Catheter Ablation Of Ventricular Arrhythmias Research Articles

Real life experience with point by point pulsed field ablation for recurrent ventricular arrhythmias

Abstract Introduction The safety and effectiveness of electroporation/point by point pulsed field ablation (PP PFA) as emerging technoloy for catheter ablation (CA) of ventricular arrhythmias (VAs) has been described till now only in case reports. Purpose The aim of this observational retrospective study is to present real life data concerning the overall performance of PP PFA for CA of recurrent VA. Methods A total number of 13 consecutive patients (11 VTs and 2 PVCs), in whom recurrent VTs after RF ablation documented, were included. In all patients the substrate location was documented beforehand based on cardiac MRI or CT with myocardial thinning. For substrate mapping a high resolution multipoint mapping catheter was used. A complete success was defined as non inducibility of any arrhythmia at the end of procedure respectively lack of VA recurrence at follow – up. Results Excepting 2 patients, all other had a non ischemic cardiomyopathy as underlying heart disease (mean age 63 ± 8 y/o, mean LVEF 42 % ± 9 %). In every patient at least one conventional RF CA has been performed previously (mean 2 ± 1) and 38 % of patients had a previous epicardial RF VT ablation. The PP PFA VT ablation was performed endocardialy in 11 patients (84 %), respectively epicardialy in 2 patients. The ablation sites had a septal location in 53 % of patients and other localisation in 47 % of patients. The applied energy was 25 A. The overall acute complete success was achieved in 77 % patients. At medium 6 ± 3 months follow up a complete success was present in 46 % cases. Most frequently a VT recurrence after PP PFA ablation was encountered in patients with combined septal and nonseptal substrate distrubution. After PP PFA, the RF CA strategy due to recurrent VAs was endocardial in 2 patients, respectively epicardial 2 in cases and bipolar in 1 case. No PP PFA redos were undergone. Three major complications have been documented (1 tamponade, 1 AV block III° and 1 complete LBBB). Conclusion As bailout strategy in patients with failed conventional CA, PP PFA represents a safe strategy. Specific complications like temporary atrioventricular or intraventricular conduction disturbancies are extremely rare, reversible but not life threathening. The midterm success is satisfactory but still limited in patients with intramural substrate.

Novel systematic processing of cardiac magnetic resonance imaging identifies target regions associated with infarct-related ventricular tachycardia

Abstract Introduction In the clinic, complete characterization of reentrant ventricular tachycardia (VT) circuits using classical electrophysiological criteria and state-of-the-art high density mapping during VT is complex, and often cannot be completed because of hemodynamic instability. This common limitation has motivated the implementation of mapping strategies during sinus rhythm or ventricular pacing aiming to identify scar regions associated with VT isthmuses or potential arrhythmogenicity. Complementary imaging-based strategies including advanced analyses of scar tissue characteristics have been also proposed for procedure planning and identification of potential arrhythmogenic regions. However, the most recent expert consensus report on catheter ablation of ventricular arrhythmia highlights the lack of agreement on the preferable signal intensity (SI) cut-off values for assessment of tissue heterogeneity and scar areas on late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) images. The latter makes LGE-CMR imaging processing highly operator-dependent and potentially sensitive to selection bias. Purpose We aimed at developing and validating a systematic processing approach on LGE-CMR images to identify potential VT corridors that may include protected isthmuses associated with VT maintenance. Methods Translational study including 18 pigs with established myocardial infarction and inducible VT undergoing in vivo characterization of the anatomical and functional myocardial substrate associated with VT maintenance. Clinical validation was conducted in a multicenter series of 33 patients with ischemic cardiomyopathy undergoing VT ablation. Three-dimensional CMR-LGE images were processed using systematic scanning of 15 signal intensity cut-off ranges to obtain surface visualization of all potential VT corridors. Analysis and comparisons of imaging and electrophysiological data were performed in individuals with full electrophysiological characterization of the isthmus sites of at least one VT morphology. Results In both the experimental pig model and patients undergoing VT ablation, all the electrophysiologically-defined isthmus sites (n=11 and n=19, respectively) showed overlapping regions with CMR-based potential VT corridors. Such imaging-based VT corridors were less specific than electrophysiologically-guided ablation lesions at functionally relevant isthmus sites (Figure). However, in patients, decreasing from 15 to 7 the number of signal intensity cut-off ranges for systematic imaging processing significantly reduced the area of imaging-based potential VT corridors, without diminishing the capability to detect functionally relevant VT isthmus sites. Conclusions Systematic processing of 3D LGE-CMR images provides unbiased identification of imaging based potential VT corridors that contain functionally relevant protected isthmus sites.

