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Background Pharmacological treatment of atrial fibrillation (AF) in the setting of Brugada syndrome (BrS) is challenging. In addition, patients with BrS with an implantable cardioverter-defibrillator (ICD) might experience inappropriate shocks for fast AF. Long-term outcome of pulmonary vein isolation in BrS has not been well established yet, and it is still unclear whether pulmonary vein triggers are the only pathophysiological mechanism of AF in BrS. The aim of the study is to assess the long-term outcomes in patients with BrS undergoing pulmonary vein isolation for paroxysmal AF compared with a matched cohort of patients without BrS. Methods and Results Sixty patients with BrS undergoing pulmonary vein isolation with cryoballoon catheter ablation for paroxysmal AF were matched with 60 patients without BrS, who underwent the same procedure. After a mean follow-up of 58.2±31.7 months, freedom from atrial tachyarrhythmias was achieved in 61.7% in the BrS group and in 78.3% in the non-BrS group (log-rank P =0.047). In particular, freedom from AF was 76.7% in the first group and in 83.3% in the second ( P =0.27), while freedom from atrial tachycardia/atrial flutter was 85% and 95% ( P =0.057). In the BrS group, 29 patients (48.3%) had an ICD and 8 (27.6%) had a previous ICD-inappropriate shock for fast AF. In the BrS cohort, ICD-inappropriate interventions for AF were significantly reduced after ablation (3.4% versus 27.6%; P =0.01). Conclusions Pulmonary vein isolation in patients with BrS was associated with higher rate of arrhythmic recurrence. Despite this, catheter ablation significantly reduced inappropriate ICD interventions in BrS patients and can be considered a therapeutic strategy to prevent inappropriate device therapies.

Background The rate of sudden cardiac death (SCD) in Brugada syndrome (BrS) is ≈1%/y. Noninvasive electrocardiographic imaging is a noninvasive mapping system that has a role in assessing BrS depolarization and repolarization abnormalities. This study aimed to analyze electrocardiographic imaging parameters during ajmaline test (AJT). Methods and Results All consecutive epicardial maps of the right ventricle outflow tract (RVOT-EPI) in BrS with CardioInsight were retrospectively analyzed. (1) RVOT-EPI activation time (RVOT-AT); (2) RVOT-EPI recovery time, and (3) RVOT-EPI activation-recovery interval (RVOT-ARI) were calculated. ∆RVOT-AT, ∆RVOT-EPI recovery time, and ∆RVOT-ARI were defined as the difference in parameters before and after AJT. SCD-BrS patients were defined as individuals presenting a history of aborted SCD. Thirty-nine patients with BrS were retrospectively analyzed and 12 patients (30.8%) were SCD-BrS. After AJT, an increase in both RVOT-AT [105.9 milliseconds versus 65.8 milliseconds, P <0.001] and RVOT-EPI recovery time [403.4 milliseconds versus 365.7 milliseconds, P <0.001] was observed. No changes occurred in RVOT-ARI [297.5 milliseconds versus 299.9 milliseconds, P =0.7]. Before AJT no differences were observed between SCD-BrS and non SCD-BrS in RVOT-AT, RVOT-EPI recovery time, and RVOT-ARI ( P =0.9, P =0.91, P =0.86, respectively). Following AJT, SCD-BrS patients showed higher RVOT-AT, higher ∆RVOT-AT, lower RVOT-ARI, and lower ∆RVOT-ARI ( P <0.001, P <0.001, P =0.007, P =0.002, respectively). At the univariate logistic regression, predictors of SCD-BrS were the following: RVOT-AT after AJT (specificity: 0.74, sensitivity 1.00, area under the curve 0.92); ∆RVOT-AT (specificity: 0.74, sensitivity 0.92, area under the curve 0.86); RVOT-ARI after AJT (specificity 0.96, sensitivity 0.58, area under the curve 0.79), and ∆RVOT-ARI (specificity 0.85, sensitivity 0.67, area under the curve 0.76). Conclusions Noninvasive electrocardiographic imaging can be useful in evaluating the results of AJT in BrS.

