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Kong MH, Castellano S, Ruppersberg P, Lizama KS, Avitall B. Visualization of electrographic flow fields of increasing complexity and detection of simulated sources during spontaneously persistent AF in an animal model. Front Cardiovasc Med 2023; 10:1223481. [PMID: 37719974 PMCID: PMC10503433 DOI: 10.3389/fcvm.2023.1223481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Accepted: 08/09/2023] [Indexed: 09/19/2023] Open
Abstract
Background Mapping algorithms have thus far been unable to localize triggers that serve as drivers of AF, but electrographic flow (EGF) mapping provides an innovative method of estimating and visualizing in vivo, near real-time cardiac wavefront propagation. Materials and Methods One-minute unipolar EGMs were recorded in the right atrium (RA) from a 64-electrode basket catheter to generate EGF maps during atrial rhythms of increasing complexity. They were obtained from 3 normal, animals in sinus rhythm (SR) and from 6 animals in which persistent AF which was induced by rapid atrial pacing. Concurrent EGF maps and high-resolution bipolar EGMs at the location of all EGF-identified sources were acquired. Pacing was subsequently conducted to create focal drivers of AF, and the accuracy of source detection at the pacing site was assessed during subthreshold, threshold and high-output pacing in the ipsilateral or contralateral atria (n = 78). Results EGF recordings showed strong coherent flow emanating from the sinus node in SR that changed direction during pacing and were blocked by ablation lesions. Additional passive rotational phenomena and lower activity sources were visualized in atrial flutter (AFL) and AF. During the AF recordings, source activity was not found to be correlated to dominant frequency or f wave amplitude observed in concurrently recorded EGMs. While pacing in AF, subthreshold pacing did not affect map properties but pacing at or above threshold created active sources that could be accurately localized without any spurious detection in 95% of cases of ipsilateral mapping when the basket covered the pacing source. Discussion EGF mapping can be used to visualize flow patterns and accurately identify sources of AF in an animal model. Source activity was not correlated to spectral properties of f-waves in concurrently obtained EGMs. The locations of sources could be pinpointed with high precision, suggesting that they may serve as prime targets for focal ablations.
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Affiliation(s)
| | | | | | - Ken S. Lizama
- Deptartment of Medicine, University of Illinois at Chicago, Chicago, IL, United States
| | - Boaz Avitall
- Deptartment of Medicine, University of Illinois at Chicago, Chicago, IL, United States
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Hemam ME, Dave AS, Rodríguez-Mañero M, Valderrábano M. Epiphenomenal Re-Entry and Spurious Focal Activation Detection by Atrial Fibrillation Mapping Algorithms. JACC Clin Electrophysiol 2021; 7:923-932. [PMID: 33812838 DOI: 10.1016/j.jacep.2020.12.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 10/28/2020] [Accepted: 12/10/2020] [Indexed: 10/21/2022]
Abstract
OBJECTIVES The purpose of this study was to validate the ability of mapping algorithms to detect rotational activations (RoA) and focal activations (FoA) during fibrillatory conduction (FC) and atrial fibrillation (AF) and understand their mechanistic relevance. BACKGROUND Mapping algorithms have been proposed to detect RoA and FoA to guide AF ablation. METHODS Rapid left atrial pacing created FC-fibrillatory electrograms-with and without AF induction in dogs (n = 17). Activation maps were constructed using Topera (Abbott, St. Paul, Minnesota) or CARTOFINDER (Biosense Webster, Irvine, California) algorithms. Mapping strategies included: panoramic noncontact mapping with a basket catheter (CARTOFINDER n = 6, Topera n = 5); and sequential contact mapping using 8-spline OctaRay catheter (Biosense Webster) (n = 6). Offline frequency and spectral analysis were also performed. Algorithm-detected RoA was manually verified. RESULTS The right atrium (RA) consistently exhibited fibrillatory signals during FC. FC with and without AF had similar left-to-right frequency gradients. Basket maps were either uninterpretable (847 of 990 Topera, 132 of 148 Cartofinder) or had unverifiable RoA. OctaRay contact mapping showed 4% RoA (n = 30 of 679) and 63% FoA (n = 429 of 679). Verified RoA clustered at consistent sites, was more common in the RA than left atrium (odds ratio: 3.5), and colocalized with sites of frequency breakdown in the crista terminalis and RA appendage. During pacing, spurious FoA sites were identified around the atria, but not at the actual pacing sites. RoA and FoA site distribution was similar during pacing with and without induction, and during induced AF. CONCLUSIONS Mapping algorithms were unable to detect pacing sites as true drivers of FC, and detected epiphenomenal RoA and FoA sites unrelated to AF induction or maintenance. Algorithm-detected RoA and FoA did not identify true AF drivers.