Effects of hemodynamic support on arrhythmia-free survival following catheter ablation of ventricular arrhythmias

Abstract Background Radiofrequency-guided catheter ablation is an established therapy for ventricular tachycardia (VA). Hemodynamic support (HS) is often required for patients suffering from incessant VA to guide ablation. Data on the outcome of patients receiving HS during VA ablation procedures are lacking. Purpose The aim of this observational study was to analyze the acute procedural success as well as long-term 36-month-VA-recurrence rates and mortality in patients requiring HS during VA ablation procedures. Methods Data from consecutive patients receiving HS during VA ablation procedures between 2015-2023 were analyzed. HS was defined as the use of an Impella, an extracorporeal membrane oxygenation (ECMO) or a left ventricular assist device (LVAD). HS-group patients were compared to patients that underwent VA ablation procedures without HS. All patients were continuously followed up in our outpatient clinic. Data on procedural parameters, acute success and complications as well as long-term VA-free survival and mortality were analyzed. Results A total of 95 consecutive patients (mean age 60.9 ± 11.0 years, 15% female) were included. 62 patients (65%, mean age 60.4±9.4 years, 16% female) receiving HS (ECMO or Impella: n=26, 42%; ECMO+Impella: n=7, 11%; LVAD: n=29, 47%) were compared to those without (mean age 61.7±13.5 years, 12 % female). In the HS-cohort a significantly lower left ventricular ejection fraction (LVEF) (p<0.001), a higher New York Heart Association (NYHA) functional class (p=0.013) and a more frequent antiarrhythmic drug use (p=0.045) was documented. Fluoroscopy times were significantly longer in the HS-group (HS: 10:22 ± 07:04 vs. no HS: 05:52 ± 02:50 minutes, p<0.001). Acute procedural success (HS: n=59, 95% vs. no HS: n=33, 100%, p=0.549) and major procedure complications (HS: n=4. 6% vs. no HS: n=4. 6%, p=1.000) were comparable between the two groups. Nevertheless, patients receiving HS had a significantly higher in-hospital mortality (HS: n=20, 32 % vs. no HS: n=2, 6%, p=0.004). The estimated 36-month-VA-free survival was comparable between the groups (Log-rank p=0.114). But Kaplan-Meier-plot analyses revealed a significantly higher estimated mortality in patients receiving HS (Log-rank p=0.002) (Figure 1). Between the subgroups (ECMO or Impella vs. LVAD) no statistically relevant differences were observed (Log-rank p=0.466). Multivariate analyses revealed HS as an independent predictor for mortality (Hazard ratio (HR) 3.259, Confidence Interval (CI) 1.060-10.015, p=0.039), but not for VA-recurrence. Conclusion In the specific cohort of patients receiving HS, VA ablation procedures seem to be safe and effective with comparable acute and long-term success- and complication-rates. The need for HS seems to be associated with an increased risk for mortality. Further studies are required to validate our initial observations.Kaplan-Meier-plot on 36-month survival

First experience of focal pulsed field ablation for premature ventricular contractions

