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Background: ARTESiA (Apixaban for the Reduction of Thrombo-Embolism in Patients With Device-Detected Sub-Clinical Atrial Fibrillation) demonstrated that apixaban, compared with aspirin, significantly reduced stroke and systemic embolism (SE) but increased major bleeding in patients with subclinical atrial fibrillation., Objectives: To help inform decision making, the authors evaluated the efficacy and safety of apixaban according to baseline CHA 2 DS 2 -VASc score., Methods: We performed a subgroup analysis according to baseline CHA 2 DS 2 -VASc score and assessed both the relative and absolute differences in stroke/SE and major bleeding., Results: Baseline CHA 2 DS 2 -VASc scores were <4 in 1,578 (39.4%) patients, 4 in 1,349 (33.6%), and >4 in 1,085 (27.0%). For patients with CHA 2 DS 2 -VASc >4, the rate of stroke was 0.98%/year with apixaban and 2.25%/year with aspirin; compared with aspirin, apixaban prevented 1.28 (95% CI: 0.43-2.12) strokes/SE per 100 patient-years and caused 0.68 (95% CI: -0.23 to 1.57) major bleeds. For CHA 2 DS 2 -VASc <4, the stroke/SE rate was 0.85%/year with apixaban and 0.97%/year with aspirin. Apixaban prevented 0.12 (95% CI: -0.38 to 0.62) strokes/SE per 100 patient-years and caused 0.33 (95% CI: -0.27 to 0.92) major bleeds. For patients with CHA 2 DS 2 -VASc =4, apixaban prevented 0.32 (95% CI: -0.16 to 0.79) strokes/SE per 100 patient-years and caused 0.28 (95% CI: -0.30 to 0.86) major bleeds., Conclusions: One in 4 patients in ARTESiA with subclinical atrial fibrillation had a CHA 2 DS 2 -VASc score >4 and a stroke/SE risk of 2.2% per year. For these patients, the benefits of treatment with apixaban in preventing stroke/SE are greater than the risks. The opposite is true for patients with CHA 2 DS 2 -VASc score <4. A substantial intermediate group (CHA 2 DS 2 -VASc =4) exists in which patient preferences will inform treatment decisions. (Apixaban for the Reduction of Thrombo-Embolism in Patients With Device-Detected Sub-Clinical Atrial Fibrillation; NCT01938248)., Competing Interests: Funding Support and Author Disclosures The ARTESiA study was funded by grants from the Canadian Institutes of Health Research (201610PTJ-378238), the Bristol Myers Squibb–Pfizer Alliance, the Heart and Stroke Foundation of Canada, the Canadian Stroke Prevention Intervention Network, Hamilton Health Sciences, the Accelerating Clinical Trials Network, the Population Health Research Institute, and Medtronic. The sponsors had no role in data analysis, interpretation, or publication. Dr Lopes has received research grants from Amgen, Boehringer Ingelheim, Bristol Myers Squibb, GlaxoSmithKline, Medtronic, Novo Nordisk, Pfizer, and Sanofi US Services Inc; and has served as a consultant to Bayer, Boehringer Ingelheim, Bristol Myers Squibb, Daiichi-Sankyo Company, GlaxoSmithKline, Medtronic, Merck, Novo Nordisk, Pfizer, Portola Pharmaceuticals, and Sanofi US Services Inc. Dr Granger has received research grants from Bayer and Boehringer Ingelheim; and has served as a consultant to Anthos, AstraZeneca, Bayer, Boehringer Ingelheim, Boston Scientific Corporation, Bristol Myers Squibb, Cadrenal, Daiichi-Sankyo Company, Janssen Global Services, LLC, Merck, Pfizer Inc, and Tenac.io. Dr McIntyre has served as a consultant to Servier Pharmaceuticals LLC. Dr Rivard has received research grants from Bayer Inc, Heart and Stroke Foundation, Canadian Institutes of Health Research (CIHR), and FRQS (Fonds de Recherche Quebec-Sante). Dr Atar has received speaker fees from Amgen, Amarin, AstraZeneca, Bayer, Boehringer Ingelheim, Bristol Myers Squibb, Merck Sharp & Dohme, Novartis, Novo Nordisk, Pfizer, Pharmacosmos, Philips, Roche Diagnostics, Sanofi, Takeda, and Vifor; and has received institutional grant support from Bristol Myers Squibb/Pfizer, Medtronic, Bayer, and Roche Diagnostics. Dr Boriani has received speaker fees from Bayer, Boston Scientific, Boehringer Ingelheim, Daiichi-Sankyo, Janssen, and Sanofi. Dr Duray has served as a consultant to Medtronic and Biotronik. Dr Gold has received institutional research support from Abbott, Boston Scientific, and Medtronic; and has received consulting fees from Boston Scientific and Medtronic. Dr Hohnloser has served as a consultant to Pfizer, Bristol Myers Squibb, Boehringer Ingelheim, and Sanofi. Dr Kutyifa has received research grants from Boston Scientific, ZOLL, National Institutes of Health, and Spire Inc; has received speaker fees from Medtronic, Abbott, and Biotronik; and has received consultant fees from Biotronik. Dr Sticherling has served as a consultant to Medtronic, Boston Scientific, and Biotronik. Dr Benz has received lecture fees from Bristol Myers Squibb and AstraZeneca; and has participated in an educational program supported by Boston Scientific (“Fellowship Herzrhythmus”). Dr Linde has received research support from the Swedish Heart Lung Foundation, Swedish Royal Society of Science, and Stockholm County Council; has received consulting fees from AstraZeneca and Roche Diagnostics; has received speaker honoraria from Novartis, AstraZeneca, Bayer, Vifor Pharma, Medtronic, and Impulse Dynamics; and has served on advisory boards for Astra Zeneca. Dr Kautzner has served as a consultant for Abbott Vascular, Biotronik, Boston Scientific Corporation, GE Healthcare, and Medtronic, Inc. Dr Mairesse has received consultant or speaker fees from Abbott, Biotronik, Microport, Bristol Myers Squibb/Pfizer, and Daiichi-Sankyo. Dr Connolly has received research grants from Pfizer Inc; and has served as a consultant for Bayer, Bristol Myers Squibb, Daiichi-Sankyo Company, and Javelin Ventures. Dr Healey has received research grants from Boston Scientific Corporation, Bristol Myers Squibb, Medtronic, and Pfizer; has served as a consultant for Bayer, Boston Scientific Corporation, Medtronic, Novartis, and Servier Affaires Medicales; and has served as an expert witness for Bayer., (Copyright © 2024 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Background: Subclinical atrial fibrillation is short-lasting and asymptomatic and can usually be detected only by long-term continuous monitoring with pacemakers or defibrillators. Subclinical atrial fibrillation is associated with an increased risk of stroke by a factor of 2.5; however, treatment with oral anticoagulation is of uncertain benefit., Methods: We conducted a trial involving patients with subclinical atrial fibrillation lasting 6 minutes to 24 hours. Patients were randomly assigned in a double-blind, double-dummy design to receive apixaban at a dose of 5 mg twice daily (2.5 mg twice daily when indicated) or aspirin at a dose of 81 mg daily. The trial medication was discontinued and anticoagulation started if subclinical atrial fibrillation lasting more than 24 hours or clinical atrial fibrillation developed. The primary efficacy outcome, stroke or systemic embolism, was assessed in the intention-to-treat population (all the patients who had undergone randomization); the primary safety outcome, major bleeding, was assessed in the on-treatment population (all the patients who had undergone randomization and received at least one dose of the assigned trial drug, with follow-up censored 5 days after permanent discontinuation of trial medication for any reason)., Results: We included 4012 patients with a mean (±SD) age of 76.8±7.6 years and a mean CHA 2 DS 2 -VASc score of 3.9±1.1 (scores range from 0 to 9, with higher scores indicating a higher risk of stroke); 36.1% of the patients were women. After a mean follow-up of 3.5±1.8 years, stroke or systemic embolism occurred in 55 patients in the apixaban group (0.78% per patient-year) and in 86 patients in the aspirin group (1.24% per patient-year) (hazard ratio, 0.63; 95% confidence interval [CI], 0.45 to 0.88; P = 0.007). In the on-treatment population, the rate of major bleeding was 1.71% per patient-year in the apixaban group and 0.94% per patient-year in the aspirin group (hazard ratio, 1.80; 95% CI, 1.26 to 2.57; P = 0.001). Fatal bleeding occurred in 5 patients in the apixaban group and 8 patients in the aspirin group., Conclusions: Among patients with subclinical atrial fibrillation, apixaban resulted in a lower risk of stroke or systemic embolism than aspirin but a higher risk of major bleeding. (Funded by the Canadian Institutes of Health Research and others; ARTESIA ClinicalTrials.gov number, NCT01938248.)., (Copyright © 2023 Massachusetts Medical Society.)

