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Okenov A, Nezlobinsky T, Zeppenfeld K, Vandersickel N, Panfilov AV. Computer based method for identification of fibrotic scars from electrograms and local activation times on the epi- and endocardial surfaces of the ventricles. PLoS One 2024; 19:e0300978. [PMID: 38625849 PMCID: PMC11020530 DOI: 10.1371/journal.pone.0300978] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Accepted: 03/07/2024] [Indexed: 04/18/2024] Open
Abstract
Cardiac fibrosis stands as one of the most critical conditions leading to lethal cardiac arrhythmias. Identifying the precise location of cardiac fibrosis is crucial for planning clinical interventions in patients with various forms of ventricular and atrial arrhythmias. As fibrosis impedes and alters the path of electrical waves, detecting fibrosis in the heart can be achieved through analyzing electrical signals recorded from its surface. In current clinical practices, it has become feasible to record electrical activity from both the endocardial and epicardial surfaces of the heart. This paper presents a computational method for reconstructing 3D fibrosis using unipolar electrograms obtained from both surfaces of the ventricles. The proposed method calculates the percentage of fibrosis in various ventricular segments by analyzing the local activation times and peak-to-peak amplitudes of the electrograms. Initially, the method was tested using simulated data representing idealized fibrosis in a heart segment; subsequently, it was validated in the left ventricle with fibrosis obtained from a patient with nonischemic cardiomyopathy. The method successfully determined the location and extent of fibrosis in 204 segments of the left ventricle model with an average error of 0.0±4.3% (N = 204). Moreover, the method effectively detected fibrotic scars in the mid-myocardial region, a region known to present challenges in accurate detection using electrogram amplitude as the primary criterion.
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Affiliation(s)
- Arstanbek Okenov
- Department of Physics and Astronomy, Ghent University, Gent, Belgium
| | - Timur Nezlobinsky
- Department of Physics and Astronomy, Ghent University, Gent, Belgium
| | - Katja Zeppenfeld
- Department of Cardiology, Leiden University Medical Centre, Leiden, The Netherlands
| | - Nele Vandersickel
- Department of Physics and Astronomy, Ghent University, Gent, Belgium
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Vandersickel N, Watanabe M, Tao Q, Fostier J, Zeppenfeld K, Panfilov AV. Dynamical anchoring of distant arrhythmia sources by fibrotic regions via restructuring of the activation pattern. PLoS Comput Biol 2018; 14:e1006637. [PMID: 30571689 PMCID: PMC6319787 DOI: 10.1371/journal.pcbi.1006637] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Revised: 01/04/2019] [Accepted: 11/09/2018] [Indexed: 11/27/2022] Open
Abstract
Rotors are functional reentry sources identified in clinically relevant cardiac arrhythmias, such as ventricular and atrial fibrillation. Ablation targeting rotor sites has resulted in arrhythmia termination. Recent clinical, experimental and modelling studies demonstrate that rotors are often anchored around fibrotic scars or regions with increased fibrosis. However, the mechanisms leading to abundance of rotors at these locations are not clear. The current study explores the hypothesis whether fibrotic scars just serve as anchoring sites for the rotors or whether there are other active processes which drive the rotors to these fibrotic regions. Rotors were induced at different distances from fibrotic scars of various sizes and degree of fibrosis. Simulations were performed in a 2D model of human ventricular tissue and in a patient-specific model of the left ventricle of a patient with remote myocardial infarction. In both the 2D and the patient-specific model we found that without fibrotic scars, the rotors were stable at the site of their initiation. However, in the presence of a scar, rotors were eventually dynamically anchored from large distances by the fibrotic scar via a process of dynamical reorganization of the excitation pattern. This process coalesces with a change from polymorphic to monomorphic ventricular tachycardia. Rotors are waves of cardiac excitation like a tornado causing cardiac arrhythmia. Recent research shows that they are found in ventricular and atrial fibrillation. Burning (via ablation) the site of a rotor can result in the termination of the arrhythmia. Recent studies showed that rotors are often anchored to regions surrounding scar tissue, where part of the tissue still survived called fibrotic tissue. However, it is unclear why these rotors anchor to these locations. Therefore, in this work, we investigated why rotors are so abundant in fibrotic tissue with the help of computer simulations. We performed simulations in a 2D model of human ventricular tissue and in a patient-specific model of a patient with an infarction. We found that even when rotors are initially at large distances from the fibrotic region, they are attracted by this region, to finally end up at the fibrotic tissue. We called this process dynamical anchoring and explained how the process works.
