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Zaatari G, Mitrani R, Bohorquez J, Ng J, Ng J, Rivner H, Velasquez A, Lambrakos L, Arora R, Goldberger JJ. Electrogram Morphology Recurrence for Mapping Persistent Atrial Fibrillation: Initial vs Redo Catheter Ablation. JACC Clin Electrophysiol 2023; 9:526-540. [PMID: 36669899 PMCID: PMC10699542 DOI: 10.1016/j.jacep.2022.11.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Revised: 09/30/2022] [Accepted: 11/02/2022] [Indexed: 01/20/2023]
Abstract
BACKGROUND Electrogram (EGM) morphology recurrence (EMR) mapping of persistent atrial fibrillation (AF) quantifies consistency of activation and is expected to be high and rapid near AF drivers. OBJECTIVES The purpose of this study was to compare EMR in left atria (LA) and right atria (RA) in patients undergoing first vs redo ablation for persistent AF. METHODS Multisite LA/RA mapping (LA: 281 ± 176 sites/patient; RA: 239 ± 166 sites/patient) before persistent AF ablation was performed in 42 patients (30 males, age 63 ± 9 years) undergoing first (Group 1, n = 32) or redo ablation (Group 2, n = 10). After cross-correlation of each automatically detected EGM with every other EGM per recording, the most recurrent electrogram morphology was identified and its frequency (Rec%) and recurrence cycle length (CLR) were computed. RESULTS In Groups 1 and 2, minimum CLR was 172.8 ± 26.0 milliseconds (LA: 178.2 ± 37.6 milliseconds, RA: 204.4 ± 34.0 milliseconds, P = 0.0005) and 186.5 ± 28.3 milliseconds (LA: 196.1 ± 38.1 milliseconds vs RA: 199.0 ± 30.2 milliseconds, P = 0.75), with Rec% 94.7% ± 10% and 93.8% ± 9.2%. Group 2 minimum CLR was not different from Group 1 (P = 0.20). Shortest CLR was in the LA in 84% of Group 1 and 50% of Group 2 patients (P = 0.04). Only 1 of 10 patients in Group 2 had the shortest CLR in the pulmonary veins (PVs) compared with 19 of 32 in Group 1 (P = 0.01). Most sites (77.6%) had Rec% <50%. CONCLUSIONS EMR identified the shortest CLR sites in the PVs in 59% of patients undergoing initial persistent AF ablation, consistent with reported success rates of ∼50% for PV isolation. The majority of sites have low recurrence and may reflect bystander sites not critical for maintaining AF. EMR provides a robust new method for quantifying consistency and rapidity of activation direction at multiple atrial sites.
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Affiliation(s)
- Ghaith Zaatari
- Division of Cardiology, Department of Medicine, University of Miami, Miami, Florida, USA
| | - Raul Mitrani
- Division of Cardiology, Department of Medicine, University of Miami, Miami, Florida, USA
| | - Jorge Bohorquez
- Department of Biomedical Engineering, University of Miami, Miami, Florida, USA
| | - Jason Ng
- University of Illinois, College of Medicine, Chicago, Illinois, USA
| | - Justin Ng
- Northwestern University, Chicago, Illinois, USA
| | - Harold Rivner
- Division of Cardiology, Department of Medicine, University of Miami, Miami, Florida, USA
| | - Alex Velasquez
- Division of Cardiology, Department of Medicine, University of Miami, Miami, Florida, USA
| | - Litsa Lambrakos
- Division of Cardiology, Department of Medicine, University of Miami, Miami, Florida, USA
| | - Rishi Arora
- Northwestern University, Chicago, Illinois, USA
| | - Jeffrey J Goldberger
- Division of Cardiology, Department of Medicine, University of Miami, Miami, Florida, USA.