Background: Cryoballoon ablation is widely used for pulmonary vein isolation in patients with atrial fibrillation. There are no data regarding the clinical efficacy of cryoballoon ablation in patients with atypical right pulmonary vein anatomy., Aim: We aimed to evaluate the impact of right pulmonary vein anatomy on the safety and efficacy of cryoballoon ablation., Methods: Patients referred for cryoballoon ablation of paroxysmal atrial fibrillation were enrolled prospectively. Left atrial computed tomography was performed before cryoballoon ablation to determine whether the right pulmonary vein anatomy was "normal" or "atypical". For patients with atypical anatomy, cryoballoon ablation was only performed for right superior and right inferior pulmonary veins, neglecting accessory pulmonary veins., Results: Overall, 303 patients were included: 254 (83.8%) with normal and 49 (16.2%) with atypical right pulmonary vein anatomy. First-freeze isolation for right superior and right inferior pulmonary veins occurred in 44 (89.8%) and 37 (75.5%) patients with atypical pulmonary vein anatomy, and in 218 (85.8%) and 217 (85.4%) patients with typical pulmonary vein anatomy, respectively (P not significant). Phrenic nerve palsies were only observed in patients with normal anatomy (0 vs. 26 [8.6%]; P=0.039). Mid-term survival free from atrial arrhythmia was similar, regardless of right pulmonary vein anatomy., Conclusions: A significant proportion of patients have atypical right pulmonary vein anatomy. Procedural characteristics, acute pulmonary vein isolation success and mid-term procedural efficacy were similar, regardless of right pulmonary vein anatomy. In addition to left-side pulmonary vein isolation, cryoballoon ablation of right superior and right inferior pulmonary veins only, neglecting accessory pulmonary veins, is sufficient to obtain acute right-side pulmonary vein isolation and mid-term sinus rhythm maintenance in patients with atypical anatomy., (Copyright © 2020. Published by Elsevier Masson SAS.)

Background: Pulmonary vein isolation (PVI) using cryoballoon ablation is widely used for rhythm control in patients with paroxysmal atrial fibrillation. This technique has a steep learning curve, and PVI can be achieved quickly in most patients. However, the right inferior pulmonary vein (RIPV) is often challenging to occlude and isolate., Aim: We aimed to analyse the efficacy of RIPV ablation using a systematic approach., Methods: Consecutive patients referred for cryoballoon ablation of paroxysmal atrial fibrillation were enrolled prospectively. A systematic approach was used for RIPV cryoablation. The primary endpoint was acute RIPV isolation during initial freeze., Results: A total of 214 patients were included. RIPV isolation during initial freeze occurred in 179 patients (82.2%). Real-time PVI could be observed in 72 patients (33.6%), whereas cryoballoon stability required pushing the Achieve™ catheter inside the RIPVs in the remaining patients. The rate of unsuccessful or aborted first freeze as a result of insufficient minimal temperature was significantly higher in patients with real-time pulmonary vein potential recording (16.7% vs. 6.3%; P=0.031). To overcome this issue and obtain both stability and real-time PVI, a dedicated "whip technique" was developed. Twelve patients (5.6%) required a redo ablation; only two of these had a reconnected RIPV., Conclusions: A systematic approach to RIPV cryoablation can lead to a high rate of first freeze application. Operators should not struggle to visualize pulmonary vein potentials before ablation, as this may decrease cryoapplication efficacy. Thus, stability should be preferred over real-time PVI for RIPV ablation. Both stability and real-time PVI can be obtained using a "whip technique"., (Copyright © 2019 Elsevier Masson SAS. All rights reserved.)

