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Shiti A, Arbil G, Shaheen N, Huber I, Setter N, Gepstein L. Utilizing human induced pluripotent stem cells to study atrial arrhythmias in the short QT syndrome. J Mol Cell Cardiol 2023; 183:42-53. [PMID: 37579942 PMCID: PMC10589759 DOI: 10.1016/j.yjmcc.2023.08.003] [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: 08/24/2022] [Revised: 07/17/2023] [Accepted: 08/11/2023] [Indexed: 08/16/2023]
Abstract
BACKGROUND Among the monogenic inherited causes of atrial fibrillation is the short QT syndrome (SQTS), a rare channelopathy causing atrial and ventricular arrhythmias. One of the limitations in studying the mechanisms and optimizing treatment of SQTS-related atrial arrhythmias has been the lack of relevant human atrial tissues models. OBJECTIVE To generate a unique model to study SQTS-related atrial arrhythmias by combining the use of patient-specific human induced pluripotent stem cells (hiPSCs), atrial-specific differentiation schemes, two-dimensional tissue modeling, optical mapping, and drug testing. METHODS AND RESULTS SQTS (N588K KCNH2 mutation), isogenic-control, and healthy-control hiPSCs were coaxed to differentiate into atrial cardiomyocytes using a retinoic-acid based differentiation protocol. The atrial identity of the cells was confirmed by a distinctive pattern of MLC2v downregulation, connexin 40 upregulation, shorter and triangular-shaped action potentials (APs), and expression of the atrial-specific acetylcholine-sensitive potassium current. In comparison to the healthy- and isogenic control cells, the SQTS-hiPSC atrial cardiomyocytes displayed abbreviated APs and refractory periods along with an augmented rapidly activating delayed-rectifier potassium current (IKr). Optical mapping of a hiPSC-based atrial tissue model of the SQTS displayed shortened APD and altered biophysical properties of spiral waves induced in this model, manifested by accelerated spiral-wave frequency and increased rotor curvature. Both AP shortening and arrhythmia irregularities were reversed by quinidine and vernakalant treatment, but not by sotalol. CONCLUSIONS Patient-specific hiPSC-based atrial cellular and tissue models of the SQTS were established, which provide examples on how this type of modeling can shed light on the pathogenesis and pharmacological treatment of inherited atrial arrhythmias.
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Affiliation(s)
- Assad Shiti
- Sohnis Family Research Laboratory for Cardiac Electrophysiology and Regenerative Medicine, The Rappaport Faculty of Medicine and Research Institute, Technion - Israel Institute of Technology, Haifa, Israel
| | - Gil Arbil
- Sohnis Family Research Laboratory for Cardiac Electrophysiology and Regenerative Medicine, The Rappaport Faculty of Medicine and Research Institute, Technion - Israel Institute of Technology, Haifa, Israel
| | - Naim Shaheen
- Sohnis Family Research Laboratory for Cardiac Electrophysiology and Regenerative Medicine, The Rappaport Faculty of Medicine and Research Institute, Technion - Israel Institute of Technology, Haifa, Israel
| | - Irit Huber
- Sohnis Family Research Laboratory for Cardiac Electrophysiology and Regenerative Medicine, The Rappaport Faculty of Medicine and Research Institute, Technion - Israel Institute of Technology, Haifa, Israel
| | - Noga Setter
- Sohnis Family Research Laboratory for Cardiac Electrophysiology and Regenerative Medicine, The Rappaport Faculty of Medicine and Research Institute, Technion - Israel Institute of Technology, Haifa, Israel
| | - Lior Gepstein
- Sohnis Family Research Laboratory for Cardiac Electrophysiology and Regenerative Medicine, The Rappaport Faculty of Medicine and Research Institute, Technion - Israel Institute of Technology, Haifa, Israel; Cardiolology Department, Rambam Health Care Campus, Haifa, Israel.
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2
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Jæger KH, Tveito A. Efficient, cell-based simulations of cardiac electrophysiology; The Kirchhoff Network Model (KNM). NPJ Syst Biol Appl 2023; 9:25. [PMID: 37316522 DOI: 10.1038/s41540-023-00288-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Accepted: 06/05/2023] [Indexed: 06/16/2023] Open
Abstract
Mathematical models based on homogenized representation of cardiac tissue have greatly improved our understanding of cardiac electrophysiology. However, these models are too coarse to investigate the dynamics at the level of the myocytes since the cells are not present in homogenized models. Recently, fine scale models have been proposed to allow for cell-level resolution of the dynamics, but these models are too computationally expensive to be used in applications like whole heart simulations of large animals. To address this issue, we propose a model that balances computational demands and physiological accuracy. The model is founded on Kirchhoff's current law, and represents every myocyte in the tissue. This allows specific properties to be assigned to individual cardiomyocytes, and other cell types like fibroblasts can be added to the model in an accurate manner while keeping the computing efforts reasonable.
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3
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Li K, Xu C, Zhu X, Wang X, Ye P, Jiang W, Wu S, Xu K, Li X, Wang Y, Zheng Q, Wang Y, Leng L, Zhang Z, Han B, Zhang Y, Qin M, Liu X. Multi-centre, prospective randomized comparison of three different substrate ablation strategies for persistent atrial fibrillation. Europace 2023; 25:euad090. [PMID: 37050858 PMCID: PMC10228617 DOI: 10.1093/europace/euad090] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2023] [Accepted: 03/16/2023] [Indexed: 04/14/2023] Open
Abstract
AIMS The optimal strategy for persistent atrial fibrillation (PerAF) is poorly defined. We conducted a multicentre, randomized, prospective trial to compare the outcomes of different ablation strategies for PerAF. METHODS AND RESULTS We enrolled 450 patients and randomly assigned them in a 1:1:1 ratio to undergo pulmonary vein isolation and subsequently undergo the following three different ablation strategies: anatomical guided ablation (ANAT group, n = 150), electrogram guided ablation (EGM group, n = 150), and extensive electro-anatomical guided ablation (EXT group, n = 150). The primary endpoint was freedom from atrial fibrillation (AF) lasting longer than 30 s at 12 months after a single ablation procedure. After 12 months of follow-up, 72% (108) of patients in the EXT group were free from AF recurrence, as compared with the 64% (96) in the EGM group (P = 0.116), and 54% (81) in the ANAT group (P = 0.002). The EXT group showed less AF/atrial tachycardia recurrence than the EGM group (60% vs. 50%, P = 0.064) and the ANAT group (60% vs. 37.3%, P < 0.001). The EXT group showed the highest rate of AF termination (66.7%), followed by 56.7% in the EGM group, and 20.7% in the ANAT group. The AF termination signified less AF recurrence at 12 months compared to patients without AF termination (30.1% vs. 42.7%, P = 0.008). Safety endpoints did not differ significantly between the three groups (P = 0.924). CONCLUSIONS Electro-anatomical guided ablation achieved the most favourable outcomes among the three ablation strategies. The AF termination is a reliable ablation endpoint.
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Affiliation(s)
- Kaige Li
- Department of Cardiology, Shanghai Chest Hospital, Shanghai Jiao Tong University, No.241 West Huaihai Road, Shanghai 200030, China
| | - Changhao Xu
- Department of Cardiology, Shanghai Chest Hospital, Shanghai Jiao Tong University, No.241 West Huaihai Road, Shanghai 200030, China
| | - Xiyao Zhu
- Department of Clinical Integration of Traditional Chinese and Western medicine, First Clinical Medical College, Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Xinhua Wang
- Department of Cardiology, Ren Ji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Ping Ye
- Department of Cardiology, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Weifeng Jiang
- Department of Cardiology, Shanghai Chest Hospital, Shanghai Jiao Tong University, No.241 West Huaihai Road, Shanghai 200030, China
| | - Shaohui Wu
- Department of Cardiology, Shanghai Chest Hospital, Shanghai Jiao Tong University, No.241 West Huaihai Road, Shanghai 200030, China
| | - Kai Xu
- Department of Cardiology, Shanghai Chest Hospital, Shanghai Jiao Tong University, No.241 West Huaihai Road, Shanghai 200030, China
| | - Xiangting Li
- Department of Cardiology, Affiliated Hospital of Jining Medical University, Jining, China
| | - Ying Wang
- Department of Cardiology, Second Affiliated Hospital of Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Qidong Zheng
- Department of Cardiology, Yuhuan Second People's Hospital, Yuhuan, China
| | - Yanzhe Wang
- Department of Cardiology, Changshu Hospital of Traditional Chinese Medicine, Changshu, China
| | - Lihua Leng
- Department of Cardiology, The PLA Navy Anqing Hospital, Anqing, China
| | - Zengtang Zhang
- Department of Cardiology, Jinan City People’s Hospital, Jinan, China
| | - Bing Han
- Department of Cardiology, Xuzhou Central Hospital, Xuzhou, China
| | - Yu Zhang
- Department of Cardiology, Shanghai Chest Hospital, Shanghai Jiao Tong University, No.241 West Huaihai Road, Shanghai 200030, China
| | - Mu Qin
- Department of Cardiology, Shanghai Chest Hospital, Shanghai Jiao Tong University, No.241 West Huaihai Road, Shanghai 200030, China
| | - Xu Liu
- Department of Cardiology, Shanghai Chest Hospital, Shanghai Jiao Tong University, No.241 West Huaihai Road, Shanghai 200030, China
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4
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Xu CH, Xiong F, Jiang WF, Liu X, Liu T, Qin M. Rotor mechanism and its mapping in atrial fibrillation. Europace 2023; 25:783-792. [PMID: 36734272 PMCID: PMC10062333 DOI: 10.1093/europace/euad002] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2022] [Accepted: 12/28/2022] [Indexed: 02/04/2023] Open
Abstract
Treatment of atrial fibrillation (AF) remains challenging despite significant progress in understanding its underlying mechanisms. The first detailed, quantitative theory of functional re-entry, the 'leading circle' model, was developed more than 40 years ago. Subsequently, in decades of study, an alternative paradigm based on spiral waves has long been postulated to drive AF. The rotor as a 'spiral wave generator' is a curved 'vortex' formed by spin motion in the two-dimensional plane, identified using advanced mapping methods in experimental and clinical AF. However, it is challenging to achieve complementary results between experimental results and clinical studies due to the limitation in research methods and the complexity of the rotor mechanism. Here, we review knowledge garnered over decades on generation, electrophysiological properties, and three-dimensional (3D) structure diversity of the rotor mechanism and make a comparison among recent clinical approaches to identify rotors. Although initial studies of rotor ablation at many independent centres have achieved promising results, some inconclusive outcomes exist in others. We propose that the clinical rotor identification might be substantially influenced by (i) non-identical surface activation patterns, which resulted from a diverse 3D form of scroll wave, and (ii) inadequate resolution of mapping techniques. With rapidly advancing theoretical and technological developments, future work is required to resolve clinically relevant limitations in current basic and clinical research methodology, translate from one to the other, and resolve available mapping techniques.
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Affiliation(s)
- Chang-Hao Xu
- Department of Cardiology, Shanghai Chest Hospital, School of Medicine,
Shanghai Jiao Tong University, 241 Huaihai West Road, Xuhui
District, Shanghai 200030, China
| | - Feng Xiong
- Montreal Heart Institute, Department of Medicine, University of
Montreal, 5000, Bélanger street, Montréal, Québec H1T
1C8, Canada
| | - Wei-Feng Jiang
- Department of Cardiology, Shanghai Chest Hospital, School of Medicine,
Shanghai Jiao Tong University, 241 Huaihai West Road, Xuhui
District, Shanghai 200030, China
| | - Xu Liu
- Department of Cardiology, Shanghai Chest Hospital, School of Medicine,
Shanghai Jiao Tong University, 241 Huaihai West Road, Xuhui
District, Shanghai 200030, China
| | - Tao Liu
- Corresponding authors. Tao Liu, 238 Jiefang Road, Wuchang
District, Wuhan, Hubei 430060, China. Tel: +86 (027) 8804 1911, Fax:+86-(027)-8804-2292.
E-mail address:; Mu Qin, 241 Huaihai
West Road, Xuhui District, Shanghai, 200030, China. Tel: +8621628219902603, Fax:
+862162821105. E-mail address:
| | - Mu Qin
- Corresponding authors. Tao Liu, 238 Jiefang Road, Wuchang
District, Wuhan, Hubei 430060, China. Tel: +86 (027) 8804 1911, Fax:+86-(027)-8804-2292.
E-mail address:; Mu Qin, 241 Huaihai
West Road, Xuhui District, Shanghai, 200030, China. Tel: +8621628219902603, Fax:
+862162821105. E-mail address:
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5
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Li TC, Li QH, Song Z, Pan DB, Zhong W, Luo J. Drift of sparse and dense spiral waves under joint external forces. Phys Rev E 2023; 107:024213. [PMID: 36932583 DOI: 10.1103/physreve.107.024213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Accepted: 02/07/2023] [Indexed: 06/18/2023]
Abstract
Many methods have been employed to investigate the drift behaviors of spiral waves in an effort to understand and control their dynamics. Drift behaviors of sparse and dense spirals induced by external forces have been investigated, yet they remain incompletely understood. Here we employ joint external forces to study and control the drift dynamics. First, sparse and dense spiral waves are synchronized by the suitable external current. Then, under another weak current or heterogeneity, the synchronized spirals undergo a directional drift, and the dependence of their drift velocity on the strength and frequency of the joint external force is studied.
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Affiliation(s)
- Teng-Chao Li
- School of Physics, Hangzhou Normal University, Hangzhou 311121, China
| | - Qi-Hao Li
- Peng Cheng Laboratory, Shenzhen, Guangdong 518066, China
| | - Zhen Song
- Peng Cheng Laboratory, Shenzhen, Guangdong 518066, China
| | - De-Bei Pan
- Department of Physics, Guangxi Medical University, Nanning 530021, China
| | - Wei Zhong
- Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials and School of Physics and Telecommunication Engineering, South China Normal University, Guangzhou 510006, China
- Guangdong-Hong Kong Joint Laboratory of Quantum Matter, Frontier Research Institute for Physics, South China Normal University, Guangzhou 510006, China
| | - Jinming Luo
- School of Mathematics, China University of Mining and Technology, Xuzhou 221008, China
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6
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Niort BC, Recalde A, Cros C, Brette F. Critical Link between Calcium Regional Heterogeneity and Atrial Fibrillation Susceptibility in Sheep Left Atria. J Clin Med 2023; 12:jcm12030746. [PMID: 36769395 PMCID: PMC9917890 DOI: 10.3390/jcm12030746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 12/30/2022] [Accepted: 01/12/2023] [Indexed: 01/20/2023] Open
Abstract
BACKGROUND Atrial fibrillation is the most sustained form of arrhythmia in the human population that leads to important electrophysiological and structural cardiac remodeling as it progresses into a chronic form. Calcium is an established key player of cellular electrophysiology in the heart, yet to date, there is no information that maps calcium signaling across the left atrium. OBJECTIVE The aim of this study is to determine whether calcium signaling is homogenous throughout the different regions of the left atrium. This work tests the hypothesis that differences across the healthy left atrium contribute to a unique, region-dependent calcium cycling and participates in the pro-arrhythmic activity during atrial fibrillation. METHODS An animal model relevant to human cardiac function (the sheep) was used to characterize both the electrical activity and the calcium signaling of three distinct left atrium regions (appendage, free wall and pulmonary veins) in control conditions and after acetylcholine perfusion (5 μM) to induce acute atrial fibrillation. High-resolution dual calcium-voltage optical mapping on the left atria of sheep was performed to explore the spatiotemporal dynamics of calcium signaling in relation to electrophysiological properties. RESULTS Action potential duration (at 80% repolarization) was not significantly different in the three regions of interest for the three pacing sites. In contrast, the time to 50% calcium transient decay was significantly different depending on the region paced and recorded. Acetylcholine perfusion and burst pacing-induced atrial fibrillation when pulmonary veins and appendage regions were paced but not when the free wall region was. Dantrolene (a ryanodine receptor blocker) did not reduce atrial fibrillation susceptibility. CONCLUSION These data provide the first evidence of heterogenous calcium signaling across the healthy left atrium. Such basal regional differences may be exacerbated during the progression of atrial fibrillation and thus play a crucial role in focal arrhythmia initiation without ryanodine receptor gating modification.
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Affiliation(s)
- Barbara C. Niort
- Centre de Recherche Cardio-Thoracique de Bordeaux (CRCTB), Inserm U1045, Univeristé de Bordeaux, F-33000 Bordeaux, France
- IHU Liryc, Electrophysiology and Heart Modeling Institute, F-33600 Pessac, France
| | - Alice Recalde
- Centre de Recherche Cardio-Thoracique de Bordeaux (CRCTB), Inserm U1045, Univeristé de Bordeaux, F-33000 Bordeaux, France
- IHU Liryc, Electrophysiology and Heart Modeling Institute, F-33600 Pessac, France
| | - Caroline Cros
- Centre de Recherche Cardio-Thoracique de Bordeaux (CRCTB), Inserm U1045, Univeristé de Bordeaux, F-33000 Bordeaux, France
- IHU Liryc, Electrophysiology and Heart Modeling Institute, F-33600 Pessac, France
| | - Fabien Brette
- Centre de Recherche Cardio-Thoracique de Bordeaux (CRCTB), Inserm U1045, Univeristé de Bordeaux, F-33000 Bordeaux, France
- IHU Liryc, Electrophysiology and Heart Modeling Institute, F-33600 Pessac, France
- Phymedexp Inserm, CNRS, Université de Montpellier, CHRU, F-34295 Montpellier, France
- Correspondence:
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7
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Adenosine and Adenosine Receptors: Advances in Atrial Fibrillation. Biomedicines 2022; 10:biomedicines10112963. [PMID: 36428533 PMCID: PMC9687155 DOI: 10.3390/biomedicines10112963] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Revised: 11/07/2022] [Accepted: 11/14/2022] [Indexed: 11/19/2022] Open
Abstract
Atrial fibrillation (AF) is the most common arrhythmia in the world. Because the key to developing innovative therapies that limit the onset and the progression of AF is to fully understand the underlying molecular mechanisms of AF, the aim of the present narrative review is to report the most recent advances in the potential role of the adenosinergic system in the pathophysiology of AF. After a comprehensive approach describing adenosinergic system signaling and the mechanisms of the initiation and maintenance of AF, we address the interactions of the adenosinergic system's signaling with AF. Indeed, adenosine release can activate four G-coupled membrane receptors, named A1, A2A, A2B and A3. Activation of the A2A receptors can promote the occurrence of delayed depolarization, while activation of the A1 receptors can shorten the action potential's duration and induce the resting membrane's potential hyperpolarization, which promote pulmonary vein firing, stabilize the AF rotors and allow for functional reentry. Moreover, the A2B receptors have been associated with atrial fibrosis homeostasis. Finally, the adenosinergic system can modulate the autonomous nervous system and is associated with AF risk factors. A question remains regarding adenosine release and the adenosine receptors' activation and whether this would be a cause or consequence of AF.