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Affiliation(s)
- Nele Vandersickel
- Department of Physics and Astronomy, Ghent University, Belgium
- * E-mail: (NV); (AVP)
| | - Masaya Watanabe
- Department of Cardiology, Leiden University Medical Center, Leiden, the Netherlands
| | - Qian Tao
- Department of Radiology, Division of Image Processing, Leiden University Medical Centre, Leiden, the Netherlands
| | - Jan Fostier
- Department of Information Technology (INTEC), IDLab, Ghent University — imec, Ghent, Belgium
| | - Katja Zeppenfeld
- Department of Cardiology, Leiden University Medical Center, Leiden, the Netherlands
| | - Alexander V. Panfilov
- Department of Physics and Astronomy, Ghent University, Belgium
- Department of Cardiology, Leiden University Medical Center, Leiden, the Netherlands
- Laboratory of Computational Biology and Medicine, Ural Federal University, Ekaterinburg, Russia
- * E-mail: (NV); (AVP)
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Cheniti G, Vlachos K, Meo M, Puyo S, Thompson N, Denis A, Duchateau J, Takigawa M, Martin C, Frontera A, Kitamura T, Lam A, Bourier F, Klotz N, Derval N, Sacher F, Jais P, Dubois R, Hocini M, Haissaguerre M. Mapping and Ablation of Idiopathic Ventricular Fibrillation. Front Cardiovasc Med 2018; 5:123. [PMID: 30280100 PMCID: PMC6153961 DOI: 10.3389/fcvm.2018.00123] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2018] [Accepted: 08/20/2018] [Indexed: 01/30/2023] Open
Abstract
Idiopathic ventricular fibrillation (IVF) is the main cause of unexplained sudden cardiac death, particularly in young patients under the age of 35. IVF is a diagnosis of exclusion in patients who have survived a VF episode without any identifiable structural or metabolic causes despite extensive diagnostic testing. Genetic testing allows identification of a likely causative mutation in up to 27% of unexplained sudden deaths in children and young adults. In the majority of cases, VF is triggered by PVCs that originate from the Purkinje network. Ablation of VF triggers in this setting is associated with high rates of acute success and long-term freedom from VF recurrence. Recent studies demonstrate that a significant subset of IVF defined by negative comprehensive investigations, demonstrate in fact subclinical structural alterations. These localized myocardial alterations are identified by high density electrogram mapping, are of small size and are mainly located in the epicardium. As reentrant VF drivers are often colocated with regions of abnormal electrograms, this localized substrate can be shown to be mechanistically linked with VF. Such areas may represent an important target for ablation.
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Affiliation(s)
- Ghassen Cheniti
- Electrophysiology and Ablation Unit, Bordeaux University Hospital (CHU), Pessac, France.,IHU Liryc, Electrophysiology and Heart Modeling Institute, Foundation Bordeaux Université, Bordeaux, France.,Department of Cardiology, Sahloul Hospital, Universite de Sousse, Sousse, Tunisia
| | - Konstantinos Vlachos
- Electrophysiology and Ablation Unit, Bordeaux University Hospital (CHU), Pessac, France.,IHU Liryc, Electrophysiology and Heart Modeling Institute, Foundation Bordeaux Université, Bordeaux, France
| | - Marianna Meo
- IHU Liryc, Electrophysiology and Heart Modeling Institute, Foundation Bordeaux Université, Bordeaux, France
| | - Stephane Puyo
- Electrophysiology and Ablation Unit, Bordeaux University Hospital (CHU), Pessac, France.,IHU Liryc, Electrophysiology and Heart Modeling Institute, Foundation Bordeaux Université, Bordeaux, France
| | - Nathaniel Thompson
- Electrophysiology and Ablation Unit, Bordeaux University Hospital (CHU), Pessac, France.,IHU Liryc, Electrophysiology and Heart Modeling Institute, Foundation Bordeaux Université, Bordeaux, France
| | - Arnaud Denis
- Electrophysiology and Ablation Unit, Bordeaux University Hospital (CHU), Pessac, France.,IHU Liryc, Electrophysiology and Heart Modeling Institute, Foundation Bordeaux Université, Bordeaux, France
| | - Josselin Duchateau
- Electrophysiology and Ablation Unit, Bordeaux University Hospital (CHU), Pessac, France.,IHU Liryc, Electrophysiology and Heart Modeling Institute, Foundation Bordeaux Université, Bordeaux, France
| | - Masateru Takigawa
- Electrophysiology and Ablation Unit, Bordeaux University Hospital (CHU), Pessac, France.,IHU Liryc, Electrophysiology and Heart Modeling Institute, Foundation Bordeaux Université, Bordeaux, France
| | - Claire Martin