Ablation of atrial fibrillation (AF) is the cornerstone therapy for patients with symptomatic AF resistant to anti-arrhythmic drugs or as first-line therapy, and is based on permanent pulmonary vein (PV) isolation. The presence of a conduction gap in a wide antral circumferential ablation lesion around PVs is often sufficient to transform an initially successful ablation into a procedural failure, thus necessitating a redo intervention. The strategy during a redo procedure is based on the detection and ablation of the reconnection gap. Finding gaps is often simple, but also sometimes challenging, because gaps may be difficult to detect, resulting in unnecessary radiofrequency delivery. The present review aimed to describe the various techniques published thus far to detect residual reconnections along the encircling ablation lines around PVs, to help electrophysiologists to detect and ablate reconnection gaps., (Copyright © 2019 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Background: The Shockless IMPLant Evaluation (SIMPLE) trial showed that defibrillation testing (DT) at the time of implantable cardioverter-defibrillator (ICD) implant did not improve shock efficacy or reduce mortality. There are no data regarding the risk of complications, including stroke, among patients with atrial fibrillation (AF) who undergo DT., Objective: The purpose of this prospectively planned substudy of SIMPLE was to evaluate the effect of DT vs no DT on clinical outcomes among patients with AF., Methods: We compared efficacy (failed appropriate shock/arrhythmic death) and safety between patients who had AF on their immediate preprocedural ECG to the rest of the study patients. Then among patients with AF we compared these outcomes between patients randomized to DT vs no DT., Results: Of the 2500 patients enrolled in SIMPLE, 251 (10%) were in AF immediately before ICD implant. AF patients had an increased risk of failed appropriate shock/arrhythmic death (adjusted hazard ratio [HR] 1.64; 95% confidence interval [CI] 1.13-2.39; P = .009) and higher all-cause mortality (adjusted HR 1.58; 95% CI 1.2-2.08; P = .001). Among AF patients, perioperative complications and stroke did not significantly differ between DT vs no-DT groups (9.2% vs 5.4%; P = .2; and 1.7% vs 1.5%; P >.999, respectively). Failed appropriate shock or arrhythmic death occurred in 35 of 251 AF patients (14%), and the no-DT group proved not inferior to the DT group (HR 0.58; 95% CI 0.30-1.15; P noninferiority = .006)., Conclusion: ICD recipients with AF are at increased risk for adverse outcomes; however, DT does not improve arrhythmic survival or shock efficacy. There is no evidence that DT increased the occurrence of perioperative stroke., (Copyright © 2018 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Background: The rate of pacemaker (PM) implantations is constantly growing. Since life expectancy of the population is projected to increase, a large number of nonagenarian patients will need PM implantation. We aimed at analyzing short- and long-term outcomes after PM implantation in nonagenarians., Methods: Patients aged ≥90 years referred for PM implantation from 2004 to 2017 were included. The primary clinical endpoint was total mortality. Secondary endpoints included procedure-related and in-hospital complications., Results: A total of 172 patients were included (92.6 ± 2.1 years, from 90.0 to 101.4 years). Procedure duration was 50.0 ± 19.7 minutes. Most of the patients had VVI devices implanted (143 pts, 83.1%) and mean hospital stay was 3.5 ± 1.5 days. Nine patients (5.2%) had short-term device-related complications and 29 patients (16.8%) had post-procedural complications, non-related to the implantation, including four leading to patients' death. During a follow-up of 22.5 months (interquartile range: 7.3-38.0), 94 patients (54.7%) died. Survival rates were 82.9% (95% confidence interval [CI]: 76.0-88.0), 73.7% (95% CI: 65.7-80.1) and 37.5% (95% CI: 27.5-47.5) after 1, 2, and 5 years, respectively. The Charlson comorbidity index was a predictive factor of procedural complications (odds ratio = 1.33; 95% CI: 1.05-1.69, P = 0.02) while having a complication (hazard ratio [HR] = 4.04; 95% CI: 1.79-9.11, P = 0.001) and atrial fibrillation (HR = 1.63; 95% CI: [1.02-2.63], P = 0.043) were predictors of post-implantation death., Conclusion: PM implantation in nonagenarians is safe, with a low risk of procedural complications, but many comorbidities-related complications can occur. Caution should be taken in this old and frail population since complications significantly impact patients' survival., (© 2018 Wiley Periodicals, Inc.)

Aims: Pulmonary vein isolation (PVI) using second-generation cryoballoon (CB2) is associated with improved outcomes compared with first generation (CB1). We aimed at investigating the characteristics of left and right PV reconnections after CB1 and CB2 ablations in patients with clinical recurrences requiring redo ablation., Methods and Results: From 2010 to 2016, 776 patients underwent 28-mm cryoballoon PVI for symptomatic paroxysmal atrial fibrillation (AF) in 3 centres, 279 with CB1 and 497 with CB2. Among them, 94 patients (12.1%) had symptomatic AF recurrences requiring a redo ablation [43 (15.4%) CB1 and 51 (10.3%) CB2]. The benefit of CB2 over CB1 was compared for each PV. Durable PVI was confirmed in 7 CB1 (16.3%) and 14 CB2 (27.4%) patients, and 2.7 ± 2.1 and 1.4 ± 1.4 gaps per patient were found, respectively (P = 0.002). Significantly more left superior and left inferior PVs were found to be isolated in CB2 compared with CB1 group (78.4% vs. 48.8%, P = 0.005 and 78.4% vs. 46.5%, P = 0.003, respectively) while the rate of durable right superior and right inferior PVs isolation were similar (68.6% vs. 60.5%, P = 0.542 and 66.7% vs. 55.8%, P = 0.387, respectively). Significantly fewer gaps were found in left PVs in CB2 patients, while there was no significant difference for right PVs. Gaps localization was similar in both groups., Conclusion: Fewer reconnection gaps are observed during redo ablations of paroxysmal AF in patients primarily ablated with CB2. This difference is driven by less reconnection gaps observed in both left PVs, while no difference was observed for right PVs.

Background: Atrial fibrillation ablation is often performed by achieving pulmonary vein isolation using the "wide antral circumferential ablation" (WACA) technique, but many pulmonary veins remain connected because of conduction gaps in the ablation line., Aim: To analyse the efficacy of a novel technique based on pacing manoeuvres to detect gaps in an initial WACA lesion., Methods: Patients referred for radiofrequency atrial fibrillation ablation were enrolled prospectively. A WACA lesion set was performed, isolating ipsilateral pulmonary veins together. If pulmonary vein isolation was not achieved, the atria were paced using an ablation catheter. For each pacing site, "activation delay" and "activation sequence" were analysed using a circular mapping catheter positioned at the pulmonary vein ostium., Results: Twenty-one patients were included. A total of 25 non-isolated WACA lesion sets were studied. Three patterns were identified: (1) the activation delays converged towards one point with the shortest delay; no modification of the activation sequence (indicating one gap); (2) the activation delays converged towards at least two close locations; no change in the activation sequence (indicating at least two close gaps); (3) the activation delays converged towards at least two remote locations; modification of the activation sequence (indicating at least two remote gaps). Pacing manoeuvres and effect of ablation allowed precise localization of gaps, ultimately leading to pulmonary vein isolation in all patients., Conclusion: This simple pacing method accurately detected the location of residual connections after WACA lesion sets performed for atrial fibrillation ablation, allowing pulmonary vein isolation to be achieved., (Copyright © 2017 Elsevier Masson SAS. All rights reserved.)

