology Unit, Department of Electrical, Electronic and Information Engineering “Guglielmo Marconi”, University of Bologna, Cesena, Italy
| | - Elisa Passini
- Computational Physiopathology Unit, Department of Electrical, Electronic and Information Engineering “Guglielmo Marconi”, University of Bologna, Cesena, Italy
- Department of Computer Science, University of Oxford, Oxford, United Kingdom
| | - Jari Hyttinen
- BioMediTech, Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Michelangelo Paci
- BioMediTech, Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Stefano Severi
- Computational Physiopathology Unit, Department of Electrical, Electronic and Information Engineering “Guglielmo Marconi”, University of Bologna, Cesena, Italy
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25
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Abstract
Computational modeling based on experimental data remains an important component in cardiac electrophysiological research, especially because clinical data such as human action potential (AP) dynamics are scarce or limited by practical or ethical concerns. Such modeling has been used to develop and test a variety of mechanistic hypotheses, with the majority of these studies involving the rate dependence of AP duration (APD) including APD restitution and conduction velocity (CV). However, there is very little information regarding the complex dynamics at the boundary of repolarization (or refractoriness) and reexcitability. Here, we developed a "minimal" ionic model of the human AP, based on in vivo human monophasic AP (MAP) recordings obtained during clinical programmed electrical stimulation (PES) to address the progressive decrease in AP take-off potential (TOP) and associated CV slowing seen during three tightly spaced extrastimuli. Recent voltage-clamp data demonstrating the effect of intracellular calcium on sodium current availability were incorporated and were required to reproduce large (>15 mV) elevations in take-off potential and progressive encroachment. Introducing clinically observed APD gradients into the model enabled us to replicate the dynamic response to PES in patients leading to conduction block and reentry formation for the positive, but not the negative, APD gradient. Finally, we modeled the dynamics of reentry and show that spiral waves follow a meandering trajectory with a period of ~180 ms. We conclude that our model reproduces a variety of electrophysiological behavior including the response to sequential premature stimuli and provides a basis for studies of the initiation of reentry in human ventricular tissue.NEW & NOTEWORTHY This work presents a new model of the action potential of the human which reproduces the complex dynamics during premature stimulation in patients.
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Affiliation(s)
- Richard A Gray
- Division of Biomedical Physics, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, Food and Drug Administration, Silver Spring, Maryland
| | - Michael R Franz
- Cardiology Division of Cardiology, Veteran Affairs Medical Center, Washington, District of Columbia.,Department of Pharmacology, Georgetown University Medical Center, Washington, District of Columbia
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26
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Zhao Y, Rafatian N, Wang EY, Wu Q, Lai BFL, Lu RX, Savoji H, Radisic M. Towards chamber specific heart-on-a-chip for drug testing applications. Adv Drug Deliv Rev 2020; 165-166:60-76. [PMID: 31917972 PMCID: PMC7338250 DOI: 10.1016/j.addr.2019.12.002] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Revised: 12/26/2019] [Accepted: 12/30/2019] [Indexed: 02/06/2023]
Abstract
Modeling of human organs has long been a task for scientists in order to lower the costs of therapeutic development and understand the pathological onset of human disease. For decades, despite marked differences in genetics and etiology, animal models remained the norm for drug discovery and disease modeling. Innovative biofabrication techniques have facilitated the development of organ-on-a-chip technology that has great potential to complement conventional animal models. However, human organ as a whole, more specifically the human heart, is difficult to regenerate in vitro, in terms of its chamber specific orientation and its electrical functional complexity. Recent progress with the development of induced pluripotent stem cell differentiation protocols, made recapitulating the complexity of the human heart possible through the generation of cells representative of atrial & ventricular tissue, the sinoatrial node, atrioventricular node and Purkinje fibers. Current heart-on-a-chip approaches incorporate biological, electrical, mechanical, and topographical cues to facilitate tissue maturation, therefore improving the predictive power for the chamber-specific therapeutic effects targeting adult human. In this review, we will give a summary of current advances in heart-on-a-chip technology and provide a comprehensive outlook on the challenges involved in the development of human physiologically relevant heart-on-a-chip.
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Affiliation(s)
- Yimu Zhao
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario M5S 3E5, Canada
| | - Naimeh Rafatian
- Division of Cardiology and Peter Munk Cardiac Center, University of Health Network, Toronto, Ontario M5G 2N2, Canada
| | - Erika Yan Wang
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario M5S 3G9, Canada
| | - Qinghua Wu
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario M5S 3G9, Canada
| | - Benjamin F L Lai
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario M5S 3G9, Canada
| | - Rick Xingze Lu
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario M5S 3G9, Canada
| | - Houman Savoji
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario M5S 3G9, Canada
| | - Milica Radisic
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario M5S 3E5, Canada; Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario M5S 3G9, Canada; Toronto General Research Institute, Toronto, Ontario M5G 2C4, Canada.
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27
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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: 89] [Impact Index Per Article: 17.8] [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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28
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McAleer CW, Pointon A, Long CJ, Brighton RL, Wilkin BD, Bridges LR, Narasimhan Sriram N, Fabre K, McDougall R, Muse VP, Mettetal JT, Srivastava A, Williams D, Schnepper MT, Roles JL, Shuler ML, Hickman JJ, Ewart L. On the potential of in vitro organ-chip models to define temporal pharmacokinetic-pharmacodynamic relationships. Sci Rep 2019; 9:9619. [PMID: 31270362 PMCID: PMC6610665 DOI: 10.1038/s41598-019-45656-4] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Accepted: 06/07/2019] [Indexed: 12/20/2022] Open
Abstract
Functional human-on-a-chip systems hold great promise to enable quantitative translation to in vivo outcomes. Here, we explored this concept using a pumpless heart only and heart:liver system to evaluate the temporal pharmacokinetic/pharmacodynamic (PKPD) relationship for terfenadine. There was a time dependent drug-induced increase in field potential duration in the cardiac compartment in response to terfenadine and that response was modulated using a metabolically competent liver module that converted terfenadine to fexofenadine. Using this data, a mathematical model was developed to predict the effect of terfenadine in preclinical species. Developing confidence that microphysiological models could have a transformative effect on drug discovery, we also tested a previously discovered proprietary AstraZeneca small molecule and correctly determined the cardiotoxic response to its metabolite in the heart:liver system. Overall our findings serve as a guiding principle to future investigations of temporal concentration response relationships in these innovative in vitro models, especially, if validated across multiple time frames, with additional pharmacological mechanisms and molecules representing a broad chemical diversity.
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Affiliation(s)
| | - Amy Pointon
- Drug Safety and Metabolism, IMED Biotech Unit, AstraZeneca, Cambridge, UK
| | - Christopher J Long
- Hesperos, Inc., 3259 Progress Dr., Room 158, Orlando, FL, 32826-3230, USA
| | - Rocky L Brighton
- Hesperos, Inc., 3259 Progress Dr., Room 158, Orlando, FL, 32826-3230, USA
| | - Benjamin D Wilkin
- Hesperos, Inc., 3259 Progress Dr., Room 158, Orlando, FL, 32826-3230, USA
| | - L Richard Bridges
- Hesperos, Inc., 3259 Progress Dr., Room 158, Orlando, FL, 32826-3230, USA
| | | | - Kristin Fabre
- Drug Safety and Metabolism, IMED Biotech Unit, AstraZeneca, Waltham, USA
| | - Robin McDougall
- Drug Safety and Metabolism, IMED Biotech Unit, AstraZeneca, Waltham, USA
| | - Victorine P Muse
- Drug Safety and Metabolism, IMED Biotech Unit, AstraZeneca, Waltham, USA
| | - Jerome T Mettetal
- Drug Safety and Metabolism, IMED Biotech Unit, AstraZeneca, Waltham, USA
| | | | - Dominic Williams
- Drug Safety and Metabolism, IMED Biotech Unit, AstraZeneca, Cambridge, UK
| | - Mark T Schnepper
- NanoScience Technology Center, 12424 Research Parkway, Suite 400, Orlando, FL, 32826, USA
| | - Jeff L Roles
- Hesperos, Inc., 3259 Progress Dr., Room 158, Orlando, FL, 32826-3230, USA
| | - Michael L Shuler
- Hesperos, Inc., 3259 Progress Dr., Room 158, Orlando, FL, 32826-3230, USA
| | - James J Hickman
- Hesperos, Inc., 3259 Progress Dr., Room 158, Orlando, FL, 32826-3230, USA.
- NanoScience Technology Center, 12424 Research Parkway, Suite 400, Orlando, FL, 32826, USA.
| | - Lorna Ewart
- Drug Safety and Metabolism, IMED Biotech Unit, AstraZeneca, Cambridge, UK.
