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Background: Nonrandomized data suggest that longer diagnosis-to-ablation time (DAT) is associated with poorer outcomes; however, a recent randomized trial found no difference in recurrences when ablation was delayed by 12 months., Objectives: This study sought to assess the impact of DAT on atrial fibrillation (AF) recurrence in patients undergoing catheter ablation for persistent AF., Methods: CAPLA (Effect of Catheter Ablation Using Pulmonary Vein Isolation With vs Without Posterior Left Atrial Wall Isolation on Atrial Arrhythmia Recurrence in Patients With Persistent Atrial Fibrillation: The CAPLA randomized clinical trial) was a multicenter trial that randomized patients with persistent AF to pulmonary vein isolation + posterior wall isolation or pulmonary vein isolation alone. Follow-up was 12 months. Outcomes were assessed after a 3-month blanking period., Results: Median DAT in the 334 patients was 28 months (Q1-Q3: 12-66 months). Patients were divided into quartile groups: Q1 was DAT 0 to 12 months (n = 84, median DAT 7 months), Q2 was DAT 13 to 28 months (n = 85, median DAT 20 months), Q3 was DAT 29 to 66 months (n = 84, median DAT 41 months), and Q4 was DAT ≥67 months (n = 81, median DAT 119 months). AF recurrence rate was 36.9% for Q1, 44.7% for Q2, 47.6% for Q3, and 56.8% for Q4 (P = 0.082). On multivariable analysis, DAT Q4 was the only factor significantly associated with risk of recurrence (HR: 1.607; 95% CI: 1.005-2.570; P = 0.048). Median AF burden was 0% (Q1-Q3: 0%-0.47%) in Q1 and 0.33% (Q1-Q3: 0%-4.6%) in Q4 (P = 0.002). Quality of life (assessed by the Atrial Fibrillation Effect on Quality-of-Life questionnaire) improved markedly in all quartiles (Q1: Δ28.8 ± 24, Q2: Δ24.4 ± 23.4, Q3: Δ21.7 ± 26.6, Q4: Δ24.6 ± 21.4; P = 0.331)., Conclusions: In a cohort of patients with persistent AF undergoing ablation in a prospective trial with standardized entry criteria and intensive electrocardiogram monitoring, those with shorter DAT had lower rates of AF recurrence. However, differences were modest, and all quartiles demonstrated very low AF burden and improvements in quality of life., Competing Interests: Funding Support and Author Disclosures Dr Chieng was supported by a National heart foundation (NHF) Post-Doctoral Fellowship. Dr William was supported by a NHF postgraduate PhD scholarship. Dr Crowley was supported by a Baker Institute PhD scholarship. Dr Segan was supported by a cofunded National Health and Medical Research Council (NHMRC)/NHF postgraduate PhD scholarship. Dr Kalman has received research and fellowship support from Medtronic, Abbott, Zoll, and Biosense Webster. Dr Kistler has received an Investigator grant from the NHMRC; received funding for consultancy and speaking engagements from Abbott Medical; and served on the advisory board with fellowship support from Biosense Webster. Dr Sanders has served on the advisory board for Medtronic, Abbott Medical, CathRx, Pacemate, and Boston Scientific; and received a practitioner fellowship from the NHMRC and NHF. Dr Lee has received consulting fees from Biosense Webster. Dr Prabhu has received a NHMRC Post-Doctoral Research Fellowship; and received consulting fees, fellowship support, and educational grants from Biosense Webster, Abbott Medical, and Boston Scientific. Dr Ling has received grants from Abbott Australia. Dr Sterns has received personal fees from Biosense Webster. Dr Ginks has served on the Speakers Bureau for Biosense Webster; and as a speaker for Abbott. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2024 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Background: Although the substrate in persistent atrial fibrillation (PeAF) is not limited to the pulmonary veins (PVs), PV isolation (PVI) remains the cornerstone ablation strategy., Objectives: The aim of this study was to describe the mechanism of outgoing wavefronts (WFs) originating in the PV sleeves during PeAF., Methods: Eleven patients presenting for first-time PeAF ablation were recruited (mean age 63.1 ± 10.9 years, 91% men). A 64-electrode catheter (Constellation; 38 mm) was positioned within the PV under fluoroscopic guidance. An inverse mapping technique was used to reconstruct unipolar atrial electrograms on the PV surface, and the resulting phase maps were used to identify incoming and outgoing WFs at the PV junction and to classify focal and re-entrant activity within the PV sleeves., Results: During PeAF, the PVs gave rise to outgoing WFs with a frequency of 3.7 s -1 (Q1-Q3: 3.4-5.4 s -1 ) compared with 3.6 s -1 (Q1-Q3: 2.8-4.2 s -1 ) for incoming WFs. Circuitous macroscopic re-entry was the dominant mechanism driving outgoing WFs (frequency of re-entry 2.7 s -1 [Q1-Q3: 2.0-3.3 s -1 ] compared with focal activity 1.4 s -1 [Q1-Q3: 1.1-1.5 s -1 ]; P < 0.006). This was initiated by incoming WFs in 80% of cases. Consecutive focal activation from the same location was infrequent (10.0% ± 6.6%, n = 10). Rotors ≥360° were never observed. The median ratio (R) of outgoing to incoming WF frequency was 1.14 (Q1-Q3: 0.84-1.75), with R > 1 in 6 of 11 PVs., Conclusions: Electric activity generated by PV sleeves during PeAF is due mainly to circuitous re-entry initiated by incoming waves, frequently with R > 1. That is, the PVs act less as drivers of atrial fibrillation than as "echo chambers" that sustain and amplify fibrillatory activity., Competing Interests: Funding Support and Author Disclosures Basket catheters were provided by Boston Scientific. Drs Al-Kaisey and Parameswaran are supported by a National Health and Medical Research Council (NHMRC) research scholarship. Prof Kalman is supported by a practitioner fellowship from the NHMRC; and has received research support from Biosense Webster and Medtronic. Drs Meng and Sunderland were supported by Endeavour Fund Grant CONT-50916-ENDSI-UOA from the New Zealand Ministry of Business and Innovation. Assoc Prof Budgett and Prof Smaill have received funding from the New Zealand Ministry of Business and Innovation and from Return on Sciences, New Zealand. Dr Kistler is a recipient of a Clinical Investigator grant from the NHMRC of Australia; has received grants from the Baker Department of Metabolic Health University of Melbourne; has received speaker fees from Abbott Medical; and has served on an advisory board for Biosense Webster. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2024 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Background: Sex-specific outcomes after catheter ablation (CA) for atrial fibrillation (AF) have reported conflicting findings., Objective: We examined the impact of female sex on outcomes in patients with persistent AF (PsAF) from the Catheter Ablation for Persistent Atrial Fibrillation: A Multicentre Randomized Trial of Pulmonary Vein Isolation vs PVI with Posterior Left Atrial Wall Isolation (CAPLA) randomized trial., Methods: A total of 338 patients with PsAF were randomized to pulmonary vein isolation (PVI) or PVI with posterior wall isolation (PWI). The primary outcome was arrhythmia recurrence at 12 months. Clinical and electroanatomical characteristics, arrhythmia recurrence, and quality of life were compared between women and men., Results: Seventy-nine women (23.4%; PVI 37; PVI + PWI 42) and 259 men (76.6%; PVI 131; PVI + PWI 128) underwent AF ablation. Women were older {median age 70.4 (interquartile range [IQR] 64.8-74.6) years vs 64.0 (IQR 56.7-69.7) years; P < .001} and had more advanced left atrial electroanatomical remodeling. At 12 months, arrhythmia-free survival was lower in women (44.3% vs 56.8% in men; hazard ratio 1.44; 95% confidence interval 1.02-2.04; log-rank, P = .036). PWI did not improve arrhythmia-free survival at 12 months (hazard ratio 1.02; 95% confidence interval 0.74-1.40; log-rank, P = .711). The median AF burden was 0% in both groups (women: IQR 0.0%-2.2% vs men: IQR 0.0%-2.8%; P = .804). Health care utilization was comparable between women (36.7%) and men (30.1%) (P = .241); however, women were more likely to undergo a repeat procedure (17.7% vs 6.9%; P = .007). Women reported more severe baseline anxiety (average Hospital Anxiety and Depression Scale [HADS] anxiety score 7.5 ± 4.9 vs 6.3 ± 4.3 in men; P = .035) and AF-related symptoms (baseline Atrial Fibrillation Effect on Quality-of-Life Questionnaire [AFEQT] score 46.7 ± 20.7 vs 55.9 ± 23.0 in men; P = .002), with comparable improvements in psychological symptoms (change in HADS anxiety score -3.8 ± 4.6 vs -3.0 ± 4.5; P = .152 (change in HADS depression score -2.9 ± 5.0 vs -2.6 ± 4.0; P = .542) and greater improvement in AFEQT score compared with men at 12 months (change in AFEQT score +45.9 ± 23.1 vs +39.2 ± 24.8; P = .048)., Conclusion: Women undergoing CA for PsAF report more significant symptoms and poorer quality of life at baseline than men. Despite higher arrhythmia recurrence and repeat procedures in women, the AF burden was comparably low, resulting in significant improvements in quality of life and psychological well-being after CA in both sexes., Competing Interests: Disclosures The following industry funding sources regarding activities outside the submitted work have been declared in accordance with the ICMJE guidelines. Dr Segan has received a combined National Heart Foundation/National Health and Medical Research Council (NHMRC) PhD scholarship. Dr Kistler is a recipient of the investigator grant from the NHMRC and has received funding from Abbott Medical for consultancy and speaking engagements and has served on the advisory board with fellowship support from Biosense Webster. Dr Kalman has received fellowship support from Medtronic and Biosense Webster. Dr Sanders has served on the advisory board of Medtronic, Abbott Medical, Boston Scientific, CathRx, and PaceMate and has received funding for research and consultancy from Medtronic, Abbott Medical, Boston Scientific, and MicroPort. Dr Lee has received consulting fees from Biosense Webster. Dr Sterns has received consulting fees from Biosense Webster. Dr Ginks has received funding for speaking engagements from Abbott and Biosense Webster. Dr Prabhu has received fellowship and training support from the National Heart Foundation, Abbott Medical, and Boston Scientific. He has also received speaker fees and advisory fees from Abbott Medical and Biosense Webster. The remaining authors have nothing to disclose., (Copyright © 2024 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Background: Non-pulmonary vein (PV) triggers are increasingly targeted during atrial fibrillation (AF) ablation. P-wave morphology (PWM) can be useful because point mapping of AF triggers is challenging. The impact of prior ablation on PWM is yet to be determined., Objectives: This study sought to report PWM before and after left atrial (LA) ablation and construct a P-wave algorithm of common non-PV trigger locations., Methods: This multicenter, prospective, observational study analyzed the paced PWM of 30 patients with persistent AF undergoing pulmonary vein isolation (PVI) and posterior wall isolation (PWI). Pace mapping was performed at the SVC, crista terminalis, inferior tricuspid annulus, coronary sinus ostium, left septum, left atrial appendage, Ligament of Marshall, and inferoposterior LA. The PWM was reported before PVI, then blinded comparisons were made post-PVI and post-PVI + PWI. A P-wave algorithm was constructed., Results: A total of 8,352 paced P waves were prospectively recorded. No significant changes in the PWM were seen post-PVI alone in 2,775 of 2,784 (99.7%) and post-PWI in 2,715 of 2,784 (97.5%). Changes in PWM were predominantly at the IPLA (53 P waves) with a positive P-wave in leads V 2 to V 6 before biphasic post-PWI, LA appendage (9 P waves), coronary sinus ostium (6 P waves), and ligament of Marshall (3 P waves). A PWM algorithm was created before PVI and accurately predicted the location in 93% post-PVI + PWI., Conclusions: Minimal change was observed in PWM post-PV and PWI aside from the IPLA location. A P-wave algorithm created before and applied after PVI + PWI provided an accuracy of 93%. PWM provides a reliable tool to guide the localization of common non-PV trigger sites even after PV and PWI., Competing Interests: Funding Support and Author Disclosures The following industry funding sources regarding activities outside the submitted work have been declared. Dr Lee has received consulting fees from Biosense Webster. Dr Kalman is a recipient of the Practitioner fellowship from the NHMRC; and has received fellowship support from Medtronic and Biosense Webster. Dr Kistler is a recipient of the investigator grant from the NHMRC; has received funding from Abbott Medical for consultancy and speaking engagements; and has served on the advisory board with fellowship support from Biosense Webster. All other authors have reported that they have no relationships relevant to the contents of this paper., (Copyright © 2024 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Background: Pulmonary vein isolation (PVI) is less effective in persistent atrial fibrillation (PerAF) than in paroxysmal atrial fibrillation (AF). However, the CAPLA (Effect of Catheter Ablation Using Pulmonary Vein Isolation With vs Without Posterior Left Atrial Wall Isolation on Atrial Arrhythmia Recurrence in Patients With Persistent Atrial Fibrillation: The CAPLA randomized clinical trial) of PVI vs posterior wall isolation (PWI) did not support empiric PWI in PerAF. We examined pulmonary vein (PV) and posterior wall (PW) electrical characteristics to determine if select patients may benefit from additional PWI., Objectives: This study sought to determine the impact of PV and PW electrical characteristics on AF ablation outcomes in the CAPLA randomized study., Methods: Participants in spontaneous AF at the time of ablation were included from the CAPLA study. The mean, shortest, and longest PV, PW, and left atrial (LA) appendage cycle length measurements were annotated preablation using a multipolar catheter for 100 consecutive cycles. Next, cardioversion was performed with a high-density LA voltage map completed. Cox proportional hazards regression was utilized to determine clinical and electroanatomic predictors of AF recurrence overall and according to ablation strategy. Follow-up included twice daily single-lead electrocardiograms or continuous monitoring for 12 months., Results: A total of 151 patients (27% female, age 65 ± 9 years, 18% long-standing PerAF, LA volume index 52 ± 16 mL/m 2 , median AF duration 5 months [IQR: 2-10 months]) were in AF on the day of procedure and were randomized to PVI alone (50%) or PVI+PWI (50%) according to the CAPLA randomized clinical trial protocol. Baseline clinical, echocardiographic, and electroanatomic parameters were comparable between groups (all P > 0.05) including PV and PW characteristics. After 12 months, freedom from AF off antiarrhythmic drug therapy was 51.7% in PVI and 49.7% in PVI+PWI (log-rank P = 0.564). Rapid PW activity was defined as less than the median of the shortest PW cycle length (140 ms) and rapid PV activity was defined as less than the median of the shortest PV cycle length (126 ms). In those with rapid PW activity, the addition of PWI was associated with greater arrhythmia-free survival (56.4%) vs PVI alone (38.6%) (HR: 0.78; 95% CI: 0.67-0.94; log-rank P = 0.030). Moreover, in those undergoing PVI only, the risk of AF recurrence was higher in those with rapid PW activity (55.3% vs 46.5% in slower PW activity; HR: 1.50, 95%CI 1.11-2.26; log-rank P = 0.036). Rapid PV activity and PV cycle length (individual PVs or average of all 4 PVs) were not associated with outcome (all P > 0.05) regardless of ablation strategy. There was no correlation between PW cycle length and posterior low voltage (r = -0.06, P = 0.496). The addition of PWI did not improve arrhythmia-free survival in subgroups with LA enlargement (LA volume index >34 mL/m 2 ) (HR: 0.69; 95% CI: 0.39-1.25; P = 0.301), posterior low-voltage zone (HR: 1.06; 95% CI: 0.68-1.66; P = 0.807), or long-standing PerAF (HR: 1.10; 95% CI: 0.71-1.72; P = 0.669)., Conclusions: Rapid PW activity is associated with an increased risk of AF recurrence post-catheter ablation. The addition of PWI in this subgroup was associated with a significant improvement in freedom from AF compared with PVI alone. The presence of rapid PW activity may identify patients with PerAF likely to benefit from PWI., Competing Interests: Funding Support and Author Disclosures This study received seed grant funding from the Baker Department of Cardiometabolic Health, University of Melbourne. The funding source had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; and preparation, review, or approval of the manuscript. The funding source has no right to veto publication or control the decision regarding to which journal the paper was submitted. Dr Segan was supported by a cofunded National Health and Medical Research Council/National Heart Foundation postgraduate scholarship. Dr Lee has received consulting fees from Biosense Webster. Dr Pathak has served on the advisory board of Medtronic, Abbott Medical, and Boston Scientific; and received funding for research and consultancy from Medtronic, Abbott Medical, Boston Scientific, and Biotronik. Dr Ginks has received funding for speaking engagements from Abbott and Biosense Webster. Dr Kalman has received fellowship support from Medtronic and Biosense Webster. Dr Kistler has received funding from Abbott Medical for consultancy and speaking engagements; and served on the advisory board with fellowship support from Biosense Webster. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2023 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Background: Pulmonary vein isolation (PVI) is less effective in patients with persistent atrial fibrillation (PsAF). Adjunctive ablation targeting low voltage areas (LVAs) may improve arrhythmia outcomes., Objectives: This study aims to compare the outcomes of adding posterior wall isolation (PWI) to PVI, vs PVI alone in PsAF patients with posterior wall LVAs., Methods: The CAPLA (Effect of Catheter Ablation Using Pulmonary Vein Isolation With vs Without Posterior Left Atrial Wall Isolation on Atrial Arrhythmia Recurrence in Patients With Persistent Atrial Fibrillation) study was a multicenter, randomized trial involving PsAF patients randomized 1:1 to either PVI alone or PVI with PWI. Voltage mapping performed during pacing pre-ablation was reviewed offline, with LVA defined as bipolar voltage of <0.5 mV. The primary endpoint was freedom from any documented atrial arrhythmia of >30 seconds off antiarrhythmic medication at 12 months after a single ablation procedure in patients with posterior LVA., Results: A total of 210 patients (average 64.6 ± 9.2 years,73.3% males, median atrial fibrillation duration 4.5 months [IQR: 2 to 8 months]) underwent multipolar left atrial mapping during coronary sinus pacing with posterior LVA present in 69 (32.9%). Patients with posterior LVA were more likely to have LVA in other atrial regions (91.7% vs 57.1%; P < 0.01), larger left atrial diameter (4.8 cm vs 4.4 cm; P < 0.01), and significantly increased risk of atrial arrhythmia recurrence at 12 months (LVA: 56.5% vs no LVA: 41.4%; HR: 1.51; 95% CI: 1.01-2.27; P = 0.04) compared to no posterior LVA. However, the addition of PWI to PVI did not significantly improve freedom from atrial arrhythmia recurrence over PVI alone (PVI with PWI: 44.8% vs PVI: 41.9%; HR: 0.95; 95% CI: 0.51-1.79; P = 0.95)., Conclusions: In patients with PsAF undergoing catheter ablation, posterior LVA was associated with a significant increase in atrial arrhythmia recurrence. However, the addition of PWI in those with posterior LVA did not reduce atrial arrhythmia recurrence over PVI alone., Competing Interests: Funding and Author Disclosures This study received seed grant funding from the Baker department of Cardiometabolic Health, University of Melbourne. Dr Lee has received consulting fees from Biosense Webster. Dr Sanders has served on advisory boards for Medtronic, Abbott Medical, Boston Scientific, CathRx, and PaceMate; and has received funding for research and consultancy from Medtronic, Abbott Medical, Boston Scientific, and Microport. Dr Kalman has received fellowship support from Medtronic and Biosense Webster. Dr Kistler has received the investigator grant from the NHMRC; has received funding from Abbott Medical for consultancy and speaking engagements; and has served on the advisory board with fellowship support from Biosense Webster. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2023 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Background: Catheter ablation is an effective strategy in atrial fibrillation (AF). However, its timing in the course of management remains unclear. The aim of this study was to determine if an early vs. delayed AF ablation strategy is associated with differences in arrhythmia outcomes during 12-month follow-up., Methods and Results: One hundred patients with symptomatic AF referred to a tertiary centre for management were randomized in a 1:1 ratio to either an early ablation strategy (within 1 month of recruitment) or a delayed ablation strategy (optimized medical therapy followed by catheter ablation at 12 months post recruitment). The primary endpoint was atrial arrhythmia free survival at 12 months post-ablation. Secondary outcomes included: (i) AF burden, (ii) AF burden by AF phenotype, and (iii) antiarrhythmic drug (AAD) use at 12 months. Overall, 89 patients completed the study protocol (Early vs. Delayed: 48 vs. 41). Mean age was 59 ± 12.9 years (29% women). Pulmonary vein isolation was achieved in 100% of patients. At 12 months, 56.3% of patients in the early ablation group were free from recurrent arrhythmia, compared with 58.6% in the delayed ablation group (HR 1.12, 95% CI 0.59-2.13, P = 0.7). All secondary outcomes showed no significant difference including median AF burden (Early vs. Delayed: 0% [IQR 3.2] vs. 0% [5], P = 0.66), median AF burden amongst paroxysmal AF patients (0% [IQR 1.1] vs. 0% [4.5], P = 0.78), or persistent AF patients (0% [IQR 22.8] vs. 0% [5.6], P = 0.45) or AAD use (33% vs. 37%, P = 0.8)., Conclusion: Compared with an early ablation strategy, delaying AF ablation by 12 months for AAD management did not result in reduced ablation efficacy., Competing Interests: Conflict of interest All authors declare no conflict of interest for this contribution., (© The Author(s) 2023. Published by Oxford University Press on behalf of the European Society of Cardiology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background: High-power, short duration (HPSD) radiofrequency ablation (RFA) is a commonly used strategy for pulmonary vein isolation (PVI)., Objectives: This study sought to compare HPSD with standard power, standard duration (SPSD) RFA in patients undergoing PVI., Methods: Patients with paroxysmal or persistent (<1 year) atrial fibrillation (AF) were randomized to HPSD (50 W) or SPSD (25-30 W) RFA to achieve PVI. Outcomes assessed included time to achieve PVI (primary), left atrial dwell time, total procedure time, first-pass isolation, PV reconnection with adenosine, procedure complications including asymptomatic cerebral emboli (ACE), and freedom from atrial arrhythmias., Results: Sixty patients (median age 66 years; 75% male) with paroxysmal (57%) or persistent (43%) AF were randomized to HPSD (n = 29) or SPSD (n = 31). Median time to achieve PVI was shorter with HPSD vs SPSD (87 minutes vs 126 minutes; P = 0.003), as was left atrial dwell time (157 minutes vs 180 minutes; P = 0.04). There were no differences in first-pass isolation (79% vs 76%; P = 0.65) or PV reconnection with adenosine (12% vs 20%; P = 0.26) between groups. At 12 months, recurrent atrial arrhythmias occurred less in the HPSD group compared with the SPSD group (n = 3 of 29 [10%] vs n = 11 of 31 [35%]; HR: 0.26; P = 0.027). There was a trend toward more ACE with HPSD RFA (40% HPSD vs 17% SPSD; P = 0.053)., Conclusions: In patients undergoing AF ablation, HPSD compared with SPSD RFA results in shorter time to achieve PVI, greater freedom from AF at 12 months, and a trend toward increased ACE., Competing Interests: Funding Support and Author Disclosures The study was funded by the Tod Spieker philanthropic fund. Dr Gerstenfeld has served on the advisory board for Biosense Webster and Farapulse, Inc; and received lecture honoraria from Biosense Webster and Abbott. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2023 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Aims: Radiofrequency (RF) ablation for pulmonary vein isolation (PVI) in atrial fibrillation (AF) is associated with the risk of oesophageal thermal injury (ETI). Higher power short duration (HPSD) ablation results in preferential local resistive heating over distal conductive heating. Although HPSD has become increasingly common, no randomized study has compared ETI risk with conventional lower power longer duration (LPLD) ablation. This study aims to compare HPSD vs. LPLD ablation on ETI risk., Methods and Results: Eighty-eight patients were randomized 1:1 to HPSD or LPLD posterior wall (PW) ablation. Posterior wall ablation was 40 W (HPSD group) or 25 W (LPLD group), with target AI (ablation index) 400/LSI (lesion size index) 4. Anterior wall ablation was 40-50 W, with a target AI 500-550/LSI 5-5.5. Endoscopy was performed on Day 1. The primary endpoint was ETI incidence. The mean age was 61 ± 9 years (31% females). The incidence of ETI (superficial ulcers n = 4) was 4.5%, with equal occurrence in HPSD and LPLD (P = 1.0). There was no difference in the median value of maximal oesophageal temperature (HPSD 38.6°C vs. LPLD 38.7°C, P = 0.43), or the median number of lesions per patient with temperature rise above 39°C (HPSD 1.5 vs. LPLD 2, P = 0.93). Radiofrequency ablation time (23.8 vs. 29.7 min, P < 0.01), PVI duration (46.5 vs. 59 min, P = 0.01), and procedure duration (133 vs. 150 min, P = 0.05) were reduced in HPSD. After a median follow-up of 12 months, AF recurrence was lower in HPSD (15.9% vs. LPLD 34.1%; hazard ratio 0.42, log-rank P = 0.04)., Conclusion: Higher power short duration ablation was associated with similarly low rates of ETI and shorter total/PVI RF ablation times when compared with LPLD ablation. Higher power short duration ablation is a safe and efficacious approach to PVI., Competing Interests: Conflict of interest: D.C. is supported by co-funded NHMRC/NHF post-graduate scholarship. The following industry funding sources regarding activities outside the submitted work have been declared in accordance with ICMJE guidelines. P.M.K. has received funding from Abbott Medical for consultancy and speaking engagements and fellowship support from Biosense Webster. J.M.K. holds a Practitioner Fellowship of the NHMRC and has research and fellowship support from Medtronic, Abbott and Biosense Webster. S.P. has a NHMRC Post Doctoral Research Fellowship. A.V. has a National Heart Foundation Early Career Fellowship. The remaining authors have nothing to disclose., (© The Author(s) 2022. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Importance: Pulmonary vein isolation (PVI) alone is less effective in patients with persistent atrial fibrillation (AF) compared with paroxysmal AF. The left atrial posterior wall may contribute to maintenance of persistent AF, and posterior wall isolation (PWI) is a common PVI adjunct. However, PWI has not been subjected to randomized comparison., Objective: To compare PVI with PWI vs PVI alone in patients with persistent AF undergoing first-time catheter ablation., Design, Setting, and Participants: Investigator initiated, multicenter, randomized clinical trial involving 11 centers in 3 countries (Australia, Canada, UK). Symptomatic patients with persistent AF were randomized 1:1 to either PVI with PWI or PVI alone. Patients were enrolled July 2018-March 2021, with 1-year follow-up completed March 2022., Interventions: The PVI with PWI group (n = 170) underwent wide antral pulmonary vein isolation followed by posterior wall isolation involving linear ablation at the roof and floor to achieve electrical isolation. The PVI-alone group (n = 168) underwent wide antral pulmonary vein isolation alone., Main Outcomes and Measures: Primary end point was freedom from any documented atrial arrhythmia of more than 30 seconds without antiarrhythmic medication at 12 months, after a single ablation procedure. The 23 secondary outcomes included freedom from atrial arrhythmia with/without antiarrhythmic medication after multiple procedures, freedom from symptomatic AF with/without antiarrhythmic medication after multiple procedures, AF burden between study groups at 12 months, procedural outcomes, and complications., Results: Among 338 patients randomized (median age, 65.6 [IQR, 13.1] years; 76.9% men), 330 (97.6%) completed the study. After 12 months, 89 patients (52.4%) assigned to PVI with PWI were free from recurrent atrial arrhythmia without antiarrhythmic medication after a single procedure, compared with 90 (53.6%) assigned to PVI alone (between-group difference, -1.2%; hazard ratio [HR], 0.99 [95% CI, 0.73-1.36]; P = .98). Of the secondary end points, 9 showed no significant difference, including freedom from atrial arrhythmia with/without antiarrhythmic medication after multiple procedures (58.2% for PVI with PWI vs 60.1% for PVI alone; HR, 1.10 [95% CI, 0.79-1.55]; P = .57), freedom from symptomatic AF with/without antiarrhythmic medication after multiple procedures (68.2% vs 72%; HR, 1.20 [95% CI, 0.80-1.78]; P = .36) or AF burden (0% [IQR, 0%-2.3%] vs 0% [IQR, 0%-2.8%], P = .47). Mean procedural times (142 [SD, 69] vs 121 [SD, 57] minutes, P < .001) and ablation times (34 [SD, 21] vs 28 [SD, 12] minutes, P < .001) were significantly shorter for PVI alone. There were 6 complications for PVI with PWI and 4 for PVI alone., Conclusions and Relevance: In patients undergoing first-time catheter ablation for persistent AF, the addition of PWI to PVI alone did not significantly improve freedom from atrial arrhythmia at 12 months compared with PVI alone. These findings do not support the empirical inclusion of PWI for ablation of persistent AF., Trial Registration: anzctr.org.au Identifier: ACTRN12616001436460.