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8
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Biendarra‐Tiegs SM, Yechikov S, Shergill B, Brumback B, Takahashi K, Shirure VS, Gonzalez RE, Houshmand L, Zhong D, Weng K, Silva J, Smith TW, Rentschler SL, George SC. An iPS-derived in vitro model of human atrial conduction. Physiol Rep 2022; 10:e15407. [PMID: 36117385 PMCID: PMC9483613 DOI: 10.14814/phy2.15407] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2022] [Revised: 04/27/2022] [Accepted: 07/14/2022] [Indexed: 11/25/2022] Open
Abstract
Atrial fibrillation (AF) is the most common arrhythmia in the United States, affecting approximately 1 in 10 adults, and its prevalence is expected to rise as the population ages. Treatment options for AF are limited; moreover, the development of new treatments is hindered by limited (1) knowledge regarding human atrial electrophysiological endpoints (e.g., conduction velocity [CV]) and (2) accurate experimental models. Here, we measured the CV and refractory period, and subsequently calculated the conduction wavelength, in vivo (four subjects with AF and four controls), and ex vivo (atrial slices from human hearts). Then, we created an in vitro model of human atrial conduction using induced pluripotent stem (iPS) cells. This model consisted of iPS-derived human atrial cardiomyocytes plated onto a micropatterned linear 1D spiral design of Matrigel. The CV (34-41 cm/s) of the in vitro model was nearly five times faster than 2D controls (7-9 cm/s) and similar to in vivo (40-64 cm/s) and ex vivo (28-51 cm/s) measurements. Our iPS-derived in vitro model recapitulates key features of in vivo atrial conduction and may be a useful methodology to enhance our understanding of AF and model patient-specific disease.
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Affiliation(s)
| | - Sergey Yechikov
- Department of Biomedical EngineeringUniversity of California, DavisDavisCaliforniaUSA
| | - Bhupinder Shergill
- Department of Biomedical EngineeringUniversity of California, DavisDavisCaliforniaUSA
| | - Brittany Brumback
- Department of Biomedical EngineeringWashington University in St. LouisSt. LouisMissouriUSA
| | - Kentaro Takahashi
- Department of MedicineWashington University in St. LouisSt. LouisMissouriUSA
| | - Venktesh S. Shirure
- Department of Biomedical EngineeringUniversity of California, DavisDavisCaliforniaUSA
| | - Ruth Estelle Gonzalez
- Department of Biomedical EngineeringUniversity of California, DavisDavisCaliforniaUSA
| | - Laura Houshmand
- Department of Biomedical EngineeringUniversity of California, DavisDavisCaliforniaUSA
| | - Denise Zhong
- Department of Biomedical EngineeringUniversity of California, DavisDavisCaliforniaUSA
| | - Kuo‐Chan Weng
- Department of Biomedical EngineeringWashington University in St. LouisSt. LouisMissouriUSA
| | - Jon Silva
- Department of Biomedical EngineeringWashington University in St. LouisSt. LouisMissouriUSA
| | - Timothy W. Smith
- Department of MedicineWashington University in St. LouisSt. LouisMissouriUSA
| | - Stacey L. Rentschler
- Department of MedicineWashington University in St. LouisSt. LouisMissouriUSA
- Department of Developmental BiologyWashington University in St. LouisSt. LouisMissouriUSA
| | - Steven C. George
- Department of Biomedical EngineeringUniversity of California, DavisDavisCaliforniaUSA
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9
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Dantas E, Orlande HRB, Dulikravich GS. Thermal ablation effects on rotors that characterize functional re-entry cardiac arrhythmia. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2022; 38:e3614. [PMID: 35543287 DOI: 10.1002/cnm.3614] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Revised: 04/29/2022] [Accepted: 05/06/2022] [Indexed: 06/14/2023]
Abstract
Thermal ablation is a well-established successful treatment for cardiac arrhythmia, but it still presents limitations that require further studies and developments. In the rotor-driven functional re-entry arrhythmia, tissue heterogeneity results on the generation of spiral/scroll waves and wave break dynamics that may cause dangerous sustainable fibrillation. The selection of the target region to perform thermal ablation to mitigate this type of arrhythmia is challenging, since it considerably affects the local electrophysiology dynamics. This work deals with the numerical simulation of the thermal ablation of a cardiac muscle tissue and its effects on the dynamics of rotor-driven functional re-entry arrhythmia. A non-homogeneous two-dimensional rectangular region is used in the present numerical analysis, where radiofrequency ablation is performed. The electrophysiology problem for the propagation of the action potential in the cardiac tissue is simulated with the Fenton-Karma model. Thermal damage caused to the tissue by the radiofrequency heating is modeled by the Arrhenius equation. The effects of size and position of a heterogeneous region in the original muscle tissue were first analyzed, in order to verify the possible existence of the functional re-entry arrhythmia during the time period considered in the simulations. For each case that exhibited re-entry arrhythmia, six different ablation procedures were analyzed, depending on the position of the radiofrequency electrode and heating time. The obtained results revealed the effects of different model parameters on the existence and possible mitigation of the functional re-entry arrhythmia.
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Affiliation(s)
- Eber Dantas
- Department of Mechanical Engineering, Politécnica/COPPE, Federal University of Rio de Janeiro - UFRJ, Rio de Janeiro, Brazil
| | - Helcio R B Orlande
- Department of Mechanical Engineering, Politécnica/COPPE, Federal University of Rio de Janeiro - UFRJ, Rio de Janeiro, Brazil
| | - George S Dulikravich
- Department of Mechanical and Materials Engineering, MAIDROC Lab., Florida International University, Miami, Florida, USA
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10
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Falkenberg M, Coleman JA, Dobson S, Hickey DJ, Terrill L, Ciacci A, Thomas B, Sau A, Ng FS, Zhao J, Peters NS, Christensen K. Identifying locations susceptible to micro-anatomical reentry using a spatial network representation of atrial fibre maps. PLoS One 2022; 17:e0267166. [PMID: 35737662 PMCID: PMC9223322 DOI: 10.1371/journal.pone.0267166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Accepted: 04/03/2022] [Indexed: 11/18/2022] Open
Abstract
Micro-anatomical reentry has been identified as a potential driver of atrial fibrillation (AF). In this paper, we introduce a novel computational method which aims to identify which atrial regions are most susceptible to micro-reentry. The approach, which considers the structural basis for micro-reentry only, is based on the premise that the accumulation of electrically insulating interstitial fibrosis can be modelled by simulating percolation-like phenomena on spatial networks. Our results suggest that at high coupling, where micro-reentry is rare, the micro-reentrant substrate is highly clustered in areas where the atrial walls are thin and have convex wall morphology, likely facilitating localised treatment via ablation. However, as transverse connections between fibres are removed, mimicking the accumulation of interstitial fibrosis, the substrate becomes less spatially clustered, and the bias to forming in thin, convex regions of the atria is reduced, possibly restricting the efficacy of localised ablation. Comparing our algorithm on image-based models with and without atrial fibre structure, we find that strong longitudinal fibre coupling can suppress the micro-reentrant substrate, whereas regions with disordered fibre orientations have an enhanced risk of micro-reentry. With further development, these methods may be useful for modelling the temporal development of the fibrotic substrate on an individualised basis.
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Affiliation(s)
- Max Falkenberg
- Centre for Complexity Science, Imperial College London, London, United Kingdom
- Department of Physics, Imperial College London, London, United Kingdom
- ElectroCardioMaths Programme, Imperial Centre for Cardiac Engineering, National Heart & Lung Institute, Imperial College London, London, United Kingdom
| | - James A. Coleman
- Department of Physics, Imperial College London, London, United Kingdom
| | - Sam Dobson
- Department of Physics, Imperial College London, London, United Kingdom
| | - David J. Hickey
- Department of Physics, Imperial College London, London, United Kingdom
| | - Louie Terrill
- Department of Physics, Imperial College London, London, United Kingdom
| | - Alberto Ciacci
- Centre for Complexity Science, Imperial College London, London, United Kingdom
- Department of Physics, Imperial College London, London, United Kingdom
- ElectroCardioMaths Programme, Imperial Centre for Cardiac Engineering, National Heart & Lung Institute, Imperial College London, London, United Kingdom
| | - Belvin Thomas
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
| | - Arunashis Sau
- ElectroCardioMaths Programme, Imperial Centre for Cardiac Engineering, National Heart & Lung Institute, Imperial College London, London, United Kingdom
| | - Fu Siong Ng
- ElectroCardioMaths Programme, Imperial Centre for Cardiac Engineering, National Heart & Lung Institute, Imperial College London, London, United Kingdom
| | - Jichao Zhao
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
| | - Nicholas S. Peters
- ElectroCardioMaths Programme, Imperial Centre for Cardiac Engineering, National Heart & Lung Institute, Imperial College London, London, United Kingdom
| | - Kim Christensen
- Centre for Complexity Science, Imperial College London, London, United Kingdom
- Department of Physics, Imperial College London, London, United Kingdom
- ElectroCardioMaths Programme, Imperial Centre for Cardiac Engineering, National Heart & Lung Institute, Imperial College London, London, United Kingdom
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11
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Quah JX, Jenkins E, Dharmaprani D, Tiver K, Smith C, Hecker T, Joseph MX, Selvanayagam JB, Tung M, Stanton T, Ahmad W, Stoyanov N, Lahiri A, Chahadi F, Singleton C, Ganesan A. Role of interatrial conduction in atrial fibrillation. Mechanistic insights from renewal theory-based fibrillatory dynamic analysis. Heart Rhythm O2 2022; 3:335-343. [PMID: 36097465 PMCID: PMC9463713 DOI: 10.1016/j.hroo.2022.05.007] [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] [Indexed: 11/27/2022] Open
Abstract
Background Interatrial conduction has been postulated to play an important role in atrial fibrillation (AF). The pathways involved in interatrial conduction during AF remain incompletely defined. Objective We recently showed physiological assessment of fibrillatory dynamics could be performed using renewal theory, which determines rates of phase singularity formation (λf) and destruction (λd). Using the renewal approach, we aimed to understand the role of the interatrial septum and other electrically coupled regions during AF. Method RENEWAL-AF is a prospective multicenter observational study recruiting AF ablation patients (ACTRN 12619001172190). We studied unipolar electrograms obtained from 16 biatrial locations prior to ablation using a 16-electrode Advisor HD Grid catheter. Renewal rate constants λf and λd were calculated, and the relationships between these rate constants in regions of interatrial connectivity were examined. Results Forty-one AF patients (28.5% female) were recruited. A positive linear correlation was observed between λf and λd (1) across the interatrial septum (λf r2 = 0.5, P < .001, λd r2 = 0.45, P < .001), (2) in regions connected by the Bachmann bundle (right atrial appendage–left atrial appendage λf r2 = 0.29, P = .001; λd r2 = 0.2, P = .008), and (3) across the inferior interatrial routes (cavotricuspid isthmus–left atrial septum λf r2 = 0.67, P < .001; λd r2 = 0.55, P < .001). Persistent AF status and left atrial volume were found to be important effect modifiers of the degree of interatrial renewal rate statistical correlation. Conclusion Our findings support the role of interseptal statistically determined electrical disrelation in sustaining AF. Additionally, renewal theory identified preferential conduction through specific interatrial pathways during fibrillation. These findings may be of importance in identifying clinically significant targets for ablation in AF patients.
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Affiliation(s)
- Jing Xian Quah
- College of Medicine and Public Health, Flinders University of South Australia, Adelaide, Australia
- Department of Cardiovascular Medicine, Flinders Medical Centre, Adelaide, Australia
| | - Evan Jenkins
- College of Science and Engineering, Flinders University of South Australia, Adelaide, Australia
| | - Dhani Dharmaprani
- College of Medicine and Public Health, Flinders University of South Australia, Adelaide, Australia
- College of Science and Engineering, Flinders University of South Australia, Adelaide, Australia
| | - Kathryn Tiver
- Department of Cardiovascular Medicine, Flinders Medical Centre, Adelaide, Australia
| | - Corey Smith
- Department of Cardiology, Fiona Stanley Hospital, Perth, Australia
| | - Teresa Hecker
- Department of Cardiovascular Medicine, Flinders Medical Centre, Adelaide, Australia
| | - Majo X. Joseph
- Department of Cardiovascular Medicine, Flinders Medical Centre, Adelaide, Australia
| | | | - Matthew Tung
- Department of Cardiovascular Medicine, Sunshine Coast University Hospital, Birtinya, Australia
| | - Tony Stanton
- Department of Cardiovascular Medicine, Sunshine Coast University Hospital, Birtinya, Australia
- School of Medicine and Dentistry, Griffith University, Sunshine Coast University Hospital, Birtinya, Australia
| | - Waheed Ahmad
- Department of Cardiovascular Medicine, Princess Alexandra Hospital, Brisbane, Australia
| | - Nik Stoyanov
- Department of Cardiology, Fiona Stanley Hospital, Perth, Australia
| | - Anandaroop Lahiri
- Department of Cardiovascular Medicine, Flinders Medical Centre, Adelaide, Australia
| | - Fahd Chahadi
- Department of Cardiovascular Medicine, Flinders Medical Centre, Adelaide, Australia
| | - Cameron Singleton
- Department of Cardiovascular Medicine, Flinders Medical Centre, Adelaide, Australia
| | - Anand Ganesan
- College of Medicine and Public Health, Flinders University of South Australia, Adelaide, Australia
- Department of Cardiovascular Medicine, Flinders Medical Centre, Adelaide, Australia
- Address reprint requests and correspondence: Dr Anand Ganesan, College of Medicine and Public Health, Flinders University, Flinders Dr, Bedford Park SA 5042, Australia.
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12
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Rotor hypothesis in the time chain of atrial fibrillation. JOURNAL OF GERIATRIC CARDIOLOGY : JGC 2022; 19:251-253. [PMID: 35572219 PMCID: PMC9068591 DOI: 10.11909/j.issn.1671-5411.2022.04.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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13
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Li QH, Xia YX, Xu SX, Song Z, Pan JT, Panfilov AV, Zhang H. Control of spiral waves in optogenetically modified cardiac tissue by periodic optical stimulation. Phys Rev E 2022; 105:044210. [PMID: 35590553 DOI: 10.1103/physreve.105.044210] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Accepted: 03/30/2022] [Indexed: 06/15/2023]
Abstract
Resonant drift of nonlinear spiral waves occurs in various types of excitable media under periodic stimulation. Recently a novel methodology of optogenetics has emerged, which allows to affect excitability of cardiac cells and tissues by optical stimuli. In this paper we study if resonant drift of spiral waves in the heart can be induced by a homogeneous weak periodic optical stimulation of cardiac tissue. We use a two-variable and a detailed model of cardiac tissue and add description of depolarizing and hyperpolarizing optogenetic ionic currents. We show that weak periodic optical stimulation at a frequency equal to the natural rotation frequency of the spiral wave induces resonant drift for both depolarizing and hyperpolarizing optogenetic currents. We quantify these effects and study how the speed of the drift and its direction depend on the initial conditions. We also derive analytical formulas based on the response function theory which correctly predict the drift velocity and its trajectory. We conclude that optogenetic methodology can be used for control of spiral waves in cardiac tissue and discuss its possible applications.