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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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Rabinovitch R, Biton Y, Braunstein D, Aviram I, Thieberger R, Rabinovitch A. Percolation and tortuosity in heart-like cells. Sci Rep 2021; 11:11441. [PMID: 34075111 PMCID: PMC8169828 DOI: 10.1038/s41598-021-90892-2] [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] [Received: 10/21/2020] [Accepted: 04/15/2021] [Indexed: 11/25/2022] Open
Abstract
In the last several years, quite a few papers on the joint question of transport, tortuosity and percolation have appeared in the literature, dealing with passage of miscellaneous liquids or electrical currents in different media. However, these methods have not been applied to the passage of action potential in heart fibrosis (HF), which is crucial for problems of heart arrhythmia, especially of atrial tachycardia and fibrillation. In this work we address the HF problem from these aspects. A cellular automaton model is used to analyze percolation and transport of a distributed-fibrosis inflicted heart-like tissue. Although based on a rather simple mathematical model, it leads to several important outcomes: (1) It is shown that, for a single wave front (as the one emanated by the heart's sinus node), the percolation of heart-like matrices is exactly similar to the forest fire case. (2) It is shown that, on the average, the shape of the transport (a question not dealt with in relation to forest fire, and deals with the delay of action potential when passing a fibrotic tissue) behaves like a Gaussian. (3) Moreover, it is shown that close to the percolation threshold the parameters of this Gaussian behave in a critical way. From the physical point of view, these three results are an important contribution to the general percolation investigation. The relevance of our results to cardiological issues, specifically to the question of reentry initiation, are discussed and it is shown that: (A) Without an ectopic source and under a mere sinus node operation, no arrhythmia is generated, and (B) A sufficiently high refractory period could prevent some reentry mechanisms, even in partially fibrotic heart tissue.
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Affiliation(s)
| | - Y Biton
- Physics Department, Ben-Gurion University, Beer-Sheva, Israel
| | - D Braunstein
- Physics Department, Sami Shamoon College of Engineering, Beer-Sheva, Israel
| | - I Aviram
- Physics Department, Ben-Gurion University, Beer-Sheva, Israel
| | - R Thieberger
- Physics Department, Ben-Gurion University, Beer-Sheva, Israel
| | - A Rabinovitch
- Physics Department, Ben-Gurion University, Beer-Sheva, Israel.
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Quah JX, Dharmaprani D, Tiver K, Lahiri A, Hecker T, Perry R, Selvanayagam JB, Joseph MX, McGavigan A, Ganesan A. Atrial fibrosis and substrate based characterization in atrial fibrillation: Time to move forwards. J Cardiovasc Electrophysiol 2021; 32:1147-1160. [PMID: 33682258 DOI: 10.1111/jce.14987] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Revised: 02/15/2021] [Accepted: 02/22/2021] [Indexed: 12/15/2022]
Abstract
Atrial fibrillation (AF) is the most commonly encountered cardiac arrhythmia in clinical practice. However, current therapeutic interventions for atrial fibrillation have limited clinical efficacy as a consequence of major knowledge gaps in the mechanisms sustaining atrial fibrillation. From a mechanistic perspective, there is increasing evidence that atrial fibrosis plays a central role in the maintenance and perpetuation of atrial fibrillation. Electrophysiologically, atrial fibrosis results in alterations in conduction velocity, cellular refractoriness, and produces conduction block promoting meandering, unstable wavelets and micro-reentrant circuits. Clinically, atrial fibrosis has also linked to poor clinical outcomes including AF-related thromboembolic complications and arrhythmia recurrences post catheter ablation. In this article, we review the pathophysiology behind the formation of fibrosis as AF progresses, the role of fibrosis in arrhythmogenesis, surrogate markers for detection of fibrosis using cardiac magnetic resonance imaging, echocardiography and electroanatomic mapping, along with their respective limitations. We then proceed to review the current evidence behind therapeutic interventions targeting atrial fibrosis, including drugs and substrate-based catheter ablation therapies followed by the potential future use of electro phenotyping for AF characterization to overcome the limitations of contemporary substrate-based methodologies.
