scholarly journals Novel approaches to mechanism-based atrial fibrillation ablation

2021 ◽  
Author(s):  
Jorge G Quintanilla ◽  
Shlomo Shpun ◽  
José Jalife ◽  
David Filgueiras-Rama
Keyword(s):  
Atrial Fibrillation ◽  
Cardiac Electrophysiology ◽  
Pulmonary Veins ◽  
Three Dimensional ◽  
New Era ◽  
Clinical Procedures ◽  
Clinical Series ◽  
Mathematical Analyses ◽  
Review State ◽  
School Supports

Abstract Modern cardiac electrophysiology has reported significant advances in the understanding of mechanisms underlying complex wave propagation patterns during atrial fibrillation (AF), although disagreements remain. One school of thought adheres to the long-held postulate that AF is the result of randomly propagating wavelets that wonder throughout the atria. Another school supports the notion that AF is deterministic in that it depends on a small number of high-frequency rotors generating three-dimensional scroll waves that propagate throughout the atria. The spiralling waves are thought to interact with anatomic and functional obstacles, leading to fragmentation and new wavelet formation associated with the irregular activation patterns documented on AF tracings. The deterministic hypothesis is consistent with demonstrable hierarchical gradients of activation frequency and AF termination on ablation at specific (non-random) atrial regions. During the last decade, data from realistic animal models and pilot clinical series have triggered a new era of novel methodologies to identify and ablate AF drivers outside the pulmonary veins. New generation electroanatomical mapping systems and multielectrode mapping catheters, complimented by powerful mathematical analyses, have generated the necessary platforms and tools for moving these approaches into clinical procedures. Recent clinical data using such platforms have provided encouraging evidence supporting the feasibility of targeting and effectively ablating driver regions in addition to pulmonary vein isolation in persistent AF. Here, we review state-of-the-art technologies and provide a comprehensive historical perspective, characterization, classification, and expected outcomes of current mechanistically based methods for AF ablation. We discuss also the challenges and expected future directions that scientists and clinicians will face in their efforts to understand AF dynamics and successfully implement any novel method into regular clinical practice.

scholarly journals Heterogeneous and anisotropic integrative model of pulmonary veins: computational study of arrhythmogenic substrate for atrial fibrillation

2013 ◽  
Vol 3 (2) ◽  
pp. 20120069 ◽  
Author(s):  
Oleg V. Aslanidi ◽  
Michael A. Colman ◽  
Marta Varela ◽  
Jichao Zhao ◽  
Bruce H. Smaill ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
High Frequency ◽  
Computational Study ◽  
Pulmonary Veins ◽  
Three Dimensional ◽  
Primary Source ◽  
Integrative Model ◽  
Micro Computed Tomography ◽  
Three Dimensional Model ◽  
Arrhythmogenic Substrate

Mechanisms underlying the genesis of re-entrant substrate for the most common cardiac arrhythmia, atrial fibrillation (AF), are not well understood. In this study, we develop a multi-scale three-dimensional computational model that integrates cellular electrophysiology of the left atrium (LA) and pulmonary veins (PVs) with the respective tissue geometry and fibre orientation. The latter is reconstructed in unique detail from high-resolution (approx. 70 μm) contrast micro-computed tomography data. The model is used to explore the mechanisms of re-entry initiation and sustenance in the PV region, regarded as the primary source of high-frequency electrical activity in AF. Simulations of the three-dimensional model demonstrate that an initial break-down of normal electrical excitation wave-fronts can be caused by the electrical heterogeneity between the PVs and LA. High tissue anisotropy is then responsible for the slow conduction and generation of a re-entrant circuit near the PVs. Evidence of such circuits has been seen clinically in AF patients. Our computational study suggests that primarily the combination of electrical heterogeneity and conduction anisotropy between the PVs and LA tissues leads to the generation of a high-frequency (approx. 10 Hz) re-entrant source near the PV sleeves, thus providing new insights into the arrhythmogenic mechanisms of excitation waves underlying AF.

scholarly journals A novel computational sheep atria model for the study of atrial fibrillation

2013 ◽  
Vol 3 (2) ◽  
pp. 20120067 ◽  
Author(s):  
Timothy D. Butters ◽  
Oleg V. Aslanidi ◽  
Jichao Zhao ◽  
Bruce Smaill ◽  
Henggui Zhang
Keyword(s):  
Atrial Fibrillation ◽  
Animal Models ◽  
Pulmonary Veins ◽  
Experimental Studies ◽  
Three Dimensional ◽  
Cell Types ◽  
Underlying Mechanisms ◽  
Detailed Computer ◽  
Atrial Cell ◽  
Atrial Excitation