Background: The success of pulmonary vein isolation (PVI) is reduced in persistent AF (PsAF) compared to paroxysmal AF. Adjunctive ablation strategies have failed to show consistent incremental benefit over PVI alone in randomized studies. The left atrial posterior wall is a potential source of non-PV triggers and atrial substrate which may promote the initiation and maintenance of PsAF. Adding posterior wall isolation (PWI) to PVI had shown conflicting outcomes, with earlier studies confounded by methodological limitations., Objectives: To determine whether combining PWI with PVI significantly improves freedom from AF recurrence, compared to PVI alone, in patients with PsAF., Methods: This is a multi-center, prospective, international randomized clinical trial. 338 patients with symptomatic PsAF refractory to anti-arrhythmic therapy (AAD) will be randomized to either PVI alone or PVI with PWI in a 1:1 ratio. PVI involves wide antral circumferential pulmonary vein (PV) isolation, utilizing contact force sensing ablation catheters. PWI involves the creation of a floor line connecting the inferior aspect of the PVs, and a roof line connecting the superior aspect of the PVs. Follow up is for a minimum of 12 months with rhythm monitoring via implantable cardiac device and/or loop monitor, or frequent intermittent monitoring with an ECG device. The primary outcome is freedom from any documented atrial arrhythmia of > 30 seconds off AAD at 12 months, after a single ablation procedure., Conclusions: This randomized study aims to determine the success and safety of adjunctive PWI to PVI in patients with persistent AF., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Catheter ablation for atrial fibrillation (AF) is indicated in symptomatic patients who are intolerant or refractory to antiarrhythmic therapy. However, outcomes from catheter ablation remain suboptimal in patients with persistent AF. Pulmonary vein antral isolation (PVAI) is established as the cornerstone of AF ablation strategies. The landmark STAR AF II study demonstrated a lack of incremental benefit with adjunctive linear and complex fractionated electrogram ablation beyond PVAI. Randomized studies thus far have failed to consistently show favorable outcomes from other trigger/substrate-based ablation approaches over PVAI alone. In this issue of the journal, we pose an interesting clinical scenario-of a middle-aged female who presents with recurrent persistent AF but was found to have enduring PVAI on repeat electrophysiologic study. Which approach should be undertaken next? In this review article, we aim to provide an overview of ablation strategies beyond PVAI. Finally in light of scant randomized data to guide decision making we have approached leading experts in the field to provide their approach to this scenario., (© 2019 Wiley Periodicals, Inc.)