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Affiliation(s)
- Majd E Hemam
- Division of Cardiac Electrophysiology, Houston Methodist DeBakey Heart and Vascular Center, Houston, Texas, USA; Department of Medicine, Rutgers New Jersey Medical School, Newark, New Jersey, USA
| | - Amish S Dave
- Division of Cardiac Electrophysiology, Houston Methodist DeBakey Heart and Vascular Center, Houston, Texas, USA
| | - Moisés Rodríguez-Mañero
- Complexo Hospitalario Universitario de Santiago de Compostela (CHUS), Santiago de Compostela, Spain
| | - Miguel Valderrábano
- Division of Cardiac Electrophysiology, Houston Methodist DeBakey Heart and Vascular Center, Houston, Texas, USA.
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Nayyar S, Ha ACT, Timmerman N, Suszko A, Ragot D, Chauhan VS. Focal and pseudo/rotational activations in human atrial fibrillation defined with automated periodicity mapping. J Cardiovasc Electrophysiol 2020; 32:212-223. [PMID: 33179399 DOI: 10.1111/jce.14812] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 10/19/2020] [Accepted: 11/01/2020] [Indexed: 11/30/2022]
Abstract
INTRODUCTION Defining atrial fibrillation (AF) wave propagation is challenging unless local signal features are discrete or periodic. Periodic focal or rotational activity may identify AF drivers. Our objective was to characterize AF propagation at sites with periodic activation to evaluate the prevalence and relationship between focal and rotational activation. METHODS We included 80 patients (61 ± 10 years, persistent AF 49%) from the FaST randomized trial that compared the efficacy of adjunctive focal site ablation versus pulmonary vein isolation. Patients underwent left atrial (LA) activation mapping with a 20-pole circular catheter during spontaneous or induced AF. Five-second bipolar and unipolar electrograms in AF were analyzed. Periodic sites were identified by spectral analysis of the bipolar electrogram. Activation maps of periodic sites were constructed using an automated, validated tracking algorithm, and classified into three patterns: focal sites (FS), rotation (RO), or pseudo-rotation (pRO). RESULTS The most common propagation pattern at periodic sites was FS for 5-s in all patients (4.9 ± 1.9 per patient). RO and pRO were observed in two and seven patients, respectively, but were all transient (3-5 cycles). Activation from a FS evolved into transient RO/pRO in five patients. No patient had autonomous RO/pRO activations. Patients with RO/pRO had greater LA surface area with periodicity (78 ± 7 vs. 63 ± 16%, p = .0002) and shorter LA periodicity CL (166 ± 10 vs. 190±28 ms, p = .0001) than the rest. CONCLUSION Using automated, regional AF periodicity mapping, FS is more prevalent and temporally stable than RO/pRO. Most RO/pRO evolve from neighboring FS. These findings and their implications for AF maintenance require verification with global, panoramic mapping.
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Affiliation(s)
- Sachin Nayyar
- Division of Cardiology, Peter Munk Cardiac Centre, Toronto General Hospital, University Health Network, Toronto, Canada
| | - Andrew C T Ha
- Division of Cardiology, Peter Munk Cardiac Centre, Toronto General Hospital, University Health Network, Toronto, Canada
| | - Nicholas Timmerman
- Division of Cardiology, Peter Munk Cardiac Centre, Toronto General Hospital, University Health Network, Toronto, Canada
| | - Adrian Suszko
- Division of Cardiology, Peter Munk Cardiac Centre, Toronto General Hospital, University Health Network, Toronto, Canada
| | - Don Ragot
- Division of Cardiology, Peter Munk Cardiac Centre, Toronto General Hospital, University Health Network, Toronto, Canada
| | - Vijay S Chauhan
- Division of Cardiology, Peter Munk Cardiac Centre, Toronto General Hospital, University Health Network, Toronto, Canada
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Navara R, Leef G, Shenasa F, Kowalewski C, Rogers AJ, Meckler G, Zaman JAB, Baykaner T, Park S, Turakhia MP, Zei P, Viswanathan M, Wang PJ, Narayan SM. Independent mapping methods reveal rotational activation near pulmonary veins where atrial fibrillation terminates before pulmonary vein isolation. J Cardiovasc Electrophysiol 2018; 29:687-695. [PMID: 29377478 DOI: 10.1111/jce.13446] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Revised: 01/16/2018] [Accepted: 01/18/2018] [Indexed: 01/02/2023]
Abstract
OBJECTIVE To investigate mechanisms by which atrial fibrillation (AF) may terminate during ablation near the pulmonary veins before the veins are isolated (PVI). INTRODUCTION It remains unstudied how AF may terminate during ablation before PVs are isolated, or how patients with PV reconnection can be arrhythmia-free. We studied patients in whom PV antral ablation terminated AF before PVI, using two independent mapping methods. METHODS We studied patients with AF referred for ablation, in whom biatrial contact basket electrograms were studied by both an activation/phase mapping method and by a second validated mapping method reported not to create false rotational activity. RESULTS In 22 patients (age 60.1 ± 10.4, 36% persistent AF), ablation at sites near the PVs terminated AF (77% to sinus rhythm) prior to PVI. AF propagation revealed rotational (n = 20) and focal (n = 2) patterns at sites of termination by mapping method 1 and method 2. Both methods showed organized sites that were spatially concordant (P < 0.001) with similar stability (P < 0.001). Vagal slowing was not observed at sites of AF termination. DISCUSSION PV antral regions where ablation terminated AF before PVI exhibited rotational and focal activation by two independent mapping methods. These data provide an alternative mechanism for the success of PVI, and may explain AF termination before PVI or lack of arrhythmias despite PV reconnection. Mapping such sites may enable targeted PV lesion sets and improved freedom from AF.