Aims: To evaluate the clinical outcome in patients undergoing repeat procedures for recurrent persistent atrial fibrillation following an index cryoballoon (CB-A) pulmonary vein isolation ablation on a mid-term follow-up of 12 months., Methods: In this propensity score-matched comparison, 50 patients undergoing left atrial posterior wall isolation (LAPWI) with the CB-A were matched to 50 patients treated with additional linear ablation using radiofrequency catheter ablation (RFCA)., Results: Meantime to repeat the procedure was 9.74 ± 4.36 months. At 12 months follow-up freedom from atrial tachyarrhythmias (ATas) was achieved in 82% of patients in the LAPWI group and in 62% of patients in the linear ablation group ( P  = .03). Regression analysis demonstrated that relapses during the blanking period and LA dimensions were independent predictors of ATas recurrences following the repeat procedure., Conclusion: LAPWI using CB-A is associated with a significantly higher freedom from atrial arrhythmias when compared with the RFCA mediated left atrial linear lesions on a mid-term follow-up of 12 months in patients with persAF undergoing a redo procedure., Competing Interests: GBC reports speaker fees for Medtronic, Biotronik, Biosense Webster, and Abbott; teaching honoraria from Medtronic and Biotronik; proctoring honoraria from Medtronic; AB is consultant for Biotronik; PB reports consulting fees and speaker honoraria from Medtronic; C.d.A. reports speaker fees for Medtronic, Biotronik, Biosense Webster, Abbott, and Boston Scientific; teaching honoraria from Medtronic, Biotronik, Abbott, and Boston Scientific; proctoring honoraria from Medtronic, Abbott, and Biotronik., (© 2021 The Authors. Journal of Arrhythmia published by John Wiley & Sons Australia, Ltd on behalf of the Japanese Heart Rhythm Society.)

Background: The novel Polarx™ cryoablation system is currently being studied for atrial fibrillation (AF) ablation. To the best of our knowledge, no study comparing the novel cryoablation system with the standard Arctic Front™ cryoballoon is available in today's literature. This study aims to compare Polarx™ and Arctic Front™ cryoballoon in terms of safety and efficacy., Methods: From a total cohort of 202 patients who underwent pulmonary vein (PV) isolation for paroxysmal AF through cryoablation, a population of 30 patients who used Polarx™ were compared with 30 propensity-score matched patients who used Arctic Front™., Results: Pulmonary vein occlusion and electrical isolation were achieved in all (100%) veins with a mean number of 1.09 ± 0.3 occlusion per vein using Polarx™ and 1.19 ± 0.5 occlusion per vein using Arctic Front™ (p = 0.6). Shorter procedure and fluoroscopy time were observed with Polarx™ group (60.5 ± 14.23 vs 73.43 ± 13.26 mins, p = 0.001; 12.83 ± 6.03 vs 17.23 ± 7.17 mins, p = 0.01, respectively). Lower cumulative freeze duration per vein was also observed with Polarx™ (203.38 ± 72.03 vs 224.9 ± 79.35 mins, p = 0.02). There was no significant difference in isolation time between the two groups (34.47 ± 21.23 vs 34.18 ± 26.79 secs, p = 0.9)., Conclusions: The novel Polarx™ cryoablation system showed similar efficacy in vein occlusion and isolation and safety profile when compared to Arctic Front™ cryoablation system. Procedure time, fluoroscopy time, and cumulative freeze duration were significantly lower with Polarx™ cryoablation system.

Background: The development of multielectrode mapping catheters has expanded the spectrum of mappable ventricular tachycardias (VTs). Full diastolic pathway recording has been associated with a high rate of VT termination during radiofrequency ablation as well as noninducibility at study end. However, the role of diastolic pathway mapping on VT recurrence has yet to be clearly elucidated. We aimed to explore the role of complete diastolic pathway activation mapping on VT recurrence., Methods: Eighty-five consecutive patients who underwent VT ablation guided by high-density mapping were enrolled. During activation mapping, the presence of electrical activity in all segments of diastole defined the evidence of having had recorded the whole diastolic interval. Patients were categorized as having recorded the full diastolic pathway, partial diastolic pathway, or no diastolic pathway map performed. Recurrences of VT were defined as appropriate implantable cardioverter defibrillator therapies or on the basis of ECG-documented arrhythmia., Results: Eighty-five patients were included. Complete recording of the diastolic pathway was achieved in 36/85 (42.4%) patients. Partial recording of the diastolic pathway of the clinical VT was achieved in 24/85 (28.2%) patients. No recording of the diastolic pathway of the clinical VT was feasible in 25/85 patients (29.4%). At a mean of 12.8 months, freedom from VT recurrence was 67% in the overall cohort. At a mean of 12.8 months, freedom from VT recurrence was 88%, 50%, and 55% in patients who had full diastolic activity recorded, partial diastolic activity recorded, or underwent substrate modification, respectively; the observed differences were statistically significant ( P =0.02)., Conclusions: Mapping of the entire diastolic pathway was associated with a higher freedom from VT recurrence as compared with partial diastolic pathway recording and substrate modification. The use of multielectrode mapping catheters in recording diastolic activity may help predict those VTs employing intramural circuits and further optimize ablation strategies.

