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Tyree TJ, Murphy P, Rappel WJ. Annihilation dynamics during spiral defect chaos revealed by particle models. CHAOS (WOODBURY, N.Y.) 2024; 34:053131. [PMID: 38787314 PMCID: PMC11141445 DOI: 10.1063/5.0203319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2024] [Accepted: 04/30/2024] [Indexed: 05/25/2024]
Abstract
Pair-annihilation events are ubiquitous in a variety of spatially extended systems and are often studied using computationally expensive simulations. Here, we develop an approach in which we simulate the pair-annihilation of spiral wave tips in cardiac models using a computationally efficient particle model. Spiral wave tips are represented as particles with dynamics governed by diffusive behavior and short-ranged attraction. The parameters for diffusion and attraction are obtained by comparing particle motion to the trajectories of spiral wave tips in cardiac models during spiral defect chaos. The particle model reproduces the annihilation rates of the cardiac models and can determine the statistics of spiral wave dynamics, including its mean termination time. We show that increasing the attraction coefficient sharply decreases the mean termination time, making it a possible target for pharmaceutical intervention.
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Affiliation(s)
- Timothy J. Tyree
- Department of Physics, University of California San Diego, San Diego, California 92093, USA
| | - Patrick Murphy
- Department of Mathematics and Statistics, San Jose State University, San Jose, California 95192, USA
| | - Wouter-Jan Rappel
- Department of Physics, University of California San Diego, San Diego, California 92093, USA
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2
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Nitta T, Asano T, Yajima T, Otsuka T, Ishii Y. Chemical ablation of the left ventricular endocardium reduces ventricular fibrillation inducibility in acute ischemic canine heart. J Arrhythm 2024; 40:325-332. [PMID: 38586838 PMCID: PMC10995593 DOI: 10.1002/joa3.12993] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Revised: 12/24/2023] [Accepted: 01/08/2024] [Indexed: 04/09/2024] Open
Abstract
Objective Ventricular fibrillation remains as the major cause of death in patients with acute myocardial infarction. Effects of trans-atrial chemical ablation of the left ventricular (LV) endocardium with Lugol's solution on ventricular fibrillation inducibility and ventricular conduction were examined in canines with acute myocardial ischemia. Materials and Methods Chemical ablation of the LV endocardium with Lugol's solution or normal saline was preformed through a left atrial appendage in 14 canines 30 min after occlusion of the left anterior coronary artery. Results Ventricular fibrillation threshold decreased after the coronary artery occlusion and increased after endocardial chemical ablation. There was a significant difference in the ventricular fibrillation threshold after chemical ablation between with Lugol's solution and with normal saline (25.9 ± 9.2 mA vs. 11.3 ± 2.7 mA, p < .01). QRS width significantly increased from 88 ± 4 msec to 116 ± 5 msec (p < .01) after the chemical ablation with Lugol's solution, and the activation map of the ventricles demonstrated a left bundle branch block ventricular conduction pattern. Histological examination of the LV endocardium showed lymphocyte infiltration for a depth of 1 mm. Conclusions Chemical ablation of the LV endocardium with Lugol's solution injures endocardial conduction system and increases ventricular fibrillation threshold in the early phase of myocardial ischemia in canines. The procedure may be useful in suppressing intractable ventricular tachyarrhythmias in patients with acute myocardial ischemia.
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Affiliation(s)
- Takashi Nitta
- Cardiovascular SurgeryNippon Medical SchoolTokyoJapan
| | - Tetsuo Asano
- Cardiovascular SurgeryNippon Medical SchoolTokyoJapan
| | | | - Toshiaki Otsuka
- Public Health (Statistical Analysis)Nippon Medical SchoolTokyoJapan
| | - Yosuke Ishii
- Cardiovascular SurgeryNippon Medical SchoolTokyoJapan
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3
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Bianconi K, Zielinski W, Fischer S, Ferlazzo J, Steenberg M, Ariyaprakai N. Brugada Syndrome as an Underlying Diagnosis for a Prehospital Seizure Dispatch. PREHOSP EMERG CARE 2023; 28:656-659. [PMID: 38059594 DOI: 10.1080/10903127.2023.2285387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Accepted: 09/18/2023] [Indexed: 12/08/2023]
Abstract
Brugada syndrome is an inherited genetic disorder known to cause a variety of patient complaints but may ultimately cause ventricular fibrillation and sudden cardiac death. We present a patient with witnessed seizure who was ultimately diagnosed with Brugada syndrome. Multiple ventricular arrhythmias complicated the case, which was managed in- and out-of-hospital.
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Affiliation(s)
| | - Wayne Zielinski
- Robert Wood Johnson Mobile Health, New Brunswick, New Jersey
| | - Scott Fischer
- Robert Wood Johnson Mobile Health, New Brunswick, New Jersey
| | - Jenna Ferlazzo
- Robert Wood Johnson Mobile Health, New Brunswick, New Jersey
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4
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Iravanian S, Uzelac I, Shah AD, Toye MJ, Lloyd MS, Burke MA, Daneshmand MA, Attia TS, Vega JD, El-Chami MF, Merchant FM, Cherry EM, Bhatia NK, Fenton FH. Complex repolarization dynamics in ex vivo human ventricles are independent of the restitution properties. Europace 2023; 25:euad350. [PMID: 38006390 PMCID: PMC10751849 DOI: 10.1093/europace/euad350] [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: 09/10/2023] [Accepted: 11/13/2023] [Indexed: 11/27/2023] Open
Abstract
AIMS The mechanisms of transition from regular rhythms to ventricular fibrillation (VF) are poorly understood. The concordant to discordant repolarization alternans pathway is extensively studied; however, despite its theoretical centrality, cannot guide ablation. We hypothesize that complex repolarization dynamics, i.e. oscillations in the repolarization phase of action potentials with periods over two of classic alternans, is a marker of electrically unstable substrate, and ablation of these areas has a stabilizing effect and may reduce the risk of VF. To prove the existence of higher-order periodicities in human hearts. METHODS AND RESULTS We performed optical mapping of explanted human hearts obtained from recipients of heart transplantation at the time of surgery. Signals recorded from the right ventricle endocardial surface were processed to detect global and local repolarization dynamics during rapid pacing. A statistically significant global 1:4 peak was seen in three of six hearts. Local (pixel-wise) analysis revealed the spatially heterogeneous distribution of Periods 4, 6, and 8, with the regional presence of periods greater than two in all the hearts. There was no significant correlation between the underlying restitution properties and the period of each pixel. CONCLUSION We present evidence of complex higher-order periodicities and the co-existence of such regions with stable non-chaotic areas in ex vivo human hearts. We infer that the oscillation of the calcium cycling machinery is the primary mechanism of higher-order dynamics. These higher-order regions may act as niduses of instability and may provide targets for substrate-based ablation of VF.
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Affiliation(s)
- Shahriar Iravanian
- Department of Medicine, Division of Cardiology, Emory University School of Medicine, 1364 Clifton Road, Atlanta, GA 30322, USA
| | - Ilija Uzelac
- Georgia Institute of Technology, Department of Physics, 837 State St NW, Atlanta, GA 30332, USA
| | - Anand D Shah
- Department of Medicine, Division of Cardiology, Emory University School of Medicine, 1364 Clifton Road, Atlanta, GA 30322, USA
| | - Mikael J Toye
- Georgia Institute of Technology, Department of Physics, 837 State St NW, Atlanta, GA 30332, USA
| | - Michael S Lloyd
- Department of Medicine, Division of Cardiology, Emory University School of Medicine, 1364 Clifton Road, Atlanta, GA 30322, USA
| | - Michael A Burke
- Department of Medicine, Division of Cardiology, Emory University School of Medicine, 1364 Clifton Road, Atlanta, GA 30322, USA
| | - Mani A Daneshmand
- Department of Surgery, Division of Cardiovascular Surgery, Emory University School of Medicine, 1364 Clifton Road, Atlanta, GA 30322, USA
| | - Tamer S Attia
- Department of Surgery, Division of Cardiovascular Surgery, Emory University School of Medicine, 1364 Clifton Road, Atlanta, GA 30322, USA
| | - John David Vega
- Department of Surgery, Division of Cardiovascular Surgery, Emory University School of Medicine, 1364 Clifton Road, Atlanta, GA 30322, USA
| | - Mikhael F El-Chami
- Department of Medicine, Division of Cardiology, Emory University School of Medicine, 1364 Clifton Road, Atlanta, GA 30322, USA
| | - Faisal M Merchant
- Department of Medicine, Division of Cardiology, Emory University School of Medicine, 1364 Clifton Road, Atlanta, GA 30322, USA
| | - Elizabeth M Cherry
- Georgia Institute of Technology, Department of Physics, 837 State St NW, Atlanta, GA 30332, USA
| | - Neal K Bhatia
- Department of Medicine, Division of Cardiology, Emory University School of Medicine, 1364 Clifton Road, Atlanta, GA 30322, USA
| | - Flavio H Fenton
- Georgia Institute of Technology, Department of Physics, 837 State St NW, Atlanta, GA 30332, USA
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5
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Chen S, Jiang L, Xu F, Pang J, Pan C, Chen Y, Wang J, Li K. Electrical-mechanical dynamical coupling between electrocardiographic and photoplethysmographic signals during cardiopulmonary resuscitation. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2023; 242:107809. [PMID: 37757567 DOI: 10.1016/j.cmpb.2023.107809] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 09/04/2023] [Accepted: 09/11/2023] [Indexed: 09/29/2023]
Abstract
BACKGROUND AND OBJECTIVE Cardiac arrest (CA) remains a significant cause of death and disability. High-quality cardiopulmonary resuscitation (CPR) can improve the survival rate of CA. A challenging issue is to find physiological indicators for screening and evaluating the cardiovascular function associated with CPR. This study aimed to investigate the electrical-mechanical dynamic coupling between electrocardiographic (ECG) and photoplethysmographic (PPG) signals for indicating cardiovascular function in the progress of CPR. METHOD The ECG and PPG signals were simultaneously collected from a porcine CA model (n = 10) induced by ventricular fibrillation, and were further divided into four periods: Baseline, CA, CPR, and recovery of spontaneous circulation (ROSC). Recurrence quantitative analysis (RQA) was applied to examine the nonlinear dynamics of the ECG and PPG signals individually, and cross recurrence quantitative analysis (CRQA) was used to examine the ECG-PPG dynamical coupling. RESULTS The CA influenced the dynamic patterns of electrical and mechanical activities and the electrical-mechanical coupling, which can be observed from the reduced entropy (ENTR) (p < 0.01), reduced determinism (DET) (p < 0.01) and reduced trapping time (TT) (p < 0.01) at CA compared to Baseline. The recurrence rate (RR), ENTR, DET, and TT at CPR were significantly lower than the parameters at ROSC but higher than those at CA. CONCLUSIONS The electrical-mechanical dynamical coupling was sensitive to CPR and able to reflect the changes in cardiac function in the process of CPR.
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Affiliation(s)
- Shuxin Chen
- Institute of Intelligent Medical Engineering, School of Control Science and Engineering, Shandong University, Jinan, China
| | - Lijun Jiang
- Department of Emergency Medicine, Qilu Hospital of Shandong University, Jinan, China; Shandong Provincial Clinical Research Center for Emergency and Critical Care Medicine, Institute of Emergency and Critical Care Medicine of Shandong University, Chest Pain Center, Qilu Hospital of Shandong University, Jinan, China; Key Laboratory of Emergency and Critical Care Medicine of Shandong Province, Key Laboratory of Cardiopulmonary Cerebral Resuscitation Research of Shandong Province, Shandong Provincial Engineering Laboratory for Emergency and Critical Care Medicine, Shandong Key Laboratory: Magnetic Field-free Medicine & Functional Imaging, Qilu Hospital of Shandong University, Jinan, China; NMPA Key Laboratory for Clinical Research and Evaluation of Innovative Drug, Qilu Hospital of Shandong University, Jinan, China
| | - Feng Xu
- Department of Emergency Medicine, Qilu Hospital of Shandong University, Jinan, China; Shandong Provincial Clinical Research Center for Emergency and Critical Care Medicine, Institute of Emergency and Critical Care Medicine of Shandong University, Chest Pain Center, Qilu Hospital of Shandong University, Jinan, China; Key Laboratory of Emergency and Critical Care Medicine of Shandong Province, Key Laboratory of Cardiopulmonary Cerebral Resuscitation Research of Shandong Province, Shandong Provincial Engineering Laboratory for Emergency and Critical Care Medicine, Shandong Key Laboratory: Magnetic Field-free Medicine & Functional Imaging, Qilu Hospital of Shandong University, Jinan, China; NMPA Key Laboratory for Clinical Research and Evaluation of Innovative Drug, Qilu Hospital of Shandong University, Jinan, China
| | - Jiaojiao Pang
- Department of Emergency Medicine, Qilu Hospital of Shandong University, Jinan, China; Shandong Provincial Clinical Research Center for Emergency and Critical Care Medicine, Institute of Emergency and Critical Care Medicine of Shandong University, Chest Pain Center, Qilu Hospital of Shandong University, Jinan, China; Key Laboratory of Emergency and Critical Care Medicine of Shandong Province, Key Laboratory of Cardiopulmonary Cerebral Resuscitation Research of Shandong Province, Shandong Provincial Engineering Laboratory for Emergency and Critical Care Medicine, Shandong Key Laboratory: Magnetic Field-free Medicine & Functional Imaging, Qilu Hospital of Shandong University, Jinan, China; NMPA Key Laboratory for Clinical Research and Evaluation of Innovative Drug, Qilu Hospital of Shandong University, Jinan, China
| | - Chang Pan
- Department of Emergency Medicine, Qilu Hospital of Shandong University, Jinan, China; Shandong Provincial Clinical Research Center for Emergency and Critical Care Medicine, Institute of Emergency and Critical Care Medicine of Shandong University, Chest Pain Center, Qilu Hospital of Shandong University, Jinan, China; Key Laboratory of Emergency and Critical Care Medicine of Shandong Province, Key Laboratory of Cardiopulmonary Cerebral Resuscitation Research of Shandong Province, Shandong Provincial Engineering Laboratory for Emergency and Critical Care Medicine, Shandong Key Laboratory: Magnetic Field-free Medicine & Functional Imaging, Qilu Hospital of Shandong University, Jinan, China; NMPA Key Laboratory for Clinical Research and Evaluation of Innovative Drug, Qilu Hospital of Shandong University, Jinan, China
| | - Yuguo Chen
- Department of Emergency Medicine, Qilu Hospital of Shandong University, Jinan, China; Shandong Provincial Clinical Research Center for Emergency and Critical Care Medicine, Institute of Emergency and Critical Care Medicine of Shandong University, Chest Pain Center, Qilu Hospital of Shandong University, Jinan, China; Key Laboratory of Emergency and Critical Care Medicine of Shandong Province, Key Laboratory of Cardiopulmonary Cerebral Resuscitation Research of Shandong Province, Shandong Provincial Engineering Laboratory for Emergency and Critical Care Medicine, Shandong Key Laboratory: Magnetic Field-free Medicine & Functional Imaging, Qilu Hospital of Shandong University, Jinan, China; NMPA Key Laboratory for Clinical Research and Evaluation of Innovative Drug, Qilu Hospital of Shandong University, Jinan, China.
| | - Jiali Wang
- Department of Emergency Medicine, Qilu Hospital of Shandong University, Jinan, China; Shandong Provincial Clinical Research Center for Emergency and Critical Care Medicine, Institute of Emergency and Critical Care Medicine of Shandong University, Chest Pain Center, Qilu Hospital of Shandong University, Jinan, China; Key Laboratory of Emergency and Critical Care Medicine of Shandong Province, Key Laboratory of Cardiopulmonary Cerebral Resuscitation Research of Shandong Province, Shandong Provincial Engineering Laboratory for Emergency and Critical Care Medicine, Shandong Key Laboratory: Magnetic Field-free Medicine & Functional Imaging, Qilu Hospital of Shandong University, Jinan, China; NMPA Key Laboratory for Clinical Research and Evaluation of Innovative Drug, Qilu Hospital of Shandong University, Jinan, China.
| | - Ke Li
- Institute of Intelligent Medical Engineering, School of Control Science and Engineering, Shandong University, Jinan, China.