Background: Female gender is associated with an increased recurrence of atrial fibrillation (AF) after catheter ablation (CA). Although AF is more common in men, women constitute a significant proportion with persistent atrial fibrillation (PsAF)., Objective: The purpose of this study was to determine whether multiple ablation procedures improves arrhythmia outcomes in females with PsAF compared to men., Methods: We performed a multicenter observational study to determine long-term arrhythmia outcomes in patients undergoing >1 CA for PsAF. CA involved pulmonary vein (PV) isolation with additional ablation including linear, posterior wall isolation, electrogram-guided, or a combination of these., Results: A total of 281 patients had >1 ablation procedure for PsAF and were included in this analysis (mean age 58.7 ± 9.3 years; 86 [30.6%] female; left atrial [LA] area 27.0 ± 5.3 cm 2 ; PsAF duration 1.7 ± 1.7 years). At mean follow-up of 45.5 ± 31.8 months, freedom from recurrent AF was present in 148 patients(52.7%) after 2.2 ± 0.5 procedures. After multivariate analysis, female gender (hazard ratio [HR] 2.10; P <.001) and enduring PV isolation (HR 1.64; P = .01) were independently associated with AF recurrence. Enduring PV isolation was significantly higher in women than in men (33.7% vs 19.5%; P = .01)., Conclusion: Female gender was independently and strongly associated with arrhythmia recurrence in patients undergoing multiple procedures for PsAF. PV reconnection was less likely, and fewer reconnected PVs occurred in women. Further studies are required to better understand the mechanisms responsible for AF in females to assist in closing the gender gap in the success of CA., (Copyright © 2019 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Background: Pulmonary vein (PV) isolation (PVI) remains the cornerstone of catheter ablation (CA) in persistent atrial fibrillation (AF) (PeAF), although less successful than for paroxysmal AF. Whether rapid or fibrillatory (PV AF) PV firing may identify patients with PeAF more likely to benefit from a PV-based ablation approach is unclear., Objective: The purpose of this study was to determine the relationship between the PV cycle length (PVCL) and the PV AF outcome after CA., Methods: Before ablation, the multipolar catheter was placed in each PV and the left atrial appendage (LAA) for 100 consecutive cycles. The presence of PV AF, the average PVCL of all 4 veins (PV 4VAverage ), the fastest vein average (PV FVAverage ), the fastest cycle length (PV Fast ) both individually and relative to the average LAA cycle length were calculated. The ablation strategy included PVI and posterior wall isolation with a minimum of 12 months follow-up., Results: A total of 123 patients underwent CA (age 62 ± 9.1 years; CHA 2 DS 2 -VASC score 1.6 ± 1.1; left ventricular ejection fraction 48% ± 13%; left atrial area 31 ± 8.7 cm 2 ; AF duration 16 ± 17 months). PVI was achieved in 100% of patients. Multiprocedure success (MPS; freedom from AF/atrial tachycardia episodes lasting >30 seconds) was achieved in 76% of patients at 24 ± 8.1 months of follow-up after 1.2 ± 0.4 procedures. PV activity was not associated with MPS either absolutely (PV 4VAverage [MPS no vs yes: 178 ± 27 ms vs 177 ± 24 ms; P = .92], PV FVAverage [P = .69], or PV Fast [P = .82]) or as a ratio relative to the LAA cycle length (PV 4VAverage /LAA 1.05 ± 0.11 vs 1.06 ± 0.21; P = .87). The presence of PV AF (31% vs 47%; P = .13) did not predict MPS., Conclusion: The rapidity of PV firing or presence of fibrillation within the PV was not predictive of outcome of CA for PeAF. PV activity does not identify patients most likely to benefit from a PV-based ablation strategy., (Copyright © 2018 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Aims: Catheter ablation to achieve posterior left atrial wall (PW) isolation may be performed as an adjunct to pulmonary vein isolation (PVI) in patients with persistent atrial fibrillation (AF). We aimed to determine whether routine adenosine challenge for dormant posterior wall conduction improved long-term outcome., Methods and Results: A total of 161 patients with persistent AF (mean age 59 ± 9 years, AF duration 6 ± 5 years) underwent catheter ablation involving circumferential PVI followed by PW isolation. Posterior left atrial wall isolation was performed with a roof and inferior wall line with the endpoint of bidirectional block. In 54 patients, adenosine 15 mg was sequentially administered to assess reconnection of the pulmonary veins and PW. Sites of transient reconnection were ablated and adenosine was repeated until no further reconnection was present. Holter monitoring was performed at 6 and 12 months to assess for arrhythmia recurrence. Posterior left atrial wall isolation was successfully achieved in 91% of 161 patients (procedure duration 191 ± 49 min, mean RF time 40 ± 19 min). Adenosine-induced reconnection of the PW was demonstrated in 17%. The single procedure freedom from recurrent atrial arrhythmia was superior in the adenosine challenge group (65%) vs. no adenosine challenge (40%, P < 0.01) at a mean follow-up of 19 ± 8 months. After multiple procedures, there was significantly improved freedom from AF between patients with vs. without adenosine PW challenge (85 vs. 65%, P = 0.01)., Conclusion: Posterior left atrial wall isolation in addition to PVI is a readily achievable ablation strategy in patients with persistent AF. Routine adenosine challenge for dormant posterior wall conduction was associated with an improvement in the success of catheter ablation for persistent AF., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2017. For permissions please email: journals.permissions@oup.com.)