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Affiliation(s)
- Jing X Quah
- College of Medicine and Public Health, Flinders University of South Australia, Adelaide, Australia.,Department of Cardiovascular Medicine, Flinders Medical Centre, 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
| | - Anandaroop Lahiri
- Department of Cardiovascular Medicine, Flinders Medical Centre, Adelaide, Australia
| | - Teresa Hecker
- Department of Cardiovascular Medicine, Flinders Medical Centre, Adelaide, Australia
| | - Rebecca Perry
- Department of Cardiovascular Medicine, Flinders Medical Centre, Adelaide, Australia.,UniSA Allied Health and Human Performance, University of South Australia, Adelaide, Australia
| | | | - Majo X Joseph
- 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
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Ciaccio EJ, Coromilas J, Wan EY, Yarmohammadi H, Saluja DS, Biviano AB, Wit AL, Peters NS, Garan H. Slow uniform electrical activation during sinus rhythm is an indicator of reentrant VT isthmus location and orientation in an experimental model of myocardial infarction. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2020; 196:105666. [PMID: 32717622 DOI: 10.1016/j.cmpb.2020.105666] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 07/12/2020] [Indexed: 06/11/2023]
Abstract
BACKGROUND To validate the predictability of reentrant circuit isthmus locations without ventricular tachycardia (VT) induction during high-definition mapping, we used computer methods to analyse sinus rhythm activation in experiments where isthmus location was subsequently verified by mapping reentrant VT circuits. METHOD In 21 experiments using a canine postinfarction model, bipolar electrograms were obtained from 196-312 recordings with 4mm spacing in the epicardial border zone during sinus rhythm and during VT. From computerized electrical activation maps of the reentrant circuit, areas of conduction block were determined and the isthmus was localized. A linear regression was computed at three different locations about the reentry isthmus using sinus rhythm electrogram activation data. From the regression analysis, the uniformity, a measure of the constancy at which the wavefront propagates, and the activation gradient, a measure that may approximate wavefront speed, were computed. The purpose was to test the hypothesis that the isthmus locates in a region of slow uniform activation bounded by areas of electrical discontinuity. RESULTS Based on the regression parameters, sinus rhythm activation along the isthmus near its exit proceeded uniformly (mean r2= 0.95±0.05) and with a low magnitude gradient (mean 0.37±0.10mm/ms). Perpendicular to the isthmus long-axis across its boundaries, the activation wavefront propagated much less uniformly (mean r2= 0.76±0.24) although of similar gradient (mean 0.38±0.23mm/ms). In the opposite direction from the exit, at the isthmus entrance, there was also less uniformity (mean r2= 0.80±0.22) but a larger magnitude gradient (mean 0.50±0.25mm/ms). A theoretical ablation line drawn perpendicular to the last sinus rhythm activation site along the isthmus long-axis was predicted to prevent VT reinduction. Anatomical conduction block occurred in 7/21 experiments, but comprised only small portions of the isthmus lateral boundaries; thus detection of sinus rhythm conduction block alone was insufficient to entirely define the VT isthmus. CONCLUSIONS Uniform activation with a low magnitude gradient during sinus rhythm is present at the VT isthmus exit location but there is less uniformity across the isthmus lateral boundaries and at isthmus entrance locations. These factors may be useful to verify any proposed VT isthmus location, reducing the need for VT induction to ablate the isthmus. Measured computerized values similar to those determined herein could therefore be assistive to sharpen specificity when applying sinus rhythm mapping to localize EP catheter ablation sites.