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Song E. Impact of noise on the instability of spiral waves in stochastic 2D mathematical models of human atrial fibrillation. J Biol Phys 2023; 49:521-533. [PMID: 37792115 PMCID: PMC10651617 DOI: 10.1007/s10867-023-09644-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Accepted: 09/08/2023] [Indexed: 10/05/2023] Open
Abstract
Sustained spiral waves, also known as rotors, are pivotal mechanisms in persistent atrial fibrillation (AF). Stochasticity is inevitable in nonlinear biological systems such as the heart; however, it is unclear how noise affects the instability of spiral waves in human AF. This study presents a stochastic two-dimensional mathematical model of human AF and explores how Gaussian white noise affects the instability of spiral waves. In homogeneous tissue models, Gaussian white noise may lead to spiral-wave meandering and wavefront break-up. As the noise intensity increases, the spatial dispersion of phase singularity (PS) points increases. This finding indicates the potential AF-protective effects of cardiac system stochasticity by destabilizing the rotors. By contrast, Gaussian white noise is unlikely to affect the spiral-wave instability in the presence of localized scar or fibrosis regions. The PS points are located at the boundary or inside the scar/fibrosis regions. Localized scar or fibrosis may play a pivotal role in stabilizing spiral waves regardless of the presence of noise. This study suggests that fibrosis and scars are essential for stabilizing the rotors in stochastic mathematical models of AF. Further patient-derived realistic modeling studies are required to confirm the role of scar/fibrosis in AF pathophysiology.
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Affiliation(s)
- Euijun Song
- Yonsei University College of Medicine, Seoul, Republic of Korea.
- , Gyeonggi, Republic of Korea.
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7
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Syomin FA, Galushka VA, Tsaturyan AK. Effect of strain-dependent conduction slowing on the re-entry formation and maintenance in cardiac muscle: 2D computer simulation. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2023; 39:e3676. [PMID: 36562353 DOI: 10.1002/cnm.3676] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Revised: 12/06/2022] [Accepted: 12/19/2022] [Indexed: 06/17/2023]
Abstract
The effect of mechano-electrical feedback on re-entry formation and maintenance was studied using a model of myocardial electromechanics that accounts for two components of myocardial conductivity and delayed strain-dependent changes in membrane capacitance that causes a conduction slowing. Two scenarios were simulated in 2D numerical experiments: (i) propagation of an excitation-contraction wave beyond the edge of a nonconductive nonexcitable obstacle; (ii) circulation of a re-entry wave around a nonconductive nonexcitable obstacle. The simulations demonstrated that the delayed strain-dependent deceleration of the conduction waves promotes the detachment of the excitation-contraction waves from the sharp edge of an elongated obstacle and modulates the re-entry waves rotating around a compact obstacle. The data show that the mechano-electrical feedback, together with an increase in the stimulation frequency and an increase in the excitation threshold, is an arrhythmogenic factor that must be taken into account when analyzing the possibility of the re-entry formation.
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Affiliation(s)
- Fyodor A Syomin
- Institute of Mechanics, Lomonosov Moscow State University, Moscow, Russia
| | | | - Andrey K Tsaturyan
- Institute of Mechanics, Lomonosov Moscow State University, Moscow, Russia
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Candia-Rivera D, Machado C. Reduced Heartbeat-Evoked Responses in a Near-Death Case Report. J Clin Neurol 2023; 19:581-588. [PMID: 37455508 PMCID: PMC10622722 DOI: 10.3988/jcn.2022.0415] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 12/30/2022] [Accepted: 01/25/2023] [Indexed: 07/18/2023] Open
Abstract
BACKGROUND AND PURPOSE Whether brain-heart communication continues under ventricular fibrillation (VF) remains to be determined. There is weak evidence of physiological changes in cortical activity under VF. Moreover, brain-heart communication has not previously been studied in this condition. We aimed to measure parallel changes in heart-rate variability (HRV), cortical activity, and brain-heart interactions in a patient who experienced VF. METHODS The EEG and EKG signals for the case report were acquired for approximately 20 h. We selected different 1-min-long segments based on the changes in the EKG waveform. We present the changes in heartbeat-evoked responses (HERs), HRV, and EEG power for each selected segment. RESULTS The overall physiological activity appeared to deteriorate as VF proceeded. Brain-heart interactions measured using HERs disappeared, with a few aberrant amplitudes appearing occasionally. The parallel changes in EEG and HRV were not pronounced, suggesting the absence of bidirectional neural control. CONCLUSIONS Our measurements of brain-heart interactions suggested that the evolving VF impairs communication between the central and autonomic nervous systems. These results may support that reduced brain-heart interactions reflect loss of consciousness and deterioration in the overall health state.
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Affiliation(s)
| | - Calixto Machado
- Department of Clinical Neurophysiology, Institute of Neurology and Neurosurgery, Havana, Cuba
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Li TC, Zhong W, Ai BQ, Zhu WJ, Li BW, Panfilov AV, Dierckx H. Reordering and synchronization of electrical turbulence in cardiac tissue through global and partial optogenetical illumination. Phys Rev E 2023; 108:034218. [PMID: 37849154 DOI: 10.1103/physreve.108.034218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Accepted: 09/06/2023] [Indexed: 10/19/2023]
Abstract
Electrical turbulence in the heart is considered the culprit of cardiac disease, including the fatal ventricular fibrillation. Optogenetics is an emerging technology that has the capability to produce action potentials of cardiomyocytes to affect the electric wave propagation in cardiac tissue, thereby possessing the potential to control the turbulence, by shining a rotating spiral pattern onto the tissue. In this paper, we present a method to reorder and synchronize electrical turbulence through optogenetics. A generic two-variable reaction-diffusion model and a simplified three-variable ionic cardiac model are used. We discuss cases involving either global or partial illumination.
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Affiliation(s)
- Teng-Chao Li
- School of Physics, Hangzhou Normal University, Hangzhou 311121, China and School of Physics and Telecommunication Engineering, South China Normal University, Guangzhou 510006, China
| | - Wei Zhong
- School of Physics and Telecommunication Engineering, South China Normal University, Guangzhou 510006, China
| | - Bao-Quan Ai
- School of Physics and Telecommunication Engineering, South China Normal University, Guangzhou 510006, China
| | - Wei-Jing Zhu
- School of Photoelectric Engineering, Guangdong Polytechnic Normal University, Guangzhou 510665, China
| | - Bing-Wei Li
- School of Physics, Hangzhou Normal University, Hangzhou 311121, China
| | - Alexander V Panfilov
- Ural Federal University, Biomed Laboratory, 620002 Ekaterinburg, Russia; Department of Physics and Astronomy, Ghent University, B-9000 Ghent, Belgium; and World-Class Research Center "Digital biodesign and personalized healthcare", I.M. Sechenov First Moscow State Medical University, 119991 Moscow, Russia
| | - Hans Dierckx
- KU Leuven Campus Kortrijk-Kulak, Department of Mathematics, Etienne Sabbelaan 53 bus 7657, 8500 Kortrijk, Belgium and iSi Health - KU Leuven Institute of Physics-based Modeling for In Silico Health, KU Leuven, Belgium
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10
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Iravanian S, Uzelac I, Shah AD, Toye MJ, Lloyd MS, Burke MA, Daneshmand MA, Attia TS, Vega JD, El-Chami M, Merchant FM, Cherry EM, Bhatia NK, Fenton FH. Higher-Order Dynamics Beyond Repolarization Alternans in Ex-Vivo Human Ventricles are Independent of the Restitution Properties. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.08.16.23293853. [PMID: 37662394 PMCID: PMC10473769 DOI: 10.1101/2023.08.16.23293853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/05/2023]
Abstract
Background Repolarization alternans, defined as period-2 oscillation in the repolarization phase of the action potentials, provides a mechanistic link between cellular dynamics and ventricular fibrillation (VF). Theoretically, higher-order periodicities (e.g., periods 4, 6, 8,...) are expected but have minimal experimental evidence. Methods We studied explanted human hearts obtained from recipients of heart transplantation at the time of surgery. Optical mapping of the transmembrane potential was performed after staining the hearts with voltage-sensitive fluorescent dyes. Hearts were stimulated at an increasing rate until VF was induced. Signals recorded from the right ventricle endocardial surface prior to induction of VF and in the presence of 1:1 conduction were processed using the Principal Component Analysis and a combinatorial algorithm to detect and quantify higher-order dynamics. Results were correlated to the underlying electrophysiological characteristics as quantified by restitution curves and conduction velocity. Results A prominent and statistically significant global 1:4 peak (corresponding to period-4 dynamics) was seen in three of the six studied hearts. Local (pixel-wise) analysis revealed the spatially heterogeneous distribution of periods 4, 6, and 8, with the regional presence of periods greater than two in all the hearts. There was no significant correlation between the underlying restitution properties and the period of each pixel. Discussion We present evidence of higher-order periodicities and the co-existence of such regions with stable non-chaotic areas in ex-vivo human hearts. We infer from the independence of the period to the underlying restitution properties that the oscillation of the excitation-contraction coupling and calcium cycling mechanisms is the primary mechanism of higher-order dynamics. These higher-order regions may act as niduses of instability that can degenerate into chaotic fibrillation and may provide targets for substrate-based ablation of VF.
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Affiliation(s)
- Shahriar Iravanian
- Department of Cardiovascular Medicine, Emory University School of Medicine, Atlanta, GA
| | - Ilija Uzelac
- Georgia Tech, Department of Physics, Atlanta, GA
| | - Anand D Shah
- Department of Cardiovascular Medicine, Emory University School of Medicine, Atlanta, GA
| | | | - Michael S. Lloyd
- Department of Cardiovascular Medicine, Emory University School of Medicine, Atlanta, GA
| | - Michael A. Burke
- Department of Cardiovascular Medicine, Emory University School of Medicine, Atlanta, GA
| | - Mani A Daneshmand
- Division of Cardiovascular Surgery, Department of Surgery, Emory University School of Medicine, Atlanta, GA
| | - Tamer S Attia
- Division of Cardiovascular Surgery, Department of Surgery, Emory University School of Medicine, Atlanta, GA
| | - J David Vega
- Division of Cardiovascular Surgery, Department of Surgery, Emory University School of Medicine, Atlanta, GA
| | - Michael El-Chami
- Department of Cardiovascular Medicine, Emory University School of Medicine, Atlanta, GA
| | - Faisal M. Merchant
- Department of Cardiovascular Medicine, Emory University School of Medicine, Atlanta, GA
| | | | - Neal K. Bhatia
- Department of Cardiovascular Medicine, Emory University School of Medicine, Atlanta, GA
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11
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Christie S, Idris S, Bennett RG, Deyell MW, Roston T, Laksman Z. Trigger and Substrate Mapping and Ablation for Ventricular Fibrillation in the Structurally Normal Heart. J Cardiovasc Dev Dis 2023; 10:jcdd10050200. [PMID: 37233167 DOI: 10.3390/jcdd10050200] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Revised: 04/28/2023] [Accepted: 04/29/2023] [Indexed: 05/27/2023] Open
Abstract
Sudden cardiac death (SCD) represents approximately 50% of all cardiovascular mortality in the United States. The majority of SCD occurs in individuals with structural heart disease; however, around 5% of individuals have no identifiable cause on autopsy. This proportion is even higher in those <40 years old, where SCD is particularly devastating. Ventricular fibrillation (VF) is often the terminal rhythm leading to SCD. Catheter ablation for VF has emerged as an effective tool to alter the natural history of this disease among high-risk individuals. Important advances have been made in the identification of several mechanisms involved in the initiation and maintenance of VF. Targeting the triggers of VF as well as the underlying substrate that perpetuates these lethal arrhythmias has the potential to eliminate further episodes. Although important gaps remain in our understanding of VF, catheter ablation has become an important option for individuals with refractory arrhythmias. This review outlines a contemporary approach to the mapping and ablation of VF in the structurally normal heart, specifically focusing on the following major conditions: idiopathic ventricular fibrillation, short-coupled ventricular fibrillation, and the J-wave syndromes-Brugada syndrome and early-repolarization syndrome.
