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Competing Interests: Disclosures Dr Della Bella has served as a consultant for Abbott and Biosense; and has received research grants from Abbott, Biosense, Biotronik, and Boston Scientific. Mr Federico Calore is an Abbott employee. Dr Filippo M. Cauti has received grants from Abbott and Biosense Webster; and is Medical Advisor for Biotronik. All other authors have no conflicts of interest to disclose.

Aims: Electrical storm (ES) is a life-threatening condition requiring a rapid management. Percutaneous stellate ganglion block (PSGB) is proved to be safe and effective on top of standard therapy, but no data are available about its early use., Methods and Results: We considered all patients enrolled from 1 July 2017 to 30 April 2024 in the STAR registry (STellate ganglion block for Arrhythmic stoRm), a multicentre, international, observational, prospective registry. We aimed to assess the effectiveness of the first PSGB only. Patients were divided into two groups depending on whether they received PSGB before [early PSGB, often due to antiarrhythmic drug (AAD) contraindication] or after (delayed PSGB) intravenous AADs (AADs other than beta-blockers). We considered 180 PSGB (26 early PSGB and 154 AAD first). In the early PSGB group, we observed a statistically significant reduction of treated arrhythmic events in the hour after PSGB compared with the hour before: 0 (0-0) vs. 4.5 (1-10), P < 0.001, and the extent of the reduction was similar in the early PSGB and delayed PSGB groups [-4.5 (-7 to -2) vs. -2.5 (-3.5 to -1.5), P = ns]. The percentage of patients free from arrhythmias was similar in the two groups up to 12 h after PSGB (81 vs. 84%, P = 0.6, after 1 h; 77 vs. 79%, P = 0.8, at 3 h; and 65 vs. 69%, P = 0.7, after 12 h)., Conclusion: Percutaneous stellate ganglion block is proved to be effective also when used early in the treatment of ES. Due to its rapidity of action, our results may suggest its early use to reduce the number of defibrillations and possibly to reduce the likelihood of a refractory ES., Competing Interests: Conflict of interest: none declared., (© The Author(s) 2024. Published by Oxford University Press on behalf of the European Society of Cardiology. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Background: Stereotactic arrhythmia radioablation (STAR) was introduced to treat ventricular tachycardia (VT) refractory to catheter ablation. No data are now available in the septal VT substrate setting, representing a challenge when using conventional techniques., Objectives: This study sought to evaluate the arrhythmic burden in patients with septal VT treated with magnetic resonance-guided STAR (MRgSTAR)., Methods: We enrolled consecutive patients with septal VT substrate. The therapy target was achieved by combining anatomic/functional and electrophysiologic information. Patients were treated with a single fraction of 25 Gy adopting MRgSTAR. All patients were clinically followed up, and all implantable cardiac devices were remotely monitored. The efficacy outcome included recurrences of any sustained VT beyond the 6-week blanking period after MRgSTAR. The safety outcome was the incidence of adverse events and atrioventricular block., Results: We included 11 patients with septal substrate VT (median age: 68 years; Q1-Q3: 64.5-78 years; 100% male). Clinical presentation was an electrical storm in 81.8% of patients. No complications occurred after MRgSTAR, and 6 (54.5%) patients were discharged on the same day of treatment. During a mean follow-up of 12 ± 6 months, the efficacy outcome occurred in 3 (27.3%) cases. A significative reduction of implantable cardioverter-defibrillator (ICD) therapy (23.6 before MRgSTAR vs 1.7 after MRgSTAR; P < 0.001) was observed. Left ventricular ejection fraction increased significantly after treatment (38% [Q1-Q3: 33.5%-42.0%] before MRgSTAR vs 43.8% [Q1-Q3: 35%-47%] after MRgSTAR; P = 0.04). No adverse effects were observed in the implantable cardioverter-defibrillator and lead system; in the 7 patients with preserved atrioventricular conduction, no atrioventricular block was reported., Conclusions: MRgSTAR represents a safe and effective strategy for treating septal VT., Competing Interests: Funding Support and Author Disclosures The 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: Data on the predictors of percutaneous stellate ganglion block (PSGB) efficacy in electrical storm are scanty., Objective: We aimed to assess whether PSGB efficacy is influenced by the arrhythmia type and cycle length before the procedure., Methods: This is a subanalysis of the multicenter STAR study. The population was stratified into 3 groups according to the median cycle length of the latest ventricular arrhythmia before PSGB: ventricular fibrillation (VF), fast ventricular tachycardia (VT), and slow VT. The primary outcome was the number of treated arrhythmic episodes (with antitachycardia pacing or direct current shocks) in the hour immediately after PSGB compared with the hour before., Results: We considered 139 PSGBs from 112 patients divided into VF (51 procedures), fast VT (44 procedures, VT cycle <375 ms), and slow VT (44 procedures, VT cycle ≥375 ms). The number of treated arrhythmic episodes in the hour after every PSGB was significantly lower compared with the hour before in all groups (VF: 0 [0-1] vs 5 [2-8], P < .001; fast VT: 0 [0-0] vs 1 [0-6.5], P < .001; slow VT: 0 [0-0] vs 1 [0-4.5], P = .001). In analyzing the reduction of the number of antitachycardia pacing sequences or direct current shocks from the hour before to the hour after PSGB, a significant trend was observed across the groups (Jonckheere-Terpstra trend P < .001), and a significant difference was observed in comparing slow VT vs VF and fast VT vs VF but not in comparing slow VT vs fast VT. VF was independently associated with the probability of reduction of treated events after PSGB., Conclusion: PSGB is an effective treatment of electrical storm in patients with all types of ventricular arrhythmias. However, its effectiveness was more pronounced in patients with VF., Competing Interests: Disclosures The authors have no conflicts of interest to disclose., (Copyright © 2024 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Competing Interests: Conflict of interest: F.C. is an Abbott employee. F.M.C. has received grants from Abbott and Biosense Webster and is medical advisor for Biotronik. N.M. has reported no relationships relevant to the contents of this paper to disclose.

Competing Interests: Declaration of competing interest Dr. Cauti has received grants from Biosense Webster and Abbott and is clinical advisor for Biotronik. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.