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29
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Nakanishi H, Lee JK, Miwa K, Masuyama K, Yasutake H, Li J, Tomoyama S, Honda Y, Deguchi J, Tsujimoto S, Hidaka K, Miyagawa S, Sawa Y, Komuro I, Sakata Y. Geometrical Patterning and Constituent Cell Heterogeneity Facilitate Electrical Conduction Disturbances in a Human Induced Pluripotent Stem Cell-Based Platform: An In vitro Disease Model of Atrial Arrhythmias. Front Physiol 2019; 10:818. [PMID: 31316396 PMCID: PMC6610482 DOI: 10.3389/fphys.2019.00818] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Accepted: 06/11/2019] [Indexed: 01/09/2023] Open
Abstract
Ectopic foci from pulmonary veins (PVs) comprise the main trigger associated with the initiation of atrial fibrillation (AF). An abrupt anatomical narrow-to-wide transition, modeled as in vitro geometrical patterning with similar configuration in the present study, is located at the junction of PVs and the left atrium (LA). Complex cellular composition, i.e., constituent cell heterogeneity, is also observed in PVs and the PVs-LA junction. High frequency triggers accompanied with anatomical irregularity and constituent cell heterogeneity provoke impaired conduction, a prerequisite for AF genesis. However, few experiments investigating the effects of these factors on electrophysiological properties using human-based cardiomyocytes (CMs) with atrial properties have been reported. The aim of the current study was to estimate whether geometrical patterning and constituent cell heterogeneity under high frequency stimuli undergo conduction disturbance utilizing an in vitro two-dimensional (2D) monolayer preparation consisting of atrial-like CMs derived from human induced pluripotent stem cells (hiPSCs) and atrial fibroblasts (Fbs). We induced hiPSCs into atrial-like CMs using a directed cardiac differentiation protocol with the addition of all-trans retinoic acid (ATRA). The atrial-like hiPSC-derived CMs (hiPSC-CMs) and atrial Fbs were transferred in defined ratios (CMs/Fbs: 100%/0% or 70%/30%) on manually fabricated plates with or without geometrical patterning imitating the PVs-LA junction. High frequency field stimulation emulating repetitive ectopic foci originated in PVs were delivered, and the electrical propagation was assessed by optical mapping. We generated high purity CMs with or without the ATRA application. ATRA-treated hiPSC-CMs exhibited significantly higher atrial-specific properties by immunofluorescence staining, gene expression patterns, and optical action potential parameters than those of ATRA-untreated hiPSC-CMs. Electrical stimuli at a higher frequency preferentially induced impaired electrical conduction on atrial-like hiPSC-CMs monolayer preparations with an abrupt geometrical transition than on those with uniform geometry. Additionally, the application of human atrial Fbs to the geometrically patterned atrial-like hiPSC-CMs tended to further deteriorate the integrity of electrical conduction compared with those using the atrial-like hiPSC-CM alone preparations. Thus, geometrical narrow-to-wide patterning under high frequency stimuli preferentially jeopardized electrical conduction within in vitro atrial-like hiPSC-CM monolayers. Constituent cell heterogeneity represented by atrial Fbs also contributed to the further deterioration of conduction stability.
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Affiliation(s)
- Hiroyuki Nakanishi
- Department of Cardiovascular Medicine, Graduate School of Medicine, Osaka University, Suita, Japan
| | - Jong-Kook Lee
- Department of Advanced Cardiovascular Regenerative Medicine, Graduate School of Medicine, Osaka University, Suita, Japan
| | - Keiko Miwa
- Department of Mechanical Engineering, Kyushu University, Fukuoka, Japan
| | - Kiyoshi Masuyama
- Department of Cardiovascular Medicine, Graduate School of Medicine, Osaka University, Suita, Japan
| | - Hideki Yasutake
- Department of Cardiovascular Medicine, Graduate School of Medicine, Osaka University, Suita, Japan
| | - Jun Li
- Department of Cardiovascular Medicine, Graduate School of Medicine, Osaka University, Suita, Japan
| | - Satoki Tomoyama
- Department of Cardiovascular Medicine, Graduate School of Medicine, Osaka University, Suita, Japan
| | - Yayoi Honda
- Preclinical Research Unit, Sumitomo Dainippon Pharma Co., Ltd., Osaka, Japan
| | - Jiro Deguchi
- Preclinical Research Unit, Sumitomo Dainippon Pharma Co., Ltd., Osaka, Japan
| | - Shinji Tsujimoto
- Regenerative & Cellular Medicine Office, Sumitomo Dainippon Pharma Co., Ltd., Osaka, Japan
| | - Kyoko Hidaka
- Department of Advanced Cardiovascular Regenerative Medicine, Graduate School of Medicine, Osaka University, Suita, Japan.,Center for Fundamental Education, The University of Kitakyushu, Kitakyushu, Japan
| | - Shigeru Miyagawa
- Department of Cardiovascular Surgery, Graduate School of Medicine, Osaka University, Suita, Japan
| | - Yoshiki Sawa
- Department of Cardiovascular Surgery, Graduate School of Medicine, Osaka University, Suita, Japan
| | - Issei Komuro
- Department of Cardiovascular Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Yasushi Sakata
- Department of Cardiovascular Medicine, Graduate School of Medicine, Osaka University, Suita, Japan
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30
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Lopez-Perez A, Sebastian R, Izquierdo M, Ruiz R, Bishop M, Ferrero JM. Personalized Cardiac Computational Models: From Clinical Data to Simulation of Infarct-Related Ventricular Tachycardia. Front Physiol 2019; 10:580. [PMID: 31156460 PMCID: PMC6531915 DOI: 10.3389/fphys.2019.00580] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Accepted: 04/25/2019] [Indexed: 12/20/2022] Open
Abstract
In the chronic stage of myocardial infarction, a significant number of patients develop life-threatening ventricular tachycardias (VT) due to the arrhythmogenic nature of the remodeled myocardium. Radiofrequency ablation (RFA) is a common procedure to isolate reentry pathways across the infarct scar that are responsible for VT. Unfortunately, this strategy show relatively low success rates; up to 50% of patients experience recurrent VT after the procedure. In the last decade, intensive research in the field of computational cardiac electrophysiology (EP) has demonstrated the ability of three-dimensional (3D) cardiac computational models to perform in-silico EP studies. However, the personalization and modeling of certain key components remain challenging, particularly in the case of the infarct border zone (BZ). In this study, we used a clinical dataset from a patient with a history of infarct-related VT to build an image-based 3D ventricular model aimed at computational simulation of cardiac EP, including detailed patient-specific cardiac anatomy and infarct scar geometry. We modeled the BZ in eight different ways by combining the presence or absence of electrical remodeling with four different levels of image-based patchy fibrosis (0, 10, 20, and 30%). A 3D torso model was also constructed to compute the ECG. Patient-specific sinus activation patterns were simulated and validated against the patient's ECG. Subsequently, the pacing protocol used to induce reentrant VTs in the EP laboratory was reproduced in-silico. The clinical VT was induced with different versions of the model and from different pacing points, thus identifying the slow conducting channel responsible for such VT. Finally, the real patient's ECG recorded during VT episodes was used to validate our simulation results and to assess different strategies to model the BZ. Our study showed that reduced conduction velocities and heterogeneity in action potential duration in the BZ are the main factors in promoting reentrant activity. Either electrical remodeling or fibrosis in a degree of at least 30% in the BZ were required to initiate VT. Moreover, this proof-of-concept study confirms the feasibility of developing 3D computational models for cardiac EP able to reproduce cardiac activation in sinus rhythm and during VT, using exclusively non-invasive clinical data.
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Affiliation(s)
- Alejandro Lopez-Perez
- Center for Research and Innovation in Bioengineering (Ci2B), Universitat Politècnica de València, Valencia, Spain
| | - Rafael Sebastian
- Computational Multiscale Simulation Lab (CoMMLab), Universitat de València, Valencia, Spain
| | - M Izquierdo
- INCLIVA Health Research Institute, Valencia, Spain.,Arrhythmia Unit, Cardiology Department, Hospital Clínico Universitario de Valencia, Valencia, Spain
| | - Ricardo Ruiz
- INCLIVA Health Research Institute, Valencia, Spain.,Arrhythmia Unit, Cardiology Department, Hospital Clínico Universitario de Valencia, Valencia, Spain
| | - Martin Bishop
- Division of Imaging Sciences & Biomedical Engineering, Department of Biomedical Engineering, King's College London, London, United Kingdom
| | - Jose M Ferrero
- Center for Research and Innovation in Bioengineering (Ci2B), Universitat Politècnica de València, Valencia, Spain
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31
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Reynard JT, Oshodi OM, Lai JC, Lai RW, Bazoukis G, Fragakis N, Letsas KP, Korantzopoulos P, Liu FZ, Liu T, Xia Y, Tse G, Li CK. Electrocardiographic conduction and repolarization markers associated with sudden cardiac death: moving along the electrocardiography waveform. Minerva Cardioangiol 2019; 67:131-144. [PMID: 30260143 DOI: 10.23736/s0026-4725.18.04775-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/11/2023]
Abstract
The QT interval along with its heart rate corrected form (QTc) are well-established ECG markers that have been found to be associated with malignant ventricular arrhythmogenesis. However, extensive preclinical and clinical investigations over the years have allowed for novel clinical ECG markers to be generated as predictors of arrhythmogenesis and sudden cardiac death. Repolarization markers include the older QTc, QT dispersion and newer Tpeak - Tend intervals, (Tpeak - Tend) / QT ratios, T-wave alternans (TWA), microvolt TWA and T-wave area dispersion. Meanwhile, conduction markers dissecting the QRS complex, such as QRS dispersion (QRSD) and fragmented QRS, were also found to correlate conduction velocity and unidirectional block with re-entrant substrates in various cardiac conditions. Both repolarization and conduction parameters can be combined into the excitation wavelength (λ). A surrogate marker for λ is the index of Cardiac Electrophysiological Balance (iCEB: QT / QRSd). Other markers based on conduction-repolarization are [QRSD x (Tpeak-Tend) / QRSd] and [QRSD x (Tpeak-Tend) / (QRSd x QT)]. Advancement in technology permitted sophisticated electrophysiological analyses such as principal component analysis and periodic repolarization dynamics to further improve risk stratification. This was closely followed by other novel indices including ventricular ectopic QRS interval, the f99 index and EntropyXQT, which integrates mathematical and physical calculations for determining the risk markers. Though proven to be effective in limited patient cohorts, more clinical studies across different cardiac pathologies are required to confirm their validity. As such, this review seeks to encapsulate the development of old and new ECG markers along with their associated utility and shortcomings in clinical practice.