Background: Early studies demonstrated relatively low success rates for pulmonary vein isolation (PVI) alone in patients with persistent atrial fibrillation (PeAF). However, the advent of new technologies and the observation that additional substrate ablation does not improve outcomes have created a new focus on PVI alone for treatment of PeAF., Objective: The purpose of this study was to systematically review the recent medical literature to determine current medium-term outcomes when a PVI-only approach is used for PeAF., Methods: An electronic database search (MEDLINE, Embase, Web of Science, PubMed, Cochrane) was performed in August 2016. Only studies of PeAF patients undergoing a "PVI only" ablation strategy using contemporary radiofrequency (RF) technology or second-generation cryoballoon (CB2) were included. A random-effects model was used to assess the primary outcome of pooled single-procedure 12-month arrhythmia-free survival. Predictors of recurrence were also examined and a meta-analysis performed if ≥4 studies examined the parameter., Results: Fourteen studies of 956 patients, of whom 45.2% underwent PVI only with RF and 54.8% with CB2, were included. Pooled single-procedure 12-month arrhythmia-free survival was 66.7% (95% confidence interval [CI] 60.8%-72.2%), with the majority of patients (80.5%) off antiarrhythmic drugs. Complication rates were very low, with cardiac tamponade occurring in 5 patients (0.6%) and persistent phrenic nerve palsy in 5 CB2 patients (0.9% of CB2). Blanking period recurrence (hazard ratio 4.68, 95% CI 1.70-12.9) was the only significant predictor of recurrence., Conclusion: A PVI-only strategy in PeAF patients with a low prevalence of structural heart disease using contemporary technology yields excellent outcomes comparable to those for paroxysmal AF ablation., (Copyright © 2017 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Introduction: ELECTROPHYSIOLOGICAL AND HEMODYNAMIC ASSESSMENT., Dormant-Af Study: The significance of adenosine induced dormant pulmonary vein (PV) conduction in atrial fibrillation (AF) ablation remains controversial. The optimal dose of adenosine to determine dormant PV conduction is yet to be systematically explored., Methods and Results: ELECTROPHYSIOLOGICAL AND HEMODYNAMIC ASSESSMENT., Dormant-Af Study: Consecutive patients undergoing index AF ablation received 3 adenosine doses (12, 18, and 24 mg) in a randomized blinded order, immediately after pulmonary vein isolation (PVI). Electrophysiological (PR prolongation, AV block (AVB) and PV reconnection) and hemodynamic (BP) parameters were measured. A total, 339 doses (113/dose) assessed 191 PVs in 50 patients (66% male, 72% PAF, 52% hypertensive). Dormant PV conduction occurred in 28% of patients (16.5% [32] of PVs). All cases were associated with AVB (AVB: PV reconnection vs. no PV reconnection 100% vs. 83%, P = 0.007). AVB occurred more frequently at 24 mg versus 12 mg (92% vs. 82%, P = 0.019) but not versus 18 mg (91%, P = 0.62). AVB duration progressed between 12 mg (12.0 ± 8.9 seconds), 18 mg (16.1 ± 9.1 seconds, P = 0.001), and 24 mg (19.0 ± 9.3 seconds, P < 0.001) doses. MBP fell further at 24 mg (ΔMBP: 27 ± 12 mmHg) and 18 mg (26 ± 13 mmHg) doses compared to 12 mg (22 ± 10 mmHg vs., P < 0.001). A significant reduction in AVB in patients >110 kg (65% vs. 91% in 70-110 kg group, P < 0.001) in response to adenosine was seen., Conclusion: ELECTROPHYSIOLOGICAL AND HEMODYNAMIC ASSESSMENT., Dormant-Af Study: An adenosine dose producing AVB is required to unmask dormant PV conduction. AVB is significantly reduced in patients >110 kg. Weight and dosing variability may in part explain the conflicting results of studies evaluating the clinical utility of adenosine in PVI., (© 2016 Wiley Periodicals, Inc.)