Objectives: The aim of this study was to describe the correlation between atrial electrogram duration map (AEDUM), spatiotemporal electrogram dispersion (STED) and low voltage areas (LVA) in patients with persistent atrial fibrillation (PsAF)., Background: The degree of left atrial (LA) tissue remodelling and augmented anisotropic conduction is one of the major issues related to PsAF ablation outcome., Methods: This study enrolled consecutive patients with PsAF undergoing pulmonary vein isolation. In all patients, voltage, AEDUM and STED maps were created, and the correlation was reported between these three mapping methods., Results: A total of 40 patients with PsAF were enrolled. The mean age was 62.2 ± 7.4 years, and males were 72.5% (n = 29). The overall bipolar voltage of the LA was 3.06 ± 1.87 mV. All patients had at least one AEDUM area (overall AEDUM area: 21.8 ± 8.2 cm 2 ); the mean longest electrogram (EGMs) duration was 90 ± 19 ms. STED areas with < 120 ms was 46.3 ± 20.2 cm 2 which covered 45 ± 22% of the LA surface. AEDUM and STED areas were most frequently reported on the roof, the anterior wall and the septum. The extension of the AEDUM areas was significantly smaller than STED areas with CL < 120 ms (21.8 ± 8.2 vs 46.3 ± 20.2; p-value < 0.0001). In 24 patients (60%), AEDUM areas was entirely included in the STED areas with CL < 120 ms. In the three (7.5%) patients with LVA, no correspondence with STED and AEDUM was noted., Conclusion: AEDUM and STED maps allow to identify areas of conductive dysfunction as a possible atrial substrate even if a normal voltage is detected., Competing Interests: Declarations. Ethics approval: The study protocol was approved by the local ethics committee. Informed consent: Written informed consent from all the patients was obtained before each procedure. Conflict of interest: MN and ADG are currently Abbott employees. All the other authors have nothing to disclose., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Background: Catheter ablation of persistent atrial fibrillation (PsAF) represents a challenge for the electrophysiologist and there are still divergences regarding the best ablative approach to adopt. Create a new map of the duration of atrial bipolar electrograms (Atrial Electrogram DUration Map, AEDUM) to recognize a functional substrate during sinus rhythm and guide a patient-tailored ablative strategy for PsAF., Methods: Forty PsAF subjects were assigned in a 1:1 ratio to either for PVI alone (Group B 1 ) or PVI+AEDUM areas ablation (Group B 2 ). A cohort of 15 patients without AF history undergoing left-sided accessory pathway ablation was used as a control group (Group A). In all patients, voltage and AEDUM maps were created during sinus rhythm. The minimum follow-up was 12 months, with rhythm monitoring via 48-h ECG Holter or by implantable cardiac device., Results: Electrogram (EGM) duration was higher in Group B than in Group A (49±16.2ms vs 34.2±3.8ms; p-value<0.001). In Group B the mean cumulative AEDUM area was 21.8±8.2cm 2 ; no difference between the two subgroups was observed (22.3±9.1cm 2 vs 21.2±7.2cm 2 ; p-value=0.45). The overall bipolar voltage recorded inside the AEDUM areas was lower than in the remaining atrial areas [median: 1.30mV (IQR: 0.71-2.38mV) vs 1.54mV (IQR: 0.79-2.97mV); p-value: <0.001)]. Low voltage areas (<0.5mV) were recorded in three (7.5%) patients in Group B. During the follow-up [median 511 days (376-845days)] patients who underwent PVI-only experienced more AF recurrence than those receiving a tailored approach (65% vs 35%; p-value= 0.04)., Conclusions: All PsAF patients exhibited AEDUM areas. An ablation approach targeting these areas resulted in a more effective strategy compared with PVI only., (© 2024. The Author(s).)