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Affiliation(s)
- Jack T Reynard
- Faculty of Medicine, Newcastle University, Newcastle Upon Tyne, UK
| | | | - Jenny C Lai
- Faculty of Medicine, Li Ka Shing Institute of Health Sciences, Chinese University of Hong Kong, Hong Kong, China
- Department of Medicine and Therapeutics, Faculty of Medicine, Chinese University of Hong Kong, Hong Kong, China
| | - Rachel W Lai
- Faculty of Medicine, Li Ka Shing Institute of Health Sciences, Chinese University of Hong Kong, Hong Kong, China
- Department of Medicine and Therapeutics, Faculty of Medicine, Chinese University of Hong Kong, Hong Kong, China
| | - George Bazoukis
- Laboratory of Cardiac Electrophysiology, Second Department of Cardiology, Evangelismos General Hospital of Athens, Athens, Greece
| | - Nikolaos Fragakis
- Third Department of Cardiology, Hippokration Hospital, Medical School, Aristotle University of Thessaloniki, Thessaloniki, Greece
- First Department of Cardiology, Medical School, University of Ioannina, Ioannina, Greece
| | - Konstantinos P Letsas
- Laboratory of Cardiac Electrophysiology, Second Department of Cardiology, Evangelismos General Hospital of Athens, Athens, Greece
| | - Panagiotis Korantzopoulos
- Third Department of Cardiology, Hippokration Hospital, Medical School, Aristotle University of Thessaloniki, Thessaloniki, Greece
- First Department of Cardiology, Medical School, University of Ioannina, Ioannina, Greece
| | - Fang-Zhou Liu
- Department of Cardiovascular Surgery, Guangdong Cardiovascular Institute, Guangdong General Hospital affiliated to South China University of Technology, Guangzhou, China
| | - Tong Liu
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin, China
| | - Yunlong Xia
- Department of Cardiology, First Affiliated Hospital of Dalian Medical University, Dalian, China
| | - Gary Tse
- Faculty of Medicine, Li Ka Shing Institute of Health Sciences, Chinese University of Hong Kong, Hong Kong, China
- Department of Medicine and Therapeutics, Faculty of Medicine, Chinese University of Hong Kong, Hong Kong, China
| | - Christien K Li
- Faculty of Medicine, Newcastle University, Newcastle Upon Tyne, UK -
- Faculty of Medicine, Li Ka Shing Institute of Health Sciences, Chinese University of Hong Kong, Hong Kong, China
- Department of Medicine and Therapeutics, Faculty of Medicine, Chinese University of Hong Kong, Hong Kong, China
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32
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Zhao Y, Rafatian N, Feric NT, Cox BJ, Aschar-Sobbi R, Wang EY, Aggarwal P, Zhang B, Conant G, Ronaldson-Bouchard K, Pahnke A, Protze S, Lee JH, Davenport Huyer L, Jekic D, Wickeler A, Naguib HE, Keller GM, Vunjak-Novakovic G, Broeckel U, Backx PH, Radisic M. A Platform for Generation of Chamber-Specific Cardiac Tissues and Disease Modeling. Cell 2019; 176:913-927.e18. [PMID: 30686581 PMCID: PMC6456036 DOI: 10.1016/j.cell.2018.11.042] [Citation(s) in RCA: 330] [Impact Index Per Article: 66.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Revised: 09/19/2018] [Accepted: 11/28/2018] [Indexed: 12/12/2022]
Abstract
Tissue engineering using cardiomyocytes derived from human pluripotent stem cells holds a promise to revolutionize drug discovery, but only if limitations related to cardiac chamber specification and platform versatility can be overcome. We describe here a scalable tissue-cultivation platform that is cell source agnostic and enables drug testing under electrical pacing. The plastic platform enabled on-line noninvasive recording of passive tension, active force, contractile dynamics, and Ca2+ transients, as well as endpoint assessments of action potentials and conduction velocity. By combining directed cell differentiation with electrical field conditioning, we engineered electrophysiologically distinct atrial and ventricular tissues with chamber-specific drug responses and gene expression. We report, for the first time, engineering of heteropolar cardiac tissues containing distinct atrial and ventricular ends, and we demonstrate their spatially confined responses to serotonin and ranolazine. Uniquely, electrical conditioning for up to 8 months enabled modeling of polygenic left ventricular hypertrophy starting from patient cells.
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Affiliation(s)
- Yimu Zhao
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON M5S 3E5, Canada
| | - Naimeh Rafatian
- Division of Cardiology and Peter Munk Cardiac Center, University of Health Network; Toronto, ON M5G 2N2, Canada
| | - Nicole T Feric
- TARA Biosystems, Inc., New York, NY 10016, USA; Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON M5S 3G9, Canada
| | - Brian J Cox
- Department of Physiology, Faculty of Medicine; University of Toronto; Toronto; Ontario, M5S 1A8, Canada; Department of Obstetrics and Gynaecology, Faculty of Medicine, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Roozbeh Aschar-Sobbi
- Division of Cardiology and Peter Munk Cardiac Center, University of Health Network; Toronto, ON M5G 2N2, Canada; TARA Biosystems, Inc., New York, NY 10016, USA
| | - Erika Yan Wang
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON M5S 3G9, Canada
| | - Praful Aggarwal
- Section of Genomic Pediatrics, Department of Pediatrics and Genomic Sciences and Precision Medicine Center, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Boyang Zhang
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON M5S 3E5, Canada; Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON M5S 3G9, Canada
| | - Genevieve Conant
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON M5S 3E5, Canada; Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON M5S 3G9, Canada
| | - Kacey Ronaldson-Bouchard
- TARA Biosystems, Inc., New York, NY 10016, USA; Department of Biomedical Engineering and Department of Medicine, Columbia University, New York, NY 10032, USA
| | - Aric Pahnke
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON M5S 3E5, Canada; Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON M5S 3G9, Canada
| | - Stephanie Protze
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5G 1A8, Canada; McEwen Stem Cell Institute, University Health Network, Toronto, ON M5G 1L7, Canada
| | - Jee Hoon Lee
- McEwen Stem Cell Institute, University Health Network, Toronto, ON M5G 1L7, Canada; BlueRock Therapeutics, MaRS Discovery District, Toronto, ON M5G 1L7, Canada
| | - Locke Davenport Huyer
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON M5S 3E5, Canada; Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON M5S 3G9, Canada
| | - Danica Jekic
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON M5S 3E5, Canada; Department of Anatomy and Cell Biology, Faculty of Science, McGill University, Montreal, QC H3A 2K6, Canada
| | - Anastasia Wickeler
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, ON M5S 3G8, Canada
| | - Hani E Naguib
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, ON M5S 3G8, Canada
| | - Gordon M Keller
- McEwen Stem Cell Institute, University Health Network, Toronto, ON M5G 1L7, Canada
| | - Gordana Vunjak-Novakovic
- Department of Biomedical Engineering and Department of Medicine, Columbia University, New York, NY 10032, USA
| | - Ulrich Broeckel
- Section of Genomic Pediatrics, Department of Pediatrics and Genomic Sciences and Precision Medicine Center, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Peter H Backx
- Division of Cardiology and Peter Munk Cardiac Center, University of Health Network; Toronto, ON M5G 2N2, Canada; Department of Physiology, Faculty of Medicine; University of Toronto; Toronto; Ontario, M5S 1A8, Canada; Department of Biology; York University, Toronto, ON M3J 1P3, Canada; Toronto General Hospital Research Institute, Toronto, ON M5G 2C4, Canada.
| | - Milica Radisic
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON M5S 3E5, Canada; Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON M5S 3G9, Canada; Toronto General Hospital Research Institute, Toronto, ON M5G 2C4, Canada.