Introduction: Atrioventricular node (AVN) ablation is usually a simple procedure but may sometimes be challenging. We aimed at identifying pre-procedural clinical predictors of challenging AVN ablation., Methods: Patients referred for AVN ablation from 2009 to 2015 were retrospectively included. Baseline clinical data, procedural variables and outcomes of AVN ablation were collected. A "challenging procedure" was defined 1) total radiofrequency delivery to get persistent AVN block≥400s, 2) need for left-sided arterial approach or 3) failure to obtain AVN ablation., Results: 200 patients were included (71±10years). A total of 37 (18.5%) patients had "challenging" procedures (including 9 failures, 4.5%), while 163 (81.5%) had "non-challenging" ablations. In multivariable analysis, male sex (Odds ratio (OR)=4.66, 95% confidence interval (CI): 1.74-12.46), body mass index (BMI, OR=1.08 per 1kg/m 2 , 95%CI 1.01-1.16), operator experience (OR=0.40, 95%CI 0.17-0.94), and moderate-to-severe tricuspid regurgitation (TR, OR=3.65, 95%CI 1.63-8.15) were significant predictors of "challenging" ablations. The proportion as a function of number of predictors was analyzed (from 0 to 4, including male sex, operator inexperience, a BMI>23.5kg/m 2 and moderate-to-severe TR). There was a gradual increase in the risk of "challenging" procedure with the number of predictors by patient (No predictor: 0%; 1 predictor: 6.3%; 2 predictors: 16.5%; 3 predictors: 32.5%; 4 predictors: 77.8%)., Conclusions: Operator experience, male sex, higher BMI and the degree of TR were independent predictors of "challenging" AVN ablation procedure. The risk increases with the number of predictors by patient., (Copyright © 2017. Published by Elsevier B.V.)

Background: Device-detected subclinical atrial fibrillation (AF) refers to infrequent, short-lasting, asymptomatic AF that is detected only with long-term continuous monitoring. Subclinical AF is common and associated with an increased risk of stroke; however, the risk of stroke with subclinical AF is lower than for clinical AF, and very few patients with subclinical AF alone have been included in large AF anticoagulation trials. The net benefit of anticoagulation in patients with subclinical AF is unknown., Design: ARTESiA is a prospective, multicenter, double-blind, randomized controlled trial, recruiting patients with subclinical AF detected by an implanted pacemaker, defibrillator, or cardiac monitor, and who have additional risk factors for stroke. Patients with clinical AF documented by surface electrocardiogram will be excluded from the study. Participants will be randomized to receive either apixaban (according to standard AF dosing) or aspirin 81mg daily. The primary outcome is the composite of stroke, transient ischemic attack with diffusion-weighted magnetic resonance imaging evidence of cerebral infarction, and systemic embolism. Approximately 4,000 patients will be enrolled from around 230 clinical sites, with an anticipated mean follow-up of 36months until 248 adjudicated primary outcome events have occurred., Summary: ARTESiA will determine whether oral anticoagulation therapy with apixaban compared with aspirin reduces the risk of stroke or systemic embolism in patients with subclinical AF and additional risk factors., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Background: Pulmonary vein (PV) isolation, using cryoballoon or radiofrequency ablation, is the cornerstone therapy for symptomatic paroxysmal atrial fibrillation (AF) refractory to antiarrhythmic drugs. One-third of the patients have recurrences, mainly due to PV reconnections., Aims: To describe the different locations of reconnection sites in patients who had previously undergone radiofrequency or cryoballoon ablation, and to compare the characteristics of the redo procedures in both instances., Methods: Demographic data and characteristics of the initial ablation (cryoballoon or radiofrequency) were collected. Number and localization of reconduction gaps, and redo characteristics were reviewed., Results: Seventy-four patients scheduled for a redo ablation of paroxysmal AF were included; 38 had been treated by radiofrequency ablation and 36 by cryoballoon ablation during the first procedure. For the initial ablation, procedural and fluoroscopy times were significantly shorter for cryoballoon ablation (147.8±52.6min vs. 226.6±64.3min [P<0.001] and 37.0±17.7min vs. 50.8±22.7min [P=0.005], respectively). Overall, an identical number of gaps was found during redo procedures of cryoballoon and radiofrequency ablations. However, a significantly higher number of gaps were located in the right superior PV for patients first ablated with radiofrequency (0.9±1.0 vs. 0.5±0.9; P=0.009). Gap localization displayed different patterns. Although not significant, redo procedures of cryoballoon ablation were slightly shorter and needed shorter durations of radiofrequency to achieve PV isolation., Conclusions: During redo procedures, gap localization pattern is different for patients first ablated with cryoballoon or radiofrequency ablation, and right superior PV reconnections occur more frequently after radiofrequency ablation. Redo ablation of a previous cryoballoon ablation appears to be easier., (Copyright © 2016 Elsevier Masson SAS. All rights reserved.)

Non-vitamin K oral anticoagulants (NOACs) are currently recommended for patients with nonvalvular atrial fibrillation since the publication of the 4 major pivotal trials evaluating the efficacy and safety of factor IIa and factor Xa inhibitors. The definition of nonvalvular atrial fibrillation is unclear, varying from one trial to another and even between North American and European guidelines, which is a source of uncertainties in clinical practice. However, many patients with atrial fibrillation present signs of valvular involvement, and clarification of this term is needed to not deny NOACs to patients based on the wrong perception that they may have valvular atrial fibrillation. The currently unique contraindications to NOACs are patients with mechanical heart valves and those with moderate-to-severe mitral stenosis, as stated by the recent 2015 position paper of the European Heart Rhythm Association. Patients with native heart valve involvement, regardless of their severity, are suitable for NOAC therapy. Patients with bioprosthetic heart valves and mitral valve repair may be suitable for NOACs except for the first 3 and the first 3-6 months postoperatively, respectively. Patients with transaortic valve implantation or percutaneous transluminal aortic valvuloplasty are also considered as being eligible for NOACs, although the bleeding risk has to be carefully considered in this population often requiring a combination with antiplatelet therapy. Future studies are warranted to increase the level of evidence of use of NOACs, particularly in patients with transaortic valve implantation and valvular surgery, and to determine whether they could be used in the future in the only 2 remaining contraindications., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Atrial fibrillation (AF) is the commonest cardiac rhythm disorder. Evaluation of patients with AF requires an electrocardiogram, but imaging techniques should be considered for defining management and driving treatment. The present document is an expert consensus from the European Association of Cardiovascular Imaging (EACVI) and the European Heart Rhythm Association. The clinical value of echocardiography, cardiac magnetic resonance (CMR), computed tomography (CT), and nuclear imaging in AF patients are challenged. Left atrial (LA) volume and strain in echocardiography as well as assessment of LA fibrosis in CMR are discussed. The value of CT, especially in planning interventions, is highlighted. Fourteen consensus statements have been reached. These may serve as a guide for both imagers and electrophysiologists for best selecting the imaging technique and for best interpreting its results in AF patients., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.)