Background: The pulmonary vein-left atrial (PV-LA) junction is key in pathogenesis of AF, and acute stretch is an important stimulus to AF. We aimed to characterize the response of the junction to acute stretch, hypothesizing that stretch would result in electrophysiological changes predisposing to re-entry., Methods and Results: Fifteen participants undergoing cardiac surgery underwent evaluation of the right superior PV-LA junction using an epicardial mapping plaque. In 10, this was performed before and after atrial stretch imposed by rapid volume expansion, and in 5, it was performed with an intervening observation period. Activation was characterized by conduction slowing and electrogram fractionation transversely across the PV-LA junction, with lines of block also demonstrated perpendicular to the junction. Conduction was decremental (plaque activation time 135.8 ± 46.8 ms with programmed extra stimuli at 10 ms above effective refractory period versus 66.1 ± 22.9 ms with pacing at 400 ms; P<0.001) and percentage fractionation was greater with programmed extra stimuli at 10 ms above (33.5%± 15.3% versus 20.7%± 14.0%, P=0.001). Right atrial pressure increased by 2.5 ± 1.8 mm Hg (P=0.002) with volume expansion. Stretch resulted in conduction slowing across the PV-LA junction (increase in activation time 10.9 ± 14.6 ms in acute stretch group versus -0.1 ± 4.5 ms in control group; P=0.002). Conduction slowing was more marked with programmed extra stimuli at 10 ms above effective refractory period than with stable pacing (13.4 ± 16.5 ms versus 1.7 ± 5.4 ms; P=0.003). Stretch resulted in a significant increase in fractionated electrograms (7.9%± 7.0% versus -0.4 ± 3.3; P=0.004)., Conclusions: Acute stretch results in conduction slowing across the PV-LA junction, with a greater degree of signal complexity. This substrate may be important in AF initiation and maintenance by promoting re-entry., (© 2014 American Heart Association, Inc.)

Background: Gender-based differences in the clinical nature of cardiac arrhythmias such as atrial fibrillation (AF) are well established., Objective: The purpose of this study was to identify any such gender-based differences in the underlying pulmonary vein and atrial substrate., Methods and Results: Thirty-eight patients with no history of AF undergoing catheter ablation for supraventricular tachycardia (SVT) and 55 with paroxysmal or persistent AF undergoing catheter ablation of AF underwent detailed electroanatomic mapping of the pulmonary veins and atria. Refractory periods in multiple locations, sinus node function, endocardial bipolar voltage, pulmonary vein and atrial conduction, and bipolar electrogram complexity were analyzed. There were no significant between-gender differences in age or other clinical variables known to impact on the atrial or pulmonary vein substrate. In neither the AF nor the non-AF cohorts were there any significant differences in atrial or pulmonary vein refractoriness, sinus node function, any measure of PV electrophysiology, or any measure of atrial electrophysiology., Conclusion: No systematic between-gender differences were observed in the PV or atrial substrate either in those with or without a history of AF, with a similar prevalence of the cardiovascular comorbidities frequently associated with atrial remodeling and AF seen in both male and female groups., (© 2014 Wiley Periodicals, Inc.)