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Affiliation(s)
- Qi-Hao Li
- Zhejiang Institute of Modern Physics and Department of Physics, Zhejiang University, Hangzhou 310027, China
- Department of Mathematics and Theories, Peng Cheng Laboratory, Shenzhen 518066, China
| | - Yuan-Xun Xia
- Zhejiang Institute of Modern Physics and Department of Physics, Zhejiang University, Hangzhou 310027, China
| | - Shu-Xiao Xu
- Zhejiang Institute of Modern Physics and Department of Physics, Zhejiang University, Hangzhou 310027, China
| | - Zhen Song
- Department of Mathematics and Theories, Peng Cheng Laboratory, Shenzhen 518066, China
| | - Jun-Ting Pan
- Ocean College, Zhejiang University, Zhoushan 316021, China
| | - Alexander V Panfilov
- Department of Physics and Astronomy, Ghent University, Ghent 9000, Belgium
- Laboratory of Computational Biology and Medicine, Ural Federal University, Ekaterinburg 620002, Russia
- World-Class Research Center "Digital biodesign and personalized healthcare," Sechenov University, Moscow 119146, Russia
| | - Hong Zhang
- Zhejiang Institute of Modern Physics and Department of Physics, Zhejiang University, Hangzhou 310027, China
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14
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Lebert J, Ravi N, Fenton FH, Christoph J. Rotor Localization and Phase Mapping of Cardiac Excitation Waves Using Deep Neural Networks. Front Physiol 2022; 12:782176. [PMID: 34975536 PMCID: PMC8718715 DOI: 10.3389/fphys.2021.782176] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Accepted: 11/11/2021] [Indexed: 11/15/2022] Open
Abstract
The analysis of electrical impulse phenomena in cardiac muscle tissue is important for the diagnosis of heart rhythm disorders and other cardiac pathophysiology. Cardiac mapping techniques acquire local temporal measurements and combine them to visualize the spread of electrophysiological wave phenomena across the heart surface. However, low spatial resolution, sparse measurement locations, noise and other artifacts make it challenging to accurately visualize spatio-temporal activity. For instance, electro-anatomical catheter mapping is severely limited by the sparsity of the measurements, and optical mapping is prone to noise and motion artifacts. In the past, several approaches have been proposed to create more reliable maps from noisy or sparse mapping data. Here, we demonstrate that deep learning can be used to compute phase maps and detect phase singularities in optical mapping videos of ventricular fibrillation, as well as in very noisy, low-resolution and extremely sparse simulated data of reentrant wave chaos mimicking catheter mapping data. The self-supervised deep learning approach is fundamentally different from classical phase mapping techniques. Rather than encoding a phase signal from time-series data, a deep neural network instead learns to directly associate phase maps and the positions of phase singularities with short spatio-temporal sequences of electrical data. We tested several neural network architectures, based on a convolutional neural network (CNN) with an encoding and decoding structure, to predict phase maps or rotor core positions either directly or indirectly via the prediction of phase maps and a subsequent classical calculation of phase singularities. Predictions can be performed across different data, with models being trained on one species and then successfully applied to another, or being trained solely on simulated data and then applied to experimental data. Neural networks provide a promising alternative to conventional phase mapping and rotor core localization methods. Future uses may include the analysis of optical mapping studies in basic cardiovascular research, as well as the mapping of atrial fibrillation in the clinical setting.
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Affiliation(s)
- Jan Lebert
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA, United States
| | - Namita Ravi
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA, United States.,Yale School of Medicine, Yale University, New Haven, CT, United States
| | - Flavio H Fenton
- School of Physics, Georgia Institute of Technology, Atlanta, GA, United States
| | - Jan Christoph
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA, United States
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15
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Jenkins EV, Dharmaprani D, Schopp M, Quah JX, Tiver K, Mitchell L, Xiong F, Aguilar M, Pope K, Akar FG, Roney CH, Niederer SA, Nattel S, Nash MP, Clayton RH, Ganesan AN. The inspection paradox: An important consideration in the evaluation of rotor lifetimes in cardiac fibrillation. Front Physiol 2022; 13:920788. [PMID: 36148313 PMCID: PMC9486478 DOI: 10.3389/fphys.2022.920788] [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: 04/15/2022] [Accepted: 08/10/2022] [Indexed: 11/18/2022] Open
Abstract
Background and Objective: Renewal theory is a statistical approach to model the formation and destruction of phase singularities (PS), which occur at the pivots of spiral waves. A common issue arising during observation of renewal processes is an inspection paradox, due to oversampling of longer events. The objective of this study was to characterise the effect of a potential inspection paradox on the perception of PS lifetimes in cardiac fibrillation. Methods: A multisystem, multi-modality study was performed, examining computational simulations (Aliev-Panfilov (APV) model, Courtmanche-Nattel model), experimentally acquired optical mapping Atrial and Ventricular Fibrillation (AF/VF) data, and clinically acquired human AF and VF. Distributions of all PS lifetimes across full epochs of AF, VF, or computational simulations, were compared with distributions formed from lifetimes of PS existing at 10,000 simulated commencement timepoints. Results: In all systems, an inspection paradox led towards oversampling of PS with longer lifetimes. In APV computational simulations there was a mean PS lifetime shift of +84.9% (95% CI, ± 0.3%) (p < 0.001 for observed vs overall), in Courtmanche-Nattel simulations of AF +692.9% (95% CI, ±57.7%) (p < 0.001), in optically mapped rat AF +374.6% (95% CI, ± 88.5%) (p = 0.052), in human AF mapped with basket catheters +129.2% (95% CI, ±4.1%) (p < 0.05), human AF-HD grid catheters 150.8% (95% CI, ± 9.0%) (p < 0.001), in optically mapped rat VF +171.3% (95% CI, ±15.6%) (p < 0.001), in human epicardial VF 153.5% (95% CI, ±15.7%) (p < 0.001). Conclusion: Visual inspection of phase movies has the potential to systematically oversample longer lasting PS, due to an inspection paradox. An inspection paradox is minimised by consideration of the overall distribution of PS lifetimes.
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Affiliation(s)
- Evan V Jenkins
- College of Medicine and Public Health, Flinders University, Adelaide, SA, Australia
| | - Dhani Dharmaprani
- College of Medicine and Public Health, Flinders University, Adelaide, SA, Australia.,College of Science and Engineering, Flinders University, Adelaide, SA, Australia
| | - Madeline Schopp
- College of Science and Engineering, Flinders University, Adelaide, SA, Australia
| | - Jing Xian Quah
- College of Medicine and Public Health, Flinders University, Adelaide, SA, Australia.,Department of Cardiovascular Medicine, Flinders Medical Centre, Adelaide, SA, Australia
| | - Kathryn Tiver
- Department of Cardiovascular Medicine, Flinders Medical Centre, Adelaide, SA, Australia
| | - Lewis Mitchell
- School of Mathematical Sciences, University of Adelaide, Adelaide, SA, Australia
| | - Feng Xiong
- Montréal Heart Institute and Université de Montréal, Montréal, QC, Canada
| | - Martin Aguilar
- Montréal Heart Institute and Université de Montréal, Montréal, QC, Canada
| | - Kenneth Pope
- College of Science and Engineering, Flinders University, Adelaide, SA, Australia
| | - Fadi G Akar
- School of Medicine, Yale University, New Haven, CT, United States
| | - Caroline H Roney
- School of Engineering and Materials Science, Queen Mary University of London, London, United Kingdom
| | - Steven A Niederer
- School of Biomedical Engineering and Imaging Sciences, Kings College London, London, United Kingdom
| | - Stanley Nattel
- Montréal Heart Institute and Université de Montréal, Montréal, QC, Canada
| | - Martyn P Nash
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Richard H Clayton
- Insigneo Institute for in Silico Medicine and Department of Computer Science, University of Sheffield, Sheffield, United Kingdom
| | - Anand N Ganesan
- College of Medicine and Public Health, Flinders University, Adelaide, SA, Australia.,Department of Cardiovascular Medicine, Flinders Medical Centre, Adelaide, SA, Australia
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16
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Li X, Shi X, Handa BS, Sau A, Zhang B, Qureshi NA, Whinnett ZI, Linton NWF, Lim PB, Kanagaratnam P, Peters NS, Ng FS. Classification of Fibrillation Organisation Using Electrocardiograms to Guide Mechanism-Directed Treatments. Front Physiol 2021; 12:712454. [PMID: 34858198 PMCID: PMC8632359 DOI: 10.3389/fphys.2021.712454] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Accepted: 09/29/2021] [Indexed: 11/13/2022] Open
Abstract
Background: Atrial fibrillation (AF) and ventricular fibrillation (VF) are complex heart rhythm disorders and may be sustained by distinct electrophysiological mechanisms. Disorganised self-perpetuating multiple-wavelets and organised rotational drivers (RDs) localising to specific areas are both possible mechanisms by which fibrillation is sustained. Determining the underlying mechanisms of fibrillation may be helpful in tailoring treatment strategies. We investigated whether global fibrillation organisation, a surrogate for fibrillation mechanism, can be determined from electrocardiograms (ECGs) using band-power (BP) feature analysis and machine learning. Methods: In this study, we proposed a novel ECG classification framework to differentiate fibrillation organisation levels. BP features were derived from surface ECGs and fed to a linear discriminant analysis classifier to predict fibrillation organisation level. Two datasets, single-channel ECGs of rat VF (n = 9) and 12-lead ECGs of human AF (n = 17), were used for model evaluation in a leave-one-out (LOO) manner. Results: The proposed method correctly predicted the organisation level from rat VF ECG with the sensitivity of 75%, specificity of 80%, and accuracy of 78%, and from clinical AF ECG with the sensitivity of 80%, specificity of 92%, and accuracy of 88%. Conclusion: Our proposed method can distinguish between AF/VF of different global organisation levels non-invasively from the ECG alone. This may aid in patient selection and guiding mechanism-directed tailored treatment strategies.
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Affiliation(s)
- Xinyang Li
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Xili Shi
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Balvinder S. Handa
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Arunashis Sau
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Bowen Zhang
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Norman A. Qureshi
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Zachary I. Whinnett
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Nick W. F. Linton
- Department of Bioengineering, Imperial College London, London, United Kingdom
| | - Phang Boon Lim
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Prapa Kanagaratnam
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Nicholas S. Peters
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Fu Siong Ng
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
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17
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He YJ, Li QH, Zhou K, Jiang R, Jiang C, Pan JT, Zheng D, Zheng B, Zhang H. Topological charge-density method of identifying phase singularities in cardiac fibrillation. Phys Rev E 2021; 104:014213. [PMID: 34412332 DOI: 10.1103/physreve.104.014213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Accepted: 06/28/2021] [Indexed: 11/07/2022]
Abstract
Spiral waves represent the key motifs of typical self-sustained dynamical patterns in excitable systems such as cardiac tissue. The motion of phase singularities (PSs) that lies at the center of spiral waves captures many qualitative and, in some cases, quantitative features of their complex dynamics. Recent clinical studies suggested that ablating the tissue at PS locations may cure atrial fibrillation. Here, we propose a different method to determine the location of PSs. Starting from the definition of the topological charge of spiral waves, we obtain the expression of the topological charge density in a discrete case. With this expression, we can calculate the topological charge at each grid in the space directly, so as to accurately identify the position of PSs.
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Affiliation(s)
- Yin-Jie He
- Zhejiang Institute of Modern Physics and Department of Physics, Zhejiang University, Hangzhou 310027, China
| | - Qi-Hao Li
- Zhejiang Institute of Modern Physics and Department of Physics, Zhejiang University, Hangzhou 310027, China
| | - Kuangshi Zhou
- Department of Cardiology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou 310016, China
| | - Ruhong Jiang
- Department of Cardiology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou 310016, China
| | - Chenyang Jiang
- Department of Cardiology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou 310016, China
| | - Jun-Ting Pan
- Ocean College, Zhejiang University, Zhoushan 316021, China
| | - Dafang Zheng
- Zhejiang Institute of Modern Physics and Department of Physics, Zhejiang University, Hangzhou 310027, China
| | - Bo Zheng
- Zhejiang Institute of Modern Physics and Department of Physics, Zhejiang University, Hangzhou 310027, China.,School of Physics and Astronomy, Yunnan University, Kunming 650091, China
| | - Hong Zhang
- Zhejiang Institute of Modern Physics and Department of Physics, Zhejiang University, Hangzhou 310027, China
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18
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Schopp M, Dharmaprani D, Kuklik P, Quah J, Lahiri A, Tiver K, Meyer C, Willems S, McGavigan AD, Ganesan AN. Spatial concentration and distribution of phase singularities in human atrial fibrillation: Insights for the AF mechanism. J Arrhythm 2021; 37:922-930. [PMID: 34386118 PMCID: PMC8339121 DOI: 10.1002/joa3.12547] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 04/10/2021] [Accepted: 04/14/2021] [Indexed: 11/11/2022] Open
Abstract
BACKGROUND Atrial fibrillation (AF) is characterized by the repetitive regeneration of unstable rotational events, the pivot of which are known as phase singularities (PSs). The spatial concentration and distribution of PSs have not been systematically investigated using quantitative statistical approaches. OBJECTIVES We utilized a geospatial statistical approach to determine the presence of local spatial concentration and global clustering of PSs in biatrial human AF recordings. METHODS 64-electrode conventional basket (~5 min, n = 18 patients, persistent AF) recordings were studied. Phase maps were produced using a Hilbert-transform based approach. PSs were characterized spatially using the following approaches: (i) local "hotspots" of high phase singularity (PS) concentration using Getis-Ord Gi* (Z ≥ 1.96, P ≤ .05) and (ii) global spatial clustering using Moran's I (inverse distance matrix). RESULTS Episodes of AF were analyzed from basket catheter recordings (H: 41 epochs, 120 000 s, n = 18 patients). The Getis-Ord Gi* statistic showed local PS hotspots in 12/41 basket recordings. As a metric of spatial clustering, Moran's I showed an overall mean of 0.033 (95% CI: 0.0003-0.065), consistent with the notion of complete spatial randomness. CONCLUSION Using a systematic, quantitative geospatial statistical approach, evidence for the existence of spatial concentrations ("hotspots") of PSs were detectable in human AF, along with evidence of spatial clustering. Geospatial statistical approaches offer a new approach to map and ablate PS clusters using substrate-based approaches.
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Affiliation(s)
- Madeline Schopp
- College of Science and EngineeringFlinders University of South AustraliaAdelaideSAAustralia
| | - Dhani Dharmaprani
- College of Science and EngineeringFlinders University of South AustraliaAdelaideSAAustralia
- College of Medicine and Public HealthFlinders University of South AustraliaAdelaideSAAustralia
| | - Pawel Kuklik
- Department of CardiologyUniversity Medical CentreHamburgGermany
| | - Jing Quah
- College of Medicine and Public HealthFlinders University of South AustraliaAdelaideSAAustralia
- Department of Cardiovascular MedicineFlinders Medical CentreAdelaideSAAustralia
| | - Anandaroop Lahiri
- Department of Cardiovascular MedicineFlinders Medical CentreAdelaideSAAustralia
| | - Kathryn Tiver
- College of Medicine and Public HealthFlinders University of South AustraliaAdelaideSAAustralia
- Department of Cardiovascular MedicineFlinders Medical CentreAdelaideSAAustralia
| | - Christian Meyer
- Department of CardiologyUniversity Medical CentreHamburgGermany
| | - Stephan Willems
- Department of CardiologyUniversity Medical CentreHamburgGermany
| | - Andrew D. McGavigan
- Department of Cardiovascular MedicineFlinders Medical CentreAdelaideSAAustralia
| | - Anand N. Ganesan
- College of Medicine and Public HealthFlinders University of South AustraliaAdelaideSAAustralia
- Department of Cardiovascular MedicineFlinders Medical CentreAdelaideSAAustralia
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19
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Investigational Anti-Atrial Fibrillation Pharmacology and Mechanisms by Which Antiarrhythmics Terminate the Arrhythmia: Where Are We in 2020? J Cardiovasc Pharmacol 2021; 76:492-505. [PMID: 33165131 PMCID: PMC7641178 DOI: 10.1097/fjc.0000000000000892] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Antiarrhythmic drugs remain the mainstay therapy for patients with atrial fibrillation (AF). A major disadvantage of the currently available anti-AF agents is the risk of induction of ventricular proarrhythmias. Aiming to reduce this risk, several atrial-specific or -selective ion channel block approaches have been introduced for AF suppression, but only the atrial-selective inhibition of the sodium channel has been demonstrated to be valid in both experimental and clinical studies. Among the other pharmacological anti-AF approaches, “upstream therapy” has been prominent but largely disappointing, and pulmonary delivery of anti-AF drugs seems to be promising. Major contradictions exist in the literature about the electrophysiological mechanisms of AF (ie, reentry or focal?) and the mechanisms by which anti-AF drugs terminate AF, making the search for novel anti-AF approaches largely empirical. Drug-induced termination of AF may or may not be associated with prolongation of the atrial effective refractory period. Anti-AF drug research has been largely based on the “suppress reentry” ideology; however, results of the AF mapping studies increasingly indicate that nonreentrant mechanism(s) plays an important role in the maintenance of AF. Also, the analysis of anti-AF drug-induced electrophysiological alterations during AF, conducted in the current study, leans toward the focal source as the prime mechanism of AF maintenance. More effort should be placed on the investigation of pharmacological suppression of the focal mechanisms.
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20
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Denham NC, Pearman CM, Madders GWP, Smith CER, Trafford AW, Dibb KM. Optimising Large Animal Models of Sustained Atrial Fibrillation: Relevance of the Critical Mass Hypothesis. Front Physiol 2021; 12:690897. [PMID: 34211405 PMCID: PMC8239221 DOI: 10.3389/fphys.2021.690897] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2021] [Accepted: 05/24/2021] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND Large animal models play an important role in our understanding of the pathophysiology of atrial fibrillation (AF). Our aim was to determine whether prospectively collected baseline variables could predict the development of sustained AF in sheep, thereby reducing the number of animals required in future studies. Our hypothesis was that the relationship between atrial dimensions, refractory periods and conduction velocity (otherwise known as the critical mass hypothesis) could be used for the first time to predict the development of sustained AF. METHODS Healthy adult Welsh mountain sheep underwent a baseline electrophysiology study followed by implantation of a neurostimulator connected via an endocardial pacing lead to the right atrial appendage. The device was programmed to deliver intermittent 50 Hz bursts of 30 s duration over an 8-week period whilst sheep were monitored for AF. RESULTS Eighteen sheep completed the protocol, of which 28% developed sustained AF. Logistic regression analysis showed only fibrillation number (calculated using the critical mass hypothesis as the left atrial diameter divided by the product of atrial conduction velocity and effective refractory period) was associated with an increased likelihood of developing sustained AF (Ln Odds Ratio 26.1 [95% confidence intervals 0.2-52.0] p = 0.048). A receiver-operator characteristic curve showed this could be used to predict which sheep developed sustained AF (C-statistic 0.82 [95% confidence intervals 0.59-1.04] p = 0.04). CONCLUSION The critical mass hypothesis can be used to predict sustained AF in a tachypaced ovine model. These findings can be used to optimise the design of future studies involving large animals.