Abstract Introduction Pulsed field ablation (PFA) has emerged as a novel strategy to achieve ablation of cardiac tissue. Clinical evidence suggests a remarkable lesion durability and safety profile for AF ablation. Nonetheless, a growing interest exists in broadening its field of application for catheter ablation of ventricular arrhythmias (VA). The CENTAURI system arises as a promising PFA system for targeting VA as it allows pulsed electric field (PEF) delivery via standard, commercially available focal ablation catheters and concomitant coupling with their mapping systems. Purpose To assess, for the first time, the feasibility of focal PFA via the CENTAURI system for premature ventricular complex (PVC) ablation. Methods We conducted a prospective analysis of patients with either high burden (>10%) or symptomatic idiopathic PVC undergoing focal PFA using CENTAURI system at our institution. Procedures were performed between December 2022 and August 2023. Acute and long-term success were defined as no PVC recurrence during a 24h in-hospital monitoring period, and ≥80% burden reduction with absence of symptoms after at least 30 days post-ablation, respectively. PVC monitoring was performed by implantable loop recorder (ILR) or surface ECG Holter monitoring. Results Fourteen patients (age range: 16-87 years; 10 females) were included. Procedures were performed via the CENTAURI system in combination with CARTO 3 system and EnSite X EP system in 4 (28.6%) and 10 cases (71.4%) respectively. Targeted ablation sites were the right ventricular outflow tract (6 cases), right moderator band (2 cases), left postero-medial papillary muscle -PM- (2 cases), and right posterior PM, tricuspid annulus, left posterior fascicle and aortomitral continuity (AMC) in one case. On average, 6.5 applications were delivered to the site of origin with a mean contact force of 11g. Procedural duration and fluoroscopy time were 102 and 8.9 minutes. Two minor complications were observed: one transitory ST depression (solved after i.v. nitrate administration) after repeated applications to AMC, and a femoral pseudoaneurysm. The remaining 12 procedures were uneventful. Although most of the procedures were performed under general anesthesia due to concerns about potential significant muscular contraction, 3 cases (21.4%) were successfully managed with light sedation, without significant muscular contraction nor map shift. Incomplete abolishment of PVC during first 24 h was observed in 2 patients (14.3%). After a median follow-up of 113 days (IQR: 83-188), recurrences were detected in one patient (7.14%). Conclusion Herein we report the feasibility and efficacy of PVC ablation using a focal PEF delivery system (CENTAURI). Furthermore, we describe the possibility of performing PVC ablation with this technology under light sedation, which might be important for minimizing anesthesia impact on PVC burden.Table of characteristicsPVC morphologies

Anatomical approach to suppression of para-Hisian ventricular arrhythmias with changes in QRS morphology following ablation at the earliest activation site

The anatomical approach for the management of para-Hisian ventricular arrhythmias (VAs) with QRS morphological changes following catheter ablation (CA) has not been well investigated. We aimed to evaluate the electrocardiographic and electrophysiological findings and ablation outcomes of para-Hisian VAs with QRS morphological changes following CA. Among 30 patients who underwent CA for para-Hisian VAs at four institutions, 10 (33%) had QRS morphological changes following ablation. All 10 patients underwent an anatomical approach, targeting the site anatomically opposite to the site where the QRS morphology had been changed by ablation. We investigated the safety and efficacy of the anatomical approach. Among the 10 patients evaluated, the approach was switched from the right ventricular septum to the left ventricular septum/aortic root in seven (RL group), whereas three underwent left-to-right switches (LR group). Following CA, the precordial transition zone tended to be earlier in the RL group and later in the LR group. In the RL group, successful VA suppression was achieved despite suboptimal pace map concordance from the left side or a relatively delayed earliest activation time. Of the 10 patients who underwent an anatomical approach, eight had procedural success, and ablation was discontinued in one due to the risk of atrioventricular block. The anatomical approach showed promising results regarding safety and efficacy. Therefore, it should be considered when QRS morphological changes are observed during or after CA of para-Hisian VAs.

Management of ventricular tachycardias: insights on centre settings, procedural workflow, endpoints, and implementation of guidelines-results from an EHRA survey.

Ventricular tachycardia (VT), and its occurrence, is still one of the main reasons for sudden cardiac death and, therefore, for increased mortality and morbidity foremost in patients with structural heart [Kahle A-K, Jungen C, Alken F-A, Scherschel K, Willems S, Pürerfellner H et al. Management of ventricular tachycardia in patients with ischaemic cardiomyopathy: contemporary armamentarium. Europace 2022;24:538-51]. Catheter ablation has become a safe and effective treatment option in patients with recurrent VT [Cronin EM, Bogun FM, Maury P, Peichl P, Chen M, Namboodiri N et al. 2019 HRS/EHRA/APHRS/LAHRS expert consensus statement on catheter ablation of ventricular arrhythmias. Heart Rhythm 2020;17:e2-154]. Previous and current guidelines provide guidance on indication for VT ablation and risk assessment and evaluation of underlying disease. However, no uniform recommendation is provided regarding procedural strategies, timing of ablation, and centre setting. Therefore, these specifics seem to differ largely, and recent data are sparse. This physician-based European Heart Rhythm Association survey aims to deliver insights on not only infrastructural settings but also procedural specifics, applied technologies, ablation strategies, and procedural endpoints. Therefore, these findings might deliver a real-world scenario of VT management and potentially are of guidance for other centres.