Background: There is a complex interplay between the atria and ventricles in atrial fibrillation (AF). Cardiac magnetic resonance (CMR) imaging provides detailed tissue characterization, identifying focal ventricular fibrosis with late gadolinium enhancement (ventricular late gadolinium enhancement) and diffuse fibrosis with postcontrast-enhanced T1 mapping. The aim of the present study was to investigate the relationship between postcontrast ventricular T1 relaxation time on CMR and freedom from AF after pulmonary vein isolation., Methods and Results: One hundred three patients undergoing catheter ablation for symptomatic AF (66% paroxysmal AF; age, 58±10 years; left atrial area, 27±7 cm(2)) underwent preprocedure CMR to determine postcontrast ventricular T1 time. Follow-up included clinical review and 7-day Holter monitors at 6 monthly intervals. All patients underwent successful pulmonary vein isolation. At a mean follow-up of 15±7 months, the single procedure success was 74%. Postcontrast ventricular T1 time was significantly shorter in patients with recurrent AF (366±73 ms) versus patients without AF recurrence (428±90 ms; P=0.002). Univariate predictors of AF recurrence included postcontrast ventricular T1 time, AF type (paroxysmal versus persistent), AF duration, and body mass index. After multivariate analysis, ventricular T1 time (P=0.03) and AF duration (P=0.03) were the only independent predictors. Freedom from AF was present in 84% of patients with a postcontrast ventricular T1 time >380 ms versus 56% in patients with a postcontrast ventricular T1 time <380 ms (P=0.002)., Conclusions: A shorter postcontrast ventricular T1 relaxation time on CMR is associated with reduced freedom from AF after catheter ablation. Diffuse ventricular fibrosis as demonstrated by CMR may, in part, explain recurrent AF after AF ablation., (© 2014 American Heart Association, Inc.)

Background: Circumferential pulmonary vein (PV) isolation is the cornerstone of catheter ablation for atrial fibrillation (AF); however, PV reconnection remains problematic., Objective: To assess the impact of PV anatomy on outcome after AF ablation., Methods: One hundred two patients with paroxysmal AF underwent cardiac magnetic resonance (60%) or computed tomography (40%) before AF ablation. PV anatomy was classified according to the presence of common PVs, accessory PVs, PV branching pattern, and the dimensions of the PV ostia, intervenous ridges (IVRs), and the left PV-left atrial appendage ridge., Results: Four discrete PVs were present in 48(47%) of the patients: a left common PV in 38(37%), a right common PV in 2(2%), an accessory right PV in 20(20%), and left PV in 4(4%). At a mean follow-up of 12 ± 4 months, 75 of 102 (74%) patients were free of recurrent AF. A LCPV was associated with an increase in freedom from AF (87% vs 66% for 4 PV anatomy; P = .03). Greater left IVR length (16.9 ± 3.5 mm vs 14.0 ± 3.0 mm; P ≤ .001) and width (1.4 ± 0.6 mm vs 1.1 ± 0.6 mm; P = .02) were associated with increased AF recurrence. After multivariate analysis, abnormal anatomy (LCPV or accessory PV) and left IVR length were found to be the only independent predictors of freedom from AF., Conclusions: Four discrete PVs are present in the minority of patients with paroxysmal AF undergoing PV isolation. The presence of a LCPV is associated with an increased freedom from AF after catheter ablation. PV anatomy may in part explain the variable outcome to electrical isolation in patients with paroxysmal AF., (Copyright © 2014 Heart Rhythm Society. All rights reserved.)

Introduction: Electrogram (EGM) characteristics are used to infer catheter-tissue contact. We examined if (a) atrial EGM characteristics predicted CF and (b) compared the value of CF versus other surrogates for predicting lesion efficacy., Methods and Results: Twelve paroxysmal AF patients underwent pulmonary vein isolation using radiofrequency (RF) ablation facilitated by a novel CF-sensing catheter. Operators were blinded to CF. EGM amplitude, width, and morphology were measured pre- and post-RF. At each RF site, average CF, force-time integral (FTI), impedance fall, time to impedance plateau, maximum power, catheter tip temperature, and total energy delivered were recorded. An effective lesion was defined based on previously validated EGM criteria for transmural lesions. There was a moderate correlation between CF and EGM amplitude (r = 0.19) and EGM width (r = -0.22). Pre-RF, EGM amplitude, and width had modest to poor discriminative capacity for identifying preablation CF (e.g., EGM amplitude identified CF>20 g with sensitivity and specificity of 67% and 60%, respectively). Preablation CF, FTI, and total energy delivered during RF were the only independent predictors of effective lesion formation. Neither pre-RF EGM amplitude/width nor power, temperature, and impedance changes during RF predicted effective lesion formation. An average CF >16 g or FTI >404 g*s had excellent sensitivity and specificity (>80%) for identifying an effective lesion., Conclusions: EGM characteristics do not reliably predict either CF before the onset of RF, nor do they predict the likelihood of an effective lesion. CF parameters were superior to power, temperature, and impedance changes during RF in predicting lesion efficacy., (© 2013 Wiley Periodicals, Inc.)

Background: Catheter-tissue contact is critical for effective lesion creation. We characterized the contact force (CF) at different anatomic sites during antral pulmonary vein (PV) isolation for atrial fibrillation., Methods and Results: Two experienced operators performed PV isolation in 22 patients facilitated by a novel CF-sensing ablation catheter in a blinded fashion. Average CF and force-time integral data from 1602 lesions were analyzed. The left and right PV antra were divided into the following: carina, superior, inferior, anterior, and posterior quadrants for analysis. There was significant variability in CF within and between different PV quadrants (P<0.05). Lowest CF of all left PV sites was at the carina and anterior quadrant, whereas highest CF was at the superior and inferior quadrants (P<0.05). Lowest CF of all right PV sites was at the carina, whereas highest CF was at the anterior and inferior quadrants (P<0.05). When comparing similar PV quadrants on the left versus right (eg, left carina versus right carina), CF was always higher in the right PVs (P<0.05), except at the superior quadrant where CF was similar in the left and right PVs (P=0.19). There was no specific pattern of anatomic distribution of excess CF (P=0.39)., Conclusions: Monitoring of catheter-tissue CF during PV isolation demonstrates significant variability in CF within and between different PV antral sites. Sites of lowest CF were the carina and anterior left PVs and the carina of the right PVs. This information may be important for improving ablation efficacy and clinical outcomes during PV isolation.

Background: The pulmonary veins (PVs) and the PV-LA (left atrium) junction are established sources of triggers initiating atrial fibrillation. In addition, they have been implicated in the maintenance of arrhythmia., Objective: To undertake high-density electrophysiological characterization of the right superior PV-LA junction in humans., Methods: Mapping was performed in 18 patients without a history of atrial fibrillation undergoing cardiac surgery. A high-density epicardial plaque was positioned at the anterior right superior pulmonary vein covering 3 regions: LA, PV-LA junction, and the PV. Isochronal maps were created during (1) sinus rhythm (SR); (2) LA pacing (LA-Pace); (3) PV pacing (PV-Pace); (4) LA programmed electrical stimulation (LA-PES); and (5) PV programmed electrical stimulation (PV-PES). Regional differences in conduction slowing/conduction block (CS/CB) and the prevalence of fractionated signals (FS) and double potentials (DPs) were assessed., Results: A region of isochronal crowding representing CS/CB developed at the PV-LA junction in 84% of the maps. Three distinct activation patterns were seen. Pattern 1: Uniform SR activation without CS/CB. LA-Pace and PES caused 1 to 2 lines of isochronal crowding (CS/CB) at the PV-LA junction. Pattern 2: CS/CB occurred at the PV-LA junction in SR. LA/PV-Pace and LA/PV-PES caused an increase in CS/CB at the PV-LA junction with widely split DPs and FS. Pattern 3: A single incomplete line of CS at the PV-LA junction in SR. With LA/PV pacing and LA/PV-PES, multiple lines (≥3) of CS/CB developed at the PV-LA junction with evidence of circuitous activation and a marked increase in DPs and FS., Conclusion: High-density epicardial mapping of the right superior pulmonary vein demonstrates marked functional conduction delay and circuitous activation patterns at the PV-LA junction, creating the substrate for reentry., (Copyright © 2012 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Aims: Increasing age is a significant risk factor for developing atrial fibrillation (AF). Pulmonary vein (PV) triggers are critical in the mechanism of AF, but little is known of the substrate changes that occur within the PVs with ageing. Therefore, we sought to identify whether ageing is associated with electroanatomic changes within the pulmonary veins., Methods and Results: Twenty-five patients undergoing ablation for left-sided supraventricular tachycardia had high-density 3D electroanatomic maps of all four PVs created. Patients were divided into two groups: group 1 aged <50 years and group 2 aged >50 years. Mean-voltage (MV), % low-voltage (LV < 0.5 mV), conduction, signal complexity, and PV muscle sleeve length and diameter were assessed. Age was 33 ± 8 vs. 66 ± 8 years for groups 1 and 2, respectively (P < 0.001). Group 2 demonstrated: (i) lower MV within the PVs (1.66 ± 1.1 vs. 1.88 ± 1.1 mV, P < 0.001); (ii) increased % LV (5.0 vs. 1.1%, P < 0.001), and increased voltage heterogeneity within the PVs (65 ± 14 vs. 55 ± 8%, P < 0.05); (iii) regional and global conduction slowing in the PVs; and (iv) increased % complex signals within the PVs (1.4 vs. 0.4%, P = 0.009). There was no difference in PV sleeve length or diameter., Conclusion: Increasing age is associated with PV electroanatomic changes characterized by a significant reduction in PV voltage, conduction slowing, and increasing signal complexity. These observations provide new insights into the potential mechanisms behind the increased prevalence of AF with advancing age.