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Affiliation(s)
- Simon Christie
- Faculty of Medicine, Division of Cardiology, University of British Columbia, Gordon & Leslie Diamond Health Care Centre, 2775 Laurel St., 9th Floor, Vancouver, BC V5Z 1M9, Canada
| | - Sami Idris
- Faculty of Medicine, Division of Cardiology, University of British Columbia, Gordon & Leslie Diamond Health Care Centre, 2775 Laurel St., 9th Floor, Vancouver, BC V5Z 1M9, Canada
| | - Richard G Bennett
- Faculty of Medicine, Division of Cardiology, University of British Columbia, Gordon & Leslie Diamond Health Care Centre, 2775 Laurel St., 9th Floor, Vancouver, BC V5Z 1M9, Canada
| | - Marc W Deyell
- Faculty of Medicine, Division of Cardiology, University of British Columbia, Gordon & Leslie Diamond Health Care Centre, 2775 Laurel St., 9th Floor, Vancouver, BC V5Z 1M9, Canada
| | - Thomas Roston
- Faculty of Medicine, Division of Cardiology, University of British Columbia, Gordon & Leslie Diamond Health Care Centre, 2775 Laurel St., 9th Floor, Vancouver, BC V5Z 1M9, Canada
| | - Zachary Laksman
- Faculty of Medicine, Division of Cardiology, University of British Columbia, Gordon & Leslie Diamond Health Care Centre, 2775 Laurel St., 9th Floor, Vancouver, BC V5Z 1M9, Canada
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12
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Iravanian S, Uzelac I, Shah AD, Toye MJ, Lloyd MS, Burke MA, Daneshmand MA, Attia TS, Vega JD, Merchant FM, Cherry EM, Bhatia NK, Fenton FH. Beyond Alternans: Detection of Higher-Order Periodicity in Ex-Vivo Human Ventricles Before Induction of Ventricular Fibrillation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.01.539003. [PMID: 37205562 PMCID: PMC10187180 DOI: 10.1101/2023.05.01.539003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Background Repolarization alternans, defined as period-2 oscillation in the repolarization phase of the action potentials, is one of the cornerstones of cardiac electrophysiology as it provides a mechanistic link between cellular dynamics and ventricular fibrillation (VF). Theoretically, higher-order periodicities (e.g., period-4, period-8,...) are expected but have very limited experimental evidence. Methods We studied explanted human hearts, obtained from the recipients of heart transplantation at the time of surgery, using optical mapping technique with transmembrane voltage-sensitive fluorescent dyes. The hearts were stimulated at an increasing rate until VF was induced. The signals recorded from the right ventricle endocardial surface just before the induction of VF and in the presence of 1:1 conduction were processed using the Principal Component Analysis and a combinatorial algorithm to detect and quantify higher-order dynamics. Results A prominent and statistically significant 1:4 peak (corresponding to period-4 dynamics) was seen in three of the six studied hearts. Local analysis revealed the spatiotemporal distribution of higher-order periods. Period-4 was localized to temporally stable islands. Higher-order oscillations (period-5, 6, and 8) were transient and primarily occurred in arcs parallel to the activation isochrones. Discussion We present evidence of higher-order periodicities and the co-existence of such regions with stable non-chaotic areas in ex-vivo human hearts before VF induction. This result is consistent with the period-doubling route to chaos as a possible mechanism of VF initiation, which complements the concordant to discordant alternans mechanism. The presence of higher-order regions may act as niduses of instability that can degenerate into chaotic fibrillation.
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13
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Ezzeddine FM, Darlington AM, DeSimone CV, Asirvatham SJ. Catheter Ablation of Ventricular Fibrillation. Card Electrophysiol Clin 2022; 14:729-742. [PMID: 36396189 DOI: 10.1016/j.ccep.2022.06.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Ventricular fibrillation (VF) is a common cause of sudden cardiac death (SCD) and is unfortunately without a cure. Current therapies focus on prevention of SCD, such as implantable cardioverter-defibrillator (ICD) implantation and anti-arrhythmic agents. Significant progress has been made in improving our understanding and ability to target the triggers of VF, via advanced mapping and ablation techniques, as well as with autonomic modulation. However, the critical substrate for VF maintenance remains incompletely defined. In this review, we discuss the evidence behind the basic mechanisms of VF and review the current role of catheter ablation in patients with VF.
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Affiliation(s)
- Fatima M Ezzeddine
- Department of Cardiovascular Medicine, Mayo Clinic, 200 First Street Southwest, Rochester, MN, USA
| | - Ashley M Darlington
- Department of Cardiovascular Medicine, Mayo Clinic, 200 First Street Southwest, Rochester, MN, USA
| | - Christopher V DeSimone
- Department of Cardiovascular Medicine, Mayo Clinic, 200 First Street Southwest, Rochester, MN, USA
| | - Samuel J Asirvatham
- Department of Cardiovascular Medicine, Mayo Clinic, 200 First Street Southwest, Rochester, MN, USA.
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14
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Uzelac I, Iravanian S, Bhatia NK, Fenton FH. Spiral wave breakup: Optical mapping in an explanted human heart shows the transition from ventricular tachycardia to ventricular fibrillation and self-termination. Heart Rhythm 2022; 19:1914-1915. [PMID: 35850399 DOI: 10.1016/j.hrthm.2022.07.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 06/29/2022] [Accepted: 07/12/2022] [Indexed: 11/27/2022]
Affiliation(s)
- Ilija Uzelac
- School of Physics, Georgia Institute of Technology, Atlanta, Georgia.
| | - Shahriar Iravanian
- Division of Cardiology, Section of Electrophysiology, Emory University Hospital, Atlanta, Georgia
| | - Neal K Bhatia
- Division of Cardiology, Section of Electrophysiology, Emory University Hospital, Atlanta, Georgia
| | - Flavio H Fenton
- School of Physics, Georgia Institute of Technology, Atlanta, Georgia
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15
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Qauli AI, Yoo Y, Marcellinus A, Lim KM. Verification of the Efficacy of Mexiletine Treatment for the A1656D Mutation on Downgrading Reentrant Tachycardia Using a 3D Cardiac Electrophysiological Model. Bioengineering (Basel) 2022; 9:531. [PMID: 36290499 PMCID: PMC9598628 DOI: 10.3390/bioengineering9100531] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 10/03/2022] [Accepted: 10/05/2022] [Indexed: 10/21/2023] Open
Abstract
The SCN5A mutations have been long associated with long QT variant 3 (LQT3). Recent experimental and computation studies have reported that mexiletine effectively treats LQT3 patients associated with the A1656D mutation. However, they have primarily focused on cellular level evaluations and have only looked at the effects of mexiletine on action potential duration (APD) or QT interval reduction. We further investigated mexiletine's effects on cardiac cells through simulations of single-cell (behavior of alternant occurrence) and 3D (with and without mexiletine). We discovered that mexiletine could shorten the cell's APD and change the alternant's occurrence to a shorter basic cycle length (BCL) between 350 and 420 ms. The alternant also appeared at a normal heart rate under the A1656D mutation. Furthermore, the 3D ventricle simulations revealed that mexiletine could reduce the likelihood of a greater spiral wave breakup in the A1656D mutant condition by minimizing the appearance of rotors. In conclusion, we found that mexiletine could provide extra safety features during therapy for LQT3 patients because it can change the alternant occurrence from a normal to a faster heart rate, and it reduces the chance of a spiral wave breakup. Therefore, these findings emphasize the promising efficacy of mexiletine in treating LQT3 patients under the A1656D mutation.
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Affiliation(s)
- Ali Ikhsanul Qauli
- Department of IT Convergence Engineering, Kumoh National Institute of Technology, Gumi 39177, Korea
- Robotics and Artificial Intelligence Engineering, Faculty of Advanced Technology and Multidiscipline, Universitas Airlangga, Surabaya 60115, Jawa Timur, Indonesia
| | - Yedam Yoo
- Department of IT Convergence Engineering, Kumoh National Institute of Technology, Gumi 39177, Korea
| | - Aroli Marcellinus
- Department of IT Convergence Engineering, Kumoh National Institute of Technology, Gumi 39177, Korea
| | - Ki Moo Lim
- Department of IT Convergence Engineering, Kumoh National Institute of Technology, Gumi 39177, Korea
- Department of Medical IT Convergence Engineering, Kumoh National Institute of Technology, Gumi 39253, Korea
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16
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Elgassim MAM, Saied ASS, Mustafa MA, Abdelrahman A, AlJaufi I, Salem W. A Rare Case of Metronidazole Overdose Causing Ventricular Fibrillation. Cureus 2022; 14:e24728. [PMID: 35676987 PMCID: PMC9166500 DOI: 10.7759/cureus.24728] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/27/2022] [Indexed: 11/25/2022] Open
Abstract
Ventricular fibrillation is not known as a complication of metronidazole poisoning. Although some arrhythmias have been reported as a complication of metronidazole intake while taking antiarrhythmic medications, most such arrhythmias are possibly related to co-ingestion of drugs with metronidazole as it affects the metabolism of these drugs. In this case, ventricular fibrillation occurred in a young patient without preexisting medical conditions or any other known drug ingestion, which was never been reported before. We present a case of an 18-year-old male brought in by the ambulance service after attempting to end his life by overdosing on metronidazole. While being transported he developed ventricular fibrillation and received an electric shock, which reverted the episode. Laboratory investigations did not show any clear cause that might have precipitated his arrhythmia.
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17
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Zang X, Zhang S, Li S, Wang X, Song W, Chen K, Ma J, Tu X, Xia Y, Zhao Y, Gao C. Evaluating Common NOS1AP Variants in Patients with Implantable Cardioverter Defibrillators for Secondary Prevention : Evaluating SNPs in NOS1AP. J Interv Card Electrophysiol 2022; 64:793-800. [PMID: 35353321 DOI: 10.1007/s10840-022-01137-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2021] [Accepted: 01/25/2022] [Indexed: 11/26/2022]
Abstract
BACKGROUND Recent research has found that single nucleotide polymorphisms (SNPs) in the nitric oxide synthase 1 adaptor protein (NOS1AP) gene are associated with altered QT intervals and sudden cardiac death (SCD). However, the clinical utility and implications of NOS1AP SNPs remain unclear. Thus, this study aimed to explore the influence of NOS1AP SNPs in patients with implantable cardioverter defibrillator (ICD) for secondary prevention. METHODS We conducted a case-control study to evaluate the most studied SNPs in NOS1AP (rs12143842, rs10494366, rs12567209, and rs16847548) in patients with ICD for secondary prevention. Patients were followed for up to 36 months from the time of ICD implantation. ICD interrogation data at 3 and 12 months, including rapid ventricular arrhythmia episodes and appropriate therapies, were then analyzed. RESULTS: A significant association was observed between rs10494366 and ICD recipients who experienced appropriate therapies. After a mean follow-up time of 31.70 ± 9.15 months, we detected significant differences among the three rs10494366 genotype groups in the distribution of ICD shocks and appropriate therapies, as well as in the correlation of rs10494366 and ICD shocks. According to Kaplan-Meier and Cox regression analyses, patients with the TT genotype had a higher risk of SCD than those with the GG genotype. CONCLUSIONS The present study revealed that NOS1AP SNP rs10494366 was associated with appropriate therapies. Specifically, the TT genotype increased ICD shocks and SCD risk in patients with ICD for secondary prevention for the first time.
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Affiliation(s)
- Xiaobiao Zang
- Department of Cardiology, Peoples Hospital of Zhengzhou University Henan Provincial Peoples Hospital, Fuwai Central China Cardiovascular Hospital, Henan Province, Zhengzhou, China
| | - Shulong Zhang
- Department of Cardiology, Affiliated Zhongshan Hospital of Dalian University, Dalian, China
| | - Sisi Li
- Gannan Medical University, Jiangxi, China
| | - Xianqing Wang
- Department of Cardiology, Peoples Hospital of Zhengzhou University Henan Provincial Peoples Hospital, Fuwai Central China Cardiovascular Hospital, Henan Province, Zhengzhou, China
| | - Weifeng Song
- Department of Cardiology, Peoples Hospital of Zhengzhou University Henan Provincial Peoples Hospital, Fuwai Central China Cardiovascular Hospital, Henan Province, Zhengzhou, China
| | - Ke Chen
- Department of Cardiology, Peoples Hospital of Zhengzhou University Henan Provincial Peoples Hospital, Fuwai Central China Cardiovascular Hospital, Henan Province, Zhengzhou, China
| | - Jifang Ma
- Department of Cardiology, Peoples Hospital of Zhengzhou University Henan Provincial Peoples Hospital, Fuwai Central China Cardiovascular Hospital, Henan Province, Zhengzhou, China
| | - Xin Tu
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology and Center for Human Genome Research, Cardio-X Institute, Huazhong University of Science and Technology, Wuhan, China
| | - Yunlong Xia
- First Affiliated Hospital of Dalian Medical University, Dalian, China
| | - Yonghui Zhao
- Department of Cardiology, Peoples Hospital of Zhengzhou University Henan Provincial Peoples Hospital, Fuwai Central China Cardiovascular Hospital, Henan Province, Zhengzhou, China.
| | - Chuanyu Gao
- Department of Cardiology, Peoples Hospital of Zhengzhou University Henan Provincial Peoples Hospital, Fuwai Central China Cardiovascular Hospital, Henan Province, Zhengzhou, China.