Aims: Remote monitoring of cardiac implantable electronic devices is a growing standard; yet, remote follow-up and management of alerts represents a time-consuming task for physicians or trained staff. This study evaluates an automatic mechanism based on artificial intelligence tools to filter atrial fibrillation (AF) alerts based on their medical significance., Methods and Results: We evaluated this method on alerts for AF episodes that occurred in 60 pacemaker recipients. AKENATON prototype workflow includes two steps: natural language-processing algorithms abstract the patient health record to a digital version, then a knowledge-based algorithm based on an applied formal ontology allows to calculate the CHA2DS2-VASc score and evaluate the anticoagulation status of the patient. Each alert is then automatically classified by importance from low to critical, by mimicking medical reasoning. Final classification was compared with human expert analysis by two physicians. A total of 1783 alerts about AF episode >5 min in 60 patients were processed. A 1749 of 1783 alerts (98%) were adequately classified and there were no underestimation of alert importance in the remaining 34 misclassified alerts., Conclusion: This work demonstrates the ability of a pilot system to classify alerts and improves personalized remote monitoring of patients. In particular, our method allows integration of patient medical history with device alert notifications, which is useful both from medical and resource-management perspectives. The system was able to automatically classify the importance of 1783 AF alerts in 60 patients, which resulted in an 84% reduction in notification workload, while preserving patient safety., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.)

The number of patients that benefit from remote monitoring of cardiac implantable electronic devices, such as pacemakers and defibrillators, is growing rapidly. Consequently, the huge number of alerts that are generated and transmitted to the physicians represents a challenge to handle. We have developed a system based on a formal ontology that integrates the alert information and the patient data extracted from the electronic health record in order to better classify the importance of alerts. A pilot study was conducted on atrial fibrillation alerts. We show some examples of alert processing. The results suggest that this approach has the potential to significantly reduce the alert burden in telecardiology. The methods may be extended to other types of connected devices.

Background: Compared with the first-generation Arctic Front cryoballoon (ARC-CB), the new Arctic Front Advance cryoballoon (ARC-Adv-CB) increases the efficient CB-tissue contact surface during freezing, which may increase the incidence of phrenic nerve (PN) palsy (PNP)., Objective: To evaluate the safety and efficacy of paroxysmal atrial fibrillation (AF) ablation with the ARC-Adv-CB as well as the merits of a predictor of PNP., Methods: AF ablation was performed by using a "single 28-mm big CB" approach. The rate of pulmonary vein (PV) isolation with a first cryoapplication was measured. The distance between the CB and a PN pacing catheter in the superior vena cava was measured to predict PNP during freezing., Results: In 147 patients, PV were isolated with a single cryoapplication in 205 (81.3%) of 252 PV treated with the ARC-CB and in 280 (90.3%) of 310 PV treated with the ARC-Adv-CB (P = .003). The mean time to PV isolation was 52 ± 34 seconds and 40 ± 25 seconds (P < .001) and the temperature at the time of isolation was -36.1 ± 10.3°C and -32.3 ± 10.2°C (P = .001) in the ARC-CB and ARC-Adv-CB groups, respectively. Mean procedure and fluoroscopy durations were significantly shorter in the ARC-Adv-CB group. Transient PNP was observed in 7(10.6%) and 20(24.4%) of the patients treated with the ARC-CB and ARC-Adv-CB, respectively (P = .048). The distance between the lateral edge of the CB and a vertical line through the tip of the pacing catheter accurately predicted PNP (P < .001)., Conclusions: The 28-mm ARC-Adv-CB enabled more efficient ablation of paroxysmal AF and shorter procedures than did the ARC-CB. This higher performance was associated with a higher incidence of PNP, which was predicted by the distance between the CB and the PN., (Copyright © 2014 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Aims: This French study was set up to collect perceptions of general practitioners (GPs), cardiologists and patients on anticoagulation therapy with vitamin K antagonists (VKA) in the management of thromboembolic risk in atrial fibrillation (AF)., Method: This is a prospective survey conducted in France, between July 1 and August 7 2011, on a sample defined to obtain a sufficient number of patient files of 133 physicians, divided into 65 cardiologists and 68 GPs., Results: Three hundred and ninety-four patients on VKA and 130 patients not receiving VKA were included in this study. For more than one in three patients, AF was diagnosed incidentally in a medical consultation for another reason. In addition, 15% and 23% of diagnoses of FA were performed after hospitalization for stroke or TIA by cardiologists and GPs, respectively. According to the patient, the doctor contacted first is a GP (52% for the GP vs. 35.5% for the cardiologist), but they state that the diagnosis was made mainly by a cardiologist (63% for the cardiologist vs. 27% for the GP). In 78% of cases, cardiologists are initial prescribers. A CHADS2 score of 0 was found in 23% of patients not receiving VKA and in 11% of patients on VKA. A CHADS2 score superior or equal to 2 is significantly more frequently found in patients with paroxysmal AF. Concerning the monitoring of the patient, GPs ensure mainly monitoring of INR. In terms of compliance, according to doctors, their patients systematically take their treatment in 91% of cases. However, by interviewing patients, 60% of non-compliant patients are considered compliant by their physician., Conclusion: This study has achieved an overview of anticoagulation treatment in AF, in France. The initiation is mainly ensured by the cardiologist and the monitoring by the GP. Assessments between cardiologists and GPs are relatively similar, however, it appears that anticoagulation treatment is under-prescribed for the patients at risk., (Copyright © 2013 Elsevier Masson SAS. All rights reserved.)

Atrial fibrillation (AF) is the most common arrhythmia in clinical practice. Pulmonary veins are a major source of ectopic activities initiating the arrhythmia and the fibrillatory conduction, associating multiple wavelets and high frequency functional reentries called "rotors". AF is responsible for atrial electrophysiological, contractile and structural remodelling, shortening the wavelength, accelerating AF cycle length and sustaining the arrhythmia. A better understanding of the mechanisms responsible for this arrhythmia led to new therapeutic approaches, including ablation, and could eventually lead to the development of new anti-arrhythmic drug agents.