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Furutani K, Tsumoto K, Chen IS, Handa K, Yamakawa Y, Sack JT, Kurachi Y. Facilitation of I Kr current by some hERG channel blockers suppresses early afterdepolarizations. J Gen Physiol 2019; 151:214-230. [PMID: 30674563 PMCID: PMC6363420 DOI: 10.1085/jgp.201812192] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Accepted: 12/06/2018] [Indexed: 01/01/2023] Open
Abstract
Some hERG channel blockers are clinically safe, but others cause fatal cardiac arrhythmias. Furutani et al. show that safe blockers facilitate channel opening in ventricular myocytes and provide a repolarization reserve at precisely the voltages and times needed to suppress arrhythmias. Drug-induced block of the cardiac rapid delayed rectifying potassium current (IKr), carried by the human ether-a-go-go-related gene (hERG) channel, is the most common cause of acquired long QT syndrome. Indeed, some, but not all, drugs that block hERG channels cause fatal cardiac arrhythmias. However, there is no clear method to distinguish between drugs that cause deadly arrhythmias and those that are clinically safe. Here we propose a mechanism that could explain why certain clinically used hERG blockers are less proarrhythmic than others. We demonstrate that several drugs that block hERG channels, but have favorable cardiac safety profiles, also evoke another effect; they facilitate the hERG current amplitude in response to low-voltage depolarization. To investigate how hERG facilitation impacts cardiac safety, we develop computational models of IKr block with and without this facilitation. We constrain the models using data from voltage clamp recordings of hERG block and facilitation by nifekalant, a safe class III antiarrhythmic agent. Human ventricular action potential simulations demonstrate the ability of nifekalant to suppress ectopic excitations, with or without facilitation. Without facilitation, excessive IKr block evokes early afterdepolarizations, which cause lethal arrhythmias. When facilitation is introduced, early afterdepolarizations are prevented at the same degree of block. Facilitation appears to prevent early afterdepolarizations by increasing IKr during the repolarization phase of action potentials. We empirically test this prediction in isolated rabbit ventricular myocytes and find that action potential prolongation with nifekalant is less likely to induce early afterdepolarization than action potential prolongation with dofetilide, a hERG channel blocker that does not induce facilitation. Our data suggest that hERG channel blockers that induce facilitation increase the repolarization reserve of cardiac myocytes, rendering them less likely to trigger lethal ventricular arrhythmias.
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Affiliation(s)
- Kazuharu Furutani
- Department of Pharmacology, Graduate School of Medicine, Osaka University, Osaka, Japan .,Center for Advanced Medical Engineering and Informatics, Osaka University, Osaka, Japan.,Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA
| | - Kunichika Tsumoto
- Department of Pharmacology, Graduate School of Medicine, Osaka University, Osaka, Japan.,Department of Physiology, Kanazawa Medical University, Ishikawa, Japan
| | - I-Shan Chen
- Department of Pharmacology, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Kenichiro Handa
- Department of Pharmacology, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Yuko Yamakawa
- Department of Pharmacology, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Jon T Sack
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA
| | - Yoshihisa Kurachi
- Department of Pharmacology, Graduate School of Medicine, Osaka University, Osaka, Japan .,Center for Advanced Medical Engineering and Informatics, Osaka University, Osaka, Japan
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Calloe K. Doctoral Dissertation: The transient outward potassium current in healthy and diseased hearts. Acta Physiol (Oxf) 2019; 225 Suppl 717:e13225. [PMID: 30628199 DOI: 10.1111/apha.13225] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2018] [Revised: 11/20/2018] [Accepted: 11/21/2018] [Indexed: 12/13/2022]
Affiliation(s)
- Kirstine Calloe
- Section for Anatomy; Biochemistry and Physiology; Department for Veterinary and Animal Sciences; Faculty of Health and Medical Sciences; University of Copenhagen; Frederiksberg C Denmark
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Carro J, Pueyo E, Rodríguez Matas JF. A response surface optimization approach to adjust ionic current conductances of cardiac electrophysiological models. Application to the study of potassium level changes. PLoS One 2018; 13:e0204411. [PMID: 30281636 PMCID: PMC6169915 DOI: 10.1371/journal.pone.0204411] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Accepted: 09/07/2018] [Indexed: 01/23/2023] Open
Abstract
Cardiac electrophysiological computational models are often developed from previously published models. The new models may incorporate additional features to adapt the model to a different species or may upgrade a specific ionic formulation based on newly available experimental data. A relevant challenge in the development of a new model is the estimation of certain ionic current conductances that cannot be reliably identified from experiments. A common strategy to estimate those conductances is by means of constrained non-linear least-squares optimization. In this work, a novel methodology is proposed for estimation of ionic current conductances of cardiac electrophysiological models by using a response surface approximation-based constrained optimization with trust region management. Polynomial response surfaces of a number of electrophysiological markers were built using statistical sampling methods. These markers included action potential duration (APD), triangulation, diastolic and systolic intracellular calcium concentration, and time constants of APD rate adaptation. The proposed methodology was applied to update the Carro et al. human ventricular action potential model after incorporation of intracellular potassium ([K+]i) dynamics. While the Carro et al. model was well suited for investigation of arrhythmogenesis, it did not allow simulation of [K+]i changes. With the methodology proposed in this study, the updated Carro et al. human ventricular model could be used to simulate [K+]i changes in response to varying extracellular potassium ([K+]o) levels. Additionally, it rendered values of evaluated electrophysiological markers within physiologically plausible ranges. The optimal values of ionic current conductances in the updated model were found in a notably shorter time than with previously proposed methodologies. As a conclusion, the response surface optimization-based approach proposed in this study allows estimating ionic current conductances of cardiac electrophysiological computational models while guaranteeing replication of key electrophysiological features and with an important reduction in computational cost with respect to previously published approaches. The updated Carro et al. model developed in this study is thus suitable for the investigation of arrhythmic risk-related conditions, including those involving large changes in potassium concentration.
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Affiliation(s)
- Jesús Carro
- Universidad San Jorge, Villanueva de Gállego, Zaragoza, Spain
- Aragón Institute for Engineering Research, University of Zaragoza, IIS Aragón, Spain
- CIBER in Bioengineering, Biomaterials & Nanomedicne (CIBER-BBN), Spain
- * E-mail:
| | - Esther Pueyo
- Aragón Institute for Engineering Research, University of Zaragoza, IIS Aragón, Spain
- CIBER in Bioengineering, Biomaterials & Nanomedicne (CIBER-BBN), Spain
| | - José F. Rodríguez Matas
- Aragón Institute for Engineering Research, University of Zaragoza, IIS Aragón, Spain
- LaBS, Department of Chemistry, Materials and Chemical Engineering “Giulio Natta”, Politecnico di Milano, Italy
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Effects of island-distribution of mid-cardiomyocytes on ventricular electrical excitation associated with the KCNQ1-linked short QT syndrome. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2018; 2017:3684-3687. [PMID: 29060698 DOI: 10.1109/embc.2017.8037657] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
AIMS Short QT syndrome (SQTS) is a new genetic disorder of the electrical system of the heart. To date, there are six gene mutations in ion channels underlying SQTS. However, functional effects of spatial heterogeneities, such as island-distribution of mid-cardiomyocytes (M island) on ventricular electrical excitation in SQTS condition are poorly understood or even not understood at all. Therefore, this study used computational modelling to investigate such possible effects. METHODS The spatial heterogeneities of ventricular tissue was studied by using ten Tusscher et al. MODEL The model was modified to simulate changes to IKs based on experimental observations of KCNQ1 V307L mutation in SQT2 condition. Cell models were coupled to construct a strand tissue, among which 35% were mid-cardiomyocytes, either distributed in island form or in band form, 25% were endocardial (ENDO), and the rest part were epicardial (EPI) cells. RESULTS In simulations, the QT interval was shortened due to the KCNQ1 V307L mutation. The model with M band form failed to reproduce a markedly increase in the T-wave height. However, the model with M island form was able to produce a markedly increased T-wave height with the V307L mutation, matching the major features of SQT clinical ECGs. CONCLUSIONS This study substantiates a causal link between the M island and T-wave amplitude in the KCNQ1-linked short QT syndrome.
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Ziegler T, Hinkel R, Kupatt C. Induced pluripotent stem cell derived cardiac models: effects of Thymosin β4. Expert Opin Biol Ther 2018; 18:111-120. [PMID: 30063852 DOI: 10.1080/14712598.2018.1473370] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
INTRODUCTION The establishment of induced pluripotent stem cells (iPSCs) and cardiomyocytes differentiated from them generated a new platform to study pathophysiological processes and to generate drug screening platforms and iPSC-derived tissues as therapeutic agents. Although major advances have been made in iPSC-reprogramming, cardiac differentiation and EHT production, reprogramming efficiency and the maturity of iPSC-CMs need to be further improved. AREAS COVERED In this review, the authors summarize the current state of the field of iPSC research, the methodology of cardiac differentiation of iPSCs, the use of iPSC-CMs as disease models and toxicity screening platforms, and the potential of EHTs as therapeutic agents. The authors furthermore highlight the mechanisms by which Thymosin β4 might enhance the production of iPSC-CMs and EHTs to improve their maturity and performance. EXPERT OPINION iPSCs derived cardiomyocytes and EHTs represent a still young research field with many problems and pitfalls that need to be resolved to realize the full potential of iPSC-CMs and EHTs. Given that Thymosin β4 directly enhances cardiac differentiation while also promoting angiogenic sprouting and vessel maturation, Tβ4 might be of particular interest as a novel agent in tackling the difficulty of iPSC-CMs and engineered heart tissue grafts.