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18
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Ono K, Iwasaki YK, Akao M, Ikeda T, Ishii K, Inden Y, Kusano K, Kobayashi Y, Koretsune Y, Sasano T, Sumitomo N, Takahashi N, Niwano S, Hagiwara N, Hisatome I, Furukawa T, Honjo H, Maruyama T, Murakawa Y, Yasaka M, Watanabe E, Aiba T, Amino M, Itoh H, Ogawa H, Okumura Y, Aoki-Kamiya C, Kishihara J, Kodani E, Komatsu T, Sakamoto Y, Satomi K, Shiga T, Shinohara T, Suzuki A, Suzuki S, Sekiguchi Y, Nagase S, Hayami N, Harada M, Fujino T, Makiyama T, Maruyama M, Miake J, Muraji S, Murata H, Morita N, Yokoshiki H, Yoshioka K, Yodogawa K, Inoue H, Okumura K, Kimura T, Tsutsui H, Shimizu W. JCS/JHRS 2020 Guideline on Pharmacotherapy of Cardiac Arrhythmias. Circ J 2022; 86:1790-1924. [DOI: 10.1253/circj.cj-20-1212] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
| | - Yu-ki Iwasaki
- Department of Cardiovascular Medicine, Nippon Medical School
| | - Masaharu Akao
- Department of Cardiovascular Medicine, National Hospital Organization Kyoto Medical Center
| | - Takanori Ikeda
- Department of Cardiovascular Medicine, Toho University Graduate School of Medicine
| | - Kuniaki Ishii
- Department of Pharmacology, Yamagata University Faculty of Medicine
| | - Yasuya Inden
- Department of Cardiology, Nagoya University Graduate School of Medicine
| | - Kengo Kusano
- Department of Cardiovascular Medicine, National Cerebral and Cardiovascular Center
| | - Yoshinori Kobayashi
- Division of Cardiology, Department of Medicine, Tokai University Hachioji Hospital
| | | | - Tetsuo Sasano
- Department of Cardiovascular Medicine, Tokyo Medical and Dental University
| | - Naokata Sumitomo
- Department of Pediatric Cardiology, Saitama Medical University International Medical Center
| | - Naohiko Takahashi
- Department of Cardiology and Clinical Examination, Faculty of Medicine, Oita University
| | - Shinichi Niwano
- Department of Cardiovascular Medicine, Kitasato University School of Medicine
| | | | | | - Tetsushi Furukawa
- Department of Bio-information Pharmacology, Medical Research Institute, Tokyo Medical and Dental University
| | - Haruo Honjo
- Research Institute of Environmental Medicine, Nagoya University
| | - Toru Maruyama
- Department of Hematology, Oncology and Cardiovascular Medicine, Kyushu University Hospital
| | - Yuji Murakawa
- The 4th Department of Internal Medicine, Teikyo University School of Medicine, Mizonokuchi Hospital
| | - Masahiro Yasaka
- Department of Cerebrovascular Medicine and Neurology, Clinical Research Institute, National Hospital Organization Kyushu Medical Center
| | - Eiichi Watanabe
- Department of Cardiology, Fujita Health University School of Medicine
| | - Takeshi Aiba
- Department of Cardiovascular Medicine, National Cerebral and Cardiovascular Center
| | - Mari Amino
- Department of Cardiovascular Medicine, Tokai University School of Medicine
| | - Hideki Itoh
- Division of Patient Safety, Hiroshima University Hospital
| | - Hisashi Ogawa
- Department of Cardiology, National Hospital Organisation Kyoto Medical Center
| | - Yasuo Okumura
- Division of Cardiology, Department of Medicine, Nihon University School of Medicine
| | - Chizuko Aoki-Kamiya
- Department of Obstetrics and Gynecology, National Cerebral and Cardiovascular Center
| | - Jun Kishihara
- Department of Cardiovascular Medicine, Kitasato University School of Medicine
| | - Eitaro Kodani
- Department of Cardiovascular Medicine, Nippon Medical School Tama Nagayama Hospital
| | - Takashi Komatsu
- Division of Cardiology, Department of Internal Medicine, Iwate Medical University School of Medicine
| | | | | | - Tsuyoshi Shiga
- Department of Clinical Pharmacology and Therapeutics, The Jikei University School of Medicine
| | - Tetsuji Shinohara
- Department of Cardiology and Clinical Examination, Faculty of Medicine, Oita University
| | - Atsushi Suzuki
- Department of Cardiology, Tokyo Women's Medical University
| | - Shinya Suzuki
- Department of Cardiovascular Medicine, The Cardiovascular Institute
| | - Yukio Sekiguchi
- Department of Cardiology, National Hospital Organization Kasumigaura Medical Center
| | - Satoshi Nagase
- Department of Cardiovascular Medicine, National Cerebral and Cardiovascular Center
| | - Noriyuki Hayami
- Department of Fourth Internal Medicine, Teikyo University Mizonokuchi Hospital
| | | | - Tadashi Fujino
- Department of Cardiovascular Medicine, Toho University, Faculty of Medicine
| | - Takeru Makiyama
- Department of Cardiovascular Medicine, Graduate School of Medicine, Kyoto University
| | - Mitsunori Maruyama
- Department of Cardiovascular Medicine, Nippon Medical School Musashi Kosugi Hospital
| | - Junichiro Miake
- Department of Pharmacology, Tottori University Faculty of Medicine
| | - Shota Muraji
- Department of Pediatric Cardiology, Saitama Medical University International Medical Center
| | | | - Norishige Morita
- Division of Cardiology, Department of Medicine, Tokai University Hachioji Hospital
| | - Hisashi Yokoshiki
- Department of Cardiovascular Medicine, Sapporo City General Hospital
| | - Koichiro Yoshioka
- Division of Cardiology, Department of Internal Medicine, Tokai University School of Medicine
| | - Kenji Yodogawa
- Department of Cardiovascular Medicine, Nippon Medical School
| | | | - Ken Okumura
- Division of Cardiology, Saiseikai Kumamoto Hospital Cardiovascular Center
| | - Takeshi Kimura
- Department of Cardiovascular Medicine, Graduate School of Medicine, Kyoto University
| | - Hiroyuki Tsutsui
- Department of Cardiovascular Medicine, Faculty of Medical Sciences, Kyushu University
| | - Wataru Shimizu
- Department of Cardiovascular Medicine, Nippon Medical School
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19
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Raleigh JS, Mayhew PD, Visser LC, Milovancev M, Kuntz CA, Formaggini L, Chiu HC, Skinner OT, Naiman JH, Oblak ML, McAnulty JF, Hoffman CL, Brückner M, Singh A. The development of ventricular fibrillation as a complication of pericardiectomy in 16 dogs. Vet Surg 2022; 51:611-619. [PMID: 35257394 DOI: 10.1111/vsu.13795] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 01/18/2022] [Accepted: 02/10/2022] [Indexed: 11/28/2022]
Abstract
OBJECTIVE To describe the clinical characteristics, perioperative protocols, and outcomes in dogs diagnosed with ventricular fibrillation (VF) while undergoing pericardiectomy. STUDY DESIGN Retrospective, multi-institutional study. ANIMALS Sixteen client-owned dogs. METHODS Cases were accrued through a listserve request posted to 3 subspecialty veterinary societies. Dogs were included if they developed VF during a pericardiectomy performed through an open or thoracoscopic approach. Data collected included signalment, history and physical examination, surgical approach, histopathology, treatment, and outcome. RESULTS Indications for pericardiectomy included idiopathic chylothorax (n = 7), neoplasia (4), idiopathic pericardial effusion (4), and foreign body granuloma (1). Surgical approaches included thoracoscopy (12), intercostal thoracotomy (3) and median sternotomy (1). Electrosurgical devices were used to complete at least part of the pericardiectomy in 15 of 16 dogs. Ventricular fibrillation appeared to be initiated during electrosurgical use in 8/15 dogs. However, in 5/15 dogs it was not obviously associated with electrosurgical use. In 3/16 dogs the timing of initiation of VF was unclear. In 7/16 dogs, cardiac arrhythmias were noted prior to the development of VF. Fourteen of 16 dogs died from intraoperative VF. CONCLUSION In most dogs ventricular fibrillation was a fatal complication of pericardiectomy. Ventricular fibrillation might be associated with the use of electrosurgical devices and cardiac manipulation during pericardiectomy although a causal link could not be established from the data in this study. CLINICAL SIGNIFICANCE Surgeons must be aware of the risk of VF during pericardial surgery. Electrosurgery might need to be used judiciously during pericardiectomy, particularly in dogs exhibiting cardiac arrythmias.
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Affiliation(s)
- Joseph S Raleigh
- Department of Surgical & Radiological Sciences, University of California-Davis, School of Veterinary Medicine, Davis, California, USA
| | - Philipp D Mayhew
- Department of Surgical & Radiological Sciences, University of California-Davis, School of Veterinary Medicine, Davis, California, USA
| | - Lance C Visser
- Department of Medicine and Epidemiology, University of California-Davis, School of Veterinary Medicine, Davis, California, USA
| | - Milan Milovancev
- Department of Clinical Sciences, Carlson College of Veterinary Medicine, Oregon State University, Corvallis, Oregon, USA
| | - Charles A Kuntz
- Southpaws Specialty Surgery Animals, Moorabbin, Victoria, Australia
| | | | | | - Owen T Skinner
- Department of Veterinary Medicine and Surgery, University of Missouri, Columbia, Missouri, USA
| | - Jaron H Naiman
- Lloyd Veterinary Medical Center, Iowa State University college of Veterinary Medicine, Ames, Iowa, USA
| | - Michelle L Oblak
- Department of Clinical Studies, Ontario Veterinary College, Guelph, Ontario, Canada
| | - Jonathan F McAnulty
- Department of Surgical Sciences, School of Veterinary Medicine, University of Wisconsin, Madison, Wisconsin, USA
| | | | | | - Ameet Singh
- Department of Clinical Studies, Ontario Veterinary College, Guelph, Ontario, Canada
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20
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Aras K, Gams A, Faye R, Brennan J, Goldrick K, Li J, Zhong Y, Chiang CH, Smith EH, Poston MD, Chivers J, Hanna P, Mori S, Ajijola OA, Shivkumar K, Hoover DB, Viventi J, Rogers JA, Bernus O, Efimov IR. Electrophysiology and Arrhythmogenesis in the Human Right Ventricular Outflow Tract. Circ Arrhythm Electrophysiol 2022; 15:e010630. [PMID: 35238622 PMCID: PMC9052172 DOI: 10.1161/circep.121.010630] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Accepted: 02/17/2022] [Indexed: 12/12/2022]
Abstract
BACKGROUND Right ventricular outflow tract (RVOT) is a common source of ventricular tachycardia, which often requires ablation. However, the mechanisms underlying the RVOT's unique arrhythmia susceptibility remain poorly understood due to lack of detailed electrophysiological and molecular studies of the human RVOT. METHODS We conducted optical mapping studies in 16 nondiseased donor human RVOT preparations subjected to pharmacologically induced adrenergic and cholinergic stimulation to evaluate susceptibility to arrhythmias and characterize arrhythmia dynamics. RESULTS We found that under control conditions, RVOT has shorter action potential duration at 80% repolarization relative to the right ventricular apical region. Treatment with isoproterenol (100 nM) shortened action potential duration at 80% repolarization and increased incidence of premature ventricular contractions (P=0.003), whereas acetylcholine (100 μM) stimulation alone had no effect on action potential duration at 80% repolarization or premature ventricular contractions. However, acetylcholine treatment after isoproterenol stimulation reduced the incidence of premature ventricular contractions (P=0.034) and partially reversed action potential duration at 80% repolarization shortening (P=0.029). Immunolabeling of RVOT (n=4) confirmed the presence of cholinergic marker VAChT (vesicular acetylcholine transporter) in the region. Rapid pacing revealed RVOT susceptibility to both concordant and discordant alternans. Investigation into transmural arrhythmia dynamics showed that arrhythmia wave fronts and phase singularities (rotors) were relatively more organized in the endocardium than in the epicardium (P=0.006). Moreover, there was a weak but positive spatiotemporal autocorrelation between epicardial and endocardial arrhythmic wave fronts and rotors. Transcriptome analysis (n=10 hearts) suggests a trend that MAPK (mitogen-activated protein kinase) signaling, calcium signaling, and cGMP-PKG (protein kinase G) signaling are among the pathways that may be enriched in the male RVOT, whereas pathways of neurodegeneration may be enriched in the female RVOT. CONCLUSIONS Human RVOT electrophysiology is characterized by shorter action potential duration relative to the right ventricular apical region. Cholinergic right ventricular stimulation attenuates the arrhythmogenic effects of adrenergic stimulation, including increase in frequency of premature ventricular contractions and shortening of wavelength. Right ventricular arrhythmia is characterized by positive spatial-temporal autocorrelation between epicardial-endocardial arrhythmic wave fronts and rotors that are relatively more organized in the endocardium.
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Affiliation(s)
- Kedar Aras
- Department of Biomedical Engineering, the George Washington University, Washington, DC
- Department of Materials Science and Engineering, Ohio State University, Columbus, OH
| | - Anna Gams
- Department of Biomedical Engineering, the George Washington University, Washington, DC
| | - Rokhaya Faye
- Department of Biomedical Engineering, the George Washington University, Washington, DC
- LIRYC Institute, Bordeaux University, France
| | - Jaclyn Brennan
- Department of Biomedical Engineering, the George Washington University, Washington, DC
| | - Katherine Goldrick
- Department of Biomedical Engineering, the George Washington University, Washington, DC
| | - Jinghua Li
- Department of Biomedical Engineering, Northwestern University, Evanston, IL
- Department of Materials Science and Engineering, Ohio State University, Columbus, OH
| | - Yishan Zhong
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, IL
| | - Chia-Han Chiang
- Department of Biomedical Engineering, Duke University, Durham, NC
| | - Elizabeth H. Smith
- Department of Biomedical Sciences, East Tennessee State University, Johnson City, TN
| | - Megan D. Poston
- Department of Biomedical Sciences, East Tennessee State University, Johnson City, TN
| | - Jacqueline Chivers
- Department of Biomedical Sciences, East Tennessee State University, Johnson City, TN
| | - Peter Hanna
- UCLA Cardiac Arrhythmia Center and Neurocardiology Research Program of Excellence, University of California Los Angeles, Los Angeles, CA
| | - Shumpei Mori
- UCLA Cardiac Arrhythmia Center and Neurocardiology Research Program of Excellence, University of California Los Angeles, Los Angeles, CA
| | - Olujimi A. Ajijola
- UCLA Cardiac Arrhythmia Center and Neurocardiology Research Program of Excellence, University of California Los Angeles, Los Angeles, CA
| | - Kalyanam Shivkumar
- UCLA Cardiac Arrhythmia Center and Neurocardiology Research Program of Excellence, University of California Los Angeles, Los Angeles, CA
| | - Donald B. Hoover
- Department of Biomedical Sciences, East Tennessee State University, Johnson City, TN
| | - Jonathan Viventi
- Department of Biomedical Engineering, Duke University, Durham, NC
| | - John A. Rogers
- Department of Biomedical Engineering, Northwestern University, Evanston, IL
| | | | - Igor R. Efimov
- Department of Biomedical Engineering, the George Washington University, Washington, DC
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21
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Jenkins EV, Dharmaprani D, Schopp M, Quah JX, Tiver K, Mitchell L, Pope K, Ganesan AN. Understanding the origins of the basic equations of statistical fibrillatory dynamics. CHAOS (WOODBURY, N.Y.) 2022; 32:032101. [PMID: 35364849 DOI: 10.1063/5.0062095] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 02/07/2022] [Indexed: 06/14/2023]
Abstract
The mechanisms governing cardiac fibrillation remain unclear; however, it most likely represents a form of spatiotemporal chaos with conservative system dynamics. Renewal theory has recently been suggested as a statistical formulation with governing equations to quantify the formation and destruction of wavelets and rotors in fibrillatory dynamics. In this perspective Review, we aim to explain the origin of the renewal theory paradigm in spatiotemporal chaos. The ergodic nature of pattern formation in spatiotemporal chaos is demonstrated through the use of three chaotic systems: two classical systems and a simulation of cardiac fibrillation. The logistic map and the baker's transformation are used to demonstrate how the apparently random appearance of patterns in classical chaotic systems has macroscopic parameters that are predictable in a statistical sense. We demonstrate that the renewal theory approach developed for cardiac fibrillation statistically predicts pattern formation in these classical chaotic systems. Renewal theory provides governing equations to describe the apparently random formation and destruction of wavelets and rotors in atrial fibrillation (AF) and ventricular fibrillation (VF). This statistical framework for fibrillatory dynamics provides a holistic understanding of observed rotor and wavelet dynamics and is of conceptual significance in informing the clinical and mechanistic research of the rotor and multiple-wavelet mechanisms of AF and VF.