Cardiac resynchronization therapy (CRT) is one of the major advances in the treatment of patients with chronic heart failure due to impaired left ventricular ejection fraction. Current guidelines recommend with the highest levels of recommendation and evidence CRT in patients with low ejection fraction wide QRS, LBBB, and mild to severe heart failure (New York Heart Association class II to IV). However, other patients might benefit from CRT. This is the case for patients with permanent atrial fibrillation, patients conventional pacemaker indication, patients with mildly impaired left ventricular function (>35 %), or asymptomatic patients (NYHA I). We will discuss in this manuscript each new potential indication for CRT.

Flecainide is a class Ic antiarrhythmic agent that has an important role as part of rhythm control strategies in patients with atrial fibrillation (AF). Early clinical data on the use of flecainide showed an increase in arrhythmias and mortality compared with placebo in patients with a previous myocardial infarction and asymptomatic or mildly symptomatic ventricular arrhythmias. These findings only apply to a specific group of patients with left ventricular dysfunction and ischaemic heart disease, but had a negative impact on the use of class Ic antiarrhythmics across all indications and patient groups. The aim of this review was to evaluate the available safety data for flecainide in the literature and to assess its current use in patients with AF. Current European guidelines now recommend the use of flecainide in carefully selected groups of patients with AF who do not have structural heart disease. This includes for the cardioversion of recent-onset AF, pretreatment prior to direct current cardioversion, out-of-hospital acute oral therapy ('pill-in-the-pocket' approach) and for the ongoing maintenance of sinus rhythm. Potential cardiac adverse effects of flecainide include proarrhythmia, conduction abnormalities and negative inotropic effects. Dizziness is the most frequent non-cardiac side effect, followed by blurred vision and difficulty focusing; these are almost all mild, transient and tolerable. Data from recent clinical trials in patients with supraventricular arrhythmias suggest that flecainide has a good tolerability profile in groups of appropriately selected patients. Caution is required when using flecainide in patients with renal dysfunction, and there are a number of drug interactions, but these are well documented and manageable. Overall, flecainide is a good choice for the pharmacological management of AF. It has a good safety record and low incidence of adverse effects, rare end-organ toxicity and a low risk of ventricular proarrhythmia. To ensure that the benefits of treatment outweigh any potential risks, careful patient selection and monitoring is required.

Aims: Atrial fibrillation (AF) may induce three kinds of atrial remodelling: morphological, contractile, and electrical. Maintain of sinus rhythm is usually associated with left atrial (LA) volume decrease, but little is known about the evolution of its mechanical properties. We sought to explore LA mechanical and morphological remodelling in patients with lone paroxysmal-AF treated by catheter ablation (CA)., Methods and Results: We prospectively included 31 patients (56.4 ± 10 years). We also followed 15 age- and gender-matched controls to get normal values. Each patient had a complete echocardiography at baseline and at 3-month and 1-year follow-up. LA-anatomical reverse remodelling was documented: indexed LA volume decreased from 39 mL/m(2) at baseline to 31 mL/m(2) at 1 year (P < 0.001). However, it remained larger than controls (31 vs. 23 mL/m(2), P = 0.001). LA compliance improved (LA lateral systolic peaks of strain = 50 vs. 31%, P < 0.05) without reaching controls values as estimated by 50 vs. 81%, P < 0.05). LA contractility increased as highlighted by A'-peak velocity (10 cm/s at 1Y-F/up vs. 7.5 at baseline, P = 0.01) and LA late diastolic peaks of strain rate (septal: -3 vs. -1 s(-1), lateral: -3 vs. -1.4 s(-1), P < 0.05). We show a functional remodelling at 1 year, with most contractile parameters being comparable to controls, whereas LA compliance remains significantly altered., Conclusion: AF-CA could reverse LA anatomical and functional remodelling. Despite improvement, LA compliance remains altered after 1 year, probably reflecting irreversible fibrosis.

Background: Atrial fibrillation developing at the acute stage of myocardial infarction is associated with untoward clinical outcomes. The aim of this study was to determine correlations between early statin therapy and atrial fibrillation in acute myocardial infarction., Methods: Patients (3396) with sinus rhythm developing acute myocardial infarction were enrolled in the French registry of Acute ST-elevation and non-ST-elevation Myocardial Infarction (FAST-MI)., Results: Atrial fibrillation developed in 7.0% of patients without and 3.9% of patients with early (≤48 h of admission) statin therapy (p<0.001). Multivariable analysis, including the propensity score for early statin treatment, showed that statin therapy was associated with reduced risk of atrial fibrillation (OR 0.64; 95% CI 0.45 to 0.92, p=0.017). Compared to patients without early statin therapy, the OR for atrial fibrillation were 0.72 (0.49 to 1.04, p=0.080), 0.52 (0.28 to 0.95, p=0.034) and 0.40 (0.18 to 0.92, p=0.030) in patients on conventional, intermediate and high doses respectively., Conclusions: This study is the first to document a correlation between early statin therapy and atrial fibrillation at the early stage of acute myocardial infarction.

Background: Radiofrequency ablation is an effective treatment for typical atrial flutter (AFL) but long-term results may be hampered by atrial fibrillation (AF)., Aims: To determine the incidence and predictors of AF during very long-term follow-up after radiofrequency ablation of typical AFL., Methods: From November 1998 to December 2000, patients who underwent successful radiofrequency ablation for cavotricuspid isthmus-dependent AFL in our centre were followed prospectively., Results: Of the 135 patients followed (mean age: 62+/-11 years), 69 (51%) had structural heart disease. Mean left ventricular ejection fraction was 52+/-11%. Patients were analysed according to preablation AF history: group 1 included patients with AFL (N=71); group 2 included patients with AFL and AF (N=64). During a median [interquartile range] follow-up of 7.8 [7.0-8.4] years, new-onset or recurrent AF was experienced by 99 (73%) patients: 44 (62%) in group 1 and 55 (86%) in group 2. Although most episodes occurred in the first 2 years postablation, AF prevalence increased continuously over time. Preablation AF history predicted AF occurrence (hazard ratio: 2.10, 95% confidence interval: 1.40-3.14; p=0.001), as did left atrial diameter (hazard ratio: 1.05 per 1 mm increase; 95% confidence interval: 1.02-1.08; p<0.001). AF evolved to become permanent in 24% of group 1 and 47% of group 2 patients (p=0.005)., Conclusion: During long-term follow-up, most patients will experience AF after ablation of typical AFL. Preablation AF history and left atrial enlargement predict postablation AF occurrence.

