scholarly journals Mutations change excitability and the probability of re-entry in a computational model of cardiac myocytes in the sleeve of the pulmonary vein

2021 ◽  
Author(s):  
Karoline Horgmo Jæger ◽  
Andrew G. Edwards ◽  
Wayne R. Giles ◽  
Aslak Tveito
Keyword(s):  
Atrial Fibrillation ◽  
Finite Element ◽  
Computational Model ◽  
Cardiac Myocytes ◽  
Human Heart ◽  
Pulmonary Veins ◽  
Anatomical Site ◽  
Societal Costs ◽  
Ectopic Beats ◽  
Primary Anatomical Site

AbstractAtrial fibrillation (AF) is a common health problem with substantial individual and societal costs. The origin of AF has been debated for more than a century, and the precise, biophysical mechanisms that are responsible for the initiation and maintenance of the chaotic electrochemical waves that define AF, remains unclear. It is well accepted that the outlet of the pulmonary veins is the primary anatomical site of AF initiation, and that electrical isolation of these regions remains the most effective treatment for AF. Furthermore, it is well known that certain ion channel or transporter mutations can significantly increase the likelihood of AF. Here, we present a computational model capable of characterizing functionally important features of the microanatomical and electrophysiological substrate that represents the transition from the pulmonary veins (PV) to the left atrium (LA) of the human heart. This model is based on a finite element representation of every myocyte in a segment of this (PV/LA) region. Thus, it allows for investigation a mix of typical PV and LA myocytes. We use the model to investigate the likelihood of ectopic beats and re-entrant waves in a cylindrical geometry representing the transition from PV to LA. In particular, we investigate and illustrate how six different AF- associated mutations can alter the probability of ectopic beats and re-entry in this region.

Spontaneous Initiation of Atrial Fibrillation by Ectopic Beats Originating in the Pulmonary Veins

1998 ◽  
Vol 339 (10) ◽  
pp. 659-666 ◽  
Author(s):  
Michel Haïssaguerre ◽  
Pierre Jaïs ◽  
Dipen C. Shah ◽  
Atsushi Takahashi ◽  
Mélèze Hocini ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Pulmonary Veins ◽  
Ectopic Beats

scholarly journals Pulmonary Vein Morphology in Patients With Paroxysmal Atrial Fibrillation Initiated by Ectopic Beats Originating From the Pulmonary Veins

Circulation ◽  
2000 ◽  
Vol 101 (11) ◽  
pp. 1274-1281 ◽  
Author(s):  
Wei-Shiang Lin ◽  
V. S. Prakash ◽  
Ching-Tai Tai ◽  
Ming-Hsiung Hsieh ◽  
Chin-Feng Tsai ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Pulmonary Vein ◽  
Paroxysmal Atrial Fibrillation ◽  
Pulmonary Veins ◽  
Ectopic Beats

scholarly journals Initiation of Atrial Fibrillation by Ectopic Beats Originating From the Pulmonary Veins

Circulation ◽  
1999 ◽  
Vol 100 (18) ◽  
pp. 1879-1886 ◽  
Author(s):  
Shih-Ann Chen ◽  
Ming-Hsiung Hsieh ◽  
Ching-Tai Tai ◽  
Chin-Feng Tsai ◽  
V. S. Prakash ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Pulmonary Veins ◽  
Ectopic Beats

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.

CT Visualization and Histopathological Assessment of Cryoablation in Pulmonary Veins

2009 ◽  
Author(s):  
Mithun M. Shenoi ◽  
Xiaoqing Zhang ◽  
Ramji T. Venkatasubramanian ◽  
Erin D. Grassl ◽  
Lenny George ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Pulmonary Vein ◽  
Pulmonary Veins ◽  
The United States ◽  
The Body ◽  
Pulmonary Vein Stenosis ◽  
Invasive Technique ◽  
Freezing Process ◽  
Ectopic Beats ◽  
Vein Stenosis