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Affiliation(s)
- Evan V Jenkins
- College of Medicine and Public Health, Flinders University, Adelaide 5042, Australia
| | - Dhani Dharmaprani
- College of Medicine and Public Health, Flinders University, Adelaide 5042, Australia
| | - Madeline Schopp
- College of Science and Engineering, Flinders University, Adelaide 5042, Australia
| | - Jing Xian Quah
- College of Medicine and Public Health, Flinders University, Adelaide 5042, Australia
| | - Kathryn Tiver
- Department of Cardiovascular Medicine, Flinders Medical Centre, Adelaide 5042, Australia
| | - Lewis Mitchell
- School of Mathematical Sciences, University of Adelaide, Adelaide 5005, Australia
| | - Kenneth Pope
- College of Science and Engineering, Flinders University, Adelaide 5042, Australia
| | - Anand N Ganesan
- College of Medicine and Public Health, Flinders University, Adelaide 5042, Australia
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OUP accepted manuscript. Eur Heart J 2022; 43:1248-1250. [DOI: 10.1093/eurheartj/ehab912] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Rappel WJ. Intermittent trapping of spiral waves in a cardiac model. Phys Rev E 2022; 105:014404. [PMID: 35193211 PMCID: PMC9020409 DOI: 10.1103/physreve.105.014404] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Accepted: 12/21/2021] [Indexed: 01/21/2023]
Abstract
Spiral waves are found in many excitable systems and are thought to play a role in the incoherent electrical activation that underlies cardiac arrhythmias. It is well-known that spiral waves can be permanently trapped by local heterogeneities. In this paper, we demonstrate that spiral waves can also be intermittently trapped by such heterogeneities. Using simulations of a cardiac model in two dimensions, we show that a tissue heterogeneity of sufficient strength or size can result in a spiral wave that is trapped for a few rotations, after which it dislodges and meanders away from the heterogeneity. We also show that these results can be captured by a particle model in which the particle represents the spiral wave tip. For both models, we construct a phase diagram which quantifies which parameter combinations of heterogeneity size and strength result in permanent, intermittent, or no trapping. Our results are consistent with clinical observations in patients with atrial fibrillation that showed that spiral wave reentry can be intermittent.
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A governing equation for rotor and wavelet number in human clinical ventricular fibrillation: Implications for sudden cardiac death. Heart Rhythm 2021; 19:295-305. [PMID: 34662707 DOI: 10.1016/j.hrthm.2021.10.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2021] [Revised: 09/29/2021] [Accepted: 10/08/2021] [Indexed: 11/21/2022]
Abstract
BACKGROUND Ventricular fibrillation (VF) is characterized by multiple wavelets and rotors. No equation to predict the number of rotors and wavelets observed during fibrillation has been validated in human VF. OBJECTIVE The purpose of this study was to test the hypothesis that a single equation derived from a Markov M/M/∞ birth-death process could predict the number of rotors and wavelets occurring in human clinical VF. METHODS Epicardial induced VF (256-electrode) recordings obtained from patients undergoing cardiac surgery were studied (12 patients; 62 epochs). Rate constants for phase singularity (PS) (which occur at the pivot points of rotors) and wavefront (WF) formation and destruction were derived by fitting distributions to PS and WF interformation and lifetimes. These rate constants were combined in an M/M/∞ governing equation to predict the number of PS and WF in VF episodes. Observed distributions were compared to those predicted by the M/M/∞ equation. RESULTS The M/M/∞ equation accurately predicted average PS and WF number and population distribution, demonstrated in all epochs. Self-terminating episodes of VF were distinguished from VF episodes requiring termination by a trend toward slower PS destruction, slower rates of PS formation, and a slower mixing rate of the VF process, indicated by larger values of the second largest eigenvalue modulus of the M/M/∞ birth-death matrix. The longest-lasting PS (associated with rotors) had shorter interactivation time intervals compared to shorter-lasting PS lasting <150 ms (∼1 PS rotation in human VF). CONCLUSION The M/M/∞ equation explains the number of wavelets and rotors observed, supporting a paradigm of VF based on statistical fibrillatory dynamics.
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Akbulut T, Saylik F, Sipal A. The association of galectin-3 level with ventricular arrhythmias and left ventricular strain in heart failure patients with implantable cardioverter defibrillator. Acta Cardiol 2021; 77:609-615. [PMID: 34427170 DOI: 10.1080/00015385.2021.1968155] [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: 10/20/2022]
Abstract
BACKGROUND Ventricular arrhythmias are life-threatening complications of heart failure (HF). Galectin-3, an indicator of fibrosis, is associated with incident HF and was found to be related to poor prognosis in these patients. We aimed to investigate the association of galectin-3 level with left ventricular (LV) arrhythmias in HF. METHODS A total of 92 non-ischaemic HF patients who had implantable cardioverter-defibrillator were included in this study. Patients were divided into two groups based on the galectin-3 level. Ventricular arrhythmic events and LV strain indices were compared between the two groups. Negative binomial regression was used to detect the independent predictors of total arrhythmic events in HF patients. RESULTS The median age was 65 (54-71) in the high galectin-3 group (HGAL) and 62 (52-68) in the low galectin-3 group (LGAL). Ventricular arrhythmic events were more frequent in HGAL than in LGAL, including non-sustained ventricular tachycardia (VTnon), sustained-VT (VTs), and ventricular fibrillation (VF) (p < 0.0001, p = 0.002, and p = 0.026, respectively). There were no statistically significant differences between HGAL and LGAL in terms of LV strain measurements. Galectin-3 level was positively significantly correlated with total arrhythmic events (r = 0.58, p < 0.001), but no correlation was found between galectin-3 and LV global longitudinal strain (r = 0.15, p = 0.16). Galectin-3 was an independent predictor of total ventricular arrhythmic events in HF patients (p < 0.0001). CONCLUSION VTnon, VTs, and VF events were higher in HGAL compared to LGAL. Galectin-3 was an independent predictor of total ventricular arrhythmic events in HF patients and might be used to detect high-risk HF patients for arrhythmic events.
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Affiliation(s)
- Tayyar Akbulut
- Department of Cardiology, Van Education and Research Hospital, Van, Turkey
| | - Faysal Saylik
- Department of Cardiology, Van Education and Research Hospital, Van, Turkey
| | - Abdulcabbar Sipal
- Department of Cardiology, Van Education and Research Hospital, Van, Turkey
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Abstract
Conduction disorders and arrhythmias remain difficult to treat and are increasingly prevalent owing to the increasing age and body mass of the general population, because both are risk factors for arrhythmia. Many of the underlying conditions that give rise to arrhythmia - including atrial fibrillation and ventricular arrhythmia, which frequently occur in patients with acute myocardial ischaemia or heart failure - can have an inflammatory component. In the past, inflammation was viewed mostly as an epiphenomenon associated with arrhythmia; however, the recently discovered inflammatory and non-canonical functions of cardiac immune cells indicate that leukocytes can be arrhythmogenic either by altering tissue composition or by interacting with cardiomyocytes; for example, by changing their phenotype or perhaps even by directly interfering with conduction. In this Review, we discuss the electrophysiological properties of leukocytes and how these cells relate to conduction in the heart. Given the thematic parallels, we also summarize the interactions between immune cells and neural systems that influence information transfer, extrapolating findings from the field of neuroscience to the heart and defining common themes. We aim to bridge the knowledge gap between electrophysiology and immunology, to promote conceptual connections between these two fields and to explore promising opportunities for future research.
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Wan R, Huang Y, Wu X. Detection of Ventricular Fibrillation Based on Ballistocardiography by Constructing an Effective Feature Set. SENSORS (BASEL, SWITZERLAND) 2021; 21:3524. [PMID: 34069374 PMCID: PMC8158750 DOI: 10.3390/s21103524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/11/2021] [Revised: 05/15/2021] [Accepted: 05/17/2021] [Indexed: 11/17/2022]
Abstract
Ventricular fibrillation (VF) is a type of fatal arrhythmia that can cause sudden death within minutes. The study of a VF detection algorithm has important clinical significance. This study aimed to develop an algorithm for the automatic detection of VF based on the acquisition of cardiac mechanical activity-related signals, namely ballistocardiography (BCG), by non-contact sensors. BCG signals, including VF, sinus rhythm, and motion artifacts, were collected through electric defibrillation experiments in pigs. Through autocorrelation and S transform, the time-frequency graph with obvious information of cardiac rhythmic activity was obtained, and a feature set of 13 elements was constructed for each 7 s segment after statistical analysis and hierarchical clustering. Then, the random forest classifier was used to classify VF and non-VF, and two paradigms of intra-patient and inter-patient were used to evaluate the performance. The results showed that the sensitivity and specificity were 0.965 and 0.958 under 10-fold cross-validation, and they were 0.947 and 0.946 under leave-one-subject-out cross-validation. In conclusion, the proposed algorithm combining feature extraction and machine learning can effectively detect VF in BCG, laying a foundation for the development of long-term self-cardiac monitoring at home and a VF real-time detection and alarm system.
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Affiliation(s)
- Rongru Wan
- Center for Biomedical Engineering, School of Information Science and Technology, Fudan University, Shanghai 200433, China; (R.W.); (Y.H.)
| | - Yanqi Huang
- Center for Biomedical Engineering, School of Information Science and Technology, Fudan University, Shanghai 200433, China; (R.W.); (Y.H.)
| | - Xiaomei Wu
- Center for Biomedical Engineering, School of Information Science and Technology, Fudan University, Shanghai 200433, China; (R.W.); (Y.H.)
- Key Laboratory of Medical Imaging Computing and Computer Assisted Intervention (MICCAI) of Shanghai, Fudan University, Shanghai 200032, China
- Shanghai Engineering Research Center of Assistive Devices, Shanghai 200093, China
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Lyu J, Huang J, Wu J, Yu T, Wei X, Lei Q. Lack of Macrophage Migration Inhibitory Factor Reduces Susceptibility to Ventricular Arrhythmias During the Acute Phase of Myocardial Infarction. J Inflamm Res 2021; 14:1297-1311. [PMID: 33854357 PMCID: PMC8039209 DOI: 10.2147/jir.s304553] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Accepted: 03/16/2021] [Indexed: 12/29/2022] Open
Abstract
Background Macrophages are involved in inflammatory responses and play a crucial role in aggravating ventricular arrhythmias (VAs) after myocardial infarction (MI). Macrophage migration inhibitory factor (MIF) participates in inflammatory responses during acute MI. In the present study, we hypothesized that knockout (KO) of MIF may prevent VAs during the acute phase of MI by inhibiting macrophage-derived pro-inflammatory mediators. Methods and Results We demonstrated that MIF-KO mice in a mouse model of MI exhibited a significant decrease in susceptibility to VAs both in vivo (84.6% vs 40.7%, P < 0.05) and ex vivo (86.7% vs 40.0%, P < 0.05) at day 3 after MI compared with that in wild-type (WT) mice. Both WT and MIF-KO mice presented similar left ventricular contractility, peri-infarct myocardial fibrosis and sympathetic reinnervation, and circulating and local norepinephrine levels during the acute phase of MI. Meanwhile, MIF-KO mice had inhibited macrophage aggregation, alleviated connexin 43 (Cx43) redistribution, and reduced level of pro-inflammatory mediators, including tumor necrosis factor-α and interleukin-1β (P < 0.05) at day 3 after MI. The differences in susceptibility to VAs, expression of pro-inflammatory mediators, and Cx43 redistribution after MI between WT and MIF-KO mice disappeared by macrophage depletion with clodronate liposomes in both groups. Furthermore, the pro-inflammatory activity of cultured peritoneal macrophages was inhibited by MIF deficiency and recovered with replenishment of exogenous MIF in vitro. Conclusion In conclusion, we found that lack of MIF reduced the susceptibility to VAs in mouse heart during the acute phase of MI by inhibiting pro-inflammatory activity of macrophages and improving gap-junction and electrical remodeling.
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Affiliation(s)
- Juanjuan Lyu
- Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, 610041, People's Republic of China
| | - Jia Huang
- Department of Anesthesiology, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, 610072, People's Republic of China.,Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital, Chengdu, 610072, People's Republic of China
| | - Jin Wu
- Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, 610041, People's Republic of China
| | - Tao Yu
- Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital, Chengdu, 610072, People's Republic of China.,Department of Cardiac Surgery, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, 610072, People's Republic of China
| | - Xinchuan Wei
- Department of Anesthesiology, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, 610072, People's Republic of China.,Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital, Chengdu, 610072, People's Republic of China
| | - Qian Lei
- Department of Anesthesiology, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, 610072, People's Republic of China.,Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital, Chengdu, 610072, People's Republic of China
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Tomii N, Yamazaki M, Ashihara T, Nakazawa K, Shibata N, Honjo H, Sakuma I. Spatial phase discontinuity at the center of moving cardiac spiral waves. Comput Biol Med 2021; 130:104217. [PMID: 33516959 DOI: 10.1016/j.compbiomed.2021.104217] [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: 09/09/2020] [Revised: 01/10/2021] [Accepted: 01/10/2021] [Indexed: 11/30/2022]
Abstract
BACKGROUND Precise analysis of cardiac spiral wave (SW) dynamics is essential for effective arrhythmia treatment. Although the phase singularity (PS) point in the spatial phase map has been used to determine the cardiac SW center for decades, quantitative detection algorithms that assume PS as a point fail to trace complex and rapid PS dynamics. Through a detailed analysis of numerical simulations, we examined our hypothesis that a boundary of spatial phase discontinuity induced by a focal conduction block exists around the moving SW center in the phase map. METHOD In a numerical simulation model of a 2D cardiac sheet, three different types of SWs (short wavelength; long wavelength; and low excitability) were induced by regulating ion channels. Discontinuities of all boundaries among adjacent cells at each instance were evaluated by calculating the phase bipolarity (PB). The total amount of phase transition (PTA) in each cell during the study period was evaluated. RESULTS Pivoting, drifting, and shifting SWs were observed in the short-wavelength, low-excitability, and long-wavelength models, respectively. For both the drifting and shifting cases, long high-PB edges were observed on the SW trajectories. In all cases, the conduction block (CB) was observed at the same boundaries. These were also identical to the boundaries in the PTA maps. CONCLUSIONS The analysis of the simulations revealed that the conduction block at the center of a moving SW induces discontinuous boundaries in spatial phase maps that represent a more appropriate model of the SW center than the PS point.