Sheep are often used as animal models for experimental studies into the underlying mechanisms of cardiac arrhythmias. Previous studies have shown that biophysically detailed computer models of the heart provide a powerful alternative to experimental animal models for underpinning such mechanisms. In this study, we have developed a family of mathematical models for the electrical action potentials of various sheep atrial cell types. The developed cell models were then incorporated into a three-dimensional anatomical model of the sheep atria, which was recently reconstructed and segmented based on anatomical features within different regions. This created a novel biophysically detailed computational model of the three-dimensional sheep atria. Using the model, we then investigated the mechanisms by which paroxysmal rapid focal activity in the pulmonary veins can transit to sustained atrial fibrillation. It was found that the anisotropic property of the atria arising from the fibre structure plays an important role in facilitating the development of fibrillatory atrial excitation waves, and the electrical heterogeneity plays an important role in its initiation.

scholarly journals A Computational Study of the Electrophysiological Substrate in Patients Suffering From Atrial Fibrillation

2021 ◽  
Vol 12 ◽  
Author(s):  
S. Pagani ◽  
L. Dede' ◽  
A. Frontera ◽  
M. Salvador ◽  
L. R. Limite ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Cardiac Electrophysiology ◽  
Computational Study ◽  
Pulmonary Veins ◽  
Coupled System ◽  
Density Mapping ◽  
Slow Conduction ◽  
Conduction Velocities ◽  
Ectopic Beats

In the context of cardiac electrophysiology, we propose a novel computational approach to highlight and explain the long-debated mechanisms behind atrial fibrillation (AF) and to reliably numerically predict its induction and sustainment. A key role is played, in this respect, by a new way of setting a parametrization of electrophysiological mathematical models based on conduction velocities; these latter are estimated from high-density mapping data, which provide a detailed characterization of patients' electrophysiological substrate during sinus rhythm. We integrate numerically approximated conduction velocities into a mathematical model consisting of a coupled system of partial and ordinary differential equations, formed by the monodomain equation and the Courtemanche-Ramirez-Nattel model. Our new model parametrization is then adopted to predict the formation and self-sustainment of localized reentries characterizing atrial fibrillation, by numerically simulating the onset of ectopic beats from the pulmonary veins. We investigate the paroxysmal and the persistent form of AF starting from electro-anatomical maps of two patients. The model's response to stimulation shows how substrate characteristics play a key role in inducing and sustaining these arrhythmias. Localized reentries are less frequent and less stable in case of paroxysmal AF, while they tend to anchor themselves in areas affected by severe slow conduction in case of persistent AF.

scholarly journals Fluoroless ablation of atrial fibrillation using intracardiac ultrasound integrated with 3D electroanatomical mapping system

EP Europace ◽  
2021 ◽  
Vol 23 (Supplement_3) ◽  
Author(s):  
B Antolic ◽  
M Jan ◽  
M Vrbajnscak ◽  
D Zizek ◽  
N Kajdic
Keyword(s):  
Atrial Fibrillation ◽  
Pulmonary Veins ◽  
Three Dimensional ◽  
Intracardiac Echocardiography ◽  
High Rate ◽  
Integration System ◽  
Funding Sources ◽  
Automatic Integration ◽  
First Pass ◽  
Intracardiac Ultrasound

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Intracardiac echocardiography (ICE) is gaining increasingly wider adoption in interventional electrophysiology (EP) and represents an all-round tool for ablation of atrial fibrillation (AF). The key upgrade to the usefulness of ICE is its integration into three-dimensional (3D) electroanatomic mapping (EAM) system (ICE/EAM automatic integration system). Purpose The aim of this single-centre retrospective study was to evaluate feasibility, safety and acute efficacy of ICE/EAM automatic integration system guided fluoroless ablation of AF.  Methods Patients with symptomatic paroxysmal or persistent AF referred for first pulmonary vein isolation (PVI) radiofrequency catheter ablation (RFCA) from September 2017 to August 2020 were included in the study. Those who underwent additional ablations for concomitant arrhythmias were excluded from statistical analysis. All procedures were performed without the use of fluoroscopy. A detailed 3D virtual anatomy of the left atrium (LA) and structures relevant to AF ablation was constructed from ultrasound contours obtained with ICE probe inside the LA. Pulmonary veins (PVs) and antral regions were additionally mapped with fast anatomical mapping. PVI was performed with contact force (CF) sensing catheter. Procedural endpoint was successful PVI.  Results A total of 56 patients underwent RFCA (35.7% females, median age 62.7 years, 53.6% paroxysmal AF). Acute PVI was achieved in all patients (100%). Adverse events were detected in two patients (3.6%). The median procedure duration was 110.5 min (IQR 100.0-133.8). First-pass isolation was achieved in 50/56 LPVs (89.3%) and in 44/56 RPVs (78.6%). In patients where first-pass isolation was no achieved, intravenous carina had to be ablated in 3/6 (50%) of LPVs and 9/12 (75%) of RPVs.  Conclusions Flouroless PVI using ICE/EAM automatic integration system is feasible, safe and acutely effective. We achieved high rate of first-pass isolation.