Background: Long-term oral anticoagulation is the mainstay therapy for thromboembolic (TE) prevention in patients with atrial fibrillation. However, left atrial appendage occlusion (LAAO) could be a safe alternative to direct oral anticoagulants (DOACs) in patients with a very high TE risk profile., Objective: The purpose of this study was to compare the safety and efficacy of LAAO vs DOACs in patients with atrial fibrillation at very high stroke risk (CHA 2 DS 2 -VASc [congestive heart failure, hypertension, age ≥ 75 years, diabetes mellitus, prior stroke or transient ischemic attack or thromboembolism, vascular disease, age 65-74 years, sex category] score ≥ 5)., Methods: Data from patients with CHA 2 DS 2 -VASc score ≥ 5 were extracted from a prospective multicenter database. To attenuate the imbalance in covariates between groups, propensity score matching was used (covariates: CHA 2 DS 2 -VASc and HAS-BLED [hypertension, abnormal renal or liver function, stroke, bleeding, labile international normalized ratio, elderly, drugs or alcohol] scores), which resulted in a matched population of 277 patients per group. The primary end point was a composite of cardiovascular death, TE events, and clinically relevant bleeding during follow-up., Results: Of 2381 patients, 554 very high risk patients were included in the study (mean age 79 ± 7 years; CHA 2 DS 2 -VASc score 5.8 ± 0.9; HAS-BLED score 3.0 ± 0.9). The mean follow-up duration was 25 ± 11 months. A higher incidence of the composite end point was documented with DOACs compared with LAAO (14.9 events per 100 patient-years in the DOAC group vs 9.4 events per 100 patient-years in the LAAO group; P = .03). The annualized clinically relevant bleeding risk was higher with DOACs (6.3% vs 3.2%; P = .04), while the risk of TE events was not different between groups (4.1% vs 3.2%; P = .63)., Conclusion: In high-risk patients, LAAO had a similar stroke prevention efficacy but a significantly lower risk of clinically relevant bleeding when compared with DOACs. The clinical benefit of LAAO became significant after 18 months of follow-up., Competing Interests: Disclosures Dr Burkhardt is a consultant for Biosense Webster and Stereotaxis. Dr Chierchia has received compensation for teaching purposes and proctoring from Medtronic, Abbott, Biotronik, Boston Scientific, and Acutus Medical. Dr de Asmundis has received research grants on behalf of the center from Biotronik, Medtronic, Abbott, LivaNova, Boston Scientific, AtriCure, Philips, and Acutus Medical and compensation for teaching purposes and proctoring from Medtronic, Abbott, Biotronik, LivaNova, Boston Scientific, AtriCure, Acutus Medical, and Daiichi Sankyo. Dr Di Biase is a consultant for Biosense Webster, Boston Scientific, Stereotaxis, and St. Jude Medical. Dr Di Biase has received speaker honoraria/travel support from Medtronic, Bristol Meyers Squibb, Pfizer, and Biotronik. Dr Natale has received speaker honoraria from Boston Scientific, Biosense Webster, St. Jude Medical, Biotronik, and Medtronic and is a consultant for Biosense Webster, St. Jude Medical, and Janssen. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2024 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Background and Aims: An electrical storm (ES) is a clinical emergency with a paucity of established treatment options. Despite initial encouraging reports about the safety and effectiveness of percutaneous stellate ganglion block (PSGB), many questions remained unsettled and evidence from a prospective multicentre study was still lacking. For these purposes, the STAR study was designed., Methods: This is a multicentre observational study enrolling patients suffering from an ES refractory to standard treatment from 1 July 2017 to 30 June 2023. The primary outcome was the reduction of treated arrhythmic events by at least 50% comparing the 12 h following PSGB with the 12 h before the procedure. STAR operators were specifically trained to both the anterior anatomical and the lateral ultrasound-guided approach., Results: A total of 131 patients from 19 centres were enrolled and underwent 184 PSGBs. Patients were mainly male (83.2%) with a median age of 68 (63.8-69.2) years and a depressed left ventricular ejection fraction (25.0 ± 12.3%). The primary outcome was reached in 92% of patients, and the median reduction of arrhythmic episodes between 12 h before and after PSGB was 100% (interquartile range -100% to -92.3%). Arrhythmic episodes requiring treatment were significantly reduced comparing 12 h before the first PSGB with 12 h after the last procedure [six (3-15.8) vs. 0 (0-1), P < .0001] and comparing 1 h before with 1 h after each procedure [2 (0-6) vs. 0 (0-0), P < .001]. One major complication occurred (0.5%)., Conclusions: The findings of this large, prospective, multicentre study provide evidence in favour of the effectiveness and safety of PSGB for the treatment of refractory ES., (© The Author(s) 2024. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Background: Modified cardiac sympathetic denervation (CSD) with stellate ganglion (SG) sparing is a novel technique for cardiac neuromodulation in patients with refractory ventricular tachycardia (VT)., Objectives: Our aim is to describe the mid- to long-term clinical outcome of the modified CSD with SG sparing in a series of patients with structural heart disease (SHD) and refractory VT., Methods: All consecutive patients with SHD and refractory VT undergoing modified CSD were enrolled. Baseline clinical characteristics and periprocedural data were collected for all patients. The primary outcome was any recurrence of sustained VT., Results: We enrolled 15 patients (age: 69.2 ± 7.9 years; male 100%) undergoing modified CSD. Left ventricular ejection fraction was 37 ± 11% and all patients had an implantable cardiac defibrillator (ICD); the underlying cardiomyopathy was non-ischemic in 73.3% of them. At least one previous ablation had been attempted in 66.6% of cases. The 73.3% of patients underwent bilateral CSD and the mean effective surgical time was 10.8 ± 2.4 min per side; no major periprocedural complication occurred. After a median follow-up time of 15 months (IQR: 8.5-24.5 months), the primary outcome occurred in 47.6% of cases. All patients experienced a reduction of ICD shocks after CSD (3.1 ICD shocks/patient before vs. 0.3 ICD shocks/patient after CSD; p-value: 0.001). Bilateral CSD and a VT cycle length < 340 ms were associated with better outcomes., Conclusions: A modified CSD approach with stellate ganglion sparing appears to be safe, fast, and effective in the treatment of patients with SHD and refractory VTs., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Introduction: Recently, a new cryoballoon (CB) technology (POLARx; Boston Scientific) has come onto the market. Preliminary data have shown that its acute safety and efficacy are similar to those of the first-generation CB. The aim of this study was to assess the medium-term outcome of pulmonary vein isolation (PVI) with the POLARxTM CB in a large multicenter registry., Methods: We prospectively collected data on 125 consecutive patients with paroxysmal atrial fibrillation (AF) who underwent PVI by means of a novel CB system. Two cases of transient phrenic nerve palsy occurred, with full recovery in the 48h post procedure; no major procedure-related adverse events were reported. During the 90-day blanking period, 4 (3.2%) patients experienced an early recurrence. After the blanking period, over a mean follow-up of 411 ± 62 days, 19 patients (15.2%) suffered an AF/atrial tachycardia (AT) recurrence. The 1-year freedom from AF/AT recurrence was 86.4% (n = 17): 10 (8%) patients had an AF recurrence, 6 (4.8%) had an AT occurrence and 1 (0.8%) suffered both events. Patients with AF/AT recurrences had both a shorter deflation time and total deflation time. Moreover, CB ablations with measured TTI < 90 s and TTI < 60 s were more frequent in patients without AF/AT recurrence (88.5% and 77.4%, respectively) than in those who experienced at least one AF/AT recurrence (67.5% and 55.0%, p = .001 and p = .005, respectively)., Conclusion: The novel POLARx cryo-balloon system is safe and effective for PV isolation, displaying a 1-year freedom from atrial arrhythmia recurrence of 86.4%, which is in line to that reported with AFA-Pro CB or RF ablation., Clinical Trial Registration: Catheter Ablation of Arrhythmias with a High-Density Mapping System in Real-World Practice (CHARISMA). URL: http://clinicaltrials.gov/ Identifier: NCT03793998. Registration date: January 4, 2019., (© 2023 The Authors. Pacing and Clinical Electrophysiology published by Wiley Periodicals LLC.)