Over 2 million adults in the United States are affected by atrial fibrillation (AF), a common cardiac arrhythmia that is associated with decreased survival, increased cardiovascular morbidities, and a decrease in quality of life. Atrial fibrillation can be initiated by ectopic beats originating in the myocardial sleeves surrounding the pulmonary veins [1]. Pulmonary vein (PV) isolation via radiofrequency ablation is the current gold standard for treating patients with drug-refractory AF [2]. However, cryoablation is emerging as a new minimally-invasive technique to achieve PV isolation. Cryoablation is fast gaining acceptance due to its minimal tissue disruption, decreased thrombogenicity, and reduced complications (RF can lead to low rate of pulmonary vein stenosis) [2]. One important question in regard to this technology is whether the PV lesion is transmural and circumferential and to what extent adjacent tissues are involved in the freezing process. As ice formation lends itself to image contrast in the body, we hypothesized that intraprocedural CT visualization of the iceball formation would allow us to predict the extent of the cryolesion and/or provide us with a measure of the adjacent tissue damage.

scholarly journals A study on pulmonary venous ostia pattern in the left atrium and its clinical applications

2018 ◽  
Vol 7 (04) ◽  
pp. 201-204
Author(s):  
Rajesh S. ◽  
Vijaya Kumar S. ◽  
Manikanda Reddy V.
Keyword(s):  
Atrial Fibrillation ◽  
Radio Frequency ◽  
Left Atrium ◽  
Pulmonary Vein ◽  
Anatomical Variation ◽  
Pulmonary Veins ◽  
Clinical Applications ◽  
Ectopic Beats ◽  
The Right ◽  
Formalin Fixed

Abstract Background & aims : Normally four pulmonary veins open into the left atrium. Frequently there are variations in the number of pulmonary veins opening in to the left atrium. Ectopic beats in atrial fibrillation commonly originates from the ostia of the pulmonary veins. The treatment of atrial fibrillation is by radio frequency ablation of the focus of origin and hence the knowledge of anatomical variation of pulmonary veins is necessary to find the ectopic focus in the origin of atrial fibrillation. Materials and Method : In this study the variation of pulmonary venous ostia pattern in the left atrium was studied in 80 formalin fixed adult cadaveric hearts. Results and Conclusion : 63 hearts showed no variation in the pulmonary venous ostia pattem which accounts for 78.75%, rest of the 17 hearts showed variation in the pulmonary venous ostia which accounts for 21.25%, the variation in the number of pulmonary veins was slightly higher for the left side [11.25%] when compared to the right sided variation [ 10%], the number of hearts which showed bilateral variation was noted in 2 hearts - both showed a single pulmonary vein opening on either side which accounts for 2.5%

scholarly journals Atrial Fibrillation Ablation: When and Why?

2020 ◽  
Vol 5 (3) ◽  
Keyword(s):  
Atrial Fibrillation ◽  
Radio Frequency ◽  
Pulmonary Veins ◽  
Atrial Fibrillation Ablation ◽  
Alternative Strategy ◽  
Optimal Outcomes ◽  
Simple Question ◽  
Ectopic Beats ◽  
Stroke Death ◽  
Present Effort

Ablation of Atrial Fibrillation (AF) has quickly become an alternative strategy to impact the adverse symptoms and outcomes associated with or caused by AF. Early reports in 1998 demonstrated spontaneous initiation of AF by ectopic beats originating in the Pulmonary Veins (PVs) followed rapidly by showing that Radio Frequency (RF) circumferential ablation around the orifices of the PVs could “electrically disconnect” the PVs from the Left Atria (LA). This resulted in the explosive growth utilizing this procedure for AF Ablation (AFA) across a wide demographic spectrum of recipients. Foreseeable healthy debates have surfaced as to who best benefits and who may actually suffer complications or harm from AFA utilizing present techniques. Disagreement also persists as to whether AFA fundamentally and universally reduces stroke, death, hospitalization or does it initiate a more nuanced set of outcomes. The present effort asks the simple question: Has AFA matured to the point of requisite explicative review? Is it time now to peel back the layers and identify which cohort will be optimally served by AFA and perhaps which ones need demonstration of benefit? The present brief review suggests that prudent employment of AFA must now identify disparities in the variables reflected in these cohort outcomes. This will enable judgment in the use of AFA and the achievement of optimal outcomes.