- Electrophysiology and Ablation Unit, Bordeaux University Hospital (CHU), Pessac, France.,IHU Liryc, Electrophysiology and Heart Modeling Institute, Foundation Bordeaux Université, Bordeaux, France.,Department of Cardiology, Royal Papworth Hospital NHS Foundation Trust, Cambridge, United Kingdom
| | - Antonio Frontera
- Electrophysiology and Ablation Unit, Bordeaux University Hospital (CHU), Pessac, France.,IHU Liryc, Electrophysiology and Heart Modeling Institute, Foundation Bordeaux Université, Bordeaux, France
| | - Takeshi Kitamura
- Electrophysiology and Ablation Unit, Bordeaux University Hospital (CHU), Pessac, France.,IHU Liryc, Electrophysiology and Heart Modeling Institute, Foundation Bordeaux Université, Bordeaux, France
| | - Anna Lam
- Electrophysiology and Ablation Unit, Bordeaux University Hospital (CHU), Pessac, France.,IHU Liryc, Electrophysiology and Heart Modeling Institute, Foundation Bordeaux Université, Bordeaux, France
| | - Felix Bourier
- Electrophysiology and Ablation Unit, Bordeaux University Hospital (CHU), Pessac, France.,IHU Liryc, Electrophysiology and Heart Modeling Institute, Foundation Bordeaux Université, Bordeaux, France
| | - Nicolas Klotz
- Electrophysiology and Ablation Unit, Bordeaux University Hospital (CHU), Pessac, France.,IHU Liryc, Electrophysiology and Heart Modeling Institute, Foundation Bordeaux Université, Bordeaux, France
| | - Nicolas Derval
- Electrophysiology and Ablation Unit, Bordeaux University Hospital (CHU), Pessac, France.,IHU Liryc, Electrophysiology and Heart Modeling Institute, Foundation Bordeaux Université, Bordeaux, France
| | - Frederic Sacher
- Electrophysiology and Ablation Unit, Bordeaux University Hospital (CHU), Pessac, France.,IHU Liryc, Electrophysiology and Heart Modeling Institute, Foundation Bordeaux Université, Bordeaux, France
| | - Pierre Jais
- Electrophysiology and Ablation Unit, Bordeaux University Hospital (CHU), Pessac, France.,IHU Liryc, Electrophysiology and Heart Modeling Institute, Foundation Bordeaux Université, Bordeaux, France
| | - Remi Dubois
- IHU Liryc, Electrophysiology and Heart Modeling Institute, Foundation Bordeaux Université, Bordeaux, France
| | - Meleze Hocini
- Electrophysiology and Ablation Unit, Bordeaux University Hospital (CHU), Pessac, France.,IHU Liryc, Electrophysiology and Heart Modeling Institute, Foundation Bordeaux Université, Bordeaux, France
| | - Michel Haissaguerre
- Electrophysiology and Ablation Unit, Bordeaux University Hospital (CHU), Pessac, France.,IHU Liryc, Electrophysiology and Heart Modeling Institute, Foundation Bordeaux Université, Bordeaux, France
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Filgueiras-Rama D, Jalife J. STRUCTURAL AND FUNCTIONAL BASES OF CARDIAC FIBRILLATION. DIFFERENCES AND SIMILARITIES BETWEEN ATRIA AND VENTRICLES. JACC Clin Electrophysiol 2016; 2:1-3. [PMID: 27042693 DOI: 10.1016/j.jacep.2015.12.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Evidence accumulated over the last 25 years suggests that, whether in the atria or ventricles, fibrillation may be explained by the self-organization of the cardiac electrical activity into rapidly spinning rotors giving way to spiral waves that break intermittently and result in fibrillatory conduction. The dynamics and frequency of such rotors depend on the ion channel composition, excitability and refractory properties of the tissues involved, as well as on the thickness and respective three-dimensional fiber structure of the atrial and ventricular chambers. Therefore, improving the understanding of fibrillation has required the use of multidisciplinary research approaches, including optical mapping, patch clamping and molecular biology, and the application of concepts derived from the theory of wave propagation in excitable media. Moreover, translation of such concepts to the clinic has recently opened new opportunities to apply novel mechanistic approaches to therapy, particularly during atrial fibrillation ablation. Here we review the current understanding of the manner in which the underlying myocardial structure and function influence rotor initiation and maintenance during cardiac fibrillation. We also examine relevant underlying differences and similarities between atrial fibrillation and ventricular fibrillation and evaluate the latest clinical mapping technologies used to identify rotors in either arrhythmia. Altogether, the data being discussed have significantly improved our understanding of the cellular and structural bases of cardiac fibrillation and pointed toward potentially exciting new avenues for more efficient and effective identification and therapy of the most complex cardiac arrhythmias.