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Affiliation(s)
- Nathan C. Denham
- Unit of Cardiac Physiology, Institute of Cardiovascular Sciences, Manchester Academic Health Sciences Centre, The University of Manchester, Manchester, United Kingdom
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21
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Abad R, Collart O, Ganesan P, Rogers AJ, Alhusseini MI, Rodrigo M, Narayan SM, Rappel WJ. Three dimensional reconstruction to visualize atrial fibrillation activation patterns on curved atrial geometry. PLoS One 2021; 16:e0249873. [PMID: 33836026 PMCID: PMC8034734 DOI: 10.1371/journal.pone.0249873] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Accepted: 03/26/2021] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND The rotational activation created by spiral waves may be a mechanism for atrial fibrillation (AF), yet it is unclear how activation patterns obtained from endocardial baskets are influenced by the 3D geometric curvature of the atrium or 'unfolding' into 2D maps. We develop algorithms that can visualize spiral waves and their tip locations on curved atrial geometries. We use these algorithms to quantify differences in AF maps and spiral tip locations between 3D basket reconstructions, projection onto 3D anatomical shells and unfolded 2D surfaces. METHODS We tested our algorithms in N = 20 patients in whom AF was recorded from 64-pole baskets (Abbott, CA). Phase maps were generated by non-proprietary software to identify the tips of spiral waves, indicated by phase singularities. The number and density of spiral tips were compared in patient-specific 3D shells constructed from the basket, as well as 3D maps from clinical electroanatomic mapping systems and 2D maps. RESULTS Patients (59.4±12.7 yrs, 60% M) showed 1.7±0.8 phase singularities/patient, in whom ablation terminated AF in 11/20 patients (55%). There was no difference in the location of phase singularities, between 3D curved surfaces and 2D unfolded surfaces, with a median correlation coefficient between phase singularity density maps of 0.985 (0.978-0.990). No significant impact was noted by phase singularities location in more curved regions or relative to the basket location (p>0.1). CONCLUSIONS AF maps and phase singularities mapped by endocardial baskets are qualitatively and quantitatively similar whether calculated by 3D phase maps on patient-specific curved atrial geometries or in 2D. Phase maps on patient-specific geometries may be easier to interpret relative to critical structures for ablation planning.
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Affiliation(s)
- Ricardo Abad
- Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, California, United States of America
| | - Orvil Collart
- Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, California, United States of America
| | - Prasanth Ganesan
- Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, California, United States of America
| | - A. J. Rogers
- Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, California, United States of America
| | - Mahmood I. Alhusseini
- Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, California, United States of America
| | - Miguel Rodrigo
- Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, California, United States of America
- Universitat Politècnica de València, Valencia, Spain
| | - Sanjiv M. Narayan
- Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, California, United States of America
- * E-mail: (SMN); (WJR)
| | - Wouter-Jan Rappel
- Department of Physics, UC San Diego, La Jolla, California, United States of America
- * E-mail: (SMN); (WJR)
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22
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Heitmann S, Shpak A, Vandenberg JI, Hill AP. Arrhythmogenic effects of ultra-long and bistable cardiac action potentials. PLoS Comput Biol 2021; 17:e1008683. [PMID: 33591969 PMCID: PMC7909657 DOI: 10.1371/journal.pcbi.1008683] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 02/26/2021] [Accepted: 01/08/2021] [Indexed: 12/04/2022] Open
Abstract
Contemporary accounts of the initiation of cardiac arrhythmias typically rely on after-depolarizations as the trigger for reentrant activity. The after-depolarizations are usually triggered by calcium entry or spontaneous release within the cells of the myocardium or the conduction system. Here we propose an alternative mechanism whereby arrhythmias are triggered autonomously by cardiac cells that fail to repolarize after a normal heartbeat. We investigated the proposal by representing the heart as an excitable medium of FitzHugh-Nagumo cells where a proportion of cells were capable of remaining depolarized indefinitely. As such, those cells exhibit bistable membrane dynamics. We found that heterogeneous media can tolerate a surprisingly large number of bistable cells and still support normal rhythmic activity. Yet there is a critical limit beyond which the medium is persistently arrhythmogenic. Numerical analysis revealed that the critical threshold for arrhythmogenesis depends on both the strength of the coupling between cells and the extent to which the abnormal cells resist repolarization. Moreover, arrhythmogenesis was found to emerge preferentially at tissue boundaries where cells naturally have fewer neighbors to influence their behavior. These findings may explain why atrial fibrillation typically originates from tissue boundaries such as the cuff of the pulmonary vein. Cardiac fibrillation is a medical condition where normal heart function is compromised as electrical activity becomes disordered. How fibrillation arises spontaneously is not fully understood. It is generally thought to be triggered by premature depolarization of the cardiac action potential in one or more cells. Those premature beats, known as after-depolarizations, subsequently initiate a self-sustaining rotor in the otherwise normal heart tissue. In this study, we propose an alternative mechanism whereby arrhythmias are initiated by cardiac cells that fail to repolarize of their own accord but still operate normally when embedded in functional heart tissue. We find that such cells can act as focal ectopic sources under appropriate conditions of inter-cellular coupling. Moreover, those cells are more prone to initiating arrhythmia when they are located on natural tissue boundaries. This may explain why atrial fibrillation typically originates from the site where the pulmonary vein attaches to the wall of the heart.
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Affiliation(s)
- Stewart Heitmann
- Victor Chang Cardiac Research Institute, Darlinghurst, NSW, Australia
- * E-mail:
| | - Anton Shpak
- Victor Chang Cardiac Research Institute, Darlinghurst, NSW, Australia
- Victor Chang Cardiac Research Institute Innovation Centre, Darlinghurst, NSW, Australia
| | - Jamie I. Vandenberg
- Victor Chang Cardiac Research Institute, Darlinghurst, NSW, Australia
- St Vincent’s Clinical School, UNSW Sydney, Kensington, NSW, Australia
| | - Adam P. Hill
- Victor Chang Cardiac Research Institute, Darlinghurst, NSW, Australia
- Victor Chang Cardiac Research Institute Innovation Centre, Darlinghurst, NSW, Australia
- St Vincent’s Clinical School, UNSW Sydney, Kensington, NSW, Australia
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23
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Lațcu DG, Enache B, Hasni K, Wedn AM, Zarqane N, Pathak A, Saoudi N. Sequential ultrahigh-density contact mapping of persistent atrial fibrillation: An efficient technique for driver identification. J Cardiovasc Electrophysiol 2020; 32:29-40. [PMID: 33155347 DOI: 10.1111/jce.14803] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 10/03/2020] [Accepted: 10/29/2020] [Indexed: 01/02/2023]
Abstract
INTRODUCTION Literature supports the existence of drivers as maintainers of atrial fibrillation (AF). Whether ultrahigh density (UHD) contact mapping may detect them is unknown. METHODS We sequentially mapped the left atrial (LA) activation during spontaneous persistent AF and performed circumferential pulmonary vein isolation (CPVI), followed by remapping and ablation of potential drivers (rotational and focal propagation sites) with Rhythmia™ in 90 patients. The time reference was an LA appendage (LAA) electrogram (EGM). Regions with uniform color were defined as "organized." Only patients (51) with no previous ablation were considered for acute results and follow-up reporting. RESULTS LA maps (175 ± 28 ml, 43578 ± 18013 EGM) were acquired in 23 ± 7 min. In all post-CPVI maps potential drivers (7.3 ± 3.2/patient) were visualized: 85% with rotational propagation and continuous low voltage in the center; the remaining with focal propagation and an organized EGM at the site of earliest activation. The RF delivery time for extra-PV driver ablation was 12.2 ± 7.9 min. There was a progressive increase of AF organization: the LAA cycle length prolonged, the number of potential drivers decreased, and the organized LA surface in AF increased from 14 ± 6% to 28 ± 16% (p = .0007). Termination of AF without cardioversion was obtained in 67%. AF recurrence rate at 15 ± 7.3 months was 17.6% after the first procedure. CONCLUSIONS Sequential UHD contact activation mapping of persistent AF allows visualization of potential drivers. A sequential strategy of CPVI followed by ablation of potential drivers with limited RF time resulted in an increasing organization of AF and good acute and long-term results.
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Affiliation(s)
| | - Bogdan Enache
- Centre Hospitalier Princesse Grace, Monaco.,University of Medecine and Pharmacy Timişoara, Timişoara, Romania
| | | | - Ahmed M Wedn
- Centre Hospitalier Princesse Grace, Monaco.,Department of Critical Care, Cairo University, Cairo, Egypt
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24
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Ho G, Lin AY, Krummen DE. Linking Electrical Drivers With Atrial Cardiomyopathy for the Targeted Treatment of Atrial Fibrillation. Front Physiol 2020; 11:570740. [PMID: 33281614 PMCID: PMC7689158 DOI: 10.3389/fphys.2020.570740] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Accepted: 09/22/2020] [Indexed: 12/19/2022] Open
Abstract
The relationship between atrial fibrillation (AF) and underlying functional and structural abnormalities has received substantial attention in the research literature over the past decade. Significant progress has been made in identifying these changes using non-invasive imaging, voltage mapping, and electrical recordings. Advances in computed tomography and cardiac magnetic resonance imaging can now provide insight regarding the presence and extent of cardiac fibrosis. Additionally, multiple technologies able to identify electrical targets during AF have emerged. However, an organized strategy to employ these resources in the targeted treatment of AF remains elusive. In this work, we will discuss the basis for mechanistic importance of atrial fibrosis and scar as potential sites promoting AF and emerging technologies to identify and target these structural and functional substrates in the electrophysiology laboratory. We also propose an approach to the use of such technologies to serve as a basis for ongoing work in the field.
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Affiliation(s)
- Gordon Ho
- Division of Cardiology, Department of Medicine, University of California, San Diego, San Diego, CA, United States
- Division of Cardiology, Veterans Affairs San Diego Medical Center, San Diego, CA, United States
| | - Andrew Y. Lin
- Division of Cardiology, Department of Medicine, University of California, San Diego, San Diego, CA, United States
- Division of Cardiology, Veterans Affairs San Diego Medical Center, San Diego, CA, United States
| | - David E. Krummen
- Division of Cardiology, Department of Medicine, University of California, San Diego, San Diego, CA, United States
- Division of Cardiology, Veterans Affairs San Diego Medical Center, San Diego, CA, United States
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25
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Lipovsky CE, Jimenez J, Guo Q, Li G, Yin T, Hicks SC, Bhatnagar S, Takahashi K, Zhang DM, Brumback BD, Goldsztejn U, Nadadur RD, Perez-Cervantez C, Moskowitz IP, Liu S, Zhang B, Rentschler SL. Chamber-specific transcriptional responses in atrial fibrillation. JCI Insight 2020; 5:135319. [PMID: 32841220 PMCID: PMC7526559 DOI: 10.1172/jci.insight.135319] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Accepted: 08/19/2020] [Indexed: 12/30/2022] Open
Abstract
Atrial fibrillation (AF) is the most common cardiac arrhythmia, yet the molecular signature of the vulnerable atrial substrate is not well understood. Here, we delineated a distinct transcriptional signature in right versus left atrial cardiomyocytes (CMs) at baseline and identified chamber-specific gene expression changes in patients with a history of AF in the setting of end-stage heart failure (AF+HF) that are not present in heart failure alone (HF). We observed that human left atrial (LA) CMs exhibited Notch pathway activation and increased ploidy in AF+HF but not in HF alone. Transient activation of Notch signaling within adult CMs in a murine genetic model is sufficient to increase ploidy in both atrial chambers. Notch activation within LA CMs generated a transcriptomic fingerprint resembling AF, with dysregulation of transcription factor and ion channel genes, including Pitx2, Tbx5, Kcnh2, Kcnq1, and Kcnip2. Notch activation also produced distinct cellular electrophysiologic responses in LA versus right atrial CMs, prolonging the action potential duration (APD) without altering the upstroke velocity in the left atrium and reducing the maximal upstroke velocity without altering the APD in the right atrium. Our results support a shared human/murine model of increased Notch pathway activity predisposing to AF. Distinct transcriptional changes occur in human left versus right atrial cardiomyocytes in atrial fibrillation, including Notch pathway activation, which alters electric properties and ploidy in murine models.
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Affiliation(s)
- Catherine E Lipovsky
- Department of Medicine, Cardiovascular Division.,Department of Developmental Biology, and
| | | | - Qiusha Guo
- Department of Medicine, Cardiovascular Division
| | - Gang Li
- Department of Medicine, Cardiovascular Division.,Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Tiankai Yin
- Department of Medicine, Cardiovascular Division
| | | | - Somya Bhatnagar
- Department of Medicine, Cardiovascular Division.,Department of Developmental Biology, and
| | | | | | - Brittany D Brumback
- Department of Medicine, Cardiovascular Division.,Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Uri Goldsztejn
- Department of Medicine, Cardiovascular Division.,Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Rangarajan D Nadadur
- Departments of Pediatrics, Pathology, and Human Genetics, Biological Sciences Division, University of Chicago, Chicago, Illinois, USA
| | - Carlos Perez-Cervantez
- Departments of Pediatrics, Pathology, and Human Genetics, Biological Sciences Division, University of Chicago, Chicago, Illinois, USA
| | - Ivan P Moskowitz
- Departments of Pediatrics, Pathology, and Human Genetics, Biological Sciences Division, University of Chicago, Chicago, Illinois, USA
| | | | - Bo Zhang
- Department of Developmental Biology, and
| | - Stacey L Rentschler
- Department of Medicine, Cardiovascular Division.,Department of Developmental Biology, and.,Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, Missouri, USA
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26
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Zhao N, Li Q, Zhang K, Wang K, He R, Yuan Y, Zhang H. Heart failure-induced atrial remodelling promotes electrical and conduction alternans. PLoS Comput Biol 2020; 16:e1008048. [PMID: 32658888 PMCID: PMC7402519 DOI: 10.1371/journal.pcbi.1008048] [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: 01/02/2020] [Revised: 08/04/2020] [Accepted: 06/12/2020] [Indexed: 11/19/2022] Open
Abstract
Heart failure (HF) is associated with an increased propensity for atrial fibrillation (AF), causing higher mortality than AF or HF alone. It is hypothesized that HF-induced remodelling of atrial cellular and tissue properties promotes the genesis of atrial action potential (AP) alternans and conduction alternans that perpetuate AF. However, the mechanism underlying the increased susceptibility to atrial alternans in HF remains incompletely elucidated. In this study, we investigated the effects of how HF-induced atrial cellular electrophysiological (with prolonged AP duration) and tissue structural (reduced cell-to-cell coupling caused by atrial fibrosis) remodelling can have an effect on the generation of atrial AP alternans and their conduction at the cellular and one-dimensional (1D) tissue levels. Simulation results showed that HF-induced atrial electrical remodelling prolonged AP duration, which was accompanied by an increased sarcoplasmic reticulum (SR) Ca2+ content and Ca2+ transient amplitude. Further analysis demonstrated that HF-induced atrial electrical remodelling increased susceptibility to atrial alternans mainly due to the increased sarcoplasmic reticulum Ca2+-ATPase (SERCA) Ca2+ reuptake, modulated by increased phospholamban (PLB) phosphorylation, and the decreased transient outward K+ current (Ito). The underlying mechanism has been suggested that the increased SR Ca2+ content and prolonged AP did not fully recover to their previous levels at the end of diastole, resulting in a smaller SR Ca2+ release and AP in the next beat. These produced Ca2+ transient alternans and AP alternans, and further caused AP alternans and Ca2+ transient alternans through Ca2+→AP coupling and AP→Ca2+ coupling, respectively. Simulation of a 1D tissue model showed that the combined action of HF-induced ion channel remodelling and a decrease in cell-to-cell coupling due to fibrosis increased the heart tissue’s susceptibility to the formation of spatially discordant alternans, resulting in an increased functional AP propagation dispersion, which is pro-arrhythmic. These findings provide insights into how HF promotes atrial arrhythmia in association with atrial alternans. Atrial Fibrillation (AF) is the most common arrhythmia in adults, especially in the elderly, with the increased incidence of stroke being a major complication that increases morbidity and mortality. The occurrence of AF is often accompanied by heart failure (HF). AF and HF are also known to have the bidirectional relationship that AF worsens HF and HF promotes AF. HF can induce atrial remodelling, including electrical remodelling, atrial fibrosis, stretch and dilatation, and oxidative stress, in which many factors are associated with arrhythmogenic atrial alternans. HF-induced atrial remodelling varies during various stages and complications of HF, but possible mechanisms underlying their pro-susceptibility to alternans have not been completely elucidated. In this study, we investigated the effects of HF-induced atrial remodelling with prolonged action potential duration (APD) and decreased cell-to-cell coupling on susceptibility to atrial alternans. Simulation results showed that HF-induced an increase in sarcoplasmic reticulum Ca2+-ATPase (SERCA) Ca2+ reuptake caused by increased phospholamban phosphorylation and a decrease in transient outward K+ current played significant roles in the genesis of Ca2+ transient alternans and action potential alternans at the single-cell level. The HF-induced decline of cell-to-cell coupling and APD prolongation promoted the genesis of spatially discordant alternans in atrial tissue. This provides insights into how HF facilitates atrial arrhythmia in relation to atrial alternans.