Introduction: Rapid PV activity is critical in initiating and maintaining AF. The underlying substrate responsible for this remains uncertain. We sought to identify if patients with paroxysmal (PAF) and persistent atrial fibrillation (PeAF) have an abnormal substrate within the pulmonary veins (PVs)., Methods and Results: Thirty-nine patients with AF (21 PAF, 18 PeAF) were compared with 15 age-matched controls with left-sided accessory pathways (AVRT). High-density 3D electroanatomic maps of the PVs were created. PV voltage, conduction, PV muscle sleeve length, effective refractory periods (ERPs) of the PVs, posterior left atrium (PLA), left atrial appendage (LAA) and distal coronary sinus (CSd), and signal complexity were assessed. Compared with controls, the PVs of AF patients had (1) lower mean-voltage and a higher % low-voltage; (2) shorter PV muscle sleeves; (3) slower conduction; (4) shorter ERP; and (5) more prevalent complex signals. Compared with the PAF group, the PeAF group had (1) higher % low voltage; (2) slower conduction; and (3) more complex signals. In PAF patients, the PLA and LAA ERPs were longer than controls and the PV ERP was shorter than controls; in PeAF patients PLA and LAA ERPs were reduced, but to a lesser extent than in the PVs. AF induction occurred during PV ERP testing in both AF groups, but not controls., Conclusions: PAF and PeAF patients demonstrate electrical and electroanatomic remodeling of the PVs compared to control patients without prior AF. Some of these changes were more marked in PeAF. , (© 2011 Wiley Periodicals, Inc.)

Background: Pulmonary vein (PV) reconnection is the Achilles heel of pulmonary vein isolation (PVI) for atrial fibrillation (AF). Dissociated pulmonary vein potentials (dPVP) may reflect abnormal PV automaticity, indicate more extensive PV muscular sleeve or may simply be an epiphenomenon., Objective: This study sought to determine the incidence, characteristics and prognostic significance of dPVP following PVI for AF., Methods: 89 consecutive patients (mean age 58.2 ± 8.4 years, 75% male, 74% paroxysmal, 26% persistent AF) underwent antral PVI using three-dimensional mapping systems with image integration with the endpoint of bidirectional PV block. Following PV electrical isolation the presence and characteristics of dPVP were recorded. Holter monitoring was performed at 3, 6 and 12 months. Acute PV reconnection was assessed over a 30-min waiting period., Results: Electrical isolation was achieved in all 372 PV targeted for ablation. 69 of 372 isolated PV (19%) demonstrated dPVP after acute electrical isolation. Sites of dPVP origin were the left superior in 36%, left inferior in 20%, right superior in 31% and right inferior in 12%. All 69 dPVP demonstrated slow activity (cycle length >1500 ms) with only four persisting more than 30 min after acute isolation. There was no difference in the clinical characteristics between dPVP-positive vs dPVP-negative patients. At a mean follow-up of 21 ± 8 months the single procedure success was 25/33 (76%) in dPVP-positive versus 39/60 (64%) in dPVP-negative patients (p = -0.3). In the eight dPVP-positive patients who underwent a second procedure, 11 of the 14 (79%) veins with initial dPVP demonstrated PV-left atrial reconnection., Conclusion: dPVP are present in 19% of PV following acute antral electrical isolation. The presence of dPVP did not predict recurrent AF following PVI.

Objectives: To report the major complication rate associated with pulmonary vein antral isolation (PVAI) in a consecutive series of 500 patients from a single center., Background: Catheter ablation for atrial fibrillation (AF) is an established procedure for refractory AF. However, the risk of major complications has been reported to range from 3.9% to 4.5% and continues to represent a cause for concern. We hypothesized that these studies may have overestimated the rate of major complications associated with PVAI in patients with a low prevalence of structural heart disease (SHD)., Methods: Data were prospectively collected from 500 consecutive AF ablation procedures on 424 patients (mean age 55 ± 11 years, 79% men, paroxysmal AF-80% and persistent AF-20%, CHADS₂ scores of 0, 1, 2, 3 present in 64%, 28%, 7%, 1%, respectively), performed between July 2006 and September 2009. All procedures were performed under general anesthesia with intraoperative transesophageal echo. PVAI was performed using a nonfluoroscopic mapping system with an endpoint of PV isolation. Adjunctive left atrial ablation was performed in 21% of patients only. Major complications were defined from a compilation of those reported in 5 prior studies reporting complications., Results: In 500 procedures, there were no instances of death, stroke/TIA, cardiac tamponade, atrioesophageal fistula, or PV stenosis. Major complications occurred in 4 procedures (0.8%): esophageal hematoma (TEE probe)--2; pharyngeal trauma--1; and retroperitoneal hematoma-1., Conclusions: AF ablation can be performed safely in young patients without structural heart disease with a low risk (<1%) of major complications when using a strategy of PVAI., (© 2010 Wiley Periodicals, Inc.)

Introduction: Pulmonary veins play an important role in triggering atrial fibrillation (AF). Pulmonary vein isolation (PVI) is an effective treatment for patients with paroxysmal AF. However, the late AF recurrence rate in long-term follow-up of circumferential PV antral isolation (PVAI) is not well documented. We sought to determine the time to recurrence of arrhythmia after PVAI, and long-term rates of sinus rhythm after circumferential PVAI., Methods: One hundred consecutive patients with a mean age of 54 ± 10 years, with paroxysmal AF who underwent PVAI procedure were analyzed. Isolation of pulmonary veins was based on an electrophysiological and anatomical approach, with a nonfluoroscopic navigation mapping system to guide antral PVI. Ablation endpoint was vein isolation confirmed with a circular mapping catheter at first and subsequent procedures. Clinical, ECG, and Holter follow-up was undertaken every 3 months in the first year postablation, every 6 months thereafter, with additional prolonged monitoring if symptoms were reported. Time to arrhythmia recurrence, and representing arrhythmias, were documented., Results: Isolation of all 4 veins was successful in 97% patients with 3.9 ± 0.3 veins isolated/patient. Follow-up after the last RF procedure was at a mean of 39 ± 10 months (range 21-66 months). After a single procedure, sinus rhythm was maintained at long-term follow-up in 49% patients without use of antiarrhythmic drugs (AADs). After repeat procedure, sinus rhythm was maintained in 57% patients without the use of AADs, and in 82% patients including patients with AADs. A total of 18 of 100 patients had 2 procedures and 4 of 100 patients had 3 procedures for recurrent AF/AT. Most (86%) AF/AT recurrences occurred ≤ 1 year after the first procedure. Mean time to recurrence was 6 ± 10 months. Kaplan-Meier analysis on antiarrhythmics showed AF free rate of 87% at 1 year and 80% at 4 years. There were no major complications., Conclusion: PVAI is an effective strategy for the prevention of AF in the majority of patients with PAF. Maintenance of SR requires repeat procedure or continuation of AADs in a significant proportion of patients. After maintenance of sinus rhythm 1-year post-PVAI, a minority of patients will subsequently develop late recurrence of AF., (© 2010 Wiley Periodicals, Inc.)

Objectives: This study aimed to characterize the long-term outcome and incidence of atrial fibrillation (AF) in patients following catheter ablation of focal atrial tachycardia (AT) from the pulmonary veins (PV)., Background: Although both AT and AF may originate from ectopic foci within PVs, it is unknown whether PV AT patients subsequently develop AF., Methods: Twenty-eight patients with 29 PV ATs (14%) from a consecutive series of 194 patients who underwent RFA for focal AT were included. Patients with concomitant AF prior to the index procedure were excluded., Results: The minimum follow-up duration was 4 years; mean age 38 +/- 18 years with symptoms for 6.5 +/- 10 years, having tried 1.5 +/- 0.9 antiarrhythmic drugs. The distribution of foci was: left superior 12 (41%), right superior 10 (34%), left inferior 5 (17%), and right inferior 2 (7%). The focus was ostial in 93% and 2-4 cm distally within the vein in 7%. Mean tachycardia cycle length was 364 +/- 90 ms. Focal ablation was performed in 25 of 28 patients. There were 6 recurrences with 5 from the original site. Twenty-six patients were available for long-term clinical follow-up. At a mean of 7.2 +/- 2.1 years, 25 of 26 (96%) were free from recurrence off antiarrhythmic drugs. No patients developed AF., Conclusions: Focal ablation for tachycardia originating from the PVs is associated with long-term freedom from both AT and AF. Therefore, although PV AT and PV AF share a common anatomic distribution, PV AT is a distinct clinical entity successfully treated with focal RFA and not associated with AF in the long term.