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Affiliation(s)
- Rachita Navara
- Division of Cardiology, Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA, USA
| | - George Leef
- Division of Cardiology, Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA, USA
| | - Fatemah Shenasa
- Division of Cardiology, Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA, USA
| | - Christopher Kowalewski
- Division of Cardiology, Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA, USA.,Friedrich-Alexander Universitaet Erlangen-Nürnberg, Erlangen, Germany
| | - Albert J Rogers
- Division of Cardiology, Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA, USA
| | - Gabriela Meckler
- Division of Cardiology, Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA, USA
| | - Junaid A B Zaman
- Division of Cardiology, Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA, USA.,Imperial Centre for Cardiac Engineering, Imperial College London, London, UK
| | - Tina Baykaner
- Division of Cardiology, Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA, USA
| | - Shirley Park
- Division of Cardiology, Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA, USA.,Veterans Affairs Palo Alto Health Care System, Palo Alto, CA, USA
| | - Mintu P Turakhia
- Division of Cardiology, Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA, USA.,Veterans Affairs Palo Alto Health Care System, Palo Alto, CA, USA
| | - Paul Zei
- Division of Cardiology, Brigham and Women's Hospital, Boston, MA, USA
| | - Mohan Viswanathan
- Division of Cardiology, Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA, USA
| | - Paul J Wang
- Division of Cardiology, Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA, USA
| | - Sanjiv M Narayan
- Division of Cardiology, Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA, USA
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Orsinger GV, Williams JD, Romanowski M. Focal activation of cells by plasmon resonance assisted optical injection of signaling molecules. ACS Nano 2014; 8:6151-62. [PMID: 24877558 PMCID: PMC4076043 DOI: 10.1021/nn5015903] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2014] [Accepted: 05/30/2014] [Indexed: 05/25/2023]
Abstract
Experimental methods for single cell intracellular delivery are essential for probing cell signaling dynamics within complex cellular networks, such as those making up the tumor microenvironment. Here, we show a quantitative and general method of interrogation of signaling pathways. We applied highly focused near-infrared laser light to optically inject gold-coated liposomes encapsulating bioactive molecules into single cells for focal activation of cell signaling. For this demonstration, we encapsulated either inositol trisphosphate (IP3), an endogenous cell signaling second messenger, or adenophostin A (AdA), a potent analogue of IP, within 100 nm gold-coated liposomes, and injected these gold-coated liposomes and their contents into the cytosol of single ovarian carcinoma cells to initiate calcium (Ca(2+)) release from intracellular stores. Upon optical injection of IP3 or AdA at doses above the activation threshold, we observed increases in cytosolic Ca(2+) concentration within the injected cell initiating the propagation of a Ca(2+) wave throughout nearby cells. As confirmed by octanol-induced inhibition, the intercellular Ca(2+) wave traveled via gap junctions. Optical injection of gold-coated liposomes represents a quantitative method of focal activation of signaling cascades of broad interest in biomedical research.
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Affiliation(s)
- Gabriel V. Orsinger
- Department of Biomedical Engineering, University of Arizona, 1657 East Helen Street, Tucson, Arizona 85721, United States
| | - Joshua D. Williams
- Department of Biomedical Engineering, University of Arizona, 1657 East Helen Street, Tucson, Arizona 85721, United States
- The University of Arizona Cancer Center, University of Arizona, 1515 North Campbell Avenue, Tucson, Arizona 85724, United States
| | - Marek Romanowski
- Department of Biomedical Engineering, University of Arizona, 1657 East Helen Street, Tucson, Arizona 85721, United States
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