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Affiliation(s)
- Naoki Tomii
- Faculty of Medicine, The University of Tokyo, 7 -3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan.
| | - Masatoshi Yamazaki
- School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan
| | - Takashi Ashihara
- Shiga University of Medical Science, Setatsukinowa-cho, Otsu-city, Shiga, 520-2192, Japan
| | - Kazuo Nakazawa
- Morinomiya University of Medical Sciences, 1-26-16 Minami-Kohoku, Suminoe-ku, Osaka City, 559-8611, Japan
| | - Nitaro Shibata
- Shinjuku Mitsui Building Clinic, 2-1-1 Nishi-Shinjuku, Shinjuku-ku, Tokyo, 163-0404, Japan
| | - Haruo Honjo
- Research Institute of Environmental Medicine, Nagoya University, Furo-cho Chikusa-ku, Nagoya City, Aichi, 464-8601, Japan
| | - Ichiro Sakuma
- School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan
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Franiak-Pietryga I, Ziemba B, Sikorska H, Jander M, Appelhans D, Bryszewska M, Borowiec M. Neurotoxicity of poly(propylene imine) glycodendrimers. Drug Chem Toxicol 2020; 45:1484-1492. [DOI: 10.1080/01480545.2020.1843472] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Ida Franiak-Pietryga
- Department of Clinical and Laboratory Genetics, Medical University of Lodz, Lodz, Poland
- GeneaMed LTD, Lodz, Poland
- University of California San Diego, Moores Cancer Center, San Diego, CA, USA
| | - Barbara Ziemba
- Department of Clinical and Laboratory Genetics, Medical University of Lodz, Lodz, Poland
- GeneaMed LTD, Lodz, Poland
| | | | | | | | - Maria Bryszewska
- Department of General Biophysics, Faculty of Biology and Environmental Protection, University of Lodz, Lodz, Poland
| | - Maciej Borowiec
- Department of Clinical and Laboratory Genetics, Medical University of Lodz, Lodz, Poland
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Lai D, Zhang Y, Zhang X. Single Lead ECG-based Ventricular Repolarization Classification for Early Identification of Unexpected Ventricular Fibrillation .. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2020; 2020:5567-5570. [PMID: 33019239 DOI: 10.1109/embc44109.2020.9176355] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Malignant ventricular arrhythmia (especially ventricular fibrillation (VF)) is the main reason which causes sudden cardiac death (SCD). This paper presents an automatic SCD-patient classifier we developed to identify patients with unexpected VF using 60-minutes continuous single-lead electrocardiograms (ECG) signals before that. Patients are classified as having SCD if the majority of their recorded ventricular repolarization (VR) is recognized as characteristic of unexpected VF. Thus, the classifier's underlying task is to recognize individual VR delineated from single-lead ECG signals as SCD VR, where VR from non-SCD patients are used as controls. With the reported clinical practices of SCD, we extracted five morphological and temporal features (both commonly used and newly developed ones) from ECG signals for VR classification. To evaluate classification performance, we trained and tested k nearest neighbor classifier, a decision tree classifier, and a Naïve Bayes classifier using five-fold cross validation on 36 one-hour ECG signals (18 from patients at risk of SCD and 18 from control people). We compared the performance of these three classifiers, and the patient-classification sensitivity is approximately 98.02-99.51%. Moreover, the k nearest neighbor with a higher accuracy (98.89%) and specificity (98.27%) performed better than the other two. Importantly, the results show obvious superiorities of performance over that in the same duration and of usefulness over several minutes given by related works.Clinical Relevance- This could be integrated into a real-time, long-term out-of-hospital SCD predictor to improve the warning veracity and bring forward the warning time, especially for patients with implantable cardiac defibrillators or pacemakers, etc..
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Muscular Thin Films for Label-Free Mapping of Excitation Propagation in Cardiac Tissue. Ann Biomed Eng 2020; 48:2425-2437. [PMID: 32314299 DOI: 10.1007/s10439-020-02513-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Accepted: 04/11/2020] [Indexed: 01/10/2023]
Abstract
Muscular thin films (MTFs), have already found a variety of applications in cardiac tissue engineering and in building of lab-on-a-chip systems. Here we present a novel approach to label-free mapping of excitation waves in the cardiomyocyte cell cultures with the use of MTFs. Neonatal rat ventricular cardiomyocytes were cultured on polydimethylsiloxane (PDMS) thin films and observed by means of off-axis illumination. Inflexions of the membrane created by the contraction of cardiomyocytes led to formation of patterns of bright and dark areas on the surface of the membrane. These patterns were recorded and analyzed for the monitoring of the contraction propagation. The method was compared with a standard optical mapping technique based on the use of a Ca2+-sensitive fluorescent dye. A good consistency of the results obtained by these two methods was demonstrated. The proposed method is non-toxic and might be of particular interest for the purpose of continuous monitoring in test systems based on human induced pluripotent stem cells.
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Meo M, Denis A, Sacher F, Duchâteau J, Cheniti G, Puyo S, Bear L, Jaïs P, Hocini M, Haïssaguerre M, Bernus O, Dubois R. Insights Into the Spatiotemporal Patterns of Complexity of Ventricular Fibrillation by Multilead Analysis of Body Surface Potential Maps. Front Physiol 2020; 11:554838. [PMID: 33071814 PMCID: PMC7538856 DOI: 10.3389/fphys.2020.554838] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Accepted: 08/12/2020] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Ventricular fibrillation (VF) is the main cause of sudden cardiac death, but its mechanisms are still unclear. We propose a noninvasive approach to describe the progression of VF complexity from body surface potential maps (BSPMs). METHODS We mapped 252 VF episodes (16 ± 10 s) with a 252-electrode vest in 110 patients (89 male, 47 ± 18 years): 50 terminated spontaneously, otherwise by electrical cardioversion (DCC). Changes in complexity were assessed between the onset ("VF start") and the end ("VF end") of VF by the nondipolar component index (N D I B S P M ), measuring the fraction of energy nonpreserved by an equivalent 3D dipole from BSPMs. Higher NDI reflected lower VF organization. We also examined other standard body surface markers of VF dynamics, including fibrillatory wave amplitude (A BSPM ), surface cycle length (BsCL BSPM ) and Shannon entropy (S h E n B S P M ). Differences between patients with and without structural heart diseases (SHD, 32 vs. NSHD, 78) were also tested at those stages. Electrocardiographic features were validated with simultaneous endocardium cycle length (CL) in a subset of 30 patients. RESULTS All BSPM markers measure an increase in electrical complexity during VF (p < 0.0001), and more significantly in NSHD patients. Complexity is significantly higher at the end of sustained VF episodes requiring DCC. Intraepisode intracardiac CL shortening (VF start 197 ± 24 vs. VF end 169 ± 20 ms; p < 0.0001) correlates with an increase in NDI, and decline in surface CL, f-wave amplitude, and entropy (p < 0.0001). In SHD patients VF is initially more complex than in NSHD patients (N D I B S P M , p = 0.0007; S h E n B S P M , p < 0.0001), with moderately slower (BsCL BSPM , p = 0.06), low-amplitude f-waves (A BSPM , p < 0.0001). In this population, lower NDI (p = 0.004) and slower surface CL (p = 0.008) at early stage of VF predict self-termination. In the NSHD group, a more abrupt increase in VF complexity is quantified by all BSPM parameters during sustained VF (p < 0.0001), whereas arrhythmia evolution is stable during self-terminating episodes, hinting at additional mechanisms driving VF dynamics. CONCLUSION Multilead BSPM analysis underlines distinct degrees of VF complexity based on substrate characteristics.
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Affiliation(s)
- Marianna Meo
- Institute of Electrophysiology and Heart Modeling (IHU Liryc), Foundation Bordeaux University, Bordeaux, France
- Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, University of Bordeaux, Bordeaux, France
- Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, Institut National de la Santé et de la Recherche Médicale, Bordeaux, France
| | - Arnaud Denis
- Institute of Electrophysiology and Heart Modeling (IHU Liryc), Foundation Bordeaux University, Bordeaux, France
- Electrophysiology and Ablation Unit, Bordeaux University Hospital, Bordeaux, France
| | - Frédéric Sacher
- Institute of Electrophysiology and Heart Modeling (IHU Liryc), Foundation Bordeaux University, Bordeaux, France
- Electrophysiology and Ablation Unit, Bordeaux University Hospital, Bordeaux, France
| | - Josselin Duchâteau
- Institute of Electrophysiology and Heart Modeling (IHU Liryc), Foundation Bordeaux University, Bordeaux, France
- Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, University of Bordeaux, Bordeaux, France
- Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, Institut National de la Santé et de la Recherche Médicale, Bordeaux, France
- Electrophysiology and Ablation Unit, Bordeaux University Hospital, Bordeaux, France
| | - Ghassen Cheniti
- Institute of Electrophysiology and Heart Modeling (IHU Liryc), Foundation Bordeaux University, Bordeaux, France
- Electrophysiology and Ablation Unit, Bordeaux University Hospital, Bordeaux, France
| | - Stéphane Puyo
- Institute of Electrophysiology and Heart Modeling (IHU Liryc), Foundation Bordeaux University, Bordeaux, France
- Electrophysiology and Ablation Unit, Bordeaux University Hospital, Bordeaux, France
| | - Laura Bear
- Institute of Electrophysiology and Heart Modeling (IHU Liryc), Foundation Bordeaux University, Bordeaux, France
- Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, University of Bordeaux, Bordeaux, France
- Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, Institut National de la Santé et de la Recherche Médicale, Bordeaux, France
| | - Pierre Jaïs
- Institute of Electrophysiology and Heart Modeling (IHU Liryc), Foundation Bordeaux University, Bordeaux, France
- Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, University of Bordeaux, Bordeaux, France
- Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, Institut National de la Santé et de la Recherche Médicale, Bordeaux, France
- Electrophysiology and Ablation Unit, Bordeaux University Hospital, Bordeaux, France
| | - Mélèze Hocini
- Institute of Electrophysiology and Heart Modeling (IHU Liryc), Foundation Bordeaux University, Bordeaux, France
- Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, University of Bordeaux, Bordeaux, France
- Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, Institut National de la Santé et de la Recherche Médicale, Bordeaux, France
- Electrophysiology and Ablation Unit, Bordeaux University Hospital, Bordeaux, France
| | - Michel Haïssaguerre
- Institute of Electrophysiology and Heart Modeling (IHU Liryc), Foundation Bordeaux University, Bordeaux, France
- Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, University of Bordeaux, Bordeaux, France
- Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, Institut National de la Santé et de la Recherche Médicale, Bordeaux, France
- Electrophysiology and Ablation Unit, Bordeaux University Hospital, Bordeaux, France
| | - Olivier Bernus
- Institute of Electrophysiology and Heart Modeling (IHU Liryc), Foundation Bordeaux University, Bordeaux, France
- Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, University of Bordeaux, Bordeaux, France
- Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, Institut National de la Santé et de la Recherche Médicale, Bordeaux, France
| | - Rémi Dubois
- Institute of Electrophysiology and Heart Modeling (IHU Liryc), Foundation Bordeaux University, Bordeaux, France
- Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, University of Bordeaux, Bordeaux, France
- Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, Institut National de la Santé et de la Recherche Médicale, Bordeaux, France
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Kharkovskaya EE, Drugova OV, Osipov GV, Mukhina IV. Effect of Mechanical Stretching of the Right Atrium of Isolated Rat Heart on Dispersion of Repolarization before Fibrillation. Bull Exp Biol Med 2020; 169:438-440. [PMID: 32889569 DOI: 10.1007/s10517-020-04904-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Indexed: 11/27/2022]
Abstract
The multi-electrode mapping method was used to analyze electrical activity of isolated rat heart under conditions of standard perfusion, pharmacological stimulation of fibrillation, and mechanical stretching of the right atrium both under normal conditions and before cardiac fibrillation. It was shown that stretching of the right atrium prevented the increase of repolarization dispersion and latency of the electrical signal in the myocardium that were observed before cardiac fibrillation.
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Affiliation(s)
- E E Kharkovskaya
- National Research N. I. Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod, Russia.
| | - O V Drugova
- National Research N. I. Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod, Russia
| | - G V Osipov
- National Research N. I. Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod, Russia
| | - I V Mukhina
- National Research N. I. Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod, Russia
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35
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Lyu J, Wang M, Kang X, Xu H, Cao Z, Yu T, Huang K, Wu J, Wei X, Lei Q. Macrophage-mediated regulation of catecholamines in sympathetic neural remodeling after myocardial infarction. Basic Res Cardiol 2020; 115:56. [DOI: 10.1007/s00395-020-0813-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Accepted: 07/20/2020] [Indexed: 12/17/2022]
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36
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Singh Y, Shakyawar D, Hu W. Non-ischemic endocardial scar geometric remodeling toward topological machine learning. Proc Inst Mech Eng H 2020; 234:1029-1035. [DOI: 10.1177/0954411920937221] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Scar tissues have been important factors in determining the progression of myocardial diseases and the development of adverse cardiac failure outcomes. Accurate segmentation of the scar tissues can be helpful to the clinicians for risk prediction and better evaluation of cardiovascular diseases. Our goal is to apply topology data analysis toward machine learning algorithms to confirm the geometry of scar tissue, in addition to gaining better visualization and quantification of the scar tissue present. We have introduced architecture for integrating geometry in the form of topology toward machine learning. Morphological image processing was carried out to define the regions of the endocardial wall. We implemented convolutional neural networks on delayed enhancement cardiac computed tomography images for the recognition of scar tissue. Segmented two-dimensional images were stacked up to build the geometry of the scar area for visualization purposes. Mathematical calculations were executed for the validation of the scar tissue in addition to performing morphological image processing and marking the scar tissue present on the endocardial wall of the left ventricular. We applied convolutional neural network over convolution and pooling the layers with small sizes; we achieved 89.23% accuracy, 91.11% sensitivity, and 87.75% specificity, and found the dissimilarity distance between the normal endocardial tissue distances to be 9.37. This new concept in this study contributes toward a better understanding of scar structure and transmural variation of the endocardial wall of the left ventricular.