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Affiliation(s)
- Na Zhao
- School of Computer Science and Technology, Harbin Institute of Technology, Harbin, China
| | - Qince Li
- School of Computer Science and Technology, Harbin Institute of Technology, Harbin, China
- Peng Cheng Laboratory, Shenzhen, China
| | - Kevin Zhang
- School of Medicine, Imperial College of London, United Kingdom
| | - Kuanquan Wang
- School of Computer Science and Technology, Harbin Institute of Technology, Harbin, China
| | - Runnan He
- School of Computer Science and Technology, Harbin Institute of Technology, Harbin, China
| | - Yongfeng Yuan
- School of Computer Science and Technology, Harbin Institute of Technology, Harbin, China
| | - Henggui Zhang
- School of Computer Science and Technology, Harbin Institute of Technology, Harbin, China
- Peng Cheng Laboratory, Shenzhen, China
- School of Physics & Astronomy, The University of Manchester, Manchester, United Kingdom
- Key Laboratory of Medical Electrophysiology of Ministry of Education and Medical Electrophysiological Key Laboratory of Sichuan Province, Institute of Cardiovascular Research, Southwest Medical University, Luzhou, China
- * E-mail:
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27
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Role of Oxidation-Dependent CaMKII Activation in the Genesis of Abnormal Action Potentials in Atrial Cardiomyocytes: A Simulation Study. BIOMED RESEARCH INTERNATIONAL 2020; 2020:1597012. [PMID: 32685443 PMCID: PMC7327560 DOI: 10.1155/2020/1597012] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Revised: 05/20/2020] [Accepted: 06/02/2020] [Indexed: 01/04/2023]
Abstract
Atrial fibrillation is a common cardiac arrhythmia with an increasing incidence rate. Particularly for the aging population, understanding the underlying mechanisms of atrial arrhythmia is important in designing clinical treatment. Recently, experiments have shown that atrial arrhythmia is associated with oxidative stress. In this study, an atrial cell model including oxidative-dependent Ca2+/calmodulin- (CaM-) dependent protein kinase II (CaMKII) activation was developed to explore the intrinsic mechanisms of atrial arrhythmia induced by oxidative stress. The simulation results showed that oxidative stress caused early afterdepolarizations (EADs) of action potentials by altering the dynamics of transmembrane currents and intracellular calcium cycling. Oxidative stress gradually elevated the concentration of calcium ions in the cytoplasm by enhancing the L-type Ca2+ current and sarcoplasmic reticulum (SR) calcium release. Owing to increased intracellular calcium concentration, the inward Na+/Ca2+ exchange current was elevated which slowed down the repolarization of the action potential. Thus, the action potential was prolonged and the L-type Ca2+ current was reactivated, resulting in the genesis of EAD. Furthermore, based on the atrial single-cell model, a two-dimensional (2D) ideal tissue model was developed to explore the effect of oxidative stress on the electrical excitation wave conduction in 2D tissue. Simulation results demonstrated that, under oxidative stress conditions, EAD hindered the conduction of electrical excitation and caused an unstable spiral wave, which could disrupt normal cardiac rhythm and cause atrial arrhythmia. This study showed the effects of excess reactive oxygen species on calcium cycling and action potential in atrial myocytes and provided insights regarding atrial arrhythmia induced by oxidative stress.
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28
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Hiram R, Naud P, Xiong F, Al-U'datt D, Algalarrondo V, Sirois MG, Tanguay JF, Tardif JC, Nattel S. Right Atrial Mechanisms of Atrial Fibrillation in a Rat Model of Right Heart Disease. J Am Coll Cardiol 2020; 74:1332-1347. [PMID: 31488271 DOI: 10.1016/j.jacc.2019.06.066] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Revised: 05/29/2019] [Accepted: 06/24/2019] [Indexed: 10/26/2022]
Abstract
BACKGROUND Conditions affecting the right heart, including diseases of the lungs and pulmonary circulation, promote atrial fibrillation (AF), but the mechanisms are poorly understood. OBJECTIVES This study sought to determine whether right heart disease promotes atrial arrhythmogenesis in a rat model of pulmonary hypertension (PH) and, if so, to define the underlying mechanisms. METHODS PH was induced in male Wistar rats with a single intraperitoneal injection of 60 mg/kg of monocrotaline, and rats were studied 21 days later when right heart disease was well developed. AF vulnerability was assessed in vivo and in situ, and mechanisms were defined by optical mapping, histochemistry, and biochemistry. RESULTS Monocrotaline-treated rats developed increased right ventricular pressure and mass, along with right atrial (RA) enlargement. AF/flutter was inducible in 32 of 32 PH rats (100%) in vivo and 11 of 12 (92%) in situ, versus 2 of 32 (6%) and 2 of 12 (17%), respectively, in control rats (p < 0.001 vs. PH for each). PH rats had significant RA (16.1 ± 0.5% of cross-sectional area, vs. 3.0 ± 0.6% in control) and left atrial (LA: 11.8 ± 0.5% vs. 5.4 ± 0.8% control) fibrosis. Multiple extracellular matrix proteins, including collagen 1 and 3, fibronectin, and matrix metalloproteinases 2 and 9, were up-regulated in PH rat RA. Optical mapping revealed significant rate-dependent RA conduction slowing and rotor activity, including stable rotors in 4 of 11 PH rats, whereas no significant conduction slowing or rotor activity occurred in the LA of monocrotaline-treated rats. Transcriptomic analysis revealed differentially enriched genes related to hypertrophy, inflammation, and fibrosis in RA of monocrotaline-treated rats versus control. Biochemical results in PH rats were compared with those of AF-prone rats with atrial remodeling in the context of left ventricular dysfunction due to myocardial infarction: myocardial infarction rat LA shared molecular motifs with PH rat RA. CONCLUSIONS Right heart disease produces a substrate for AF maintenance due to RA re-entrant activity, with an underlying substrate prominently involving RA fibrosis and conduction abnormalities.
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Affiliation(s)
- Roddy Hiram
- Montreal Heart Institute (MHI), Department of Medicine, Université de Montréal, Montreal, Quebec, Canada
| | - Patrice Naud
- Montreal Heart Institute (MHI), Department of Medicine, Université de Montréal, Montreal, Quebec, Canada
| | - Feng Xiong
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec, Canada
| | - Doa'a Al-U'datt
- Montreal Heart Institute (MHI), Department of Medicine, Université de Montréal, Montreal, Quebec, Canada
| | - Vincent Algalarrondo
- Montreal Heart Institute (MHI), Department of Medicine, Université de Montréal, Montreal, Quebec, Canada
| | - Martin G Sirois
- Montreal Heart Institute (MHI), Department of Medicine, Université de Montréal, Montreal, Quebec, Canada
| | - Jean-François Tanguay
- Montreal Heart Institute (MHI), Department of Medicine, Université de Montréal, Montreal, Quebec, Canada
| | - Jean-Claude Tardif
- Montreal Heart Institute (MHI), Department of Medicine, Université de Montréal, Montreal, Quebec, Canada
| | - Stanley Nattel
- Montreal Heart Institute (MHI), Department of Medicine, Université de Montréal, Montreal, Quebec, Canada; Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec, Canada; IHU Liryc and Fondation Bordeaux Université, Bordeaux, France; Institute of Pharmacology, West German Heart and Vascular Center, Faculty of Medicine, University Duisburg-Essen, Essen, Germany.
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29
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Liu T, Xiong F, Qi XY, Xiao J, Villeneuve L, Abu-Taha I, Dobrev D, Huang C, Nattel S. Altered calcium handling produces reentry-promoting action potential alternans in atrial fibrillation-remodeled hearts. JCI Insight 2020; 5:133754. [PMID: 32255765 DOI: 10.1172/jci.insight.133754] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Accepted: 03/25/2020] [Indexed: 12/19/2022] Open
Abstract
Atrial fibrillation (AF) alters atrial cardiomyocyte (ACM) Ca2+ handling, promoting ectopic beat formation. We examined the effects of AF-associated remodeling on Ca2+-related action potential dynamics and consequences for AF susceptibility. AF was maintained electrically in dogs by right atrial (RA) tachypacing. ACMs isolated from AF dogs showed increased Ca2+ release refractoriness, spontaneous Ca2+ spark frequency, and cycle length (CL) threshold for Ca2+ and action potential duration (APD) alternans versus controls. AF increased the in situ CL threshold for Ca2+/APD alternans and spatial dispersion in Ca2+ release recovery kinetics, leading to spatially discordant alternans associated with reentrant rotor formation and susceptibility to AF induction/maintenance. The clinically available agent dantrolene reduced Ca2+ leak and CL threshold for Ca2+/APD alternans in ACMs and AF dog right atrium, while suppressing AF susceptibility; caffeine increased Ca2+ leak and CL threshold for Ca2+/APD alternans in control dog ACMs and RA tissues. In vivo, the atrial repolarization alternans CL threshold was increased in AF versus control, as was AF vulnerability. Intravenous dantrolene restored repolarization alternans threshold and reduced AF vulnerability. Immunoblots showed reduced expression of total and phosphorylated ryanodine receptors and calsequestrin in AF and unchanged phospholamban/SERCA expression. Thus, along with promoting spontaneous ectopy, AF-induced Ca2+ handling abnormalities favor AF by enhancing vulnerability to repolarization alternans, promoting initiation and maintenance of reentrant activity; dantrolene provides a lead molecule to target this mechanism.
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Affiliation(s)
- Tao Liu
- Montreal Heart Institute, Department of Medicine, Université de Montréal, Montréal, Québec, Canada.,Department of Cardiology, Renmin Hospital of Wuhan University, China.,Cardiovascular Research Institute, Wuhan University, China.,Hubei Key Laboratory of Cardiology, Wuhan, China
| | - Feng Xiong
- Montreal Heart Institute, Department of Medicine, Université de Montréal, Montréal, Québec, Canada.,Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada
| | - Xiao-Yan Qi
- Montreal Heart Institute, Department of Medicine, Université de Montréal, Montréal, Québec, Canada
| | - Jiening Xiao
- Montreal Heart Institute, Department of Medicine, Université de Montréal, Montréal, Québec, Canada
| | - Louis Villeneuve
- Montreal Heart Institute, Department of Medicine, Université de Montréal, Montréal, Québec, Canada
| | - Issam Abu-Taha
- Institute of Pharmacology, West German Heart and Vascular Center, Faculty of Medicine, University Duisburg-Essen, Germany
| | - Dobromir Dobrev
- Institute of Pharmacology, West German Heart and Vascular Center, Faculty of Medicine, University Duisburg-Essen, Germany
| | - Congxin Huang
- Department of Cardiology, Renmin Hospital of Wuhan University, China.,Cardiovascular Research Institute, Wuhan University, China.,Hubei Key Laboratory of Cardiology, Wuhan, China
| | - Stanley Nattel
- Montreal Heart Institute, Department of Medicine, Université de Montréal, Montréal, Québec, Canada.,Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada.,Institute of Pharmacology, West German Heart and Vascular Center, Faculty of Medicine, University Duisburg-Essen, Germany.,IHU LIRYC Institute, Fondation Bordeaux Université, Bordeaux, France
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30
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The Therapeutic Potential of MicroRNAs in Atrial Fibrillation. Mediators Inflamm 2020; 2020:3053520. [PMID: 32256190 PMCID: PMC7091547 DOI: 10.1155/2020/3053520] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 03/03/2020] [Indexed: 12/12/2022] Open
Abstract
One of the most globally prevalent supraventricular arrhythmias is atrial fibrillation (AF). Knowledge of the structures and functions of messenger RNA (mRNA) has recently increased. It is no longer viewed as solely an intermediate molecule between DNA and proteins but has come to be seen as a dynamic and modifiable gene regulator. This new perspective on mRNA has led to rising interest in it and its presence in research into new therapeutic schemes. This paper, therefore, focuses on microRNAs (miRNAs), which are small noncoding RNAs that regulate posttranscriptional gene expression and play a vital role in the physiology and normative development of cardiovascular systems. This means they play an equally vital role in the development and progression of cardiovascular diseases. In recent years, multiple studies have pinpointed particular miRNA expression profiles as being associated with varying histological features of AF. These studies have been carried out in both animal models and AF patients. The emergence of miRNAs as biomarkers and their therapeutic potential in AF patients will be discussed in the body of this paper.
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31
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Zaman J, Baykaner T, Narayan SM. Mapping and Ablation of Rotational and Focal Drivers in Atrial Fibrillation. Card Electrophysiol Clin 2020; 11:583-595. [PMID: 31706467 DOI: 10.1016/j.ccep.2019.08.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Drivers are increasingly studied ablation targets for atrial fibrillation (AF). However, results from ablation remain controversial. First, outcomes vary between centers and patients. Second, it is unclear how best to perform driver ablation. Third, there is a lack of practical guidance on how to identify critical from secondary sites using different AF mapping methods. This article addresses each of these issues.
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Affiliation(s)
- Junaid Zaman
- Stanford University, 780 Welch Road, Suite CJ250F, Stanford, CA 94305, USA; Imperial College London, London, UK
| | - Tina Baykaner
- Department of Medicine/Cardiovascular Medicine, Stanford University, 780 Welch Road, Suite CJ250F, Stanford, CA 94305, USA
| | - Sanjiv M Narayan
- Department of Medicine/Cardiovascular Medicine and Cardiovascular Institute, Stanford University, 780 Welch Road, Suite CJ250F, MC 5773, Stanford, CA 94305, USA.
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Handa BS, Li X, Aras KK, Qureshi NA, Mann I, Chowdhury RA, Whinnett ZI, Linton NW, Lim PB, Kanagaratnam P, Efimov IR, Peters NS, Ng FS. Granger Causality-Based Analysis for Classification of Fibrillation Mechanisms and Localization of Rotational Drivers. Circ Arrhythm Electrophysiol 2020; 13:e008237. [PMID: 32064900 PMCID: PMC7069398 DOI: 10.1161/circep.119.008237] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Accepted: 02/04/2020] [Indexed: 11/16/2022]
Abstract
BACKGROUND The mechanisms sustaining myocardial fibrillation remain disputed, partly due to a lack of mapping tools that can accurately identify the mechanism with low spatial resolution clinical recordings. Granger causality (GC) analysis, an econometric tool for quantifying causal relationships between complex time-series, was developed as a novel fibrillation mapping tool and adapted to low spatial resolution sequentially acquired data. METHODS Ventricular fibrillation (VF) optical mapping was performed in Langendorff-perfused Sprague-Dawley rat hearts (n=18), where novel algorithms were developed using GC-based analysis to (1) quantify causal dependence of neighboring signals and plot GC vectors, (2) quantify global organization with the causality pairing index, a measure of neighboring causal signal pairs, and (3) localize rotational drivers (RDs) by quantifying the circular interdependence of neighboring signals with the circular interdependence value. GC-based mapping tools were optimized for low spatial resolution from downsampled optical mapping data, validated against high-resolution phase analysis and further tested in previous VF optical mapping recordings of coronary perfused donor heart left ventricular wedge preparations (n=12), and adapted for sequentially acquired intracardiac electrograms during human persistent atrial fibrillation mapping (n=16). RESULTS Global VF organization quantified by causality pairing index showed a negative correlation at progressively lower resolutions (50% resolution: P=0.006, R2=0.38, 12.5% resolution, P=0.004, R2=0.41) with a phase analysis derived measure of disorganization, locations occupied by phase singularities. In organized VF with high causality pairing index values, GC vector mapping characterized dominant propagating patterns and localized stable RDs, with the circular interdependence value showing a significant difference in driver versus nondriver regions (0.91±0.05 versus 0.35±0.06, P=0.0002). These findings were further confirmed in human VF. In persistent atrial fibrillation, a positive correlation was found between the causality pairing index and presence of stable RDs (P=0.0005,R2=0.56). Fifty percent of patients had RDs, with a low incidence of 0.9±0.3 RDs per patient. CONCLUSIONS GC-based fibrillation analysis can measure global fibrillation organization, characterize dominant propagating patterns, and map RDs using low spatial resolution sequentially acquired data.
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Affiliation(s)
- Balvinder S. Handa
- National Heart & Lung Institute, Imperial College London, United Kingdom (B.S.H., X.L., N.A.Q., I.M., R.A.C., Z.I.W., N.W.F.L., P.B.L., P.K., N.S.P., F.S.N.)
| | - Xinyang Li
- National Heart & Lung Institute, Imperial College London, United Kingdom (B.S.H., X.L., N.A.Q., I.M., R.A.C., Z.I.W., N.W.F.L., P.B.L., P.K., N.S.P., F.S.N.)
| | - Kedar K. Aras
- Department of Biomedical Engineering, George Washington University, Washington, DC (K.K.A., I.R.E.)
| | - Norman A. Qureshi
- National Heart & Lung Institute, Imperial College London, United Kingdom (B.S.H., X.L., N.A.Q., I.M., R.A.C., Z.I.W., N.W.F.L., P.B.L., P.K., N.S.P., F.S.N.)
| | - Ian Mann
- National Heart & Lung Institute, Imperial College London, United Kingdom (B.S.H., X.L., N.A.Q., I.M., R.A.C., Z.I.W., N.W.F.L., P.B.L., P.K., N.S.P., F.S.N.)
| | - Rasheda A. Chowdhury
- National Heart & Lung Institute, Imperial College London, United Kingdom (B.S.H., X.L., N.A.Q., I.M., R.A.C., Z.I.W., N.W.F.L., P.B.L., P.K., N.S.P., F.S.N.)
| | - Zachary I. Whinnett
- National Heart & Lung Institute, Imperial College London, United Kingdom (B.S.H., X.L., N.A.Q., I.M., R.A.C., Z.I.W., N.W.F.L., P.B.L., P.K., N.S.P., F.S.N.)
| | - Nick W.F. Linton
- National Heart & Lung Institute, Imperial College London, United Kingdom (B.S.H., X.L., N.A.Q., I.M., R.A.C., Z.I.W., N.W.F.L., P.B.L., P.K., N.S.P., F.S.N.)
| | - Phang Boon Lim
- National Heart & Lung Institute, Imperial College London, United Kingdom (B.S.H., X.L., N.A.Q., I.M., R.A.C., Z.I.W., N.W.F.L., P.B.L., P.K., N.S.P., F.S.N.)
| | - Prapa Kanagaratnam
- National Heart & Lung Institute, Imperial College London, United Kingdom (B.S.H., X.L., N.A.Q., I.M., R.A.C., Z.I.W., N.W.F.L., P.B.L., P.K., N.S.P., F.S.N.)
| | - Igor R. Efimov
- Department of Biomedical Engineering, George Washington University, Washington, DC (K.K.A., I.R.E.)
| | - Nicholas S. Peters
- National Heart & Lung Institute, Imperial College London, United Kingdom (B.S.H., X.L., N.A.Q., I.M., R.A.C., Z.I.W., N.W.F.L., P.B.L., P.K., N.S.P., F.S.N.)