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Affiliation(s)
- Tilman Ziegler
- a I. Medizinische Klinik & Poliklinik, Klinikum rechts der Isar , Technical University of Munich , Munich , Germany.,b DZHK (German Center for Cardiovascular Research), partner site Munich Heart Alliance , Munich , German
| | - Rabea Hinkel
- a I. Medizinische Klinik & Poliklinik, Klinikum rechts der Isar , Technical University of Munich , Munich , Germany.,b DZHK (German Center for Cardiovascular Research), partner site Munich Heart Alliance , Munich , German.,c Institute for Cardiovascular Prevention , Ludwig Maximilians University of Munich , Munich , Germany
| | - Christian Kupatt
- a I. Medizinische Klinik & Poliklinik, Klinikum rechts der Isar , Technical University of Munich , Munich , Germany.,b DZHK (German Center for Cardiovascular Research), partner site Munich Heart Alliance , Munich , German
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Janusek D, Svehlikova J, Zelinka J, Weigl W, Zaczek R, Opolski G, Tysler M, Maniewski R. The roles of mid-myocardial and epicardial cells in T-wave alternans development: a simulation study. Biomed Eng Online 2018; 17:57. [PMID: 29739399 PMCID: PMC5941457 DOI: 10.1186/s12938-018-0492-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Accepted: 04/28/2018] [Indexed: 01/31/2023] Open
Abstract
Background The occurrence of T-wave alternans in electrocardiographic signals was recently linked to susceptibility to ventricular arrhythmias and sudden cardiac death. Thus, by detecting and comprehending the origins of T-wave alternans, it might be possible to prevent such events. Results Here, we simulated T-wave alternans in a computer-generated human heart model by modulating the action potential duration and amplitude during the first part of the repolarization phase. We hypothesized that changes in the intracardiac alternans patterns of action potential properties would differentially influence T-wave alternans measurements at the body surface. Specifically, changes were simulated globally in the whole left and right ventricles to simulate concordant T-wave alternans, and locally in selected regions to simulate discordant and regional discordant, hereinafter referred to as “regional”, T-wave alternans. Body surface potential maps and 12-lead electrocardiographic signals were then computed. In depth discrimination, the influence of epicardial layers on T-wave alternans development was significantly higher than that of mid-myocardial cells. Meanwhile, spatial discrimination revealed that discordant and regional action potential property changes had a higher influence on T-wave alternans amplitude than concordant changes. Notably, varying T-wave alternans sources yielded distinct body surface potential map patterns for T-wave alternans amplitude, which can be used for location of regions within hearts exhibiting impaired repolarization. The highest ability for T-wave alternans detection was achieved in lead V1. Ultimately, we proposed new parameters Vector Magnitude Alternans and Vector Angle Alternans, with higher ability for T-wave alternans detection when using multi-lead electrocardiographic signals processing than for single leads. Finally, QT alternans was found to be associated with the process of T-wave alternans generation. Conclusions The distributions of the body surface T-wave alternans amplitude have been shown to have unique patterns depending on the type of alternans (concordant, discordant or regional) and the location of the disturbance in the heart. The influence of epicardial cells on T-wave alternans development is significantly higher than that of mid-myocardial cells, among which the sub-endocardial layer exerted the highest influence. QT interval alternans is identified as a phenomenon that correlate with T-wave alternans.
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Affiliation(s)
- D Janusek
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, 4 Ks Trojdena Str., 02-109, Warsaw, Poland.
| | - J Svehlikova
- Institute of Measurement Science, Slovak Academy of Sciences, Bratislava, Slovakia
| | - J Zelinka
- Institute of Measurement Science, Slovak Academy of Sciences, Bratislava, Slovakia
| | - W Weigl
- Department of Surgical Sciences/Anaesthesiology and Intensive Care, Uppsala University, Akademiska Hospital, Uppsala, Sweden
| | - R Zaczek
- Department of Cardiology, Central Clinical Hospital of Medical University of Warsaw, Warsaw, Poland
| | - G Opolski
- Department of Cardiology, Central Clinical Hospital of Medical University of Warsaw, Warsaw, Poland
| | - M Tysler
- Institute of Measurement Science, Slovak Academy of Sciences, Bratislava, Slovakia
| | - R Maniewski
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, 4 Ks Trojdena Str., 02-109, Warsaw, Poland
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Dunn KK, Palecek SP. Engineering Scalable Manufacturing of High-Quality Stem Cell-Derived Cardiomyocytes for Cardiac Tissue Repair. Front Med (Lausanne) 2018; 5:110. [PMID: 29740580 PMCID: PMC5928319 DOI: 10.3389/fmed.2018.00110] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Accepted: 04/03/2018] [Indexed: 12/29/2022] Open
Abstract
Recent advances in the differentiation and production of human pluripotent stem cell (hPSC)-derived cardiomyocytes (CMs) have stimulated development of strategies to use these cells in human cardiac regenerative therapies. A prerequisite for clinical trials and translational implementation of hPSC-derived CMs is the ability to manufacture safe and potent cells on the scale needed to replace cells lost during heart disease. Current differentiation protocols generate fetal-like CMs that exhibit proarrhythmogenic potential. Sufficient maturation of these hPSC-derived CMs has yet to be achieved to allow these cells to be used as a regenerative medicine therapy. Insights into the native cardiac environment during heart development may enable engineering of strategies that guide hPSC-derived CMs to mature. Specifically, considerations must be made in regard to developing methods to incorporate the native intercellular interactions and biomechanical cues into hPSC-derived CM production that are conducive to scale-up.
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Affiliation(s)
- Kaitlin K Dunn
- University of Wisconsin-Madison, Chemical and Biological Engineering, Madison, WI, United States
| | - Sean P Palecek
- University of Wisconsin-Madison, Chemical and Biological Engineering, Madison, WI, United States
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Spitalieri P, Talarico RV, Caioli S, Murdocca M, Serafino A, Girasole M, Dinarelli S, Longo G, Pucci S, Botta A, Novelli G, Zona C, Mango R, Sangiuolo F. Modelling the pathogenesis of Myotonic Dystrophy type 1 cardiac phenotype through human iPSC-derived cardiomyocytes. J Mol Cell Cardiol 2018; 118:95-109. [PMID: 29551391 DOI: 10.1016/j.yjmcc.2018.03.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Revised: 03/12/2018] [Accepted: 03/14/2018] [Indexed: 12/20/2022]
Abstract
Myotonic Dystrophy type 1 (DM1) is a multisystemic disease, autosomal dominant, caused by a CTG repeat expansion in DMPK gene. We assessed the appropriateness of patient-specific induced pluripotent stem cell-derived cardiomyocytes (CMs) as a model to recapitulate some aspects of the pathogenetic mechanism involving cardiac manifestations in DM1 patients. Once obtained in vitro, CMs have been characterized for their morphology and their functionality. CMs DM1 show intranuclear foci and transcript markers abnormally spliced respect to WT ones, as well as several irregularities in nuclear morphology, probably caused by an unbalanced lamin A/C ratio. Electrophysiological characterization evidences an abnormal profile only in CMs DM1 such that the administration of antiarrythmic drugs to these cells highlights even more the functional defect linked to the disease. Finally, Atomic Force Measurements reveal differences in the biomechanical behaviour of CMs DM1, in terms of frequencies and synchronicity of the beats. Altogether the complex phenotype described in this work, strongly reproduces some aspects of the human DM1 cardiac phenotype. Therefore, the present study provides an in vitro model suggesting novel insights into the mechanisms leading to the development of arrhythmogenesis and dilatative cardiomyopathy to consider when approaching to DM1 patients, especially for the risk assessment of sudden cardiac death (SCD). These data could be also useful in identifying novel biomarkers effective in clinical settings and patient-tailored therapies.
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Affiliation(s)
- Paola Spitalieri
- Dept of Biomedicine and Prevention, University of Rome "Tor Vergata", Rome, Italy
| | - Rosa V Talarico
- Dept of Biomedicine and Prevention, University of Rome "Tor Vergata", Rome, Italy
| | | | - Michela Murdocca
- Dept of Biomedicine and Prevention, University of Rome "Tor Vergata", Rome, Italy
| | | | | | | | | | - Sabina Pucci
- Dept of Biomedicine and Prevention, University of Rome "Tor Vergata", Rome, Italy
| | - Annalisa Botta
- Dept of Biomedicine and Prevention, University of Rome "Tor Vergata", Rome, Italy
| | - Giuseppe Novelli
- Dept of Biomedicine and Prevention, University of Rome "Tor Vergata", Rome, Italy
| | - Cristina Zona
- I.R.C.C.S. S. Lucia, Rome, Italy; Dept of Systems Medicine, University of Rome "Tor Vergata", Rome, Italy
| | | | - Federica Sangiuolo
- Dept of Biomedicine and Prevention, University of Rome "Tor Vergata", Rome, Italy.