Introduction: Cardiac involvement is common and may become clinically relevant in approximately 5%-10% of patients with systemic sarcoidosis. Although reduced left ventricular ejection fraction is a recognized predictor of mortality, recent studies have suggested an increased risk of ventricular arrhythmia (VAs) and sudden cardiac death (SCD) in patients with cardiac sarcoidosis (CS) and evidence of late gadolinium enhancement-cardiac magnetic resonance (LGE-CMR), irrespective of the underlying left ventricular systolic function. We performed a meta-analysis to assess the correlation between VAs/SCD and presence of LGE-CMR in CS patients., Methods: We systematically searched Medline, Embase, and Cochrane electronic databases up to January 2, 2023, for studies enrolling patients with suspected or confirmed CS undergoing LGE-CMR. Clinical outcomes of interest included clinically relevant VAs, defined as sustained ventricular tachycardia, ventricular fibrillation, SCD, or aborted SCD during follow-up. The effect size was estimated using a random-effect model as risk ratio (RR) and relative 95% confidence interval (CI)., Results: A total of 14 studies fulfilled the selection criteria and were included in the final analysis. Among 1273 patients, LGE was detected in 465 (36.5%; Group LGE+). Males accounted for 45.2% (95% CI: 40.5%-55.7%) of the total population and the average age was 56.8 (95% CI: 52.7%-60.9) years. A total of 104 (22.3%) of 465 LGE+ patients experienced a clinically relevant VA, compared to 6 (0.7%) of 808 LGE- ones. LGE+ was associated with a ninefold increased risk in life-threatening VAs (22.3% vs. 0.7%; RR = 9.52; 95% CI [5.18-17.49]; p < .0001) compared to patients without LGE (heterogeneity I 2  = 0%)., Conclusion: In our meta-analysis, LGE+ in patients with CS was associated with a ninefold increased risk in life-threatening VAs compared to patients without LGE., (© 2023 Wiley Periodicals LLC.)

Background: The analysis of the wave-front activation patterns is crucial for the comprehension and treatment of ventricular tachycardia (VT). The ventricular electrograms duration map (VEDUM) is a potential method to identify areas (VEDUM area) with slow and inhomogeneous activation. There is no available data on the characteristics and the arrhythmogenic role of VEDUM areas identified during sinus/paced rhythm., Methods: Patients referred for VT ablation were enrolled at 3 different centers. VEDUM maps during sinus/paced rhythm as well as substrate and functional maps were created; activation mapping was performed for all hemodynamically tolerated VT., Results: Thirty-two patients (mean age:70.1±9.4 years; males 93.8%) were enrolled. The VEDUM approach was achieved in all patients and the mean size of the VEDUM area was 12.1±6.9 cm 2 (interquartile range, 7.8-14.9 cm 2 ). A significative difference was observed between the electrogram duration in the VEDUM area and the normal tissue (163.7 ms [interquartile range, 142.3-199.2 ms]; versus 65.5 ms [interquartile range, 59.5-76.2 ms]; P <0.001). The VEDUM area was visualized in a dense scar (<0.5 mV) in 19 (59.4%) patients. A deceleration zone and late potentials were recorded inside the VEDUM area in 56.3% and 81.3%, respectively. When a complete VT activation mapping was available, the isthmus projected in the VEDUM area in 93.5% of patients; 8 of them had multiple VTs mapped and in the 87.5% all VT isthmuses were included in the VEDUM area., Conclusions: VEDUM maps allow the identification of discrete areas of inhomogeneous and slow conduction. They represent a potential target for VT ablation, including patients with multiple morphologies., Competing Interests: Disclosures M. Niscola is currently an Abbott employee. The other authors report no conflicts.

Introduction: Cephalic vein cutdown (CVC) and axillary vein puncture (AVP) are both recommended for transvenous implantation of leads for cardiac implantable electronic devices (CIEDs). Nonetheless, it is still debated which of the two techniques has a better safety and efficacy profile., Methods: We systematically searched Medline, Embase, and Cochrane electronic databases up to September 5, 2022, for studies that evaluated the efficacy and safety of AVP and CVC reporting at least one clinical outcome of interest. The primary endpoints were acute procedural success and overall complications. The effect size was estimated using a random-effect model as risk ratio (RR) and relative 95% confidence interval (CI)., Results: Overall, seven studies were included, which enrolled 1771 and 3067 transvenous leads (65.6% [n = 1162] males, average age 73.4 ± 14.3 years). Compared to CVC, AVP showed a significant increase in the primary endpoint (95.7 % vs. 76.1 %; RR: 1.24; 95% CI: 1.09-1.40; p = .001) (Figure 1). Total procedural time (mean difference [MD]: -8.25 min; 95% CI: -10.23 to -6.27; p < .0001; I 2  = 0%) and venous access time (MD: -6.24 min; 95% CI: -7.01 to -5.47; p < .0001; I 2  = 0%) were significantly shorter with AVP compared to CVC. No differences were found between AVP and CVC for incidence overall complications (RR: 0.56; 95% CI: 0.28-1.10; p = .09), pneumothorax (RR: 0.72; 95% CI: 0.13-4.0; p = .71), lead failure (RR: 0.58; 95% CI: 0.23-1.48; p = .26), pocket hematoma/bleeding (RR: 0.58; 95% CI: 0.15-2.23; p = .43), device infection (RR: 0.95; 95% CI: 0.14-6.60; p = .96) and fluoroscopy time (MD: -0.24 min; 95% CI: -0.75 to 0.28; p = .36)., Conclusion: Our meta-analysis suggests that AVP may improve procedural success and reduce total procedural time and venous access time compared to CVC., (© 2023 Wiley Periodicals LLC.)