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Affiliation(s)
- Yashbir Singh
- Biomedical Engineering, Chung Yuan Christian University, Taoyuan
| | - Deepa Shakyawar
- Biomedical Engineering, Chung Yuan Christian University, Taoyuan
| | - Weichih Hu
- Biomedical Engineering, Chung Yuan Christian University, Taoyuan
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37
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Cardiac Spiral Wave Termination by Linear Regional Cooling Toward the Anatomical Boundary of the Heart. J Med Biol Eng 2020. [DOI: 10.1007/s40846-020-00517-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Abstract
Purpose
We hypothesized that linear regional cooling (LRC) toward the atrio-ventricular groove (AV-G) can move the spiral wave (SW) center to the AV-G effectively and terminate SW. The effectiveness of LRC in ex vivo 2D ventricle rabbit experiments was tested.
Methods
We developed an experimental system to operate LRC and optical mapping simultaneously. To realize simultaneous cooling and optical mapping, a transparent cooling device was developed. LRC for 60 s toward 2D subepicardial ventricular myocardium of Langendorff-perfused rabbit hearts (n = 4) was conducted during constant pacing and persistent ventricular tachyarrhythmias (VTs).
Results
Action potential duration at 90% repolarization (APD90) at the cooling area was prolonged by LRC from 187 to 228 ms. 41% of persistent VTs were terminated by LRC (12/29 cases). Cases where the original SW center moved toward the AV-G were observed via optical mapping. However, there were some cases where VT was not terminated by LRC. When the action potential duration (APD) of VT sustained cases were analyzed, LRC prolonged APD, but the APD prolonged area did not move toward the AV-G in most VT sustained cases
Conclusion
Proper LRC toward the AV-G near the original SW center could move this center toward the AV-G and terminate SW excitation.
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Comparison of Electromechanical Delay during Ventricular Tachycardia and Fibrillation under Different Conductivity Conditions Using Computational Modeling. COMPUTATIONAL AND MATHEMATICAL METHODS IN MEDICINE 2020; 2020:9501985. [PMID: 32300375 PMCID: PMC7146094 DOI: 10.1155/2020/9501985] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Accepted: 02/25/2020] [Indexed: 01/27/2023]
Abstract
Electromechanical delay (EMD) is the time interval between local myocyte depolarization and the onset of myofiber shortening. Previously, researchers measured EMD during sinus rhythm and ectopic pacing in normal and heart failure conditions. However, to our knowledge, there are no reports regarding EMD during another type of rhythms or arrhythmia. The goal of this study was to quantify EMD during sinus rhythm, tachycardia, and ventricular fibrillation conditions. We hypothesized that EMD under sinus rhythm is longer due to isovolumetric contraction which is imprecise during arrhythmia. We used a realistic model of 3D electromechanical ventricles. During sinus rhythm, EMD was measured in the last cycle of cardiac systole under steady conditions. EMD under tachycardia and fibrillation conditions was measured during the entire simulation, resulting in multiple EMD values. We assessed EMD for the following 3 conduction velocities (CVs): 31 cm/s, 51 cm/s, and 69 cm/s. The average EMD during fibrillation condition was the shortest corresponding to 53.45 ms, 55.07 ms, and 50.77 ms, for the CVs of 31 cm/s, 51 cm/s, and 69 cm/s, respectively. The average EMD during tachycardia was 58.61 ms, 58.33 ms, and 52.50 ms for the three CVs. Under sinus rhythm with action potential duration restitution (APDR) slope 0.7, the average EMD was 66.35 ms, 66.41 ms, and 66.60 ms in line with the three CVs. This result supports our hypothesis that EMD under sinus rhythm is longer than that under tachyarrhythmia conditions. In conclusion, this study observed and quantified EMD under tachycardia and ventricular fibrillation conditions. This simulation study has widened our understanding of EMD in 3D ventricles under chaotic conditions.
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Zimik S, Pandit R, Majumder R. Anisotropic shortening in the wavelength of electrical waves promotes onset of electrical turbulence in cardiac tissue: An in silico study. PLoS One 2020; 15:e0230214. [PMID: 32168323 PMCID: PMC7069633 DOI: 10.1371/journal.pone.0230214] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Accepted: 02/24/2020] [Indexed: 12/03/2022] Open
Abstract
Several pathological conditions introduce spatial variations in the electrical properties of cardiac tissue. These variations occur as localized or distributed gradients in ion-channel functionality over extended tissue media. Electrical waves, propagating through such affected tissue, demonstrate distortions, depending on the nature of the ionic gradient in the diseased substrate. If the degree of distortion is large, reentrant activity may develop, in the form of rotating spiral (2d) and scroll (3d) waves of electrical activity. These reentrant waves are associated with the occurrence of lethal cardiac rhythm disorders, known as arrhythmias, such as ventricular tachycardia (VT) and ventricular fibrillation (VF), which are believed to be common precursors of sudden cardiac arrest. By using state-of-the-art mathematical models for generic, and ionically-realistic (human) cardiac tissue, we study the detrimental effects of these ionic gradients on electrical wave propagation. We propose a possible mechanism for the development of instabilities in reentrant wave patterns, in the presence of ionic gradients in cardiac tissue, which may explain how one type of arrhythmia (VT) can degenerate into another (VF). Our proposed mechanism entails anisotropic reduction in the wavelength of the excitation waves because of anisotropic variation in its electrical properties, in particular the action potential duration (APD). We find that the variation in the APD, which we induce by varying ion-channel conductances, imposes a spatial variation in the spiral- or scroll-wave frequency ω. Such gradients in ω induce anisotropic shortening of wavelength of the spiral or scroll arms and eventually leads to instabilitites.
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Affiliation(s)
- Soling Zimik
- Centre for Condensed Matter Theory, Department of Physics, Indian Institute of Science, Bangalore, India
| | - Rahul Pandit
- Centre for Condensed Matter Theory, Department of Physics, Indian Institute of Science, Bangalore, India
| | - Rupamanjari Majumder
- Laboratory for Fluid Physics, Pattern Formation and Biocomplexity, Max Planck Institute for Dynamics and Self-Organization, Göttingen, Germany
- * E-mail:
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40
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Heikhmakhtiar AK, Lee CH, Song KS, Lim KM. Computational prediction of the effect of D172N KCNJ2 mutation on ventricular pumping during sinus rhythm and reentry. Med Biol Eng Comput 2020; 58:977-990. [PMID: 32095980 DOI: 10.1007/s11517-020-02124-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Accepted: 01/07/2020] [Indexed: 01/30/2023]
Abstract
The understanding of cardiac arrhythmia under genetic mutations has grown in interest among researchers. Previous studies focused on the effect of the D172N mutation on electrophysiological behavior. In this study, we analyzed not only the electrophysiological activity but also the mechanical responses during normal sinus rhythm and reentry conditions by using computational modeling. We simulated four different ventricular conditions including normal case of ten Tusscher model 2006 (TTM), wild-type (WT), heterozygous (WT/D172N), and homozygous D172N mutation. The 2D simulation result (in wire-shaped mesh) showed the WT/D172N and D172N mutation shortened the action potential duration by 14%, and by 23%, respectively. The 3D electrophysiological simulation results showed that the electrical wavelength between TTM and WT conditions were identical. Under sinus rhythm condition, the WT/D172N and D172N reduced the pumping efficacy with a lower left ventricle (LV) and aortic pressures, stroke volume, ejection fraction, and cardiac output. Under the reentry conditions, the WT condition has a small probability of reentry. However, in the event of reentry, WT has shown the most severe condition. Furthermore, we found that the position of the rotor or the scroll wave substantially influenced the ventricular pumping efficacy during arrhythmia. If the rotor stays in the LV, it will cause very poor pumping performance. Graphical Abstract A model of a ventricular electromechanical system. This whole model was established to observe the effect of D172N KCNJ2 mutation on ventricular pumping behavior during sinus rhythm and reentry conditions. The model consists of two components; electrical component and mechanical component. The electrophysiological model based on ten Tusscher et al. with the IK1 D172N KCNJ2 mutation, and the myofilament dynamic (cross-bridge) model based on Rice et al. study. The 3D electrical component is a ventricular geometry based on MRI which composed of nodes representing single-cell with electrophysiological activation. The 3D ventricular mechanic is a finite element mesh composed of single-cells myofilament dynamic model. Both components were coupled with Ca2+ concentration. We used Gaussian points for the calcium interpolation from the electrical mesh to the mechanical mesh.
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Affiliation(s)
- Aulia Khamas Heikhmakhtiar
- Department of IT Convergence Engineering, Kumoh National Institute of Technology, Gumi, Republic of Korea
| | - Chung Hao Lee
- Department of Aerospace and Mechanical Engineering, University of Oklahoma, Norman, OK, USA
| | - Kwang Soup Song
- Department of Medical IT Convergence Engineering, Kumoh National Institute of Technology, Gumi, Republic of Korea
| | - Ki Moo Lim
- Department of IT Convergence Engineering, Kumoh National Institute of Technology, Gumi, Republic of Korea.
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41
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Clauss S, Bleyer C, Schüttler D, Tomsits P, Renner S, Klymiuk N, Wakili R, Massberg S, Wolf E, Kääb S. Animal models of arrhythmia: classic electrophysiology to genetically modified large animals. Nat Rev Cardiol 2020; 16:457-475. [PMID: 30894679 DOI: 10.1038/s41569-019-0179-0] [Citation(s) in RCA: 121] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Arrhythmias are common and contribute substantially to cardiovascular morbidity and mortality. The underlying pathophysiology of arrhythmias is complex and remains incompletely understood, which explains why mostly only symptomatic therapy is available. The evaluation of the complex interplay between various cell types in the heart, including cardiomyocytes from the conduction system and the working myocardium, fibroblasts and cardiac immune cells, remains a major challenge in arrhythmia research because it can be investigated only in vivo. Various animal species have been used, and several disease models have been developed to study arrhythmias. Although every species is useful and might be ideal to study a specific hypothesis, we suggest a practical trio of animal models for future use: mice for genetic investigations, mechanistic evaluations or early studies to identify potential drug targets; rabbits for studies on ion channel function, repolarization or re-entrant arrhythmias; and pigs for preclinical translational studies to validate previous findings. In this Review, we provide a comprehensive overview of different models and currently used species for arrhythmia research, discuss their advantages and disadvantages and provide guidance for researchers who are considering performing in vivo studies.
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Affiliation(s)
- Sebastian Clauss
- Department of Medicine I, University Hospital Munich, Campus Grosshadern, Ludwig-Maximilians University Munich (LMU), Munich, Germany. .,DZHK (German Centre for Cardiovascular Research), Partner Site Munich, Munich Heart Alliance (MHA), Munich, Germany.
| | - Christina Bleyer
- Department of Medicine I, University Hospital Munich, Campus Grosshadern, Ludwig-Maximilians University Munich (LMU), Munich, Germany.,DZHK (German Centre for Cardiovascular Research), Partner Site Munich, Munich Heart Alliance (MHA), Munich, Germany
| | - Dominik Schüttler
- Department of Medicine I, University Hospital Munich, Campus Grosshadern, Ludwig-Maximilians University Munich (LMU), Munich, Germany.,DZHK (German Centre for Cardiovascular Research), Partner Site Munich, Munich Heart Alliance (MHA), Munich, Germany
| | - Philipp Tomsits
- Department of Medicine I, University Hospital Munich, Campus Grosshadern, Ludwig-Maximilians University Munich (LMU), Munich, Germany.,DZHK (German Centre for Cardiovascular Research), Partner Site Munich, Munich Heart Alliance (MHA), Munich, Germany
| | - Simone Renner
- Institute of Molecular Animal Breeding and Biotechnology, Ludwig-Maximilians University Munich (LMU), Munich, Germany.,DZD (German Centre for Diabetes Research), Neuherberg, Germany
| | - Nikolai Klymiuk
- Institute of Molecular Animal Breeding and Biotechnology, Ludwig-Maximilians University Munich (LMU), Munich, Germany
| | - Reza Wakili
- Universitätsklinikum Essen, Westdeutsches Herz- und Gefäßzentrum Essen, Essen, Germany
| | - Steffen Massberg
- Department of Medicine I, University Hospital Munich, Campus Grosshadern, Ludwig-Maximilians University Munich (LMU), Munich, Germany.,DZHK (German Centre for Cardiovascular Research), Partner Site Munich, Munich Heart Alliance (MHA), Munich, Germany
| | - Eckhard Wolf
- DZHK (German Centre for Cardiovascular Research), Partner Site Munich, Munich Heart Alliance (MHA), Munich, Germany.,Institute of Molecular Animal Breeding and Biotechnology, Ludwig-Maximilians University Munich (LMU), Munich, Germany.,DZD (German Centre for Diabetes Research), Neuherberg, Germany
| | - Stefan Kääb
- Department of Medicine I, University Hospital Munich, Campus Grosshadern, Ludwig-Maximilians University Munich (LMU), Munich, Germany.,DZHK (German Centre for Cardiovascular Research), Partner Site Munich, Munich Heart Alliance (MHA), Munich, Germany
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42
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Investigation of the Role of Myocyte Orientations in Cardiac Arrhythmia Using Image-Based Models. Biophys J 2019; 117:2396-2408. [PMID: 31679763 PMCID: PMC6990390 DOI: 10.1016/j.bpj.2019.09.041] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Revised: 09/13/2019] [Accepted: 09/23/2019] [Indexed: 11/24/2022] Open
Abstract
Cardiac electrical excitation-propagation is influenced by myocyte orientations (cellular organization). Quantitatively understanding this relationship presents a significant research challenge, especially during arrhythmias in which excitation patterns become complex. Tissue-scale simulations of cardiac electrophysiology, incorporating both dynamic action potential behavior and image-based myocardial architecture, provide an approach to investigate three-dimensional (3D) propagation of excitation waves in the heart. In this study, we aimed to assess the importance of natural variation in myocyte orientations on cardiac arrhythmogenesis using 3D tissue electrophysiology simulations. Three anatomical models (i.e., describing myocyte orientations) of healthy rat ventricles—obtained using diffusion tensor imaging at 100 μm resolution—were registered to a single biventricular geometry (i.e., a single cardiac shape), in which the myocyte orientations could be represented by each of the diffusion tensor imaging data sets or by an idealized rule-based description. The Fenton-Karma cellular excitation model was modified to reproduce rat ventricular action potential duration restitution to create reaction-diffusion cardiac electrophysiology models. Over 250 3D simulations were performed to investigate the effects of myocyte orientations on the following: 1) ventricular activation, 2) location-dependent arrhythmia induction via rapid pacing, and 3) dynamics of re-entry averaged over multiple episodes. It was shown that 1) myocyte orientation differences manifested themselves in local activation times, but the influence on total activation time was small; 2) differences in myocyte orientations could critically affect the inducibility and persistence of arrhythmias for specific stimulus-location/cycle-length combinations; and 3) myocyte orientations alone could be an important determinant of scroll wave break, although no significant differences were observed in averaged arrhythmia dynamics between the four myocyte orientation scenarios considered. Our results show that myocyte orientations are an important determinant of arrhythmia inducibility, persistence, and scroll wave break. These findings suggest that where specificity is desired (for example, when predicting location-dependent, patient-specific arrhythmia inducibility), subject-specific myocyte orientations may be important.