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Tse G, Yan BP. Traditional and novel electrocardiographic conduction and repolarization markers of sudden cardiac death. Europace 2018; 19:712-721. [PMID: 27702850 DOI: 10.1093/europace/euw280] [Citation(s) in RCA: 105] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Accepted: 08/11/2016] [Indexed: 12/20/2022] Open
Abstract
Sudden cardiac death, frequently due to ventricular arrhythmias, is a significant problem globally. Most affected individuals do not arrive at hospital in time for medical treatment. Therefore, there is an urgent need to identify the most-at-risk patients for insertion of prophylactic implantable cardioverter defibrillators. Clinical risk markers derived from electrocardiography are important for this purpose. They can be based on repolarization, including corrected QT (QTc) interval, QT dispersion (QTD), interval from the peak to the end of the T-wave (Tpeak - Tend), (Tpeak - Tend)/QT, T-wave alternans (TWA), and microvolt TWA. Abnormal repolarization properties can increase the risk of triggered activity and re-entrant arrhythmias. Other risk markers are based solely on conduction, such as QRS duration (QRSd), which is a surrogate marker of conduction velocity (CV) and QRS dispersion (QRSD) reflecting CV dispersion. Conduction abnormalities in the form of reduced CV, unidirectional block, together with a functional or a structural obstacle, are conditions required for circus-type or spiral wave re-entry. Conduction and repolarization can be represented by a single parameter, excitation wavelength (λ = CV × effective refractory period). λ is an important determinant of arrhythmogenesis in different settings. Novel conduction-repolarization markers incorporating λ include Lu et al.' index of cardiac electrophysiological balance (iCEB: QT/QRSd), [QRSD× (Tpeak - Tend)/QRSd] and [QRSD × (Tpeak - Tend)/(QRSd × QT)] recently proposed by Tse and Yan. The aim of this review is to provide up to date information on traditional and novel markers and discuss their utility and downfalls for risk stratification.
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Affiliation(s)
- Gary Tse
- Department of Medicine and Therapeutics, Chinese University of Hong Kong, Hong Kong, SAR, P.R. China
| | - Bryan P Yan
- Department of Medicine and Therapeutics, Chinese University of Hong Kong, Hong Kong, SAR, P.R. China.,Department of Epidemiology and Preventive Medicine, Monash University, Clayton, VIC, Australia
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Besser RR, Ishahak M, Mayo V, Carbonero D, Claure I, Agarwal A. Engineered Microenvironments for Maturation of Stem Cell Derived Cardiac Myocytes. Am J Cancer Res 2018; 8:124-140. [PMID: 29290797 PMCID: PMC5743464 DOI: 10.7150/thno.19441] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Accepted: 10/19/2017] [Indexed: 01/11/2023] Open
Abstract
Through the use of stem cell-derived cardiac myocytes, tissue-engineered human myocardial constructs are poised for modeling normal and diseased physiology of the heart, as well as discovery of novel drugs and therapeutic targets in a human relevant manner. This review highlights the recent bioengineering efforts to recapitulate microenvironmental cues to further the maturation state of newly differentiated cardiac myocytes. These techniques include long-term culture, co-culture, exposure to mechanical stimuli, 3D culture, cell-matrix interactions, and electrical stimulation. Each of these methods has produced various degrees of maturation; however, a standardized measure for cardiomyocyte maturation is not yet widely accepted by the scientific community.
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Colman MA, Perez Alday EA, Holden AV, Benson AP. Trigger vs. Substrate: Multi-Dimensional Modulation of QT-Prolongation Associated Arrhythmic Dynamics by a hERG Channel Activator. Front Physiol 2017; 8:757. [PMID: 29046643 PMCID: PMC5632683 DOI: 10.3389/fphys.2017.00757] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Accepted: 09/19/2017] [Indexed: 11/13/2022] Open
Abstract
Background: Prolongation of the QT interval of the electrocardiogram (ECG), underlain by prolongation of the action potential duration (APD) at the cellular level, is linked to increased vulnerability to cardiac arrhythmia. Pharmacological management of arrhythmia associated with QT prolongation is typically achieved through attempting to restore APD to control ranges, reversing the enhanced vulnerability to Ca2+-dependent afterdepolarisations (arrhythmia triggers) and increased transmural dispersion of repolarisation (arrhythmia substrate) associated with APD prolongation. However, such pharmacological modulation has been demonstrated to have limited effectiveness. Understanding the integrative functional impact of pharmacological modulation requires simultaneous investigation of both the trigger and substrate. Methods: We implemented a multi-scale (cell and tissue) in silico approach using a model of the human ventricular action potential, integrated with a model of stochastic 3D spatiotemporal Ca2+ dynamics, and parameter modification to mimic prolonged QT conditions. We used these models to examine the efficacy of the hERG activator MC-II-157c in restoring APD to control ranges, examined its effects on arrhythmia triggers and substrates, and the interaction of these arrhythmia triggers and substrates. Results: QT prolongation conditions promoted the development of spontaneous release events underlying afterdepolarisations during rapid pacing. MC-II-157c applied to prolonged QT conditions shortened the APD, inhibited the development of afterdepolarisations and reduced the probability of afterdepolarisations manifesting as triggered activity in single cells. In tissue, QT prolongation resulted in an increased transmural dispersion of repolarisation, which manifested as an increased vulnerable window for uni-directional conduction block. In some cases, MC-II-157c further increased the vulnerable window through its effects on INa. The combination of stochastic release event modulation and transmural dispersion of repolarisation modulation by MC-II-157c resulted in an integrative behavior wherein the arrhythmia trigger is reduced but the arrhythmia substrate is increased, leading to variable and non-linear overall vulnerability to arrhythmia. Conclusion: The relative balance of reduced trigger and increased substrate underlies a multi-dimensional role of MC-II-157c in modulation of cardiac arrhythmia vulnerability associated with prolonged QT interval.
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Affiliation(s)
- Michael A Colman
- School of Biomedical Sciences and Multidisciplinary Cardiovascular Research Centre, University of Leeds, Leeds, United Kingdom
| | - Erick A Perez Alday
- Division of Cardiovascular Medicine, Oregon Health and Science University, Portland, OR, United States
| | - Arun V Holden
- School of Biomedical Sciences and Multidisciplinary Cardiovascular Research Centre, University of Leeds, Leeds, United Kingdom
| | - Alan P Benson
- School of Biomedical Sciences and Multidisciplinary Cardiovascular Research Centre, University of Leeds, Leeds, United Kingdom
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Campos FO, Shiferaw Y, Vigmond EJ, Plank G. Stochastic spontaneous calcium release events and sodium channelopathies promote ventricular arrhythmias. CHAOS (WOODBURY, N.Y.) 2017; 27:093910. [PMID: 28964108 PMCID: PMC5568869 DOI: 10.1063/1.4999612] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Premature ventricular complexes (PVCs), the first initiating beats of a variety of cardiac arrhythmias, have been associated with spontaneous calcium release (SCR) events at the cell level. However, the mechanisms underlying the degeneration of such PVCs into arrhythmias are not fully understood. The objective of this study was to investigate the conditions under which SCR-mediated PVCs can lead to ventricular arrhythmias. In particular, we sought to determine whether sodium (Na+) current loss-of-function in the structurally normal ventricles provides a substrate for unidirectional conduction block and reentry initiated by SCR-mediated PVCs. To achieve this goal, a stochastic model of SCR was incorporated into an anatomically accurate compute model of the rabbit ventricles with the His-Purkinje system (HPS). Simulations with reduced Na+ current due to a negative-shift in the steady-state channel inactivation showed that SCR-mediated delayed afterdepolarizations led to PVC formation in the HPS, where the electrotonic load was lower, conduction block, and reentry in the 3D myocardium. Moreover, arrhythmia initiation was only possible when intrinsic electrophysiological heterogeneity in action potential within the ventricles was present. In conclusion, while benign in healthy individuals SCR-mediated PVCs can lead to life-threatening ventricular arrhythmias when combined with Na+ channelopathies.