Predictors of unsuccessful radiofrequency catheter ablation of idiopathic ventricular arrhythmias in children

Ventricular arrhythmias (VAs) in children are generally idiopathic and have a benign course. Catheter ablation (CA) is increasingly becoming a first-line treatment option in children with idiopathic VAs. Acute ablation success reaches 100% procedures and long-term – 87%. Predictors of outcomes of CA in pediatric patients with idiopathic VAs have not been fully investigated.Aim: To identify predictors of long-term unsuccessful outcomes of CA in pediatric idiopathic VAs.Material and Methods. This retrospective study included 164 children aged 7 to 17 years with idiopathic VAs, who underwent CA from 2011 until 2023 in Almazov National Medical Research Centre. Efficiency was assessed in acute period and 6 months after CA.Results. In this study the acute success was 92% and long-term success was 88,4%. In multivariable models, multifocal VAs (odds ratio: 8,814; 95% CI: 1,943–39,981; p = 0,005), effectiveness of antiarrhythmic therapy (odds ratio: 16,522; 95%CI: 1,959–139,374; p = 0,010) and noninducibility of VAs during procedure (odds ratio: 9,369; 95% CI: 1,400–62,684; 0,021), become predictors of long-term unsuccessful outcomes of CA in pediatric idiopathic VAs.Conclusion. In our study there were identified independent predictors of long-term noneffective CA in children with idiopathic VAs, such as multifocal VAs, effectiveness of antiarrhythmic therapy, and noninducibility of VAs CA. In patients with presence of two or more ventricular foci and the effectivness of antiarrhythmic therapy, prolongate drug therapy may be more preferable.

Anesthetic Management for Ventricular Tachycardia Ablation: A National Anesthesia Clinical Outcomes Registry Analysis

Objectives: We analyzed anesthetic management trends during ventricular tachycardia (VT) ablation, hypothesizing that (1) monitored anesthesia care (MAC) is more commonly used than general anesthesia (GA), (2) MAC use significantly increased after release of the 2019 Expert Consensus Statement on Catheter Ablation of Ventricular Arrhythmias, and (3) anesthetic approach varies based on patient and hospital characteristics. Design: Retrospective study. Setting: National Anesthesia Clinical Outcomes Registry data. Participants: Patients ≥18 years who underwent elective VT ablation between 2013-2021. Interventions: None. Measurements and main results: Covariates were selected a priori within multivariate models, and interrupted time-series analysis was performed. Of the 15,505 patients who underwent VT ablation between 2013-2021, 9,790 (63.1%) received GA. After the 2019 Expert Consensus Statement on Catheter Ablation of Ventricular Arrhythmias supported avoidance of GA, no statistically significant increase in MAC was evident (immediate change in intercept post-consensus statement release AOR 1.41, p=0.1629; change in slope post-consensus statement release AOR 1.06 per quarter, p=0.1591). Multivariate analysis demonstrated that sex, ASA physical status, age, and geographic location were statistically significantly associated with anesthetic approach. Conclusions: GA has remained the primary anesthetic type for VT ablation despite the 2019 Expert Consensus Statement on Catheter Ablation of Ventricular Arrhythmias suggesting its avoidance in idiopathic VT. Achieving widespread clinical practice change is an ongoing challenge in medicine, emphasizing the importance of developing effective implementation strategies to facilitate awareness of guideline release and subsequent adherence to and adoption of recommendations.

Stroke and Bleeding Risks of Endocardial Ablation for Ventricular Arrhythmias

BackgroundRisks of radiofrequency catheter ablation for ventricular arrhythmias include emboli and bleeding complications but data on antithrombotic regimens are limited and guidelines do not specify a systematic approach. ObjectivesThis study sought to assess embolic and bleeding complications in relation to pre-periprocedure and post-periprocedure antithrombotic regimens. MethodsProspective assessment for complications was performed for 663 endocardial radiofrequency catheter ablation procedures in 616 consecutive patients (median age 64 years [Q1-Q3: 54-73 years], 70.3% men, 71.6% with cardiomyopathy, 44.5% with sustained ventricular tachycardia). ResultsThere were 2 strokes (0.3%; 95% CI: 0.0%-0.8%), 1 transient ischemic attack (0.15%), and 2 pulmonary emboli (0.3%). There were 39 bleeding complications (5.9%) including 11 pericardial effusions (1.7%), and 28 related to vascular access (4.2%). Consistent with the prevalence of coronary artery disease (47.5%), atrial fibrillation (30.0%), and prior stroke (10.6%), preprocedure, 464 patients (70.0%) were taking antithrombotic agents including 220 (33.2%) taking aspirin alone (ASA), and 163 (24.6%) taking warfarin or a direct acting oral anticoagulant (DOAC). Preprocedure non-ASA antiplatelet use (OR: 2.846; P = 0.011) and DOAC use (OR: 2.585; P = 0.032) were associated with risk of bleeding complications. Following ablation, 49.8% of patients were treated with ASA 325 mg/d and 30.3% received DOACs or warfarin. New DOAC or warfarin administration was initiated in only 6.6% of patients. Overall, 39.7% of patients continued the same preprocedure antithrombotic regimen. ConclusionsStroke is a rare complication of radiofrequency catheter ablation for ventricular arrhythmia using ASA 325 mg/d as a minimal postprocedure regimen with more potent regimens for selected patients.