Background: Multicenter ventricular tachycardia (VT) ablation studies have shown poorer outcomes compared with single-center experiences. This difference could be related to heterogeneous mapping and ablation strategies., Objectives: This study evaluated a homogenous simplified catheter ablation strategy for different substrates and compared the results with those of a single referral center., Methods: This was a multicenter prospective VT ablation registry of patients with the following 4 causes of VT: previous myocardial infarction; previous myocarditis; arrhythmogenic right ventricular dysplasia; or idiopathic dilated cardiomyopathy. The procedural protocol included precise mapping and ablation steps with the combined endpoint of late potential (LP) abolition and noninducibility of VT. The long-term primary efficacy endpoint was freedom from VT., Results: A total of 309 patients were enrolled. LPs were present in 70% of patients and were abolished in 83%. At the end of the procedure 74% of LPs were noninducible. The primary combined endpoint of LP abolition and noninducibility was achieved in 64% of patients with LPs at baseline. Freedom from VT at 12 months was observed in 67% of patients. In the overall study group, VT inducibility was the only predictor of freedom from VT (P = 0.013). In patients with LPs, the VT recurrence rate was lower both for patients with complete LP abolition (P = 0.040) and for patients meeting the composite endpoint (P = 0.035)., Conclusions: A standardized VT mapping and ablation technique reproduced the procedural outcomes of a single referral center in a multicenter prospective study. LP abolition and noninducibility were effective in reducing VT recurrences in patients with 4 causes of cardiomyopathy. (Ventricular Tachycardia Ablation Registry; NCT03649022)., Competing Interests: Funding Support and Author Disclosures This work was supported by Abbott for Contract Research Organisation activities. Dr Della Bella has served as a consultant for Abbott and Biosense; and has received research grants from Abbott, Biosense, Biotronik, and Boston Scientific. 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: Spatial differences in conduction velocity (CV) are critical for cardiac arrhythmias induction. We propose a method for an automated CV calculation to identify areas of slower conduction during cardiac arrhythmias and sinus rhythm., Methods: Color-coded representations of the isochronal activation map using data coming from the RHYTHMIA™ Mapping System were reproduced by applying a temporal isochronal window at 20 ms. Geodesic distances of the 3D mesh were calculated using an algorithm selecting the minimum distance pathway (MDP). The CV estimation was performed considering points on the boundary of two spatially and temporally adjacent isochrones. For each of the boundary points of a given isochrone, the nearest boundary point of the consecutive isochrone was chosen, the MDP was evaluated, and a map of CV was created. The proposed method has been applied to a population of 29 patients., Results: In all cases of perimitral atrial flutter (16 pts out of 29 (55%)), areas with significantly low CV (< 30 cm/s) were found. Half of the cases present regions with low CV located in the anterior wall. No case with low CV at the so-called LA isthmus was observed. Right atrial maps during common atrial flutters showed low CV areas mainly located in the inferior inter-atrial septum. No areas of low CV were observed in subjects without a history of atrial arrhythmia while pts affected by paroxysmal AF showed areas with a limited extension of low CV., Conclusions: The proposed software for automated CV estimation allows the identification of low CV areas, potentially helping electrophysiologists to plan the ablation strategy., (© 2022. The Author(s).)

Introduction: The implantable cardioverter defibrillator (ICD) has been demonstrated to successfully prevent sudden cardiac death (SCD) in children and young adults. A wide range of device-related complications/malfunctions have been described, which depend on the intrinsic design of the defibrillation system (transvenous-implantable cardioverter defibrillator [TV-ICD] vs. subcutaneous-implantable cardioverter defibrillator [S-ICD])., Objective: To compare the device-related complications and inappropriate shocks with TV-ICD versus S-ICD., Methods and Results: Electronic databases were queried for studies focusing on the prevention of SCD in children and young adults with TV-ICD or S-ICD. The effect size was estimated using a random-effect model as odds ratio (OR) and relative 95% confidence interval (CI). The primary endpoint was a composite of any device-related complications and inappropriate shocks. We identified a total of five studies including 236 patients (Group S-ICD: 76 patients; Group TV-ICD: 160 patients) with a mean follow-up time of 54.2 ± 24.9 months. S-ICD implantation contributed to a significant reduction in the risk of the primary endpoint of any device-related complications and inappropriate shocks (OR: 0.18; 95% CI: 0.05-0.73; p = .02). S-ICD was also associated with a significantly lower incidence of inappropriate shocks (OR: 0.28; 95% CI: 0.11-0.74; p = .01) and lead-related complications (OR: 0.18; 95% CI: 0.05-0.66; p = .01). A trend toward a higher risk of pocket complications (OR: 5.91; 95% CI: 0.98-35.63; p = .05) was recorded in patients with S-ICD., Conclusion: Children and young adults undergoing S-ICD implantation may have a lower risk of a composite of device-related complications and inappropriate shocks, compared to TV-ICD patients., (© 2022 Wiley Periodicals LLC.)

Cardiac sympathetic denervation (CSD) is a valuable option in the setting of refractory ventricular arrhythmias in patient with structural heart disease. Since the procedure was introduced for non structural heart disease patients the techniques evolved and were modified to be adopted in several settings. In this state-of-the-art article we revised different techniques, their rationale, strengths, and pitfalls., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Background: Atrial fibrillation (AF) and heart failure (HF) often coexist and synergistically contribute to an increased risk of hospitalization, stroke, and mortality. Objective: To compare the efficacy of catheter ablation (CA) versus medical therapy (MT) in HF patients with AF. Methods: Electronic databases were queried for randomized controlled trials (RCTs) of CA versus MT of AF in patients with HF. Risk ratios (RRs), mean differences (MDs), and 95% confidence intervals (CIs) were measured using the Mantel−Haenszel method. Results: A total of nine RCTs enrolling 2155 patients met the inclusion criteria. Compared to MT, CA led to a significant reduction in the composite of all-cause mortality and HF hospitalization (24.6% vs. 37.1%; RR: 0.65 (95% CI: 0.53−0.80); p < 0.0001), all-cause mortality (8.8% vs. 13.6%; RR: 0.65 (95% CI: 0.51−0.82); p = 0.0005), HF hospitalization (15.4% vs. 22.4%; (RR: 0.67 (95% CI: 0.54−0.82); p = 0.0001), AF recurrence (31.8% vs. 77.0%; RR: 0.36 (95% CI: 0.24−0.54); p < 0.0001), and cardiovascular (CV) death (4.9% vs. 8.4%; RR: 0.58 (95% CI: 0.39−0.86); p = 0.007). CA improved the left ventricular ejection fraction (MD:4.76% (95% CI: 2.35−7.18); p = 0.0001), 6 min walk test (MD: 20.48 m (95% CI: 10.83−30.14); p < 0.0001), peak oxygen consumption (MD: 3.1 2mL/kg/min (95% CI: 1.01−5.22); p = 0.004), Minnesota Living with Heart Failure Questionnaire score (MD: −6.98 (95% CI: −12−03, −1.93); p = 0.007), and brain natriuretic peptide levels (MD:−133.94 pg/mL (95% CI: −197.33, −70.55); p < 0.0001). Conclusions: In HF patients, AF catheter ablation was superior to MT in reducing CV and all-cause mortality. Further significant benefits occurred within the ablation group in terms of HF hospitalizations, AF recurrences, the systolic function, exercise capacity, and quality of life.