Background: Arrhythmia recurrence after atrial fibrillation (AF) ablation is often associated with pulmonary vein reconnection (PVR). We prospectively examined anatomical sites of both acute and chronic PVR., Methods: One hundred and fifty AF patients underwent PV wide encirclement and sites where immediate electrical isolation (EI) occurred were tagged using electroanatomic mapping/CT integration (Cartomerge, Biosense Webster, Diamond Bar, CA, USA). After 30 minutes PVs were checked and acute PVR sites marked at reisolation. Chronic PVR sites were marked at the time of repeat procedures., Results: On the left, immediate EI sites were predominantly on the intervenous ridge (IVR) and PV-left atrial appendage (PV-LAA) ridge. On the right they were at the roof, IVR, and floor of the PVs. Ninety-eight of one hundred and fifty patients had PVs checked after >30 minutes. Thirty-two of ninety-eight had acute PVR. This was mostly on the IVR and PV-LAA ridge on the left (88%), and on the roof and IVR on the right (78%). At repeat procedure, 38/39 patients had chronic PVR, predominantly on the IVR (61%) and PV-LAA ridge (21%) on the left, and on the roof, IVR, and floor of the right PVs (79%). There was minimal acute or chronic PVR posteriorly. Acutely PVR occurred close to the immediate EI site 60% of the time, but only 30% of the time chronically., Conclusion: Acute and chronic PVR sites have a preferential distribution. This may be determined by anatomical and technical factors. Knowledge of immediate EI sites may be beneficial acutely, but with chronic PVR a careful survey is required. These findings may help target ablation, improving safety and success.

Aims: A detailed appreciation of the left atrial/pulmonary venous (LA/PV) anatomy may be important in improving the safety and success of catheter ablation for AF. The aim of this randomized study was to determine the impact of computed tomographic (CT) integration into an electroanatomic mapping (EAM) system on clinical outcome in patients undergoing catheter ablation for atrial fibrillation (AF)., Methods and Results: Eighty patients with AF were randomized to undergo first-time wide encirclement of ipsilateral PV pairs using EAM alone (40 patients) or with CT (40 patients, Cartomerge). Wide encirclement of the pulmonary veins was performed using irrigated radiofrequency ablation with the electrophysiological endpoint of electrical isolation (EI). The primary endpoint was single-procedure success at 6 month follow up. Acute and long-term procedural outcomes were also determined. There was no significant difference in single procedure success between EAM (56%) and cavotricuspid isthmus image (CTI) (50%) groups (P = 0.9). Acute procedural outcomes (EI, PV reconnection, sinus rhythm restored by ablation in persistent AF), fluoroscopy, and procedure durations (EI of right PVs, EI of left PVs, total) did not differ significantly between EAM and CTI groups., Conclusion: Image integration to guide catheter ablation for AF did not significantly improve the clinical outcome. Achieving PV EI is the critical determinant of procedural success rather than the mapping tools used to achieve it.

Background: Catheter ablation (CA) by wide encirclement of pulmonary veins (WEPV) restores sinus rhythm in up to 95%. Complex PV-left atrial (LA) connections make achieving electrical isolation (EI) challenging. We examined anatomical and technical features associated with resistance to EI during WEPV in a prospective study., Methods: One hundred one consecutive patients with symptomatic AF underwent first-time CA guided by electroanatomic mapping and CT integration (Cartomerg). Following double-transseptal access, WEPV was performed. After completion of PV encirclement, the line was mapped and where no signal could be obtained, CA was performed inside the WE line at the site of earliest PV breakthrough on the circular mapping catheter. Sites of EI were tagged. Anatomic studies of corresponding regions of the venoatrial junction in 24 adult hearts were performed., Results: Sites resistant to EI were located at the inferior quadrant (P < 0.001) for the RSPV, superior quadrant (P < 0.001) for the RIPV, and the inferior and anterior quadrants (P < 0.001) for the LSPV. EI was significantly less frequent at the posterior quadrant (P < 0.001) for the LIPV. To achieve EI, CA was necessary inside the WE on the intervenous ridge on the right in 51% and on the left in 41%. The LPV/LAA ridge was investigated by anatomic studies that demonstrated considerable variation in the narrowest width (3-23.7 mm) and transmural thickness (1-5 mm)., Conclusion: Sites of EI after WEPV have a preferential distribution determined by anatomic features. CA on the intervenous ridge is required in a significant proportion of patients to achieve EI. Atrial folds and ridges increase myocardial thickness creating technical and anatomic challenges for achieving transmural lesions.

Introduction: Focal atrial fibrillation (AF) may initiate with an irregular rapid burst of atrial ectopic (AE) activity from a pulmonary vein (PV) focus, but how AF is maintained it is not known. The crista terminalis (CT) is an important line of block in atrial flutter (AFL), but its role in AF has not been determined. The aim of this study was to examine the conduction properties of the CT during onset of AF., Methods and Results: In 10 patients (mean age 38 +/- 8 years), we analyzed conduction across the CT during onset of focal AF from an arrhythmogenic PV and during pacing from the same PV at cycle lengths of 700 and 300 ms. A 20-pole catheter was positioned on the CT using intracardiac echocardiography. In 10 control patients with no history of AF, we analyzed conduction across the CT during pacing from the distal coronary sinus at 700 and 300 ms. In all 10 AF patients, AF was initiated with 1 to 9 AE beats (median 5) from a PV. During sinus rhythm, there were no split components (SC) recorded on the CT. During PV AE activity, discrete SC were recorded on the CT in all patients over 6.3 +/- 0.9 bipoles (3.7 +/- 0.3 cm). Maximal splitting of SC was 66 +/- 31 ms (37-139). There was an inverse relationship between AE coupling intervals and the degree of splitting between SC in all patients. Degeneration to AF was preceded by progressive decrement across the CT. SC were recorded during PV pacing at 700 and 300 ms (maximal distance between SC of 24 +/- 3 ms and 43 +/- 5 ms, respectively, P < 0.001). Maximum SC at CT in controls was 13 +/- 8 ms at 700 ms (P = 0.06 vs AF patients) and 16 +/- 9 ms at 300 ms (P < 0.01 vs AF patients)., Conclusion: (1) These observations provide evidence of anisotropic, decremental conduction across the CT during onset of focal AF and during pacing from the same PV. A line of functional conduction block develops along this anatomic structure (CT). Whether this line of block acts as an initiator of AF or simply contributes passively to nonuniform fibrillatory conduction is unknown. (2) In some patients with focal AF, development of conduction block along the CT may provide a substrate for typical AFL.

Background: The objective of this study was to describe the electrophysiological characteristics, anatomic distribution, and long-term outcome after focal ablation (RFA) of pulmonary vein (PV) atrial tachycardia (AT). Both atrial fibrillation (AF) and AT may be due to a rapidly firing focus in the PVs. Whether these represent two aspects of the same process is unknown., Methods and Results: Twenty-seven patients with 28 PV(16%) ATs of a consecutive series of 172 undergoing RFA for focal AT are reported. The mean age was 39+/-16 years, with symptoms for 9+/-14 years resistant to 1.7+/-0.8 medications. AT occurred spontaneously or with isoproterenol in all patients and was not inducible with PES in any. The distribution of PV ATs was right superior PV, 11; left superior PV, 11; left inferior PV, 5; and right inferior PV, 1; 26of 28 foci (93%) were ostial. RFA was successful in 28 of 28 PV ATs acutely. RFA was focal in 25 of 28, with PV isolation of a single target vein in 3. There were 4 recurrences at a mean of 3.3 months. Repeat RFA was performed in all 4 and successful in 3 of 4. All but one recurrence occurred from the same site. Long-term success was achieved in 26 of 27 (96%) patients at mean follow-up of 25+/-22 months. No patients have had subsequent development of AF or AT from a different site., Conclusions: PV AT has a distribution similar to PV AF, with a propensity to upper veins. However, the majority of foci are ostial, and only a small percentage occur from deep in the PV. Focal RFA is associated with high long-term success, with freedom from both AT from other sites and from AF. PV AT is a localized process and therefore may be different from PV AF.