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Affiliation(s)
- Edward J Ciaccio
- Department of Medicine - Division of Cardiology, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA; ElectroCardioMaths Programme, Imperial Centre for Cardiac Engineering, Imperial College London, London, UK.
| | - James Coromilas
- Department of Medicine - Division of Cardiovascular Disease and Hypertension, Rutgers University, New Brunswick, NJ, USA
| | - Elaine Y Wan
- Department of Medicine - Division of Cardiology, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA
| | - Hirad Yarmohammadi
- Department of Medicine - Division of Cardiology, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA
| | - Deepak S Saluja
- Department of Medicine - Division of Cardiology, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA
| | - Angelo B Biviano
- Department of Medicine - Division of Cardiology, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA
| | - Andrew L Wit
- Department of Pharmacology, Columbia University College of Physicians and Surgeons, New York, NY, USA
| | - 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 College of Physicians and Surgeons, New York, NY 10032, USA
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Ciacci A, Falkenberg M, Manani KA, Evans TS, Peters NS, Christensen K. Understanding the transition from paroxysmal to persistent atrial fibrillation. PHYSICAL REVIEW RESEARCH 2020; 2:023311. [PMID: 32607500 PMCID: PMC7326608 DOI: 10.1103/physrevresearch.2.023311] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Atrial fibrillation (AF) is the most common cardiac arrhytmia, characterized by the chaotic motion of electrical wavefronts in the atria. In clinical practice, AF is classified under two primary categories: paroxysmal AF, short intermittent episodes separated by periods of normal electrical activity; and persistent AF, longer uninterrupted episodes of chaotic electrical activity. However, the precise reasons why AF in a given patient is paroxysmal or persistent is poorly understood. Recently, we have introduced the percolation-based Christensen-Manani-Peters (CMP) model of AF which naturally exhibits both paroxysmal and persistent AF, but precisely how these differences emerge in the model is unclear. In this paper, we dissect the CMP model to identify the cause of these different AF classifications. Starting from a mean-field model where we describe AF as a simple birth-death process, we add layers of complexity to the model and show that persistent AF arises from reentrant circuits which exhibit an asymmetry in their probability of activation relative to deactivation. As a result, different simulations generated at identical model parameters can exhibit fibrillatory episodes spanning several orders of magnitude from a few seconds to months. These findings demonstrate that diverse, complex fibrillatory dynamics can emerge from very simple dynamics in models of AF.
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Affiliation(s)
- Alberto Ciacci
- Blackett Laboratory, Imperial College London, London SW7 2BW, United Kingdom
- Center for Complexity Science, Imperial College London, London SW7 2AZ, United Kingdom
- ElectroCardioMaths Programme, Imperial Centre for Cardiac Engineering, Imperial College London, London W12 0NN, United Kingdom
| | - Max Falkenberg
- Blackett Laboratory, Imperial College London, London SW7 2BW, United Kingdom
- Center for Complexity Science, Imperial College London, London SW7 2AZ, United Kingdom
- ElectroCardioMaths Programme, Imperial Centre for Cardiac Engineering, Imperial College London, London W12 0NN, United Kingdom
| | - Kishan A. Manani
- Blackett Laboratory, Imperial College London, London SW7 2BW, United Kingdom
- Center for Complexity Science, Imperial College London, London SW7 2AZ, United Kingdom
- National Heart and Lung Institute, Imperial College London, London W12 0NN, United Kingdom
| | - Tim S. Evans
- Blackett Laboratory, Imperial College London, London SW7 2BW, United Kingdom
- Center for Complexity Science, Imperial College London, London SW7 2AZ, United Kingdom
| | - Nicholas S. Peters
- ElectroCardioMaths Programme, Imperial Centre for Cardiac Engineering, Imperial College London, London W12 0NN, United Kingdom
| | - Kim Christensen
- Blackett Laboratory, Imperial College London, London SW7 2BW, United Kingdom
- Center for Complexity Science, Imperial College London, London SW7 2AZ, United Kingdom
- ElectroCardioMaths Programme, Imperial Centre for Cardiac Engineering, Imperial College London, London W12 0NN, United Kingdom
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