A patient with symptomatic persistent atrial fibrillation and recurrences after pulmonary vein isolation (PVI) underwent a second ablation procedure. The PVs were found isolated and the left atrial substrate tissue was mapped. During sinus rhythm, the voltage map resulted in a normal range (>0,5mV) while a map of EGMs durations revealed an area presenting prolonged EGMs (>45 ms) in the anterior region. The activation map of this area demonstrated abnormal conduction and a non-uniform anisotropism when compared with areas in which EGM's normal durations were recorded. The EGMs duration map may offer additional clinical information on the areas presenting abnormal conduction predisposing arrhythmias maintenance in patients suffering from persistent atrial fibrillation., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Introduction: Low-voltage activity beyond pulmonary veins (PVs) may contribute to the failure of ablation of atrial fibrillation (AF) in the long term. We aimed to assess the presence of gaps (PVG) and residual potential (residual antral potential [RAP]) within the antral scar by means of an ultra-high-density mapping (UHDM) system., Methods: We studied consecutive patients from the CHARISMA registry who were undergoing AF ablation and had complete characterization of residual PV antral activity. The Lumipoint™ (Boston Scientific) map-analysis tool was used sequentially on each PV component. The ablation endpoint was PV isolation (PVI) and electrical quiescence in the antral region., Results: Fifty-eight cases of AF ablation were analyzed. A total of 86 PVGs in 34 (58.6%) patients and 44 RAPs in 34 patients (58.6%) were found. In 16 (27.6%) cases, we found at least one RAP in patients with complete absence of PV conduction. RAPs showed a lower mean voltage than PVG (0.3 ± 0.2 mV vs. 0.7 ± 0.5 mV, p < .0001), whereas the mean number of electrogram peaks was higher (8.4 ± 1.4 vs. 3.2 ± 1.5, p < .0001). The percentage of patients in whom RAPs were detected through Lumipoint™ was higher than through propagation map analysis (58.6% vs. 36.2%, p = .025). Acute procedural success was 100%, with all PVs successfully isolated and RAPs completely abolished in all study patients. During a mean follow-up of 453 ± 133 days, 6 patients (10.3%) suffered an AF/AT recurrence., Conclusion: Local vulnerabilities in antral lesion sets were easily discernible by means of the UHDM system in both de novo and redo patients when no PV conduction was present., (© 2022 Wiley Periodicals LLC.)

Background: Radiofrequency (RF) lesion creation is related to the heat propagation induced by RF application on tissues. Thermocouple embedded in the RF antenna are not able to predict deep tissue temperature at various level., Objectives: This study aims to investigate the influence of power delivered on radiofrequency catheter ablation (RFCA) effects by means of high resolved 2D temperature maps., Methods: Three trials of four ablations (12 applications) were executed on each specimen of healthy excised swine myocardium in different application points at four RF power values (30 W, 40 W, 50 W, and 60 W) for a fixed treatment time. All the data provided by the fiber Bragg gratings (FBGs) were analyzed. Temperature variations (ΔT) in time recorded in the 28 sites of measurements were reported. Also, temperature maps showing the ΔT spatial distribution reached within the tissue at the end of the RFCA were produced and displayed, together with the representation of the lethal isotherm. Moreover, the time of achievement of the lethal isotherm at different tissue depths (from 1 to 8 mm) was evaluated for the four power settings., Results: Temperature trends reported comparable profiles across the different power settings. ΔT values and ΔT rising times showed dependence on the sensors' proximity to the RF energy source and on the set RF power. Temperature maps confirmed that heat propagation occurs preferentially along the width of the tissue than in the depth. Also, for the adjusted treatment time, no power setting guarantees lesions thicker than 6 mm., Conclusions: ΔT maximal values and ΔT rising time strongly depends on the proximity of the tissues to RF energy source, as well as on the RF power setting. A plateau is reached in lesion size, regardless of the power setting. A first correlation between lesion size, power setting, and time to achieve lethal isotherms has been established., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Background: The antral region of pulmonary veins (PV)s seems to play a key role in a strategy aimed at preventing atrial fibrillation (AF) recurrence. Particularly, low-voltage activity in tissue such as the PV antra and residual potential within the antral scar likely represent vulnerabilities in antral lesion sets, and ablation of these targets seems to improve freedom from AF. The aim of this study is to validate a structured application of an approach that includes the complete abolition of any antral potential achieving electrical quiescence in antral regions., Methods: The improveD procEdural workfLow for cathETEr ablation of paroxysmal AF with high density mapping system and advanced technology (DELETE AF) study is a prospective, single-arm, international post-market cohort study designed to demonstrate a low rate of clinical atrial arrhythmias recurrence with an improved procedural workflow for catheter ablation of paroxysmal AF, using the most advanced point-by-point RF ablation technology in a multicenter setting. About 300 consecutive patients with standard indications for AF ablation will be enrolled in this study. Post-ablation, all patients will be monitored with ambulatory event monitoring, starting within 30 days post-ablation to proactively detect and manage any recurrences within the 90-day blanking period, as well as Holter monitoring at 3, 6, 9, and 12 months post-ablation. Healthcare resource utilization, clinical data, complications, patients' medical complaints related to the ablation procedure and patient's reported outcome measures will be prospectively traced and evaluated., Discussion: The DELETE AF trial will provide additional knowledge on long-term outcome following a structured ablation workflow, with high density mapping, advanced algorithms and local impedance technology, in an international multicentric fashion. DELETE AF is registered at ClinicalTrials.gov (NCT05005143)., (© 2022 The Authors. Clinical Cardiology published by Wiley Periodicals LLC.)