Background: Clinical outcomes after ablation of persistent atrial fibrillation remain suboptimal. Identification of AF drivers using a novel integrated mapping technique may be crucial to ameliorate the clinical outcome., Methods and Results: Persistent AF patients were prospectively enrolled to undergo high-density electrophysiological mapping to identify repetitive-regular activities (RRas) before modified circumferential pulmonary vein (PV) ablation. They have been randomly assigned (1:1 ratio) to ablation of RRa followed by modified circumferential PV ablation (mapping group; n=41) or modified circumferential PV ablation alone (control group; n=40). The primary end point was freedom from arrhythmic recurrences at 1 year. In total, 81 persistent AF patients (74% male; mean age, 61.7±10.6 years) underwent mapping/ablation procedure. The regions exhibiting RRa were 479 in 81 patients (5.9±2.4 RRa per patient): 232 regions in the mapping group (n=41) and 247 in the control group (n=40). Overall, 185 of 479 (39%) RRas were identified within the PVs, whereas 294 of 479 (61%) in non-PV regions. Mapping-guided ablation resulted in higher arrhythmia termination rate when compared with conventional strategy (25/41, 61% versus 12/40, 30%; P <0.007). Total radiofrequency duration ( P =0.38), mapping ( P =0.46), and fluoroscopy times ( P =0.69) were not significantly different between the groups. No major procedure-related adverse events occurred. After 1 year, 73.2% of mapping group patients were free from recurrences versus 50% of control group ( P =0.03)., Conclusions: Targeted ablation of regions showing RRa provided an adjunctive benefit in terms of arrhythmia freedom at 1-year follow-up in the treatment of persistent AF. These findings might support a patient-tailored strategy in subjects with nonparoxysmal AF and should be confirmed by additional larger, randomized, multicenter studies., Clinical Trial Registration: URL: https://www.clinicaltrials.gov. Unique identifier NCT02571218., (© 2018 American Heart Association, Inc.)

Aims: Continuous rhythm monitoring is valuable for adequate atrial fibrillation (AF) management in the clinical setting. Subcutaneous leadless implantable cardiac monitors (ICMs) yield an improved AF detection, overcoming the intrinsic limitations of the currently available external recording systems, thus resulting in a more accurate patient treatment. The study purpose was to assess the detection performance of a novel three-vector ICM device equipped with a dedicated AF algorithm., Methods and Results: Sixty-six patients (86.4% males; mean age 60.4 ± 9.4 years) at risk to present AF episodes, having undergone the novel ICM implant (BioMonitor, Biotronik SE&Co. KG, Berlin, Germany), were enrolled. External 48-h ECG Holter was performed 4 weeks after the device implantation. The automatic ICM AF classification was compared with the manual Holter arrhythmia recordings. Of the overall study population, 63/66 (95.5%) had analysable Holter data, 39/63 (62%) showed at least one true AF episode. All these patients had at least one AF episode stored in the ICM. On Holter monitoring, 24/63 (38%) patients did not show AF episodes, in 16 of them (16/24, 67%), the ICM confirmed the absence of AF. The AF detection sensitivity and positive predictive value for episodes' analysis were 95.4 and 76.3%, respectively., Conclusion: Continuous monitoring using this novel device, equipped with a dedicated detection algorithm, yields an accurate and reliable detection of AF episodes. The ICM is a promising tool for tailoring individual AF patient management. Further long-term prospective studies are necessary to confirm these encouraging results., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.)