- Department of Biomedical Engineering, George Washington University, Washington, DC (K.K.A., I.R.E.)
| | - Fu Siong Ng
- National Heart & Lung Institute, Imperial College London, United Kingdom (B.S.H., X.L., N.A.Q., I.M., R.A.C., Z.I.W., N.W.F.L., P.B.L., P.K., N.S.P., F.S.N.)
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Gagné S, Jacquemet V. Time resolution for wavefront and phase singularity tracking using activation maps in cardiac propagation models. CHAOS (WOODBURY, N.Y.) 2020; 30:033132. [PMID: 32237790 DOI: 10.1063/1.5133077] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Accepted: 03/02/2020] [Indexed: 06/11/2023]
Abstract
The dynamics of cardiac fibrillation can be described by the number, the trajectory, the stability, and the lifespan of phase singularities (PSs). Accurate PS tracking is straightforward in simple uniform tissues but becomes more challenging as fibrosis, structural heterogeneity, and strong anisotropy are combined. In this paper, we derive a mathematical formulation for PS tracking in two-dimensional reaction-diffusion models. The method simultaneously tracks wavefronts and PS based on activation maps at full spatiotemporal resolution. PS tracking is formulated as a linear assignment problem solved by the Hungarian algorithm. The cost matrix incorporates information about distances between PS, chirality, and wavefronts. A graph of PS trajectories is generated to represent the creations and annihilations of PS pairs. Structure-preserving graph transformations are applied to provide a simplified description at longer observation time scales. The approach is validated in 180 simulations of fibrillation in four different types of substrates featuring, respectively, wavebreaks, ionic heterogeneities, fibrosis, and breakthrough patterns. The time step of PS tracking is studied in the range from 0.1 to 10 ms. The results show the benefits of improving time resolution from 1 to 0.1 ms. The tracking error rate decreases by an order of magnitude because the occurrence of simultaneous events becomes less likely. As observed on PS survival curves, the graph-based analysis facilitates the identification of macroscopically stable rotors despite wavefront fragmentation by fibrosis.
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Affiliation(s)
- Samuel Gagné
- Institut de Génie Biomédical, Département de Pharmacologie et Physiologie, Université de Montréal, C.P. 6128, succursale Centre-ville, Montréal, Quebec H3C 3J7, Canada
| | - Vincent Jacquemet
- Institut de Génie Biomédical, Département de Pharmacologie et Physiologie, Université de Montréal, C.P. 6128, succursale Centre-ville, Montréal, Quebec H3C 3J7, Canada
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Abstract
Determining optimal treatment strategies for complex arrhythmogenesis in AF is confounded by the lack of consensus regarding the mechanisms causing AF. Studies report different mechanisms for AF, ranging from hierarchical drivers to anarchical multiple activation wavelets. Differences in the assessment of AF mechanisms are likely due to AF being recorded across diverse models using different investigational tools, spatial scales and clinical populations. The authors review different AF mechanisms, including anatomical and functional re-entry, hierarchical drivers and anarchical multiple wavelets. They then describe different cardiac mapping techniques and analysis tools, including activation mapping, phase mapping and fibrosis identification. They explain and review different data challenges, including differences between recording devices in spatial and temporal resolutions, spatial coverage and recording surface, and report clinical outcomes using different data modalities. They suggest future research directions for investigating the mechanisms underlying human AF.
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Affiliation(s)
- Caroline H Roney
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, UK.,Imperial Centre for Cardiac Engineering, Imperial College London, London, UK
| | - Andrew L Wit
- Imperial Centre for Cardiac Engineering, Imperial College London, London, UK.,Department of Pharmacology, Columbia University College of Physicians and Surgeons, New York, NY, US
| | - Nicholas S Peters
- Imperial Centre for Cardiac Engineering, Imperial College London, London, UK.,National Heart and Lung Institute, Imperial College London, London, UK
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Dharmaprani D, Schopp M, Kuklik P, Chapman D, Lahiri A, Dykes L, Xiong F, Aguilar M, Strauss B, Mitchell L, Pope K, Meyer C, Willems S, Akar FG, Nattel S, McGavigan AD, Ganesan AN. Renewal Theory as a Universal Quantitative Framework to Characterize Phase Singularity Regeneration in Mammalian Cardiac Fibrillation. Circ Arrhythm Electrophysiol 2019; 12:e007569. [PMID: 31813270 DOI: 10.1161/circep.119.007569] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
BACKGROUND Despite a century of research, no clear quantitative framework exists to model the fundamental processes responsible for the continuous formation and destruction of phase singularities (PS) in cardiac fibrillation. We hypothesized PS formation/destruction in fibrillation could be modeled as self-regenerating Poisson renewal processes, producing exponential distributions of interevent times governed by constant rate parameters defined by the prevailing properties of each system. METHODS PS formation/destruction were studied in 5 systems: (1) human persistent atrial fibrillation (n=20), (2) tachypaced sheep atrial fibrillation (n=5), (3) rat atrial fibrillation (n=4), (5) rat ventricular fibrillation (n=11), and (5) computer-simulated fibrillation. PS time-to-event data were fitted by exponential probability distribution functions computed using maximum entropy theory, and rates of PS formation and destruction (λf/λd) determined. A systematic review was conducted to cross-validate with source data from literature. RESULTS In all systems, PS lifetime and interformation times were consistent with underlying Poisson renewal processes (human: λf, 4.2%/ms±1.1 [95% CI, 4.0-5.0], λd, 4.6%/ms±1.5 [95% CI, 4.3-4.9]; sheep: λf, 4.4%/ms [95% CI, 4.1-4.7], λd, 4.6%/ms±1.4 [95% CI, 4.3-4.8]; rat atrial fibrillation: λf, 33%/ms±8.8 [95% CI, 11-55], λd, 38%/ms [95% CI, 22-55]; rat ventricular fibrillation: λf, 38%/ms±24 [95% CI, 22-55], λf, 46%/ms±21 [95% CI, 31-60]; simulated fibrillation λd, 6.6-8.97%/ms [95% CI, 4.1-6.7]; R2≥0.90 in all cases). All PS distributions identified through systematic review were also consistent with an underlying Poisson renewal process. CONCLUSIONS Poisson renewal theory provides an evolutionarily preserved universal framework to quantify formation and destruction of rotational events in cardiac fibrillation.
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Affiliation(s)
- Dhani Dharmaprani
- College of Medicine and Public Health (D.D., D.C., A.D.M., A.N.G.), Flinders University of South Australia, Adelaide, SA, Australia.,College of Science and Engineering (D.D., M.S., K.P.), Flinders University of South Australia, Adelaide, SA, Australia
| | - Madeline Schopp
- College of Science and Engineering (D.D., M.S., K.P.), Flinders University of South Australia, Adelaide, SA, Australia
| | - Pawel Kuklik
- Department of Cardiology, Asklepios Clinic St Georg (P.K., C.M.)
| | - Darius Chapman
- College of Medicine and Public Health (D.D., D.C., A.D.M., A.N.G.), Flinders University of South Australia, Adelaide, SA, Australia
| | - Anandaroop Lahiri
- Department of Cardiovascular Medicine, Flinders Medical Centre, Adelaide, SA, Australia (A.L., L.D., A.D.M., A.N.G.)
| | - Lukah Dykes
- Department of Cardiovascular Medicine, Flinders Medical Centre, Adelaide, SA, Australia (A.L., L.D., A.D.M., A.N.G.)
| | - Feng Xiong
- Department of Medicine, Montréal Heart Institute and Université de Montréal, Canada (F.X., M.A., S.N.)
| | - Martin Aguilar
- Department of Medicine, Montréal Heart Institute and Université de Montréal, Canada (F.X., M.A., S.N.)
| | | | - Lewis Mitchell
- School of Mathematical Sciences, University of Adelaide, SA, Australia (L.M.)
| | - Kenneth Pope
- College of Science and Engineering (D.D., M.S., K.P.), Flinders University of South Australia, Adelaide, SA, Australia
| | - Christian Meyer
- Department of Cardiology, Asklepios Clinic St Georg (P.K., C.M.)
| | - Stephan Willems
- Department of Cardiology, University Medical Centre, Hamburg, Germany (S.W.)
| | - Fadi G Akar
- Icahn School of Medicine, Mount Sinai, NY (B.S., F.G.A.)
| | - Stanley Nattel
- Department of Medicine, Montréal Heart Institute and Université de Montréal, Canada (F.X., M.A., S.N.)
| | - Andrew D McGavigan
- College of Medicine and Public Health (D.D., D.C., A.D.M., A.N.G.), Flinders University of South Australia, Adelaide, SA, Australia.,Department of Cardiovascular Medicine, Flinders Medical Centre, Adelaide, SA, Australia (A.L., L.D., A.D.M., A.N.G.)
| | - Anand N Ganesan
- College of Medicine and Public Health (D.D., D.C., A.D.M., A.N.G.), Flinders University of South Australia, Adelaide, SA, Australia.,Department of Cardiovascular Medicine, Flinders Medical Centre, Adelaide, SA, Australia (A.L., L.D., A.D.M., A.N.G.)
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Falkenberg M, Ford AJ, Li AC, Lawrence R, Ciacci A, Peters NS, Christensen K. Unified mechanism of local drivers in a percolation model of atrial fibrillation. Phys Rev E 2019; 100:062406. [PMID: 31962501 PMCID: PMC7314598 DOI: 10.1103/physreve.100.062406] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Indexed: 11/07/2022]
Abstract
The mechanisms of atrial fibrillation (AF) are poorly understood, resulting in disappointing success rates of ablative treatment. Different mechanisms defined largely by different atrial activation patterns have been proposed and, arguably, this dispute has slowed the progress of AF research. Recent clinical evidence suggests a unifying mechanism of local drivers based on sustained reentrant circuits in the complex atrial architecture. Here, we present a percolation inspired computational model showing spontaneous emergence of AF that strongly supports, and gives a theoretical explanation for, the clinically observed diversity of activation. We show that the difference in surface activation patterns is a direct consequence of the thickness of the discrete network of heart muscle cells through which electrical signals percolate to reach the imaged surface. The model naturally follows the clinical spectrum of AF spanning sinus rhythm, paroxysmal AF, and persistent AF as the decoupling of myocardial cells results in the lattice approaching the percolation threshold. This allows the model to make the prediction that, for paroxysmal AF, reentrant circuits emerge near the endocardium, but in persistent AF they emerge deeper in the bulk of the atrial wall. If experimentally verified, this may go towards explaining the lowering ablation success rate as AF becomes more persistent.
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Affiliation(s)
- Max Falkenberg
- Blackett Laboratory, Imperial College London, London SW7 2AZ, United Kingdom
- Centre for Complexity Science, Imperial College London, London SW7 2AZ, United Kingdom
- Centre for Cardiac Engineering, Imperial College London, London W12 0NN, United Kingdom
| | - Andrew J. Ford
- Blackett Laboratory, Imperial College London, London SW7 2AZ, United Kingdom
| | - Anthony C. Li
- Blackett Laboratory, Imperial College London, London SW7 2AZ, United Kingdom
| | - Robert Lawrence
- Blackett Laboratory, Imperial College London, London SW7 2AZ, United Kingdom
| | - Alberto Ciacci
- Blackett Laboratory, Imperial College London, London SW7 2AZ, United Kingdom
- Centre for Complexity Science, Imperial College London, London SW7 2AZ, United Kingdom
- Centre for Cardiac Engineering, Imperial College London, London W12 0NN, United Kingdom
| | - Nicholas S. Peters
- Centre for Cardiac Engineering, Imperial College London, London W12 0NN, United Kingdom
- National Heart & Lung Institute, Imperial College London, London, W12 0NN, United Kingdom
| | - Kim Christensen
- Blackett Laboratory, Imperial College London, London SW7 2AZ, United Kingdom
- Centre for Complexity Science, Imperial College London, London SW7 2AZ, United Kingdom
- Centre for Cardiac Engineering, Imperial College London, London W12 0NN, United Kingdom
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Qin M, Jiang WF, Wu SH, Xu K, Liu X. Electrogram dispersion-guided driver ablation adjunctive to high-quality pulmonary vein isolation in atrial fibrillation of varying durations. J Cardiovasc Electrophysiol 2019; 31:48-60. [PMID: 31701626 DOI: 10.1111/jce.14268] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Revised: 10/29/2019] [Accepted: 11/05/2019] [Indexed: 01/25/2023]
Abstract
OBJECTIVE To investigate the role of driver mechanism and the effect of electrogram dispersion-guided driver mapping and ablation in atrial fibrillation (AF) at different stages of progression. METHODS A total of 256 consecutive patients with AF who had undergone pulmonary vein isolation (PVI) plus driver ablation or conventional ablation were divided into three groups: paroxysmal atrial fibrillation (PAF; group A, n = 51); persistent atrial fibrillation (PsAF; group B, n = 38); and long standing-persistent atrial fibrillation (LS-PsAF; group C, n = 39). PVI was performed with the guidance of the ablation index. The electrogram dispersion was analyzed for driver mapping. RESULTS The most prominent driver regions were at roof (28.0%), posterior wall (17.6%), and bottom (21.3%). From patients with PAF to those with PsAF and LS-PsAF: the complexity of extra-pulmonary vein (PV) drivers including distribution, mean number, and area of dispersion region increased (P < .001). Patients who underwent driver ablation vs conventional ablation had higher procedural AF termination rate (76.6% vs 28.1%; P < .001). With AF progression, the termination rate gradually decreased from group A to group C, and the role of PVI in AF termination was also gradually weakened from group A to group C (39.6%, 7.4%, and 4.3%; P < .001) in patients with driver ablation. At the end of the follow-up, the rate of sinus rhythm maintenance was higher in patients with driver ablation than those with conventional ablation (89.1% vs 70.3%; P < .001). CONCLUSION The formation of extra-PV drivers provides an important mechanism for AF maintenance with their complexity increasing with AF progression. Electrogram dispersion-guided driver ablation appears to be an efficient adjunctive approach to PVI for AF treatment.
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Affiliation(s)
- Mu Qin
- Department of Cardiology, Shanghai Chest Hospital, Shanghai Jiaotong University, Shanghai, China
| | - Wei-Feng Jiang
- Department of Cardiology, Shanghai Chest Hospital, Shanghai Jiaotong University, Shanghai, China
| | - Shao-Hui Wu
- Department of Cardiology, Shanghai Chest Hospital, Shanghai Jiaotong University, Shanghai, China
| | - Kai Xu
- Department of Cardiology, Shanghai Chest Hospital, Shanghai Jiaotong University, Shanghai, China
| | - Xu Liu
- Department of Cardiology, Shanghai Chest Hospital, Shanghai Jiaotong University, Shanghai, China
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Wolf M, Tavernier R, Zeidan Z, El Haddad M, Vandekerckhove Y, Pooter JD, Phlips T, Strisciuglio T, Almorad A, Kyriakopoulou M, Lycke M, Duytschaever M, Knecht S. Identification of repetitive atrial activation patterns in persistent atrial fibrillation by direct contact high-density electrogram mapping. J Cardiovasc Electrophysiol 2019; 30:2704-2712. [PMID: 31588635 DOI: 10.1111/jce.14214] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 08/08/2019] [Accepted: 08/31/2019] [Indexed: 11/30/2022]
Abstract
INTRODUCTION Recent studies have characterized drivers in persistent atrial fibrillation using automated algorithm detection with panoramic endocardial mapping by means of basket catheters. We aimed to identify repetitive atrial activation patterns (RAAPs) during ongoing atrial fibrillation (AF) based upon automated annotation of unipolar electrograms (EGMs) recorded with a high-density regional endocardial contact mapping catheter. METHODS In 14 persistent AF patients, high-resolution EGMs were recorded for 30 seconds at sequential PentaRay (Biosense Inc) positions covering the entire biatrial surface. All recordings were reviewed off-line with dedicated software allowing automated annotation of the local activation time of the unipolar fibrillatory EGMs (CARTOFINDER; Biosense Inc). RAAPs were defined as a consistent activation pattern (for ≥3 consecutive beats) of either focal activity with centrifugal spread (RAAPfocal ) or rotational activity across the PentaRay splines spanning the AF cycle length (RAAProtational ). RESULTS A total of 498 PentaRay recordings were analyzed (35.6 ± 7.6 per patient). The number of PentaRay recordings displaying RAAP was 9.8 ± 3.1 per patient (range = 3-15), of which 2.4 ± 2.4 RAAProtational (range = 0-7), and 7.4 ± 4.4 RAAPfocal (range = 1-13). 77% of RAAPs portrayed focal firing. The median number of repetitions per 30 second recording was 11 (range = 3-225) per recording. RAAPs were observed both in the right atrium (RA) (35%) and left atrium (LA) (65%), with the majority being near the left PVs/appendage (35% of all RAAPs) and the superior vena cava/right appendage (23% of all RAAPs). CONCLUSION High-resolution, sequential endocardial EGM-based mapping allows identification of RAAPs in persistent AF. In our series, focal firing was the most frequently observed pattern.