Purpose: Highly localized impedance (LI) measurements during atrial fibrillation (AF) ablation have emerged as a viable real-time indicator of tissue characteristics and the consequent durability of the lesions created. We investigated the impact of catheter-tissue contact force (CF) on LI behavior during pulmonary vein isolation (PVI)., Methods: Forty-five consecutive patients of the CHARISMA registry undergoing de novo AF radiofrequency (RF) catheter ablation with a novel open-irrigated-tip catheter endowed with CF and LI measurement capabilities (Stablepoint™ catheter, Boston Scientific) were included., Results: A total of 2895 point-by-point RF applications were analyzed (RF delivery time (DT) = 8.7±4s, CF = 13 ±±8 g, LI drop = 23 ±±7 Ω). All PVs were successfully isolated in an overall procedure time of 118 ±±34 min (fluoroscopy time = 13 ±±8 min). The magnitude of LI drop weakly correlated with CF (r = 0.13, 95% confidence interval (CI): 0.09 to 0.16, p < 0.0001), whereas both CF and LI drop inversely correlated with DT (r = -0.26, 95%CI: -0.29 to -0.22, p < 0.0001 for CF; r = -0.36, 95%CI: -0.39 to -0.33, p < 0.0001 for LI). For each 10 g of CF, LI drop markedly increased from 22.4 ± 7 Ω to 24.0 ± 8 Ω at 5 to 25 g CF intervals (5-14 g of CF vs 15-24 g of CF, p < 0.0001), whereas it showed smooth transition over 25 g (24.8 ± 7Ω at ≥ 25 g CF intervals, p = 0.0606 vs 15-24 g of CF). No major complications occurred during the procedures or within 30 days., Conclusions: CF significantly affects LI drop and probable consequent lesion formation during RF PVI. The benefit of higher contact (> 25 g) between the catheter and the tissue appears to have less impact on LI drop., Trial Registration: Catheter Ablation of Arrhythmias With High Density Mapping System in the Real World Practice (CHARISMA). URL: http://clinicaltrials.gov/ Identifier: NCT03793998., (© 2022. The Author(s).)

Background Sudden cardiac arrest (SCA) may be caused by an acute and reversible myocardial injury, a chronic and irreversible myocardial damage, or a primary ventricular arrhythmia. Cardiac magnetic resonance imaging may identify myocardial edema (ME), which denotes acute and reversible myocardial damage. We evaluated the arrhythmic outcome of SCA survivors during follow-up and tested the prognostic role of ME. Methods and Results We included a consecutive series of 101 (71% men, median age 47 years) SCA survivors from 9 collaborative centers who underwent early (<1 month) cardiac magnetic resonance imaging and received an implantable cardioverter-defibrillator (ICD). On T2-weighted sequences, ME was found in 18 of 101 (18%) patients. According to cardiac magnetic resonance imaging findings, the arrhythmic SCA was ascribed to acute myocardial injury (either ischemic [n=10] or inflammatory [n=8]), to chronic structural heart diseases (ischemic heart disease [n=11], cardiomyopathy [n=20], or other [n=23]), or to primarily arrhythmic syndrome (n=29). During a follow-up of 47 months (28 to 67 months), 24 of 101 (24%) patients received an appropriate ICD intervention. ME was associated with a significantly higher survival free from both any ICD interventions (log-rank=0.04) and ICD shocks (log-rank=0.03) and remained an independent predictor of better arrhythmic outcome after adjustment for left ventricular ejection fraction and late gadolinium enhancement. The risk of appropriate ICD intervention was unrelated to the type of underlying heart disease. Conclusions ME on early cardiac magnetic resonance imaging, which denotes an acute and transient arrhythmogenic substrate, predicted a favorable long-term arrhythmic outcome of SCA survivors. These findings may have a substantial impact on future guidelines on the management of SCA survivors.

This case report describes a third successful attempt to ablate a focal atrial tachycardia originating from the left atrial appendage in a highly symptomatic 49-year-old woman using a combined endocardial-epicardial approach, which could be taken into consideration as a safe and effective alternative method for treating similar arrhythmias originating from complex sites., Competing Interests: The authors report no conflicts of interest for the published content., (Copyright: © 2021 Innovations in Cardiac Rhythm Management.)

Nowadays, ablation of ventricular tachycardia (VT) in structural heart disease is an increasingly used procedure. In fact, it is the most effective strategy in controlling arrhythmic burden in VT patients. The ablative approaches are the result of the last 10 years of technological advances (Catheters, 3D mapping systems) and the constant study of the pathophysiological mechanisms underlying arrhythmic circuits. This presentation seeks to revisit the state of the art in the ablative treatment of VT., (Published on behalf of the European Society of Cardiology. © The Author(s) 2021.)