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Affiliation(s)
- David Filgueiras-Rama
- Fundación Centro Nacional de Investigaciones Cardiovasculares, Carlos III (CNIC)., Myocardial Pathophysiology Area, Madrid, Spain; Hospital Clínico San Carlos, Cardiology department, Madrid, Spain
| | - José Jalife
- Fundación Centro Nacional de Investigaciones Cardiovasculares, Carlos III (CNIC)., Myocardial Pathophysiology Area, Madrid, Spain; Center for Arrhythmia Research, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, EEUU
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Krummen DE, Hayase J, Morris DJ, Ho J, Smetak MR, Clopton P, Rappel WJ, Narayan SM. Rotor stability separates sustained ventricular fibrillation from self-terminating episodes in humans. J Am Coll Cardiol 2014; 63:2712-21. [PMID: 24794115 DOI: 10.1016/j.jacc.2014.03.037] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/29/2013] [Revised: 03/23/2014] [Accepted: 03/29/2014] [Indexed: 10/25/2022]
Abstract
OBJECTIVES This study mapped human ventricular fibrillation (VF) to define mechanistic differences between episodes requiring defibrillation versus those that spontaneously terminate. BACKGROUND VF is a leading cause of mortality; yet, episodes may also self-terminate. We hypothesized that the initial maintenance of human VF is dependent upon the formation and stability of VF rotors. METHODS We enrolled 26 consecutive patients (age 64 ± 10 years, n = 13 with left ventricular dysfunction) during ablation procedures for ventricular arrhythmias, using 64-electrode basket catheters in both ventricles to map VF prior to prompt defibrillation per the institutional review board-approved protocol. A total of 52 inductions were attempted, and 36 VF episodes were observed. Phase analysis was applied to identify biventricular rotors in the first 10 s or until VF terminated, whichever came first (11.4 ± 2.9 s to defibrillator charging). RESULTS Rotors were present in 16 of 19 patients with VF and in all patients with sustained VF. Sustained, but not self-limiting VF, was characterized by greater rotor stability: 1) rotors were present in 68 ± 17% of cycles in sustained VF versus 11 ± 18% of cycles in self-limiting VF (p < 0.001); and 2) maximum continuous rotations were greater in sustained (17 ± 11, range 7 to 48) versus self-limiting VF (1.1 ± 1.4, range 0 to 4, p < 0.001). Additionally, biventricular rotor locations in sustained VF were conserved across multiple inductions (7 of 7 patients, p = 0.025). CONCLUSIONS In patients with and without structural heart disease, the formation of stable rotors identifies individuals whose VF requires defibrillation from those in whom VF spontaneously self-terminates. Future work should define the mechanisms that stabilize rotors and evaluate whether rotor modulation may reduce subsequent VF risk.
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Affiliation(s)
- David E Krummen
- University of California San Diego, San Diego, California; Veterans Affairs San Diego Healthcare System, San Diego, California.
| | - Justin Hayase
- University of California San Diego, San Diego, California; Veterans Affairs San Diego Healthcare System, San Diego, California
| | - David J Morris
- University of California San Diego, San Diego, California; Veterans Affairs San Diego Healthcare System, San Diego, California
| | - Jeffrey Ho
- University of California San Diego, San Diego, California; Veterans Affairs San Diego Healthcare System, San Diego, California
| | - Miriam R Smetak
- Veterans Affairs San Diego Healthcare System, San Diego, California
| | - Paul Clopton
- Veterans Affairs San Diego Healthcare System, San Diego, California
| | | | - Sanjiv M Narayan
- University of California San Diego, San Diego, California; Veterans Affairs San Diego Healthcare System, San Diego, California
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