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Affiliation(s)
- Michael Wolf
- Department of Cardiology, Sint-Jan Hospital Bruges, Bruges, Belgium.,Department of Cardiology, Hartcentrum ZNA Middelheim, Antwerp, Belgium.,Department of Cardiology, Cardiovascular Research Institute Maastricht, Maastricht University Medical Center+, Maastricht, The Netherlands
| | - René Tavernier
- Department of Cardiology, Sint-Jan Hospital Bruges, Bruges, Belgium
| | - Ziad Zeidan
- Clinical Development - Research and Development, Biosense Webster, Inc, South Diamond Bar, California
| | - Milad El Haddad
- Department of Cardiology, Sint-Jan Hospital Bruges, Bruges, Belgium
| | | | - Jan De Pooter
- Department of Cardiology, Sint-Jan Hospital Bruges, Bruges, Belgium
| | - Thomas Phlips
- Department of Cardiology, Sint-Jan Hospital Bruges, Bruges, Belgium
| | | | | | | | - Michelle Lycke
- Department of Cardiology, Sint-Jan Hospital Bruges, Bruges, Belgium
| | | | - Sébastien Knecht
- Department of Cardiology, Sint-Jan Hospital Bruges, Bruges, Belgium
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Ciaccio EJ, Wan EY, Saluja DS, Acharya UR, Peters NS, Garan H. Addressing challenges of quantitative methodologies and event interpretation in the study of atrial fibrillation. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2019; 178:113-122. [PMID: 31416540 PMCID: PMC6748794 DOI: 10.1016/j.cmpb.2019.06.017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2019] [Revised: 05/21/2019] [Accepted: 06/14/2019] [Indexed: 05/06/2023]
Abstract
Atrial fibrillation (AF) is the commonest arrhythmia, yet the mechanisms of its onset and persistence are incompletely known. Although techniques for quantitative assessment have been investigated, there have been few attempts to integrate this information to advance disease treatment protocols. In this review, key quantitative methods for AF analysis are described, and suggestions are provided for the coordination of the available information, and to develop foci and directions for future research efforts. Quantitative biologists may have an interest in this topic in order to develop machine learning and tools for arrhythmia characterization, but they may perhaps have a minimal background in the clinical methodology and in the types of observed events and mechanistic hypotheses that have thus far been developed. We attempt to address these issues via exploration of the published literature. Although no new data is presented in this review, examples are shown of current lines of investigation, and in particular, how electrogram analysis and whole-chamber quantitative modeling of the left atrium may be useful to characterize fibrillatory patterns of activity, so as to propose avenues for more efficacious acquisition and interpretation of AF data.
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Affiliation(s)
- Edward J Ciaccio
- Department of Medicine - Division of Cardiology, Columbia University Medical Center, New York, NY, USA; ElectroCardioMaths Programme, Imperial Centre for Cardiac Engineering, Imperial College London, London, UK.
| | - Elaine Y Wan
- Department of Medicine - Division of Cardiology, Columbia University Medical Center, New York, NY, USA
| | - Deepak S Saluja
- Department of Medicine - Division of Cardiology, Columbia University Medical Center, New York, NY, USA
| | - U Rajendra Acharya
- Department of Electronics and Computer Engineering, Ngee Ann Polytechnic, Singapore
| | - Nicholas S Peters
- ElectroCardioMaths Programme, Imperial Centre for Cardiac Engineering, Imperial College London, London, UK
| | - Hasan Garan
- Department of Medicine - Division of Cardiology, Columbia University Medical Center, New York, NY, USA
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40
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Kowalewski CAB, Shenasa F, Rodrigo M, Clopton P, Meckler G, Alhusseini MI, Swerdlow MA, Joshi V, Hossainy S, Zaman JAB, Baykaner T, Rogers AJ, Brachmann J, Miller JM, Krummen DE, Sauer WH, Peters NS, Wang PJ, Narayan SM. Interaction of Localized Drivers and Disorganized Activation in Persistent Atrial Fibrillation: Reconciling Putative Mechanisms Using Multiple Mapping Techniques. Circ Arrhythm Electrophysiol 2019; 11:e005846. [PMID: 29884620 DOI: 10.1161/circep.117.005846] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Accepted: 04/05/2018] [Indexed: 12/27/2022]
Abstract
BACKGROUND Mechanisms for persistent atrial fibrillation (AF) are unclear. We hypothesized that putative AF drivers and disorganized zones may interact dynamically over short time scales. We studied this interaction over prolonged durations, focusing on regions where ablation terminates persistent AF using 2 mapping methods. METHODS We recruited 55 patients with persistent AF in whom ablation terminated AF prior to pulmonary vein isolation from a multicenter registry. AF was mapped globally using electrograms for 360±45 cycles using (1) a published phase method and (2) a commercial activation/phase method. RESULTS Patients were 62.2±9.7 years, 76% male. Sites of AF termination showed rotational/focal patterns by methods 1 and 2 (51/55 vs 55/55; P=0.13) in spatially conserved regions, yet fluctuated over time. Time points with no AF driver showed competing drivers elsewhere or disordered waves. Organized regions were detected for 61.6±23.9% and 70.6±20.6% of 1 minute per method (P=nonsignificant), confirmed by automatic phase tracking (P<0.05). To detect AF drivers with >90% sensitivity, 8 to 32 s of AF recordings were required depending on driver definition. CONCLUSIONS Sites at which persistent AF terminated by ablation show organized activation that fluctuate over time, because of collision from concurrent organized zones or fibrillatory waves, yet recur in conserved spatial regions. Results were similar by 2 mapping methods. This network of competing mechanisms should be reconciled with existing disorganized or driver mechanisms for AF, to improve clinical mapping and ablation of persistent AF. CLINICAL TRIAL REGISTRATION URL: http://www.clinicaltrials.gov. Unique identifier: NCT02997254.
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Affiliation(s)
- Christopher A B Kowalewski
- Department of Medicine, Stanford University, CA (C.A.B.K., F.S., M.R., P.C., G.M., M.I.A., M.A.S., V.J., J.A.B.Z., T.B., A.J.R., P.J.W., S.M.N.).,Department of Cardiology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Germany (C.A.B.K.)
| | - Fatemah Shenasa
- Department of Medicine, Stanford University, CA (C.A.B.K., F.S., M.R., P.C., G.M., M.I.A., M.A.S., V.J., J.A.B.Z., T.B., A.J.R., P.J.W., S.M.N.)
| | - Miguel Rodrigo
- Department of Medicine, Stanford University, CA (C.A.B.K., F.S., M.R., P.C., G.M., M.I.A., M.A.S., V.J., J.A.B.Z., T.B., A.J.R., P.J.W., S.M.N.)
| | - Paul Clopton
- Department of Medicine, Stanford University, CA (C.A.B.K., F.S., M.R., P.C., G.M., M.I.A., M.A.S., V.J., J.A.B.Z., T.B., A.J.R., P.J.W., S.M.N.)
| | - Gabriela Meckler
- Department of Medicine, Stanford University, CA (C.A.B.K., F.S., M.R., P.C., G.M., M.I.A., M.A.S., V.J., J.A.B.Z., T.B., A.J.R., P.J.W., S.M.N.)
| | - Mahmood I Alhusseini
- Department of Medicine, Stanford University, CA (C.A.B.K., F.S., M.R., P.C., G.M., M.I.A., M.A.S., V.J., J.A.B.Z., T.B., A.J.R., P.J.W., S.M.N.)
| | - Mark A Swerdlow
- Department of Medicine, Stanford University, CA (C.A.B.K., F.S., M.R., P.C., G.M., M.I.A., M.A.S., V.J., J.A.B.Z., T.B., A.J.R., P.J.W., S.M.N.)
| | - Vijay Joshi
- Department of Medicine, Stanford University, CA (C.A.B.K., F.S., M.R., P.C., G.M., M.I.A., M.A.S., V.J., J.A.B.Z., T.B., A.J.R., P.J.W., S.M.N.)
| | - Samir Hossainy
- Department of Engineering, University of California, Berkeley (S.H.)
| | - Junaid A B Zaman
- Department of Medicine, Stanford University, CA (C.A.B.K., F.S., M.R., P.C., G.M., M.I.A., M.A.S., V.J., J.A.B.Z., T.B., A.J.R., P.J.W., S.M.N.).,ElectroCardioMaths Programme, Imperial College, London, United Kingdom (J.A.B.Z., N.S.P.)
| | - Tina Baykaner
- Department of Medicine, Stanford University, CA (C.A.B.K., F.S., M.R., P.C., G.M., M.I.A., M.A.S., V.J., J.A.B.Z., T.B., A.J.R., P.J.W., S.M.N.)
| | - Albert J Rogers
- Department of Medicine, Stanford University, CA (C.A.B.K., F.S., M.R., P.C., G.M., M.I.A., M.A.S., V.J., J.A.B.Z., T.B., A.J.R., P.J.W., S.M.N.)
| | | | - John M Miller
- Department of Medicine, Indiana University, Indianapolis (J.M.M.)
| | - David E Krummen
- Department of Medicine, University of California San Diego (D.E.K.)
| | - William H Sauer
- Department of Medicine, University of Colorado, Denver (W.H.S.)
| | - Nicholas S Peters
- ElectroCardioMaths Programme, Imperial College, London, United Kingdom (J.A.B.Z., N.S.P.)
| | - Paul J Wang
- Department of Medicine, Stanford University, CA (C.A.B.K., F.S., M.R., P.C., G.M., M.I.A., M.A.S., V.J., J.A.B.Z., T.B., A.J.R., P.J.W., S.M.N.)
| | - Sanjiv M Narayan
- Department of Medicine, Stanford University, CA (C.A.B.K., F.S., M.R., P.C., G.M., M.I.A., M.A.S., V.J., J.A.B.Z., T.B., A.J.R., P.J.W., S.M.N.).
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41
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Grace A, Willems S, Meyer C, Verma A, Heck P, Zhu M, Shi X, Chou D, Dang L, Scharf C, Scharf G, Beatty G. High-resolution noncontact charge-density mapping of endocardial activation. JCI Insight 2019; 4:126422. [PMID: 30895945 DOI: 10.1172/jci.insight.126422] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 02/11/2019] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Spatial resolution in cardiac activation maps based on voltage measurement is limited by far-field interference. Precise characterization of electrical sources would resolve this limitation; however, practical charge-based cardiac mapping has not been achieved. METHODS A prototype algorithm, developed from first principles of electrostatic field theory, derives charge density (CD) as a spatial representation of the true sources of the cardiac field. The algorithm processes multiple, simultaneous, noncontact voltage measurements within the cardiac chamber to inversely derive the global distribution of CD sources across the endocardial surface. RESULTS Comparison of CD to an established computer-simulated model of atrial conduction demonstrated feasibility in terms of spatial, temporal, and morphologic metrics. Inverse reconstruction matched simulation with median spatial errors of 1.73 mm and 2.41 mm for CD and voltage, respectively. Median temporal error was less than 0.96 ms and morphologic correlation was greater than 0.90 for both CD and voltage. Activation patterns observed in human atrial flutter reproduced those established through contact maps, with a 4-fold improvement in resolution noted for CD over voltage. Global activation maps (charge density-based) are reported in atrial fibrillation with confirmed reduction of far-field interference. Arrhythmia cycle-length slowing and termination achieved through ablation of critical points demonstrated in the maps indicates both mechanistic and pathophysiological relevance. CONCLUSION Global maps of cardiac activation based on CD enable classification of conduction patterns and localized nonpulmonary vein therapeutic targets in atrial fibrillation. The measurement capabilities of the approach have roles spanning deep phenotyping to therapeutic application. TRIAL REGISTRATION ClinicalTrials.gov NCT01875614. FUNDING The National Institute for Health Research (NIHR) Translational Research Program at Royal Papworth Hospital and Acutus Medical.
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Affiliation(s)
- Andrew Grace
- Royal Papworth Hospital Foundation Trust, Cambridge University Health Partners, Cambridge, United Kingdom.,Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Stephan Willems
- University Heart Center, University Hospital, Hamburg-Eppendorf, Hamburg, Germany
| | - Christian Meyer
- University Heart Center, University Hospital, Hamburg-Eppendorf, Hamburg, Germany
| | - Atul Verma
- Southlake Regional Health Center, Newmarket, University of Toronto, Ontario, Canada
| | - Patrick Heck
- Royal Papworth Hospital Foundation Trust, Cambridge University Health Partners, Cambridge, United Kingdom
| | - Min Zhu
- Acutus Medical Inc., Carlsbad, California, USA
| | - Xinwei Shi
- Acutus Medical Inc., Carlsbad, California, USA
| | | | - Lam Dang
- Cardiovascular Center, Klinik im Park, Zürich, Switzerland
| | | | - Günter Scharf
- Physics Institute, University of Zurich, Zurich, Switzerland
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42
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Cantwell CD, Mohamied Y, Tzortzis KN, Garasto S, Houston C, Chowdhury RA, Ng FS, Bharath AA, Peters NS. Rethinking multiscale cardiac electrophysiology with machine learning and predictive modelling. Comput Biol Med 2019; 104:339-351. [PMID: 30442428 PMCID: PMC6334203 DOI: 10.1016/j.compbiomed.2018.10.015] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 10/04/2018] [Accepted: 10/14/2018] [Indexed: 11/17/2022]
Abstract
We review some of the latest approaches to analysing cardiac electrophysiology data using machine learning and predictive modelling. Cardiac arrhythmias, particularly atrial fibrillation, are a major global healthcare challenge. Treatment is often through catheter ablation, which involves the targeted localised destruction of regions of the myocardium responsible for initiating or perpetuating the arrhythmia. Ablation targets are either anatomically defined, or identified based on their functional properties as determined through the analysis of contact intracardiac electrograms acquired with increasing spatial density by modern electroanatomic mapping systems. While numerous quantitative approaches have been investigated over the past decades for identifying these critical curative sites, few have provided a reliable and reproducible advance in success rates. Machine learning techniques, including recent deep-learning approaches, offer a potential route to gaining new insight from this wealth of highly complex spatio-temporal information that existing methods struggle to analyse. Coupled with predictive modelling, these techniques offer exciting opportunities to advance the field and produce more accurate diagnoses and robust personalised treatment. We outline some of these methods and illustrate their use in making predictions from the contact electrogram and augmenting predictive modelling tools, both by more rapidly predicting future states of the system and by inferring the parameters of these models from experimental observations.
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Affiliation(s)
- Chris D Cantwell
- ElectroCardioMaths Group, Imperial College Centre for Cardiac Engineering, Imperial College London, London, UK; Department of Aeronautics, Imperial College London, South Kensington Campus, London, UK.
| | - Yumnah Mohamied
- ElectroCardioMaths Group, Imperial College Centre for Cardiac Engineering, Imperial College London, London, UK; National Heart and Lung Institute, Imperial College London, South Kensington Campus, London, UK
| | - Konstantinos N Tzortzis
- ElectroCardioMaths Group, Imperial College Centre for Cardiac Engineering, Imperial College London, London, UK; National Heart and Lung Institute, Imperial College London, South Kensington Campus, London, UK
| | - Stef Garasto
- ElectroCardioMaths Group, Imperial College Centre for Cardiac Engineering, Imperial College London, London, UK; Department of Bioengineering, Imperial College London, South Kensington Campus, London, UK
| | - Charles Houston
- ElectroCardioMaths Group, Imperial College Centre for Cardiac Engineering, Imperial College London, London, UK; National Heart and Lung Institute, Imperial College London, South Kensington Campus, London, UK
| | - Rasheda A Chowdhury
- ElectroCardioMaths Group, Imperial College Centre for Cardiac Engineering, Imperial College London, London, UK; National Heart and Lung Institute, Imperial College London, South Kensington Campus, London, UK
| | - Fu Siong Ng
- ElectroCardioMaths Group, Imperial College Centre for Cardiac Engineering, Imperial College London, London, UK; National Heart and Lung Institute, Imperial College London, South Kensington Campus, London, UK
| | - Anil A Bharath
- ElectroCardioMaths Group, Imperial College Centre for Cardiac Engineering, Imperial College London, London, UK; Department of Bioengineering, Imperial College London, South Kensington Campus, London, UK
| | - Nicholas S Peters
- ElectroCardioMaths Group, Imperial College Centre for Cardiac Engineering, Imperial College London, London, UK; National Heart and Lung Institute, Imperial College London, South Kensington Campus, London, UK
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43
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Lin R, Zeng C, Xu K, Wu S, Qin M, Liu X. Dispersion-guided ablation in conjunction with circumferential pulmonary vein isolation is superior to stepwise ablation approach for persistent atrial fibrillation. Int J Cardiol 2018; 278:97-103. [PMID: 30587415 DOI: 10.1016/j.ijcard.2018.12.051] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Revised: 11/25/2018] [Accepted: 12/18/2018] [Indexed: 12/26/2022]
Abstract
BACKGROUND Due to the lack of optimal ablation strategy, the success rate of persistent atrial fibrillation (AF) is still low. We hypothesize that a strategy that targeting pulmonary triggers and dispersion areas in atria improves prognosis of persistent AF. METHODS We prospectively enrolled 142 persistent AF patients admitted for catheter ablation. These patients were randomly assigned in a 1:1 ratio to ablation with circumferential pulmonary vein isolation (CPVI) + ablation of electrogram dispersion areas (71 patients, group A) or stepwise ablation strategy (71 patients, group B). RESULTS Procedural time and fluoroscopy time did not differ between group A and group B (204.6 ± 26.9 min vs 207.8 ± 26.3 min and 7.3 ± 1.3 min vs 7.1 ± 1.3 min, respectively, P > 0.05), however, radiofrequency delivery time in group A was significantly shorter than that in group B (70 ± 7.2 min vs 83.2 ± 9.1 min, P < 0.001). In total, 265 electrogram dispersion areas were identified in 67 patients, and the most prominent areas were roof, bottom, and inferoposterior wall. The rates of acute AF endpoint (including AF termination and AFCL elongation >30 ms) and termination in group A were significantly higher than that in group B (97.2% vs. 71.8% and 70.4% vs. 15.5%, respectively, P < 0.001). During a follow-up period of 204 ± 67 days, both AF-free and AF/AT-free survival in group A were significantly higher than that in group B (P = 0.012 and P = 0.014, respectively). CONCLUSION Dispersion-guided ablation in conjunction with CPVI is efficient, personalized, and accurate for persistent AF.