Objectives: This study compared chronic right ventricular (RV) pacing at the septum versus apex., Background: Chronic RV apical pacing may be detrimental to ventricular function. This randomized, pilot study examined whether, compared with apical, permanent septal pacing preserves cardiac function., Methods: Ablation of the atrioventricular junction for permanent AF, followed by implantation of a DDDR pacemaker connected to two ventricular leads was performed in 28 patients. One lead screwed into the septum and another placed at the apex were connected to the atrial and ventricular port, respectively. Septum or apex was paced by programming AAIR or VVIR modes, respectively. Patients were randomly assigned, 4 months later, to pacing at one site for 3 months, and crossed over to the other for 3 months. New York Heart Association class, QRS width and axis, left ventricular ejection fraction (LVEF), exercise duration, and peak oxygen uptake were measured. Results in patients with LVEF > 45% and < or = 45% were compared., Results: Septal pacing was associated with shorter QRS (145 +/- 4 msec vs 170 +/- 4 msec, P < 0.01) and normal axis (40 degrees +/- 10 degrees vs -71 +/- 4 degrees , P < 0.01). At 3 months, among patients with baseline LVEF < or = 45%, LVEF was 42 +/- 5% after septal pacing versus 37 +/- 4% after apical pacing (P < 0.001)., Conclusion: In contrast to RV apical pacing, chronic RV septal pacing preserved LVEF in patients with baseline LVEF < or = 45%.

Atrial fibrillation is the most common sustained rhythm disturbance, with a heterogeneous presentation, occurring in the presence or absence of detectable heart disease or related symptoms, evolving in paroxysmal, persistent or permanent forms. Prevalence and incidence are mainly depending on age and congestive heart failure. Atrial fibrillation is frequently observed in elderly population. Prognosis can be poor, owing to the risk of embolic events, mainly ischaemic strokes, with a rate of 5% yearly, and to an increased mortality rate, about twice that of persons in normal sinus rhythm. Atrial fibrillation can present as an isolated arrhythmia (20 to 40% of cases) or be associated with an underlying cardiac disease which exerts a main influence on prognosis.

Aims: Pulmonary vein isolation (PVI) using second-generation cryoballoon (CB2) is associated with improved outcomes compared with first generation (CB1). We aimed at investigating the characteristics of left and right PV reconnections after CB1 and CB2 ablations in patients with clinical recurrences requiring redo ablation.Methods and results: From 2010 to 2016, 776 patients underwent 28-mm cryoballoon PVI for symptomatic paroxysmal atrial fibrillation (AF) in 3 centres, 279 with CB1 and 497 with CB2. Among them, 94 patients (12.1%) had symptomatic AF recurrences requiring a redo ablation [43 (15.4%) CB1 and 51 (10.3%) CB2]. The benefit of CB2 over CB1 was compared for each PV. Durable PVI was confirmed in 7 CB1 (16.3%) and 14 CB2 (27.4%) patients, and 2.7 ± 2.1 and 1.4 ± 1.4 gaps per patient were found, respectively (P = 0.002). Significantly more left superior and left inferior PVs were found to be isolated in CB2 compared with CB1 group (78.4% vs. 48.8%, P = 0.005 and 78.4% vs. 46.5%, P = 0.003, respectively) while the rate of durable right superior and right inferior PVs isolation were similar (68.6% vs. 60.5%, P = 0.542 and 66.7% vs. 55.8%, P = 0.387, respectively). Significantly fewer gaps were found in left PVs in CB2 patients, while there was no significant difference for right PVs. Gaps localization was similar in both groups.Conclusion: Fewer reconnection gaps are observed during redo ablations of paroxysmal AF in patients primarily ablated with CB2. This difference is driven by less reconnection gaps observed in both left PVs, while no difference was observed for right PVs. [ABSTRACT FROM AUTHOR]

Atrial fibrillation (AF) is the commonest cardiac rhythm disorder. Evaluation of patients with AF requires an electrocardiogram, but imaging techniques should be considered for defining management and driving treatment. The present document is an expert consensus from the European Association of Cardiovascular Imaging (EACVI) and the European Heart Rhythm Association. The clinical value of echocardiography, cardiac magnetic resonance (CMR), computed tomography (CT), and nuclear imaging in AF patients are challenged. Left atrial (LA) volume and strain in echocardiography as well as assessment of LA fibrosis in CMR are discussed. The value of CT, especially in planning interventions, is highlighted. Fourteen consensus statements have been reached. These may serve as a guide for both imagers and electrophysiologists for best selecting the imaging technique and for best interpreting its results in AF patients. [ABSTRACT FROM AUTHOR]

Aims: Remote monitoring of cardiac implantable electronic devices is a growing standard; yet, remote follow-up and management of alerts represents a time-consuming task for physicians or trained staff. This study evaluates an automatic mechanism based on artificial intelligence tools to filter atrial fibrillation (AF) alerts based on their medical significance.Methods and Results: We evaluated this method on alerts for AF episodes that occurred in 60 pacemaker recipients. AKENATON prototype workflow includes two steps: natural language-processing algorithms abstract the patient health record to a digital version, then a knowledge-based algorithm based on an applied formal ontology allows to calculate the CHA2DS2-VASc score and evaluate the anticoagulation status of the patient. Each alert is then automatically classified by importance from low to critical, by mimicking medical reasoning. Final classification was compared with human expert analysis by two physicians. A total of 1783 alerts about AF episode >5 min in 60 patients were processed. A 1749 of 1783 alerts (98%) were adequately classified and there were no underestimation of alert importance in the remaining 34 misclassified alerts.Conclusion: This work demonstrates the ability of a pilot system to classify alerts and improves personalized remote monitoring of patients. In particular, our method allows integration of patient medical history with device alert notifications, which is useful both from medical and resource-management perspectives. The system was able to automatically classify the importance of 1783 AF alerts in 60 patients, which resulted in an 84% reduction in notification workload, while preserving patient safety. [ABSTRACT FROM AUTHOR]