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Affiliation(s)
- Fernando O Campos
- Department of Congenital Heart Diseases and Pediatric Cardiology, German Heart Institute Berlin, Berlin, Germany
| | - Yohannes Shiferaw
- Department of Physics, California State University, Northridge, California 91330, USA
| | | | - Gernot Plank
- Institute of Biophysics, Medical University of Graz, Graz, Austria
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45
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Kienast R, Handler M, Stöger M, Baumgarten D, Hanser F, Baumgartner C. Modeling hypothermia induced effects for the heterogeneous ventricular tissue from cellular level to the impact on the ECG. PLoS One 2017; 12:e0182979. [PMID: 28813535 PMCID: PMC5558962 DOI: 10.1371/journal.pone.0182979] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Accepted: 07/27/2017] [Indexed: 11/18/2022] Open
Abstract
Hypothermia has a profound impact on the electrophysiological mechanisms of the heart. Experimental investigations provide a better understanding of electrophysiological alterations associated with cooling. However, there is a lack of computer models suitable for simulating the effects of hypothermia in cardio-electrophysiology. In this work, we propose a model that describes the cooling-induced electrophysiological alterations in ventricular tissue in a temperature range from 27°C to 37°C. To model the electrophysiological conditions in a 3D left ventricular tissue block it was essential to consider the following anatomical and physiological parameters in the model: the different cell types (endocardial, M, epicardial), the heterogeneous conductivities in longitudinal, transversal and transmural direction depending on the prevailing temperature, the distinct fiber orientations and the transmural repolarization sequences. Cooling-induced alterations on the morphology of the action potential (AP) of single myocardial cells thereby are described by an extension of the selected Bueno-Orovio model for human ventricular tissue using Q10 temperature coefficients. To evaluate alterations on tissue level, the corresponding pseudo electrocardiogram (pECG) was calculated. Simulations show that cooling-induced AP and pECG-related parameters, i.e. AP duration, morphology of the notch of epicardial AP, maximum AP upstroke velocity, AP rise time, QT interval, QRS duration and J wave formation are in good accordance with literature and our experimental data. The proposed model enables us to further enhance our knowledge of cooling-induced electrophysiological alterations from cellular to tissue level in the heart and may help to better understand electrophysiological mechanisms, e.g. in arrhythmias, during hypothermia.
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Affiliation(s)
- Roland Kienast
- Institute of Electrical and Biomedical Engineering, UMIT–University for Health Sciences, Medical Informatics and Technology, Hall, Tyrol, Austria
- * E-mail:
| | - Michael Handler
- Institute of Electrical and Biomedical Engineering, UMIT–University for Health Sciences, Medical Informatics and Technology, Hall, Tyrol, Austria
| | - Markus Stöger
- Institute of Electrical and Biomedical Engineering, UMIT–University for Health Sciences, Medical Informatics and Technology, Hall, Tyrol, Austria
| | - Daniel Baumgarten
- Institute of Electrical and Biomedical Engineering, UMIT–University for Health Sciences, Medical Informatics and Technology, Hall, Tyrol, Austria
- Institute of Biomedical Engineering and Informatics, Technische Universität Ilmenau, Ilmenau, Germany
| | - Friedrich Hanser
- Institute of Electrical and Biomedical Engineering, UMIT–University for Health Sciences, Medical Informatics and Technology, Hall, Tyrol, Austria
| | - Christian Baumgartner
- Institute of Electrical and Biomedical Engineering, UMIT–University for Health Sciences, Medical Informatics and Technology, Hall, Tyrol, Austria
- Institute of Health Care Engineering with European Testing Center of Medical Devices, Graz University of Technology, Graz, Austria
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46
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Lemoine MD, Mannhardt I, Breckwoldt K, Prondzynski M, Flenner F, Ulmer B, Hirt MN, Neuber C, Horváth A, Kloth B, Reichenspurner H, Willems S, Hansen A, Eschenhagen T, Christ T. Human iPSC-derived cardiomyocytes cultured in 3D engineered heart tissue show physiological upstroke velocity and sodium current density. Sci Rep 2017; 7:5464. [PMID: 28710467 PMCID: PMC5511281 DOI: 10.1038/s41598-017-05600-w] [Citation(s) in RCA: 122] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Accepted: 06/12/2017] [Indexed: 12/16/2022] Open
Abstract
Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CM) are a promising tool for drug testing and modelling genetic disorders. Abnormally low upstroke velocity is a current limitation. Here we investigated the use of 3D engineered heart tissue (EHT) as a culture method with greater resemblance to human heart tissue in comparison to standard technique of 2D monolayer (ML) format. INa was measured in ML or EHT using the standard patch-clamp technique. INa density was ~1.8 fold larger in EHT (-18.5 ± 1.9 pA/pF; n = 17) than in ML (-10.3 ± 1.2 pA/pF; n = 23; p < 0.001), approaching densities reported for human CM. Inactivation kinetics, voltage dependency of steady-state inactivation and activation of INa did not differ between EHT and ML and were similar to previously reported values for human CM. Action potential recordings with sharp microelectrodes showed similar upstroke velocities in EHT (219 ± 15 V/s, n = 13) and human left ventricle tissue (LV, 253 ± 7 V/s, n = 25). EHT showed a greater resemblance to LV in CM morphology and subcellular NaV1.5 distribution. INa in hiPSC-CM showed similar biophysical properties as in human CM. The EHT format promotes INa density and action potential upstroke velocity of hiPSC-CM towards adult values, indicating its usefulness as a model for excitability of human cardiac tissue.
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Affiliation(s)
- Marc D Lemoine
- Department of Cardiology-Electrophysiology, University Heart Center, Hamburg, Germany. .,Department of Experimental Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany. .,DZHK (German Center for Cardiovascular Research), partner site Hamburg/Kiel/Lübeck, Hamburg, Germany.
| | - Ingra Mannhardt
- Department of Experimental Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,DZHK (German Center for Cardiovascular Research), partner site Hamburg/Kiel/Lübeck, Hamburg, Germany
| | - Kaja Breckwoldt
- Department of Experimental Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,DZHK (German Center for Cardiovascular Research), partner site Hamburg/Kiel/Lübeck, Hamburg, Germany
| | - Maksymilian Prondzynski
- Department of Experimental Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,DZHK (German Center for Cardiovascular Research), partner site Hamburg/Kiel/Lübeck, Hamburg, Germany
| | - Frederik Flenner
- Department of Experimental Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,DZHK (German Center for Cardiovascular Research), partner site Hamburg/Kiel/Lübeck, Hamburg, Germany
| | - Bärbel Ulmer
- Department of Experimental Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,DZHK (German Center for Cardiovascular Research), partner site Hamburg/Kiel/Lübeck, Hamburg, Germany
| | - Marc N Hirt
- Department of Experimental Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,DZHK (German Center for Cardiovascular Research), partner site Hamburg/Kiel/Lübeck, Hamburg, Germany
| | - Christiane Neuber
- Department of Experimental Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,DZHK (German Center for Cardiovascular Research), partner site Hamburg/Kiel/Lübeck, Hamburg, Germany
| | - András Horváth
- Department of Experimental Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Szeged, Szeged, Hungary
| | - Benjamin Kloth
- Department of Cardiovascular Surgery, University Heart Center, Hamburg, Germany
| | | | - Stephan Willems
- Department of Cardiology-Electrophysiology, University Heart Center, Hamburg, Germany.,DZHK (German Center for Cardiovascular Research), partner site Hamburg/Kiel/Lübeck, Hamburg, Germany
| | - Arne Hansen
- Department of Experimental Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,DZHK (German Center for Cardiovascular Research), partner site Hamburg/Kiel/Lübeck, Hamburg, Germany
| | - Thomas Eschenhagen
- Department of Experimental Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,DZHK (German Center for Cardiovascular Research), partner site Hamburg/Kiel/Lübeck, Hamburg, Germany
| | - Torsten Christ
- Department of Experimental Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany. .,DZHK (German Center for Cardiovascular Research), partner site Hamburg/Kiel/Lübeck, Hamburg, Germany.
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47
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Osadchii OE. Role of abnormal repolarization in the mechanism of cardiac arrhythmia. Acta Physiol (Oxf) 2017; 220 Suppl 712:1-71. [PMID: 28707396 DOI: 10.1111/apha.12902] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
In cardiac patients, life-threatening tachyarrhythmia is often precipitated by abnormal changes in ventricular repolarization and refractoriness. Repolarization abnormalities typically evolve as a consequence of impaired function of outward K+ currents in cardiac myocytes, which may be caused by genetic defects or result from various acquired pathophysiological conditions, including electrical remodelling in cardiac disease, ion channel modulation by clinically used pharmacological agents, and systemic electrolyte disorders seen in heart failure, such as hypokalaemia. Cardiac electrical instability attributed to abnormal repolarization relies on the complex interplay between a provocative arrhythmic trigger and vulnerable arrhythmic substrate, with a central role played by the excessive prolongation of ventricular action potential duration, impaired intracellular Ca2+ handling, and slowed impulse conduction. This review outlines the electrical activity of ventricular myocytes in normal conditions and cardiac disease, describes classical electrophysiological mechanisms of cardiac arrhythmia, and provides an update on repolarization-related surrogates currently used to assess arrhythmic propensity, including spatial dispersion of repolarization, activation-repolarization coupling, electrical restitution, TRIaD (triangulation, reverse use dependence, instability, and dispersion), and the electromechanical window. This is followed by a discussion of the mechanisms that account for the dependence of arrhythmic vulnerability on the location of the ventricular pacing site. Finally, the review clarifies the electrophysiological basis for cardiac arrhythmia produced by hypokalaemia, and gives insight into the clinical importance and pathophysiology of drug-induced arrhythmia, with particular focus on class Ia (quinidine, procainamide) and Ic (flecainide) Na+ channel blockers, and class III antiarrhythmic agents that block the delayed rectifier K+ channel (dofetilide).