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43
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Liang C, Wang K, Li Q, Bai J, Zhang H. Influence of the distribution of fibrosis within an area of myocardial infarction on wave propagation in ventricular tissue. Sci Rep 2019; 9:14151. [PMID: 31578428 PMCID: PMC6775234 DOI: 10.1038/s41598-019-50478-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Accepted: 09/13/2019] [Indexed: 12/22/2022] Open
Abstract
The presence of fibrosis in heart tissue is strongly correlated with an incidence of arrhythmia, which is a leading cause of sudden cardiac death (SCD). However, it remains incompletely understood how different distributions, sizes and positions of fibrotic tissues contribute to arrhythmogenesis. In this study, we designed 4 different ventricular models mimicking wave propagation in cardiac tissues under normal, myocardial infarction (MI), MI with random fibrosis and MI with gradient fibrosis conditions. Simulation results of ideal square tissues indicate that vulnerable windows (VWs) of random and gradient fibrosis distributions are similar with low levels of fibrosis. However, with a high level of fibrosis, the VWs significantly increase in random fibrosis tissue but not in gradient fibrosis tissue. In addition, we systematically analyzed the effects of the size and position of fibrosis tissues on VWs. Simulation results show that it is more likely for a reentry wave to appear when the length of the infarcted area is greater than 25% of the perimeter of the ventricle, when the width is approximately half that of the ventricular wall, or when the infarcted area is attached to the inside or outside of the ventricular wall.
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Affiliation(s)
- Cuiping Liang
- School of Computer Science and Technology, Harbin Institute of Technology, Harbin, Heilongjiang, China
| | - Kuanquan Wang
- School of Computer Science and Technology, Harbin Institute of Technology, Harbin, Heilongjiang, China.
| | - Qince Li
- School of Computer Science and Technology, Harbin Institute of Technology, Harbin, Heilongjiang, China.
| | - Jieyun Bai
- School of Computer Science and Technology, Harbin Institute of Technology, Harbin, Heilongjiang, China
| | - Henggui Zhang
- School of Computer Science and Technology, Harbin Institute of Technology, Harbin, Heilongjiang, China.,School of Physics and Astronomy, The University of Manchester, Manchester, UK.,Space Institute of Southern China, Shenzhen, China.,Key Laboratory of Medical Electrophysiology, Ministry of Education, Collaborative Innovation Center for Prevention and Treatment of Cardiovascular Disease/Institute of Cardiovascular Research, Southwest Medical University, Luzhou, China
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44
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Antoneli PC, Goulart JT, Bonilha I, de Carvalho DD, de Oliveira PX. Heart defibrillation: relationship between pacing threshold and defibrillation probability. Biomed Eng Online 2019; 18:96. [PMID: 31519192 PMCID: PMC6743100 DOI: 10.1186/s12938-019-0715-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Accepted: 09/03/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Considering the clinical importance of the ventricular fibrillation and that the most used therapy to reverse it has a critical side effect on the cardiac tissue, it is desirable to optimize defibrillation parameters to increase its efficiency. In this study, we investigated the influence of stimuli duration on the relationship between pacing threshold and defibrillation probability. RESULTS We found out that 0.5-ms-long pulses had a lower ratio of defibrillation probability to the pacing threshold, although the higher the pulse duration the lower is the electric field intensity required to defibrillate the hearts. CONCLUSION The appropriate choice of defibrillatory shock parameters is able to increase the efficiency of the defibrillation improving the survival chances after the occurrence of a severe arrhythmia. The relationship between pulse duration and the probability of reversal of fibrillation shows that this parameter cannot be underestimated in defibrillator design since different pulse durations have different levels of safety.
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Affiliation(s)
- Priscila C Antoneli
- Department of Biomedical Engineering, School of Electrical and Computer Engineering-FEEC, University of Campinas-UNICAMP, Rua Alexander Fleming 163, Cidade Universitária Zeferino Vaz, Campinas, SP, CEP 13083-881, Brazil
| | - Jair T Goulart
- Department of Physiological Sciences, Institute of Biology, University of Brasilia-UnB, Campus Universitário Darcy Ribeiro-Asa Norte, Brasília, DF, CEP 70910-900, Brazil
| | - Isabella Bonilha
- Laboratory of Myocardial Ischemia/Reperfusion, Faculty of Medical Science, University of Campinas-UNICAMP, Rua Cinco de Junho, 350, Bloco 1, Cidade Universitária Zeferino Vaz, Campinas, SP, CEP 13083-877, Brazil
| | - Daniela D de Carvalho
- Laboratory of Myocardial Ischemia/Reperfusion, Faculty of Medical Science, University of Campinas-UNICAMP, Rua Cinco de Junho, 350, Bloco 1, Cidade Universitária Zeferino Vaz, Campinas, SP, CEP 13083-877, Brazil
| | - Pedro X de Oliveira
- Department of Biomedical Engineering, School of Electrical and Computer Engineering-FEEC, University of Campinas-UNICAMP, Rua Alexander Fleming 163, Cidade Universitária Zeferino Vaz, Campinas, SP, CEP 13083-881, Brazil. .,Center for Biomedical Engineering, University of Campinas-UNICAMP, Rua Alexander Fleming 163, Cidade Universitária Zeferino Vaz, Campinas, SP, CEP 13083-881, Brazil.
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45
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Aras KK, Faye NR, Cathey B, Efimov IR. Critical Volume of Human Myocardium Necessary to Maintain Ventricular Fibrillation. Circ Arrhythm Electrophysiol 2019; 11:e006692. [PMID: 30376733 DOI: 10.1161/circep.118.006692] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
BACKGROUND Abnormal QT intervals, long QT or short QT, have been epidemiologically linked with sudden cardiac death because of ventricular fibrillation (VF). Consequently, Food and Drug Administration recommends testing all pharmacological agents for QT toxicity as a risk factor for cardiac toxicity. Such tests assess QT/QTc interval, which represents ventricular depolarization and repolarization. However, the current QT toxicity analysis does not account for the well-known anisotropy in cardiac tissue conductivity. Mines demonstrated in 1913 that cardiac wavelength (λ) determines inducibility of reentrant arrhythmia, where both repolarization time or action potential duration and conduction velocity determine λ=action potential duration×conduction velocity. We aimed to determine the role of anisotropic wavelength in inducibility of VF in explanted human left ventricular preparations. We tested the hypothesis that 3-dimensional cardiac wavelength, which takes into account anisotropic cardiac tissue conductivity, can accurately predict VF sustainability. METHODS We conducted panoramic optical mapping of coronary perfused human left ventricular wedge preparations subjected to pharmacologically induced shortening and prolongation of action potential duration, by IK,ATP agonist pinacidil and antagonist glybenclamide, respectively. This measured action potential duration, conduction velocity, and thus determined pacing cycle length-dependent wavelengths in longitudinal (λL), transverse (λTV), and transmural (λTM) directions using S1S1 pacing protocol, from which wavelength volume (Vλ) was determined, as Vλ=λL×λTV×λTM, and compared with tissue volume. We tested a hypothesis that tissue volume/Vλ ratio can predict VF sustainability. RESULTS At baseline, at pacing rate of 240 beats per minute, the wavelengths were λL=9.6±0.6 cm, λTV=4.2±0.3 cm, and λTM=5.8±0.2 cm, respectively (n=7), and thus Vλ=246.4±42.1 cm3. Administration of pinacidil at escalating concentrations progressively decreased Vλ, and VF became sustained, when tissue volume/Vλ was above safety factor κ=4.4±0.6 (n=9) during rapid pacing. Treatment with glybenclamide decreased VT/Vλ below κ at any pacing rate and prevented VF sustainability. CONCLUSIONS Sustained VF was only sustained in ventricular volume exceeding critical Vλ=λL×λTV×λTM.
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Affiliation(s)
- Kedar K Aras
- Department of Biomedical Engineering, George Washington University, Washington, DC
| | - Ndeye Rokhaya Faye
- Department of Biomedical Engineering, George Washington University, Washington, DC
| | - Brianna Cathey
- Department of Biomedical Engineering, George Washington University, Washington, DC
| | - Igor R Efimov
- Department of Biomedical Engineering, George Washington University, Washington, DC
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46
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Affiliation(s)
- Kedar K Aras
- From the Department of Biomedical Engineering, George Washington University, DC
| | - Matthew W Kay
- From the Department of Biomedical Engineering, George Washington University, DC
| | - Igor R Efimov
- From the Department of Biomedical Engineering, George Washington University, DC.
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47
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Nishimura M, Tokoro T, Takatani T, Sato N, Hashimoto T, Kobayashi H, Ono T. Circulating Aminoterminal Propeptide of Type III Procollagen as a Biomarker of Cardiovascular Events in Patients Undergoing Hemodialysis. J Atheroscler Thromb 2019; 26:340-350. [PMID: 30111669 PMCID: PMC6456459 DOI: 10.5551/jat.45138] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Accepted: 07/18/2018] [Indexed: 11/25/2022] Open
Abstract
AIM Type Ⅲ collagen abundantly exists in the cardiovascular system, including the aorta and heart. We prospectively investigated whether serum levels of aminoterminal propeptide of type Ⅲ procollagen (PⅢNP), a circulating biomarker of cardiovascular fibrosis, could predict cardiovascular events in patients undergoing hemodialysis. METHODS Serum PⅢNP concentrations were measured in 244 patients undergoing maintenance hemodialysis (men, 126; women, 118; mean age, 64±11 years; dialysis duration, 11.5±7.8 years) by immunoradiometric assay in February 2005. The endpoint was cardiovascular events, and the patients were followed up until the endpoint was reached, or until January 31, 2011. RESULTS During the follow-up for 4.7±1.8 years, cardiovascular events occurred in 78 (30.3%) of 244 patients. Stepwise Cox hazard analysis revealed that cardiovascular events were associated with increased serum PⅢNP concentration (1 U/mL; hazard ratio, 1.616; P=0.0001). The median serum PⅢNP concentrations were higher in patients with cardiovascular events than in those without (2.30±0.19 U/mL vs 1.30±0.03 U/mL; P<0.0001). When the patients were assigned to subgroups based on serum PⅢNP cut-off value for cardiovascular events of 1.75 U/mL, defined by receiver operating characteristic analysis, cardiovascular event-free survival rates at 5 years were lower (P=0.0001) in the subgroup of serum PⅢNP ≥1.75 U/mL than in that of serum PⅢNP <1.75 U/mL (31.9% vs 88.2%). CONCLUSIONS Serum PⅢNP could be a new biomarker for predicting the cardiovascular events in patients undergoing hemodialysis.
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Affiliation(s)
- Masato Nishimura
- Cardiovascular Division, Toujinkai Satellite Clinic, Kyoto, Japan
| | - Toshiko Tokoro
- Department of Nephrology, Toujinkai Hospital, Kyoto, Japan
| | - Toru Takatani
- Department of Nephrology, Toujinkai Hospital, Kyoto, Japan
| | - Nodoka Sato
- Department of Urology, Toujinkai Hospital, Kyoto, Japan
| | | | | | - Toshihiko Ono
- Department of Urology, Toujinkai Hospital, Kyoto, Japan
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Anderson RD, Kumar S, Kalman JM, Sanders P, Sacher F, Hocini M, Jais P, Haïsaguerre M, Lee G. Catheter Ablation of Ventricular Fibrillation. Heart Lung Circ 2019; 28:110-122. [DOI: 10.1016/j.hlc.2018.09.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Revised: 08/29/2018] [Accepted: 09/05/2018] [Indexed: 10/28/2022]
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Zykov VS. Spiral wave initiation in excitable media. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2018; 376:rsta.2017.0379. [PMID: 30420544 PMCID: PMC6232601 DOI: 10.1098/rsta.2017.0379] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 05/08/2018] [Indexed: 05/15/2023]
Abstract
Spiral waves represent an important example of dissipative structures observed in many distributed systems in chemistry, biology and physics. By definition, excitable media occupy a stationary resting state in the absence of external perturbations. However, a perturbation exceeding a threshold results in the initiation of an excitation wave propagating through the medium. These waves, in contrast to acoustic and optical ones, disappear at the medium's boundary or after a mutual collision, and the medium returns to the resting state. Nevertheless, an initiation of a rotating spiral wave results in a self-sustained activity. Such activity unexpectedly appearing in cardiac or neuronal tissues usually destroys their dynamics which results in life-threatening diseases. In this context, an understanding of possible scenarios of spiral wave initiation is of great theoretical importance with many practical applications.This article is part of the theme issue 'Dissipative structures in matter out of equilibrium: from chemistry, photonics and biology (part 2)'.
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Affiliation(s)
- V S Zykov
- Max Planck Institute for Dynamics and Self-Organization, Goettingen, Germany
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Zykov VS. Spiral wave initiation in excitable media. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2018; 376:rsta.2017.0385. [PMID: 30420544 DOI: 10.1098/rsta.2017.0385] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 07/19/2018] [Indexed: 05/20/2023]
Abstract
Spiral waves represent an important example of dissipative structures observed in many distributed systems in chemistry, biology and physics. By definition, excitable media occupy a stationary resting state in the absence of external perturbations. However, a perturbation exceeding a threshold results in the initiation of an excitation wave propagating through the medium. These waves, in contrast to acoustic and optical ones, disappear at the medium's boundary or after a mutual collision, and the medium returns to the resting state. Nevertheless, an initiation of a rotating spiral wave results in a self-sustained activity. Such activity unexpectedly appearing in cardiac or neuronal tissues usually destroys their dynamics which results in life-threatening diseases. In this context, an understanding of possible scenarios of spiral wave initiation is of great theoretical importance with many practical applications.This article is part of the theme issue 'Dissipative structures in matter out of equilibrium: from chemistry, photonics and biology (part 2)'.
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Affiliation(s)
- V S Zykov
- Max Planck Institute for Dynamics and Self-Organization, Goettingen, Germany
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