Aims Inappropriate therapy delivered by implantable cardioverter defibrillators (ICDs) remains a challenge. The OPERA registry measured the times to, and studied the determinants of, first appropriate (FAT) and inappropriate (FIT) therapies delivered by single-, dual- and triple-chamber [cardiac resynchronization therapy defibrillator (CRT-D)] ICD. Methods and results We entered 636 patients (mean age = 62.0 ± 13.5 years; 88% men) in the registry, of whom 251 received single-, 238 dual-, and 147 triple-chamber ICD, for primary (30.5%) or secondary (69.5%) indications. We measured times to FAT and FIT as a function of multiple clinical characteristics, examined the effects of various algorithm components on the likelihood of FAT and FIT delivery, and searched for predictors of FAT and FIT. Over 22.8 ± 8.8 months of observation, 184 patients (28.9%) received FAT and 70 (11.0%) received FIT. Ventricular tachycardia (VT) was the trigger of 88% of FAT, and supraventricular tachycardia was the trigger of 91% of FIT. The median times to FIT (90 days; range 49–258) and FAT (171 days; 50–363) were similar. The rate of FAT was higher (P <0.001) in patients treated for secondary than primary indications, while that of FIT were similar in both groups. Out of 57 analysable FIT, 27 (47.4%) could have been prevented by fine tuning the device programming like the sustained rate duration or the VT discrimination algorithm. Conclusions First inappropriate therapy occurred in 11% of 636 ICD recipients followed for ∼2 years. Nearly 50% of FIT could have been prevented by improving device programming. [ABSTRACT FROM PUBLISHER]

DAUBERT, J.-C., et al.: Intra- and Interatrial Conduction Delay: Implications for Cardiac Pacing. Atrial conduction disorders are frequent in elderly subjects and/or those with structural heart diseases, mainly mitral valve disease, hyperthrophic cardiomyopathies, and hypertension. The resultant electrophysiological and electromechanical abnormalities are associated with a higher risk of paroxysmal or persistent atrial tachyarrhythmias, either atrial fibrillation, typical or atypical flutter or other forms of atrial tachycardias. Such an association is not fortuitous because intra- and interatrial conduction abnormalities delays disrupt (spatial and temporal dispersion) electrical activation, thus promoting the initiation and perpetuation of reentrant circuits. Preventive therapeutic interventions induce variable, sometimes paradoxical effects as with the proarrhythmic effect of class I antiarrhythmic drugs. Similarly, atrial pacing may promote proarrhythmias or an antiarrhythmic effect according to the pacing site(s) and mode. Multisite atrial pacing was conceived to correct, as much as possible, abnormal activation induced by spontaneous intra- or interatrial conduction disorders or by single site atrial pacing, which are situations responsible for commonly refractory arrhythmias. Atrial electrical resynchronization can also be used to correct mechanical abnormalities like left heart AV dyssynchrony resulting from intraatrial conduction delays. (PACE 2004; 27:507–525) [ABSTRACT FROM AUTHOR]

Introduction: Results of previous studies suggest that atrial resynchronization by multisite atrial placing may contribute to prevention of recurrences in patients with drug-refractory atrial tachyarrhythmias and significant intra-atrial conduction delay. Methods and Results: To verify this hypothesis, a prospective noncontrolled study of 86 patients (mean age 66 ± 10 years) was conducted in a single center between January 1989 and February 1998. Inclusion criteria were P wave duration ≥120 msec with interatrial conduction time ≥100 msec, and history of multiple recurrences of atrial tachyarrhythmias (mean 7 ± 4.8 episodes) evolving in a persistent mode for at least 6 months despite optimized drug treatment (mean 2.7 ± 1.8 drugs/patient). Patients were chronically implanted with a pacing system that ensured permanent biatrial pacing using two atrial leads, one placed in the high right atrium and the other one into the mid or the distal part of the coronary sinus. P wave duration decreased from a mean value of 187 ± 29 msec before implant to 106 ± 14 msec (P < 0.0001) under biatrial pacing. After a 33-month mean follow-up (range 6 to 109), 55 patients (64%) remained in sinus rhythm, including 28 patients (32.6%) without any documented recurrence and 27 patients with one or more recurrences in a paroxysmal or in a persistent form. In these 55 patients, drug treatment was significantly reduced in relation to the preimplantation period (1.4 ± 0.6 vs 1.7 ± 0.5 drugs/patient; P = 0.011). The other 31 patients went into chronic atrial arrhythmia after a mean period of 26 months. The only predictive factor of positive response was a spontaneous P wave duration <160 msec at baseline. Conclusion: The results are consistent with a preventive effect of permanent biatrial pacing on recurrent and drug-refractory atrial arrhythmias associated with intra-atrial conduction delay. [ABSTRACT FROM AUTHOR]

Introduction Pulmonary vein (PV) isolation has become a cornerstone therapy for symptomatic paroxysmal AF refractory to anti-arrhythmic drugs. Nowadays, the most common energies used to achieve PV isolation are cryoenergy and radiofrequency (RF). However, approximately one third of the patients have recurrences, mainly due to PV reconnections. Little is known about the characteristics of the redo procedure, depending on the choice of the initial energy. Methods Patients referred to our center for a RF redo ablation procedure of symptomatic paroxysmal AF (PxAF) between 2010 and 2014 were retrospectively enrolled. Demographic data and characteristics of the initial ablation, i.e. cryoenergy or RF ablations, were collected. Number and location of PV gaps, and redo characteristics were reviewed. Results 74 patients scheduled for a redo ablation of AF were included, 38 and 36 using RF or cryoablation for the first procedure, respectively. For the initial ablation, procedural and fluoroscopy times were significantly shorter when using cryoenergy (147.8±52.6 vs. 226.6±64.3 min, p<0.001, and 37.0±17.7 vs. 50.8±22.7 min, p=0.005, respectively). Overall, an identical number of gaps were found during redo procedures of cryo and RF ablations. However, a significantly higher number of gaps were located in the right superior PV (RSPV) for patient first ablated with RF (0.9±1.0 vs. 0.5±0.9, p=0.009). The location of gaps was different, predominantly found in the anterior and superior parts of the left superior PV (LSPV), the anterior and inferior part of the left inferior PV (LIPV), the superior part of the right superior PV (RSPV), and in the postero-inferior part of the right inferior PV (RIPV) when using RF as the initial energy. For patient first ablated with cryoenergy, gaps were predominantly found in the anterior part of the left PV, evenly distributed in the RSPV, and in the postero-inferior part of the RIPV. Although not significant, redo procedures of cryoablations were slightly shorter and needed less RF duration times to achieve PV isolation (160.0±55.7 vs. 175.7±59.1 min, p=NS, and 954.1±796.7 vs. 1476.7±1269.6, p=NS). Conclusion During redo procedures, gaps location pattern is different for patients first ablated with cryo or RF energy, and RSPV reconnections occur more frequently after RF ablation, probably due to poor contact in this region. Procedural characteristics of the redo ablation are similar. Abstract 0029 – Figure: Localization of gaps, during the redo procedure [ABSTRACT FROM AUTHOR]