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

Author(s):  
Shunsuke Kawai ◽  
Yasushi Mukai ◽  
Shujiro Inoue ◽  
Daisuke Yakabe ◽  
Kazuhiro Nagaoka ◽  
...  

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.

2017 ◽  
Vol 38 (suppl_1) ◽  
Author(s):  
S. Kawai ◽  
Y. Mukai ◽  
S. Inoue ◽  
A. Chishaki ◽  
H. Tsutsui ◽  
...  

2019 ◽  
Author(s):  
Jun Ding ◽  
Jing Xu ◽  
Wei Ma ◽  
Bingwei Chen ◽  
Peigen Yang ◽  
...  

Abstract Background : The optimal dosage for cryoablation of atrial fibrillation (Cryo-AF) is still unknown. To evaluate the efficacy of an individualized freeze duration, we compared the clinical outcome of patients treated with a time-to-pulmonary vein isolation (TT-PVI) or temperature-guided ablation protocol to the outcome of patients treated with a conventional ablation protocol. Methods: A total of 164 consecutive patients were included in the study. One method employed was a conventional dosing protocol (at least 2 applications of 180 seconds each)(the Cryo-AF Conventional group n=84), and the second method had a shorter protocol that was based on the TT-PVI or achievement of -40°C within 60 seconds (the Cryo-AF Dosing group n=80). Results: We treated 656 pulmonary veins (PVs) with 1420 cryotherapy applications. The mean number of applications per patient was 8.7±0.8, with no difference between groups (Cryo-AF Conventional , 8.7±0.8 versus Cryo-AF Dosing ,8.6±0.8; P =0.359). The Cryo-AF Dosing group required significantly less total cryotherapy application time (990.60±137.77versus 1501.58±89.60 seconds; P <0.001) and left atrial dwell time (69.91±6.91 versus 86.48±7.03 minutes; P <0.001) than the Cryo-AF Conventional group. Additionally, the Cryo-AF Dosing group required significantly less total procedure time (95.03±6.50 versus 112.43±7.11 minutes; P <0.001). We observed acute ATP-induced or spontaneous vein electric reconnections in 13 veins (1.98%) after 20 minutes. The reconnection rates between the Cryo-AF Conventional and Cryo-AF Dosing groups were similar in that 2.98% and 0.94% of the initially isolated veins were reconnected, respectively, ( P =0.061). There was no difference in the recurrence rate of free atrial arrhythmia after a 1-year follow-up, which were 78.75% in the Cryo-AF Dosing group versus 78.57% in the Cryo-AF Conventional group ( P =0.978). Conclusion: A novel Cryo-AF dosing protocol guided by temperature or the TT-PVI can be used to individualize an ablation strategy. This new protocol can lead to a significant reduction in duration of the procedure, the cryoenergy dosage and the left atrial dwell time. The procedure had equal safety and similar acute and 1-year follow-up outcomes compared to the conventional approach.


2021 ◽  
Author(s):  
Sara Rita Vacirca

Objective: Intraoperative CARTO Mapping for Atrial Fibrillation ablation in cardiac surgery. Background: Surgical ablation of Atrial Fibrillation is usually performed without mapping. The study aims to determine if intraoperative CARTO can be useful to guide the ablating procedure. Methods and Findings: Fourteen patients with symptomatic and drug-refractory concomitant AF were operated on in 2003 and 2004. CARTO mapping was performed before and after surgical bipolar radio-frequency ablation. Application of energy was repeated when residual electrical activity was detected at the pulmonary veins-atrial junction. Pacing wires were applied on right and left pulmonary veins distally to the ablation line to confirm the exit block. The mapping protocol was completed in 12 patients. Acute left atrium-pulmonary vein isolation was achieved after single or double energy application in 2/12 (16.6%) and 9/12 (75%) patients, respectively. The mean duration of the mapping and ablation procedure was 67 minutes. At discharge, PV isolation persisted in 10 patients: exit block was confirmed by the absence of pacing through the pulmonary veins electrodes. After a mean follows up of 181 months, no further recurrent AF events were registered in 9/12 (69.2%) patients. Conclusions: CARTO system is useful during open-heart surgery to guide the ablating strategy.


PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e1579 ◽  
Author(s):  
Wiesława Klimek-Piotrowska ◽  
Mateusz K. Hołda ◽  
Katarzyna Piątek ◽  
Mateusz Koziej ◽  
Jakub Hołda

Background.It is well known that the pulmonary veins (PVs), especially their myocardial sleeves play a critical role in the initiation and maintenance of atrial fibrillation. Understanding the PV anatomy is crucial for the safety and efficacy of all procedures performed on PVs. The aim of this study was to present normal distal PV anatomy and to create a juxtaposition of all PV ostium variants.Methods.A total of 130 randomly selected autopsied adult human hearts (Caucasian) were examined. The number of PVs ostia was evaluated and their diameter was measured. The ostium-to-last-tributary distance and macroscopic presence of myocardial sleeves were also evaluated.Results.Five hundred forty-one PV ostia were identified. Four classical PV ostia patterns (two left and two right PVs) were observed in 70.8% of all cases. The most common variant was the classical pattern with additional middle right PV (19.2%), followed by the common ostium for the left superior and the inferior PVs (4.44%). Mean diameters of PV ostia (for the classical pattern) were: left superior = 13.8 ± 2.9 mm; left inferior = 13.3 ± 3.4 mm; right superior = 14.3 ± 2.9 mm; right inferior = 13.7 ± 3.3 mm. When present, the additional middle right PV ostium had the smallest PV ostium diameter in the heart (8.2 ± 4.1 mm). The mean ostium-to-last-tributary (closest to the atrium) distances were: left superior = 15.1 ± 4.6 mm; left inferior = 13.5 ± 4.0 mm; right superior = 11.8 ± 4.0 mm; right inferior = 11.0 ± 3.7 mm. There were no statistically significant differences between sexes in ostia diameters and ostium-to-last-tributary distances.Conclusion.Only 71% of the cases have four standard pulmonary veins. The middle right pulmonary vein is present in almost 20% of patients. Presented data can provide useful information for the clinicians during interventional procedures or radiologic examinations of PVs.


1998 ◽  
Vol 339 (10) ◽  
pp. 659-666 ◽  
Author(s):  
Michel Haïssaguerre ◽  
Pierre Jaïs ◽  
Dipen C. Shah ◽  
Atsushi Takahashi ◽  
Mélèze Hocini ◽  
...  

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 ◽  
...  

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 ◽  
...  

2021 ◽  
Vol 12 ◽  
Author(s):  
S. Pagani ◽  
L. Dede' ◽  
A. Frontera ◽  
M. Salvador ◽  
L. R. Limite ◽  
...  

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.


2019 ◽  
Author(s):  
Jun Ding ◽  
Jing Xu ◽  
Wei Ma ◽  
Bingwei Chen ◽  
Peigen Yang ◽  
...  

Abstract Background : The optimal dosage for cryoablation of atrial fibrillation (Cryo-AF) is still unknown. To evaluate the efficacy of an individualized freeze duration, we compared the clinical outcome of patients treated with a time-to-pulmonary vein isolation (TT-PVI) or temperature-guided ablation protocol to the outcome of patients treated with a conventional ablation protocol. Methods: A total of 164 consecutive patients were included in the study. One method employed was a conventional dosing protocol (at least 2 applications of 180 seconds each)(the Cryo-AF Conventional group n=84), and the second method had a shorter protocol that was based on the TT-PVI or achievement of -40°C within 60 seconds (the Cryo-AF Dosing group n=80). Results: We treated 656 pulmonary veins (PVs) with 1420 cryotherapy applications. The mean number of applications per patient was 8.7±0.8, with no difference between groups (Cryo-AF Conventional , 8.7±0.8 versus Cryo-AF Dosing ,8.6±0.8; P =0.359). The Cryo-AF Dosing group required significantly less total cryotherapy application time (990.60±137.77versus 1501.58±89.60 seconds; P <0.001) and left atrial dwell time (69.91±6.91 versus 86.48±7.03 minutes; P <0.001) than the Cryo-AF Conventional group. Additionally, the Cryo-AF Dosing group required significantly less total procedure time (95.03±6.50 versus 112.43±7.11 minutes; P <0.001). We observed acute ATP-induced or spontaneous vein electric reconnections in 13 veins (1.98%) after 20 minutes. The reconnection rates between the Cryo-AF Conventional and Cryo-AF Dosing groups were similar in that 2.98% and 0.94% of the initially isolated veins were reconnected, respectively, ( P =0.061). There was no difference in the recurrence rate of free atrial arrhythmia after a 1-year follow-up, which were 78.75% in the Cryo-AF Dosing group versus 78.57% in the Cryo-AF Conventional group ( P =0.978). Conclusion: A novel Cryo-AF dosing protocol guided by temperature or the TT-PVI can be used to individualize an ablation strategy. This new protocol can lead to a significant reduction in duration of the procedure, the cryoenergy dosage and the left atrial dwell time. The procedure had equal safety and similar acute and 1-year follow-up outcomes compared to the conventional approach.


Author(s):  
Mithun M. Shenoi ◽  
Xiaoqing Zhang ◽  
Ramji T. Venkatasubramanian ◽  
Erin D. Grassl ◽  
Lenny George ◽  
...  

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.


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