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Affiliation(s)
- Rongjie Lin
- Department of Cardiology, Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - Cong Zeng
- Department of Cardiology, Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - Kai Xu
- Department of Cardiology, Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - Shaohui Wu
- Department of Cardiology, Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - Mu Qin
- Department of Cardiology, Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai, China.
| | - Xu Liu
- Department of Cardiology, Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai, China.
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44
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Qin M, Lin RJ, Wu SH, Liu X. Extra pulmonary vein driver mapping and ablation in paroxysmal atrial fibrillation by electrogram dispersion analysis. J Cardiovasc Electrophysiol 2018; 30:164-170. [PMID: 30375072 DOI: 10.1111/jce.13784] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Revised: 10/13/2018] [Accepted: 10/23/2018] [Indexed: 11/28/2022]
Abstract
BACKGROUND The adjunctive approach is still unknown for atrial fibrillation (AF), which cannot be terminated after pulmonary vein isolation (PVI). We hypothesized that the driver ablation plus PVI was superior to PVI alone. METHODS AND RESULTS A total of 98 patients with paroxysmal AF were enrolled in this study and were divided into two groups, with one group undergoing PVI (n = 49) and the other group undergoing PVI + driver ablation (n = 49). The driver regions were defined as clusters of bipolar electrograms that displayed spatial dispersion spread over mean AF cycle length at a minimum of three adjacent bipolars of a PentaRay catheter. During the procedure, the most prominent driver regions before PVI were the roof (n = 27; 55.1%), PV antrum (n = 23; 46.9%), and the inferoposterior wall (n = 11; 22.4%). PVI can eliminate all drivers at PV antrum, but only terminate 30.4% of AF in the driver group. The AF termination rate in the driver ablation group was significantly higher than that in conventional ablation (93.9% vs 40.6%; P < 0.001). The rate of freedom from atrial tachyarrhythmia episodes by a single procedure at 6 months was significantly higher in the driver group than in the conventional group (91.6% vs 72.4%; P = 0.02). CONCLUSION The present method is effective for AF driver identification. It guided ablation adjunctive to PVI increasing the rate of AF termination and improving the outcomes in patients with paroxysmal AF.
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Affiliation(s)
- Mu Qin
- Department of Cardiology, Shanghai Chest Hospital, Shanghai Jiaotong University, Shanghai, China
| | - Rong-Jie Lin
- Department of Cardiology, Shanghai Chest Hospital, Shanghai Jiaotong University, Shanghai, China
| | - Shao-Hui Wu
- Department of Cardiology, Shanghai Chest Hospital, Shanghai Jiaotong University, Shanghai, China
| | - Xu Liu
- Department of Cardiology, Shanghai Chest Hospital, Shanghai Jiaotong University, Shanghai, China
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45
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Jacquemet V. Phase singularity detection through phase map interpolation: Theory, advantages and limitations. Comput Biol Med 2018; 102:381-389. [DOI: 10.1016/j.compbiomed.2018.07.014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 07/18/2018] [Accepted: 07/19/2018] [Indexed: 10/28/2022]
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46
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Handa BS, Roney CH, Houston C, Qureshi NA, Li X, Pitcher DS, Chowdhury RA, Lim PB, Dupont E, Niederer SA, Cantwell CD, Peters NS, Ng FS. Analytical approaches for myocardial fibrillation signals. Comput Biol Med 2018; 102:315-326. [PMID: 30025847 PMCID: PMC6215772 DOI: 10.1016/j.compbiomed.2018.07.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Revised: 07/11/2018] [Accepted: 07/11/2018] [Indexed: 12/11/2022]
Abstract
Atrial and ventricular fibrillation are complex arrhythmias, and their underlying mechanisms remain widely debated and incompletely understood. This is partly because the electrical signals recorded during myocardial fibrillation are themselves complex and difficult to interpret with simple analytical tools. There are currently a number of analytical approaches to handle fibrillation data. Some of these techniques focus on mapping putative drivers of myocardial fibrillation, such as dominant frequency, organizational index, Shannon entropy and phase mapping. Other techniques focus on mapping the underlying myocardial substrate sustaining fibrillation, such as voltage mapping and complex fractionated electrogram mapping. In this review, we discuss these techniques, their application and their limitations, with reference to our experimental and clinical data. We also describe novel tools including a new algorithm to map microreentrant circuits sustaining fibrillation.
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Affiliation(s)
- Balvinder S Handa
- ElectroCardioMaths, Imperial Centre for Cardiac Engineering, National Heart & Lung Institute, Imperial College London, United Kingdom
| | - Caroline H Roney
- Division of Imaging Sciences and Bioengineering, King's College London, United Kingdom
| | - Charles Houston
- ElectroCardioMaths, Imperial Centre for Cardiac Engineering, National Heart & Lung Institute, Imperial College London, United Kingdom
| | - Norman A Qureshi
- ElectroCardioMaths, Imperial Centre for Cardiac Engineering, National Heart & Lung Institute, Imperial College London, United Kingdom
| | - Xinyang Li
- ElectroCardioMaths, Imperial Centre for Cardiac Engineering, National Heart & Lung Institute, Imperial College London, United Kingdom
| | - David S Pitcher
- ElectroCardioMaths, Imperial Centre for Cardiac Engineering, National Heart & Lung Institute, Imperial College London, United Kingdom
| | - Rasheda A Chowdhury
- ElectroCardioMaths, Imperial Centre for Cardiac Engineering, National Heart & Lung Institute, Imperial College London, United Kingdom
| | - Phang Boon Lim
- ElectroCardioMaths, Imperial Centre for Cardiac Engineering, National Heart & Lung Institute, Imperial College London, United Kingdom
| | - Emmanuel Dupont
- ElectroCardioMaths, Imperial Centre for Cardiac Engineering, National Heart & Lung Institute, Imperial College London, United Kingdom
| | - Steven A Niederer
- Division of Imaging Sciences and Bioengineering, King's College London, United Kingdom
| | - Chris D Cantwell
- ElectroCardioMaths, Imperial Centre for Cardiac Engineering, National Heart & Lung Institute, Imperial College London, United Kingdom; Department of Aeronautics, Imperial College London, United Kingdom
| | - Nicholas S Peters
- ElectroCardioMaths, Imperial Centre for Cardiac Engineering, National Heart & Lung Institute, Imperial College London, United Kingdom
| | - Fu Siong Ng
- ElectroCardioMaths, Imperial Centre for Cardiac Engineering, National Heart & Lung Institute, Imperial College London, United Kingdom.
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47
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Wann D, Waks JW, Kramer DB. Clinical and regulatory considerations for novel electrophysiology mapping systems: Lessons from FIRM. PACING AND CLINICAL ELECTROPHYSIOLOGY: PACE 2018; 41:1669-1680. [DOI: 10.1111/pace.13509] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 08/23/2018] [Accepted: 09/12/2018] [Indexed: 11/28/2022]
Affiliation(s)
- Daniel Wann
- Division of Cardiology, Richard A. and Susan F. Smith Center for Outcomes Research in Cardiology, Beth Israel Deaconess Medical Center; Harvard Medical School; Boston Massachusetts
| | - Jonathan W. Waks
- Division of Cardiology, Richard A. and Susan F. Smith Center for Outcomes Research in Cardiology, Beth Israel Deaconess Medical Center; Harvard Medical School; Boston Massachusetts
| | - Daniel B. Kramer
- Division of Cardiology, Richard A. and Susan F. Smith Center for Outcomes Research in Cardiology, Beth Israel Deaconess Medical Center; Harvard Medical School; Boston Massachusetts
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48
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Cheniti G, Vlachos K, Pambrun T, Hooks D, Frontera A, Takigawa M, Bourier F, Kitamura T, Lam A, Martin C, Dumas-Pommier C, Puyo S, Pillois X, Duchateau J, Klotz N, Denis A, Derval N, Jais P, Cochet H, Hocini M, Haissaguerre M, Sacher F. Atrial Fibrillation Mechanisms and Implications for Catheter Ablation. Front Physiol 2018; 9:1458. [PMID: 30459630 PMCID: PMC6232922 DOI: 10.3389/fphys.2018.01458] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 09/26/2018] [Indexed: 01/14/2023] Open
Abstract
AF is a heterogeneous rhythm disorder that is related to a wide spectrum of etiologies and has broad clinical presentations. Mechanisms underlying AF are complex and remain incompletely understood despite extensive research. They associate interactions between triggers, substrate and modulators including ionic and anatomic remodeling, genetic predisposition and neuro-humoral contributors. The pulmonary veins play a key role in the pathogenesis of AF and their isolation is associated to high rates of AF freedom in patients with paroxysmal AF. However, ablation of persistent AF remains less effective, mainly limited by the difficulty to identify the sources sustaining AF. Many theories were advanced to explain the perpetuation of this form of AF, ranging from a single localized focal and reentrant source to diffuse bi-atrial multiple wavelets. Translating these mechanisms to the clinical practice remains challenging and limited by the spatio-temporal resolution of the mapping techniques. AF is driven by focal or reentrant activities that are initially clustered in a relatively limited atrial surface then disseminate everywhere in both atria. Evidence for structural remodeling, mainly represented by atrial fibrosis suggests that reentrant activities using anatomical substrate are the key mechanism sustaining AF. These reentries can be endocardial, epicardial, and intramural which makes them less accessible for mapping and for ablation. Subsequently, early interventions before irreversible remodeling are of major importance. Circumferential pulmonary vein isolation remains the cornerstone of the treatment of AF, regardless of the AF form and of the AF duration. No ablation strategy consistently demonstrated superiority to pulmonary vein isolation in preventing long term recurrences of atrial arrhythmias. Further research that allows accurate identification of the mechanisms underlying AF and efficient ablation should improve the results of PsAF ablation.
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Affiliation(s)
- Ghassen Cheniti
- Cardiac Electrophysiology Department, Hopital Haut Leveque, Bordeaux, France.,Electrophysiology and Heart Modeling Institute (LIRYC), Bordeaux University, Pessac, France.,Cardiology Department, Hopital Sahloul, Universite de Sousse, Sousse, Tunisia
| | - Konstantinos Vlachos
- Cardiac Electrophysiology Department, Hopital Haut Leveque, Bordeaux, France.,Electrophysiology and Heart Modeling Institute (LIRYC), Bordeaux University, Pessac, France
| | - Thomas Pambrun
- Cardiac Electrophysiology Department, Hopital Haut Leveque, Bordeaux, France.,Electrophysiology and Heart Modeling Institute (LIRYC), Bordeaux University, Pessac, France
| | - Darren Hooks
- Cardiology Department, Wellington Hospital, Wellington, New Zealand
| | - Antonio Frontera
- Cardiac Electrophysiology Department, Hopital Haut Leveque, Bordeaux, France.,Electrophysiology and Heart Modeling Institute (LIRYC), Bordeaux University, Pessac, France
| | - Masateru Takigawa
- Cardiac Electrophysiology Department, Hopital Haut Leveque, Bordeaux, France.,Electrophysiology and Heart Modeling Institute (LIRYC), Bordeaux University, Pessac, France
| | - Felix Bourier
- Cardiac Electrophysiology Department, Hopital Haut Leveque, Bordeaux, France.,Electrophysiology and Heart Modeling Institute (LIRYC), Bordeaux University, Pessac, France
| | - Takeshi Kitamura
- Cardiac Electrophysiology Department, Hopital Haut Leveque, Bordeaux, France.,Electrophysiology and Heart Modeling Institute (LIRYC), Bordeaux University, Pessac, France
| | - Anna Lam
- Cardiac Electrophysiology Department, Hopital Haut Leveque, Bordeaux, France.,Electrophysiology and Heart Modeling Institute (LIRYC), Bordeaux University, Pessac, France
| | - Claire Martin
- Cardiac Electrophysiology Department, Hopital Haut Leveque, Bordeaux, France.,Electrophysiology and Heart Modeling Institute (LIRYC), Bordeaux University, Pessac, France
| | | | - Stephane Puyo
- Electrophysiology and Heart Modeling Institute (LIRYC), Bordeaux University, Pessac, France
| | - Xavier Pillois
- Cardiac Electrophysiology Department, Hopital Haut Leveque, Bordeaux, France
| | - Josselin Duchateau
- Cardiac Electrophysiology Department, Hopital Haut Leveque, Bordeaux, France.,Electrophysiology and Heart Modeling Institute (LIRYC), Bordeaux University, Pessac, France
| | - Nicolas Klotz
- Cardiac Electrophysiology Department, Hopital Haut Leveque, Bordeaux, France.,Electrophysiology and Heart Modeling Institute (LIRYC), Bordeaux University, Pessac, France
| | - Arnaud Denis
- Cardiac Electrophysiology Department, Hopital Haut Leveque, Bordeaux, France.,Electrophysiology and Heart Modeling Institute (LIRYC), Bordeaux University, Pessac, France
| | - Nicolas Derval
- Cardiac Electrophysiology Department, Hopital Haut Leveque, Bordeaux, France.,Electrophysiology and Heart Modeling Institute (LIRYC), Bordeaux University, Pessac, France
| | - Pierre Jais
- Cardiac Electrophysiology Department, Hopital Haut Leveque, Bordeaux, France.,Electrophysiology and Heart Modeling Institute (LIRYC), Bordeaux University, Pessac, France
| | - Hubert Cochet
- Electrophysiology and Heart Modeling Institute (LIRYC), Bordeaux University, Pessac, France.,Department of Cardiovascular Imaging, Hopital Haut Leveque, Bordeaux, France
| | - Meleze Hocini
- Cardiac Electrophysiology Department, Hopital Haut Leveque, Bordeaux, France.,Electrophysiology and Heart Modeling Institute (LIRYC), Bordeaux University, Pessac, France
| | - Michel Haissaguerre
- Cardiac Electrophysiology Department, Hopital Haut Leveque, Bordeaux, France.,Electrophysiology and Heart Modeling Institute (LIRYC), Bordeaux University, Pessac, France
| | - Frederic Sacher
- Cardiac Electrophysiology Department, Hopital Haut Leveque, Bordeaux, France.,Electrophysiology and Heart Modeling Institute (LIRYC), Bordeaux University, Pessac, France
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Verma A, Sarkozy A, Skanes A, Duytschaever M, Bulava A, Urman R, Amos YA, Potter TD. Characterization and significance of localized sources identified by a novel automated algorithm during mapping of human persistent atrial fibrillation. J Cardiovasc Electrophysiol 2018; 29:1480-1488. [DOI: 10.1111/jce.13742] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Revised: 07/11/2018] [Accepted: 07/31/2018] [Indexed: 11/27/2022]
Affiliation(s)
- Atul Verma
- Department of Cardiology, Southlake Regional Health Center, University of Toronto Canada
| | | | - Allan Skanes
- Department of Cardiology, London Health Sciences CenterLondon Canada
| | | | - Alan Bulava
- Department of Cardiology, University of South BohemiaCeske Budejovice Czech Republic
| | - Roy Urman
- Haifa Technology Center, Biosense WebsterHaifa Israel
| | - Yariv A. Amos
- Haifa Technology Center, Biosense WebsterHaifa Israel
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Vidmar D, Alhusseini MI, Narayan SM, Rappel WJ. Characterizing Electrogram Signal Fidelity and the Effects of Signal Contamination on Mapping Human Persistent Atrial Fibrillation. Front Physiol 2018; 9:1232. [PMID: 30237766 PMCID: PMC6135945 DOI: 10.3389/fphys.2018.01232] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Accepted: 08/15/2018] [Indexed: 11/30/2022] Open
Abstract
Objective: Determining accurate intracardiac maps of atrial fibrillation (AF) in humans can be difficult, owing primarily to various sources of contamination in electrogram signals. The goal of this study is to develop a measure for signal fidelity and to develop methods to quantify robustness of observed rotational activity in phase maps subject to signal contamination. Methods: We identified rotational activity in phase maps of human persistent AF using the Hilbert transform of sinusoidally recomposed signals, where localized ablation at rotational sites terminated fibrillation. A novel measure of signal fidelity was developed to quantify signal quality. Contamination is then introduced to the underlying electrograms by removing signals at random, adding noise to computations of cycle length, and adding realistic far-field signals. Mean tip number N and tip density δ, defined as the proportion of time a region contains a tip, at the termination site are computed to compare the effects of contamination. Results: Domains of low signal fidelity correspond to the location of rotational cores. Removing signals and altering cycle length accounted for minor changes in tip density, while targeted removal of low fidelity electrograms can result in a significant increase in tip density and stability. Far-field contamination was found to obscure rotation at the termination site. Conclusion: Rotational activity in clinical AF can produce domains of low fidelity electrogram recordings at rotational cores. Observed rotational patterns in phase maps appear most sensitive to far-field activation. These results may inform novel methods to map AF in humans which can be tested directly in patients at electrophysiological study and ablation.
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Affiliation(s)
- David Vidmar
- Department of Physics, University of California, San Diego, San Diego, CA, United States
| | - Mahmood I. Alhusseini
- Division of Cardiology, Department of Medicine, Stanford University, Stanford, CA, United States
| | - Sanjiv M. Narayan
- Division of Cardiology, Department of Medicine, Stanford University, Stanford, CA, United States
| | - Wouter-Jan Rappel
- Department of Physics, University of California, San Diego, San Diego, CA, United States
- *Correspondence: Wouter-Jan Rappel
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