scholarly journals Intracardiac Echocardiography during Catheter-Based Ablation of Atrial Fibrillation

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Jürgen Biermann ◽  
Christoph Bode ◽  
Stefan Asbach
Keyword(s):  
Atrial Fibrillation ◽  
Left Atrium ◽  
Pulmonary Veins ◽  
Three Dimensional ◽  
Interatrial Septum ◽  
Intracardiac Echocardiography ◽  
Success Rates ◽  
Adjacent Structures ◽  
Intracardiac Ultrasound ◽  
Dimensional Object

Accurate delineation of the variable left atrial anatomy is of utmost importance during anatomically based ablation procedures for atrial fibrillation targeting the pulmonary veins and possibly other structures of the atria. Intracardiac echocardiography allows real-time visualisation of the left atrium and adjacent structures and thus facilitates precise guidance of catheter-based ablation of atrial fibrillation. In patients with abnormal anatomy of the atria and/or the interatrial septum, intracardiac ultrasound might be especially valuable to guide transseptal access. Software algorithms like CARTOSound (Biosense Webster, Diamond Bar, USA) offer the opportunity to reconstruct multiple two-dimensional ultrasound fans generated by intracardiac echocardiography to a three-dimensional object which can be merged to a computed tomography or magnetic resonance imaging reconstruction of the left atrium. Intracardiac ultrasound reduces dwell time of catheters in the left atrium, fluoroscopy, and procedural time and is invaluable concerning early identification of potential adverse events. The application of intracardiac echocardiography has the great capability to improve success rates of catheter-based ablation procedures.

Three‐Dimensional Reconstruction of Pulmonary Veins in Patients with Atrial Fibrillation and Controls:

2003 ◽  
Vol 26 (1p1) ◽  
pp. 8-15 ◽  
Author(s):  
ALEJANDRO PEREZ‐LUGONES ◽  
PAULO R. SCHVARTZMAN ◽  
ROBERT SCHWEIKERT ◽  
PATRICK J. TCHOU ◽  
WALID SALIBA ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Pulmonary Veins ◽  
Three Dimensional ◽  
Three Dimensional Reconstruction ◽  
Dimensional Reconstruction

scholarly journals Balloon Devices for Atrial Fibrillation Therapy

2015 ◽  
Vol 4 (1) ◽  
pp. 58 ◽  
Author(s):  
Andreas Metzner ◽  
Erik Wissner ◽  
Tina Lin ◽  
Feifan Ouyang ◽  
Karl-Heinz Kuck ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Alternative Energy ◽  
Pulmonary Veins ◽  
Balloon Catheter ◽  
Three Dimensional ◽  
Single Shot ◽  
Alternative Energy Sources ◽  
First Line Therapy ◽  
Three Dimensional Mapping ◽  
Endoscopic Ablation

Ablation of atrial fibrillation (AF) is an established treatment option for symptomatic patients refractory to antiarrhythmic medication. In patients with paroxysmal AF, ablation can be offered as first-line therapy when performed in an experienced centre. The accepted cornerstone for all ablation strategies is isolation of the pulmonary veins. However, it is still challenging to achieve contiguous, transmural, permanent lesions using radio-frequency current (RFC) based catheters in conjunction with a three-dimensional mapping system and the learning curve remains long. These limitations have kindled interest in developing and evaluating novel catheter designs that incorporate alternative energy sources. Novel catheters include balloon-based ablation systems, incorporating different energy modalities such as laser (HeartlightTM, CardioFocus, Marlborough, MA, US), RFC (Hot Balloon Catheter, Hayama Arrhythmia Institute, Kanagawa, Japan) and cryo-energy (ArcticFront, Medtronic, Inc., Minneapolis, MN, US). While the cryoballoon (CB) and the radiofrequency hot balloon (RHB) are single-shot devices, the endoscopic ablation system (EAS) allows for point-by-point ablation. The CB and EAS are well established as safe, time-efficient and effective ablation tools. Initial studies using the RHB could also demonstrate promising results. However, more data are required.

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