Background: Bipolar electrogram (EGM) duration is indicative of local activation property and, if prolonged, is useful to discover areas of slow conduction favoring arrhythmias., Objective: The present study aimed to create a map of EGM duration during the ventricular tachycardia (VT) (Ventricular Electrograms DUration as a Method map [VEDUM map]) to verify if the slowest activation area is crucial for reentry and could represent a suitable target for rapid VT interruption during ablation., Methods: Prospectively 30 patients were enrolled for this study. Twenty-one patients were selected, and 24 VT maps with complete circuit delineation (>90% tachycardia cycle length) were analyzed. Activation and VEDUM maps during VT as well as voltage maps during sinus rhythm were created., Results: Twenty-two of 24 VTs (88%) were interrupted during the first radiofrequency delivery (mean time 7.3 ± 5.4 seconds; range 3-25 seconds) at the area with the longest EGM duration (212 ± 47 ms; range 113-330 ms). The mean percentage of the cycle length of VT covered by the EGM with the longest duration was 58% ± 12%. In 9 patients (37%), the longest EGM was located at the isthmus entrance, at the exit in 7 maps (30%), and the mid-isthmuses in 8 maps (33%). In 6 patients (25%), the EGM covered the full diastolic phase. The mean isthmus width was 28 ± 11 mm (range 16-48 mm; median 25 mm)., Conclusion: A VEDUM map is highly accurate in defining a conductive vulnerable zone of the VT circuit. The longest EGM duration within the isthmus is highly predictive of rapid VT termination at the first radiofrequency delivery even in the case of large isthmuses., (Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Background: Highly localized impedance (LI) measurements during atrial fibrillation (AF) ablation have recently emerged as a viable real-time indicator of tissue characteristics and durability of the lesions created. We report the outcomes of acute and long-term clinical evaluation of the new DirectSense algorithm in AF ablation., Methods: Consecutive patients undergoing AF ablation were included in the CHARISMA registry. RF delivery was guided by the DirectSense algorithm, which records the magnitude and time-course of the impedance drop. The ablation endpoint was pulmonary vein isolation (PVI), as assessed by the entrance and exit block., Results: 3556 point-by-point first-pass RF applications of >10 s duration were analyzed in 153 patients (mean age=59 ± 10 years, 70% men, 61% paroxysmal AF, 39% persistent AF). The mean baseline LI was 105 ± 15 Ω before ablation and 92 ± 12 Ω after ablation (p < .0001). Both absolute drops in LI and the time to LI drop (LI drop/τ) were greater at successful ablation sites (n = 3122, 88%) than at ineffective ablation sites (n = 434, 12%) (14 ± 8 Ω vs 6 ± 4 Ω, p < .0001 for LI; 0.73 [0.41-1.25] Ω/s vs. 0.35[0.22-0.59 Ω/s, p < .0001 for LI drop/τ). No major complications occurred during or after the procedures. All PVs had been successfully isolated. During a mean follow-up of 366 ± 130 days, 18 patients (11.8%) suffered an AF/atrial tachycardia recurrence after the 90-day blanking period., Conclusion: The magnitude and time-course of the LI drop during RF delivery were associated with effective lesion formation. This ablation strategy for PVI guided by LI technology proved safe and effective and resulted in a very low rate of AF recurrence over 1-year follow-up., (© 2021 Wiley Periodicals LLC.)

Background: No data exist on the ability of the novel Rhythmia 3-D mapping system to minimize fluoroscopy exposure during transcatheter ablation of arrhythmias. We report data on the feasibility and safety of a minimal fluoroscopic approach using this system in supraventricular tachycardia (SVT) procedures., Methods: Consecutive patients were enrolled in the CHARISMA registry at 12 centers. All right-sided procedures performed with the Rhythmia mapping system were analyzed. The acquired electroanatomic information was used to reconstruct 3-D cardiac geometry; fluoroscopic confirmation was used whenever deemed necessary., Results: Three hundred twenty-five patients (mean age = 56 ± 17 years, 57% male) were included: 152 atrioventricular nodal reentrant tachycardia, 116 atrial flutter, 41 and 16 right-sided accessory pathway and atrial tachycardia, respectively. Overall, 27 481 s of fluoroscopy were used (84.6 ± 224 s per procedure, equivalent effective dose = 1.1 ± 3.7 mSv per patient). One hundred ninety-two procedures (59.1%) were completed without the use of fluoroscopy (zero fluoroscopy, ZF). In multivariate analysis, the presence of a fellow in training (OR = 0.15, 95% CI: 0.05-0.46; p = .0008), radiofrequency application (0.99, 0.99-1.00; p = .0002), and mapping times (0.99, 0.99-1.00; p = .042) were all inversely associated with ZF approach. Acute procedural success was achieved in 97.8% of the cases (98.4 vs. 97% in the ZF vs. non-ZF group; p = .4503). During a mean of 290.7 ± 169.6 days follow-up, no major adverse events were reported, and recurrence of the primary arrhythmia was 2.5% (2.1 vs. 3% in the ZF vs. non-ZF group; p = .7206)., Conclusions: The Rhythmia mapping system permits transcatheter ablation of right-sided SVT with minimal fluoroscopy exposure. Even more, in most cases, the system enables a ZF approach, without affecting safety and efficacy., (© 2021 Wiley Periodicals LLC.)

Objectives: This study aimed to describe the preliminary results of a modified sympathicotomy for cardiac sympathetic denervation (CSD), which may reduce the predictive risk and intraoperative surgical time of the procedure., Background: CSD, in patients with refractory ventricular tachycardia (VT), is comprehensively recognized as an important treatment option for patients with structural heart disease as well as congenital inherited arrhythmia syndrome., Methods: We consecutively enrolled 5 patients with refractory VT. Baseline demographic, medical, and surgical data as well as arrhythmia outcomes and procedural complications were evaluated., Results: A total of 5 patients (mean age: 67.4 years) were enrolled for the treatment of refractory VT with a modified CSD technique. In 3 of 5 patients, an overall reduction in VT burden (ranging from 75% to 100%) and VT number was observed after the CSD despite an in-hospital early recurrence., Conclusions: A modified CSD (sympathicotomy T2-T5) with stellate ganglion sparing and the use of unipolar radiofrequency is feasible, effective, and safe in the setting of untreatable VT., Competing Interests: Funding Support and Author Disclosures Dr. Cauti has received support from Abbott and Boston Scientific for EP and CRM proctoring. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2021 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Cardiac radiofrequency ablation (RFA) has received substantial attention for the treatment of multiple arrhythmias. In this scenario, there is an ever-growing demand for monitoring the temperature trend inside the tissue as it may allow an accurate control of the treatment effects, with a consequent improvement of the clinical outcomes. There are many methods for monitoring temperature in tissues undergoing RFA, which can be divided into invasive and non-invasive. This paper aims to provide an overview of the currently available techniques for temperature detection in this clinical scenario. Firstly, we describe the heat generation during RFA, then we report the principle of work of the most popular thermometric techniques and their features. Finally, we introduce their main applications in the field of cardiac RFA to explore the applicability in clinical settings of each method.

Competing Interests: The authors report no conflicts of interest for the published content.

Competing Interests: The authors report no conflicts of interest for the published content.