Radiofrequency catheter ablation of ventricular arrhythmias in patients with hypertrophic cardiomyopathy

BackgroundCompared to other non-ischemic substrates, there is limited data on the role and outcome of catheter ablation in HCM. The objective of this study is to assess the safety and efficacy of catheter ablation for the treatment of VT in patients with HCM. MethodsFourteen patients with HCM and drug refractory VT who underwent catheter ablation at a single center were included in this study. The data was evaluated retrospectively. Acute success, procedure-related complications, and long-term outcomes were documented during follow up. ResultsAmong the 14 patients (mean age 48.2 ± 8.2 years, 85.7% males, mean LVEF 42.6 ± 6.5%), 4 had an apical aneurysm. Eleven patients had evidence of scar-related VT and three patients had a bundle-branch re-entry VT. The most common sites for scar-related VT were the border-zones of the apical aneurysms, basal septum, and LV lateral wall. Patient either underwent an endocardial ablation or a combined endocardial and epicardial ablation. Acute success was achieved in all patients. In 6 patients VT was terminated during ablation. In two patients, non-clinical VTs were inducible at the end of the procedure. No major or minor complications were observed during and after the procedure in all patients. During long-term follow up, elimination of VTs reached 78%. ConclusionCatheter ablation of VT in patients with HCM is safe and successful in eliminating VT. Combining endocardial and epicardial ablation techniques can potentially lead to better outcomes in these patients. Bundle branch re-entry should be considered as a potential mechanism of VT in patients with HCM.

How Imaging Techniques Improve Ventricular Arrhythmia Ablation: A Multimodality-Based Approach

Although implantable cardioverter defibrillators offer the best protection against sudden cardiac death, catheter ablation for ventricular arrhythmias (VAs) can modify or prevent this event from occurring. In order to achieve a successful ablation, the correct identification of the underlying arrhythmogenic substrate is mandatory to tailor the pre-procedural planning of an ablative procedure as appropriately as possible. We propose that several of the imaging modalities currently used could be merged, including echocardiography (also intracardiac), cardiac magnetic resonance, cardiac computed tomography, nuclear techniques, and electroanatomic mapping. The aim of this state-of-the-art review is to present the value of each modality, that is, its benefits and limitations, in the assessment of arrhythmogenic substrate. Moreover, VAs can be also idiopathic, and in this paper we will underline the role of these techniques in facilitating the ablative procedure. Finally, a hands-on workflow for approaching such a VA and future perspectives will be presented.

Catheter ablation of ventricular arrhythmias in arrhythmogenic cardiomyopathy - comparison of different approaches and results of genetic testing

Abstract Introduction Arrhythmogenic cardiomyopathy (ACM) is a disease characterized by fatty-fibrous remodeling of the myocardium and a high risk of ventricular tachycardia (VT). Catheter ablation is an effective method that prevents VT recurrences. Although the arrhythmogenic substrate in ACM is located dominantly in the epicardium, in some patients VT can be effectively suppressed only by endocardial ablation. Purpose Retrospective analysis of catheter ablation results of VT in patients with ACM and right ventricular involvement. Methods Between 2001-2021, catheter ablation of VT was performed in 51 patients (mean age 43±18 years, 9 women) with a clinical diagnosis of ACM and right ventricular involvement. Pathogenic/likely pathogenic mutation was detected during the genetic testing in 80% of patients. Repeated ablation procedures were necessary to suppress VT (a total of 1.9±1.3 procedures/patient). According to the approach, patients were divided into three groups: A - endocardial ablation only (n=20); B - endocardial ablation first, followed by epicardial approach (n=15); C- primary epicardial approach (n=16). Results The primary epicardial approach (group C) compared to the endocardial approach (group A+B) was associated with better VT free survival (Figure 1, p<0.02) and significantly fewer procedures needed to suppress arrhythmia recurrences (1.1±0.2 vs 2.3±1.5 procedures/patient; p<0.005). Patients in whom an endocardial approach (group A) was sufficient to control arrhythmias were significantly older than patients in whom an epicardial approach (group B) had to be used (52.9±15.1 vs 36.0±16.0 years; p<0.001). The frequency of pathogenic mutations did not differ among groups (A - 83% vs B - 71% vs C - 86%; p=n.s.). The most commonly found mutation was in the gene for plakophilin 2 (51% of all patients). Conclusion Epicardial VT ablation in ACM patients with right ventricular involvement leads to the most effective control of arrhythmias. Endocardial ablation alone may be sufficient to control VT in older patients. The identification of a pathogenic/likely pathogenic mutation does not seem to be relevant for choice of ablation approach.Figure 1