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Affiliation(s)
- O. E. Osadchii
- Department of Health Science and Technology; University of Aalborg; Aalborg Denmark
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48
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Luo C, Wang K, Zhang H. In silico assessment of the effects of quinidine, disopyramide and E-4031 on short QT syndrome variant 1 in the human ventricles. PLoS One 2017. [PMID: 28632743 PMCID: PMC5478111 DOI: 10.1371/journal.pone.0179515] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Aims Short QT syndrome (SQTS) is an inherited disorder associated with abnormally abbreviated QT intervals and an increased incidence of atrial and ventricular arrhythmias. SQT1 variant (linked to the rapid delayed rectifier potassium channel current, IKr) of SQTS, results from an inactivation-attenuated, gain-of-function mutation (N588K) in the KCNH2-encoded potassium channels. Pro-arrhythmogenic effects of SQT1 have been well characterized, but less is known about the possible pharmacological antiarrhythmic treatment of SQT1. Therefore, this study aimed to assess the potential effects of E-4031, disopyramide and quinidine on SQT1 using a mathematical model of human ventricular electrophysiology. Methods The ten Tusscher et al. biophysically detailed model of the human ventricular action potential (AP) was modified to incorporate IKr Markov chain (MC) formulations based on experimental data of the kinetics of the N588K mutation of the KCNH2-encoded subunit of the IKr channels. The modified ventricular cell model was then integrated into one-dimensional (1D) strand, 2D regular and realistic tissues with transmural heterogeneities. The channel-blocking effect of the drugs on ion currents in healthy and SQT1 cells was modeled using half-maximal inhibitory concentration (IC50) and Hill coefficient (nH) values from literatures. Effects of drugs on cell AP duration (APD), effective refractory period (ERP) and pseudo-ECG traces were calculated. Effects of drugs on the ventricular temporal and spatial vulnerability to re-entrant excitation waves were measured. Re-entry was simulated in both 2D regular and realistic ventricular tissue. Results At the single cell level, the drugs E-4031 and disopyramide had hardly noticeable effects on the ventricular cell APD at 90% repolarization (APD90), whereas quinidine caused a significant prolongation of APD90. Quinidine prolonged and decreased the maximal transmural AP heterogeneity (δV); this led to the decreased transmural heterogeneity of APD across the 1D strand. Quinidine caused QT prolongation and a decrease in the T-wave amplitude, and increased ERP and decreased temporal susceptibility of the tissue to the initiation of re-entry and increased the minimum substrate size necessary to prevent re-entry in the 2D regular model, and further terminated re-entrant waves in the 2D realistic model. Quinidine exhibited significantly better therapeutic effects on SQT1 than E-4031 and disopyramide. Conclusions The simulated pharmacological actions of quinidine exhibited antiarrhythmic effects on SQT1. This study substantiates a causal link between quinidine and QT interval prolongation in SQT1 and suggests that quinidine may be a potential pharmacological agent for treating SQT1 patients.
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Affiliation(s)
- Cunjin Luo
- 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
- * E-mail: (KW); (HZ)
| | - Henggui Zhang
- School of Computer Science and Technology, Harbin Institute of Technology (HIT), Harbin, China
- School of Physics and Astronomy, The University of Manchester, Manchester, United Kingdom
- Space Institute of Southern China, Shenzhen, China
- * E-mail: (KW); (HZ)
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49
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Luo C, Wang K, Zhang H. Effects of amiodarone on short QT syndrome variant 3 in human ventricles: a simulation study. Biomed Eng Online 2017; 16:69. [PMID: 28592292 PMCID: PMC5463381 DOI: 10.1186/s12938-017-0369-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Accepted: 06/01/2017] [Indexed: 01/23/2023] Open
Abstract
Background Short QT syndrome (SQTS) is a newly identified clinical disorder associated with atrial and/or ventricular arrhythmias and increased risk of sudden cardiac death (SCD). The SQTS variant 3 is linked to D172N mutation to the KCNJ2 gene that causes a gain-of-function to the inward rectifier potassium channel current (IK1), which shortens the ventricular action potential duration (APD) and effective refractory period (ERP). Pro-arrhythmogenic effects of SQTS have been characterized, but less is known about the possible pharmacological treatment of SQTS. Therefore, in this study, we used computational modeling to assess the effects of amiodarone, class III anti-arrhythmic agent, on human ventricular electrophysiology in SQT3. Methods The ten Tusscher et al. model for the human ventricular action potentials (APs) was modified to incorporate IK1 formulations based on experimental data of Kir2.1 channels (including WT, WT-D172N and D172N conditions). The modified cell model was then implemented to construct one-dimensional (1D) and 2D tissue models. The blocking effects of amiodarone on ionic currents were modeled using IC50 and Hill coefficient values from literatures. Effects of amiodarone on APD, ERP and pseudo-ECG traces were computed. Effects of the drug on the temporal and spatial vulnerability of ventricular tissue to genesis and maintenance of re-entry were measured, as well as on the dynamic behavior of re-entry. Results Amiodarone prolonged the ventricular cell APD and decreased the maximal voltage heterogeneity (δV) among three difference cells types across transmural ventricular wall, leading to a decreased transmural heterogeneity of APD along a 1D model of ventricular transmural strand. Amiodarone increased cellular ERP, prolonged QT interval and decreased the T-wave amplitude. It reduced tissue’s temporal susceptibility to the initiation of re-entry and increased the minimum substrate size necessary to sustain re-entry in the 2D tissue. Conclusions At the therapeutic-relevant concentration of amiodarone, the APD and ERP at the single cell level were increased significantly. The QT interval in pseudo-ECG was prolonged and the re-entry in tissue was prevented. This study provides further evidence that amiodarone may be a potential pharmacological agent for preventing arrhythmogenesis for SQT3 patients. Electronic supplementary material The online version of this article (doi:10.1186/s12938-017-0369-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Cunjin Luo
- School of Computer Science and Technology, Harbin Institute of Technology (HIT), Harbin, 150001, China
| | - Kuanquan Wang
- School of Computer Science and Technology, Harbin Institute of Technology (HIT), Harbin, 150001, China.
| | - Henggui Zhang
- School of Computer Science and Technology, Harbin Institute of Technology (HIT), Harbin, 150001, China. .,School of Physics and Astronomy, The University of Manchester, Manchester, M13 9PL, UK. .,Space Institute of Southern China, Shenzhen, 518117, China.
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50
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Scuderi GJ, Butcher J. Naturally Engineered Maturation of Cardiomyocytes. Front Cell Dev Biol 2017; 5:50. [PMID: 28529939 PMCID: PMC5418234 DOI: 10.3389/fcell.2017.00050] [Citation(s) in RCA: 125] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2017] [Accepted: 04/18/2017] [Indexed: 12/11/2022] Open
Abstract
Ischemic heart disease remains one of the most prominent causes of mortalities worldwide with heart transplantation being the gold-standard treatment option. However, due to the major limitations associated with heart transplants, such as an inadequate supply and heart rejection, there remains a significant clinical need for a viable cardiac regenerative therapy to restore native myocardial function. Over the course of the previous several decades, researchers have made prominent advances in the field of cardiac regeneration with the creation of in vitro human pluripotent stem cell-derived cardiomyocyte tissue engineered constructs. However, these engineered constructs exhibit a functionally immature, disorganized, fetal-like phenotype that is not equivalent physiologically to native adult cardiac tissue. Due to this major limitation, many recent studies have investigated approaches to improve pluripotent stem cell-derived cardiomyocyte maturation to close this large functionality gap between engineered and native cardiac tissue. This review integrates the natural developmental mechanisms of cardiomyocyte structural and functional maturation. The variety of ways researchers have attempted to improve cardiomyocyte maturation in vitro by mimicking natural development, known as natural engineering, is readily discussed. The main focus of this review involves the synergistic role of electrical and mechanical stimulation, extracellular matrix interactions, and non-cardiomyocyte interactions in facilitating cardiomyocyte maturation. Overall, even with these current natural engineering approaches, pluripotent stem cell-derived cardiomyocytes within three-dimensional engineered heart tissue still remain mostly within the early to late fetal stages of cardiomyocyte maturity. Therefore, although the end goal is to achieve adult phenotypic maturity, more emphasis must be placed on elucidating how the in vivo fetal microenvironment drives cardiomyocyte maturation. This information can then be utilized to develop natural engineering approaches that can emulate this fetal microenvironment and thus make prominent progress in pluripotent stem cell-derived maturity toward a more clinically relevant model for cardiac regeneration.
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Affiliation(s)
- Gaetano J Scuderi
- Meinig School of Biomedical Engineering, Cornell UniversityIthaca, NY, USA
| | - Jonathan Butcher
- Meinig School of Biomedical Engineering, Cornell UniversityIthaca, NY, USA
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