scholarly journals Location and coupling interval of an ectopic excitation determine the initiation of atrial fibrillation from the pulmonary veins

2021 ◽  
Author(s):  
Shunsuke Kawai ◽  
Yasushi Mukai ◽  
Shujiro Inoue ◽  
Daisuke Yakabe ◽  
Kazuhiro Nagaoka ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Pulmonary Veins ◽  
Ectopic Beat ◽  
Conduction Delay ◽  
Conduction Time ◽  
Coupling Interval ◽  
Ectopic Beats ◽  
The Mean ◽  
Ectopic Excitation ◽  
Anisotropic Conduction

Background and Objective: Ectopic beats originating from the pulmonary vein (PV) trigger atrial fibrillation (AF). The purpose of this study was to clarify the electrophysiological determinant of AF initiation from the PVs. Methods: Pacing studies were performed with a single extra stimulus mimicking an ectopic beat in the left superior pulmonary veins (LSPVs) in 62 patients undergoing AF ablation. Inducibility of AF, effective refractory period (ERP) and conduction properties within the PVs were analyzed. Results: A single extra stimulus in LSPV induced AF in 20 patients (32% of all patients) at the mean coupling interval (CI) of 172 ms. A CI-dependent anisotropic conduction at the AF onset was visualized in a 3D-mapping. Onset of AF was site-specific with reproducibility in each individual. Mean ERP in LSPV in the AF inducible group was shorter than that in the AF non-inducible group (182 ± 55 ms vs 254 ± 51 ms, P<0.0001). LSPV ERP dispersion was greater in the AF inducible group than in the AF non-inducible group (45 ± 28 ms vs 27 ± 19 ms, P<0.01). Circumferential intra-PV conduction time (IPVCT) exhibited decremental properties in response to shortening of CI, and the prolongation of IPVCT in the AF inducible site was greater than that in the AF non-inducible site (P<0.05) in each individual. Conclusions: Location and coupling interval of an ectopic excitation ultimately determine the initiation of AF from the PVs. ERP dispersion and circumferential conduction delay may lead to anisotropic conduction and reentry within the PVs that initiate AF.

scholarly journals 58Location and coupling interval of ectopic beats have key roles in the onset of atrial fibrillation from the pulmonary veins

2017 ◽  
Vol 38 (suppl_1) ◽  
Author(s):  
S. Kawai ◽  
Y. Mukai ◽  
S. Inoue ◽  
A. Chishaki ◽  
H. Tsutsui ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Pulmonary Veins ◽  
Coupling Interval ◽  
Ectopic Beats

scholarly journals Catheter Ablation of Paroxysmal Atrial Fibrillation Originating from Non-pulmonary Vein Areas

2018 ◽  
Vol 7 (4) ◽  
pp. 1 ◽  
Author(s):  
Satoshi Higa ◽  
Li-Wei Lo ◽  
Shih-Ann Chen ◽  
◽  
◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Catheter Ablation ◽  
Left Atrium ◽  
Paroxysmal Atrial Fibrillation ◽  
Current Knowledge ◽  
Pulmonary Veins ◽  
Cure Rate ◽  
Safety And Efficacy ◽  
Ectopic Beats ◽  
Af Recurrence

Pulmonary veins (PVs) are a major source of ectopic beats that initiate AF. PV isolation from the left atrium is an effective therapy for the majority of paroxysmal AF. However, investigators have reported that ectopy originating from non-PV areas can also initiate AF. Patients with recurrent AF after persistent PV isolation highlight the need to identify non-PV ectopy. Furthermore, adding non-PV ablation after multiple AF ablation procedures leads to lower AF recurrence and a higher AF cure rate. These findings suggest that non-PV ectopy is important in both the initiation and recurrence of AF. This article summarises current knowledge about the electrophysiological characteristics of non-PV AF, suitable mapping and ablation strategies, and the safety and efficacy of catheter ablation of AF initiated by ectopic foci originating from non-PV areas.

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