Catheter ablation of ventricular tachycardia: strategies to improve outcomes.

Catheter ablation of ventricular arrhythmias has evolved considerably since it was first described more than 3 decades ago. Advancements in understanding the underlying substrate, utilizing pre-procedural imaging, and evolving ablation techniques have improved the outcomes of catheter ablation. Ensuring safety and efficacy during catheter ablation requires adequate planning, including analysis of the 12 lead ECG and appropriate pre-procedural imaging. Defining the underlying arrhythmogenic substrate and disease eitology allow for the developed of tailored ablation strategies, especially for patients with non-ischemic cardiomyopathies. During ablation, the type of anesthesia can affect VT induction, the quality of the electro-anatomic map, and the stability of the catheter during ablation. For high risk patients, appropriate selection of hemodynamic support can increase the success of VT ablation. For patients in whom VT is hemodynamically unstable or difficult to induce, substrate modification strategies can aid in safe and successful ablation. Recently, there has been an several advancements in substrate mapping strategies that can be used to identify and differentiate local late potentials. The incorporation of high-definition mapping and contact-sense technologies have both had incremental benefits on the success of ablation procedures. It is crucial to harness newer technology and ablation strategies with the highest level of peri-procedural safety to achieve optimal long-term outcomes in patients undergoing VT ablation.

Emergency out-of-hours catheter ablation for ventricular arrhythmia storm: a UK and Australian experience.

There are limited data on emergency catheter ablation (CA) for ventricular arrhythmia (VA) storm. We describe the feasibility and safety of performing emergency CA in an out-of-hours setting for VA storm refractory to medical therapy at 2 tertiary hospitals. Twenty-five consecutive patients underwent out-of-hours (5pm-8am [weekday] or Friday 5pm-Monday 8am [weekend]) CA for VA storm refractory to anti-arrhythmic drugs and sedation. Baseline and procedural characteristics along with outcomes were compared to 91 consecutive patients undergoing weekday daytime-hours (8am-5pm) CA for VA storm. More patients undergoing out-of-hours CA had a left ventricular ejection fraction ≤35% (68% vs. 42%, P = 0.022), chronic kidney disease (60% vs. 20%, P < 0.001), and presented following a resuscitated out-of-hospital cardiac arrest (56% vs. 5%, P < 0.001), compared to the daytime-hours group. During median follow-up (377 [interquartile range 138-826] days), both groups experienced similar survival free from recurrent VA and VA storm. Survival free from cardiac transplant and/or mortality was lower in the out-of-hours group (44% vs. 81%, P = 0.007), but out-of-hours CA was not independently associated with increased cardiac transplant and/or mortality (hazard ratio 1.34, 95% confidence interval 0.61-2.96, P = 0.47). Of the 11 patients in the out-of-hours group who survived follow-up, VA-free survival was 91% and VA storm-free survival was 100% at 1-year after CA. Out-of-hours CA may occasionally be required to control VA storm and can be safe and efficacious in this scenario. During follow-up, cardiac transplant and/or mortality is common but undergoing out-of-hours CA was not predictive of this composite endpoint.

Impact of cardiac sympathetic denervation on electrical storms in patients with cardiomyopathies

Abstract Funding Acknowledgements Type of funding sources: None. Background Cardiac Sympathetic Denervation (CSD) has been recently proposed for the treatment of refractory ventricular arrhythmias (VAs) in patients with cardiomyopathy (CMP). A multicentric American case series suggested a greater efficacy of the bilateral (BCSD), compared to the left-side only procedure (LCSD), albeit with a potential impact on chronotropism. The impact of CSD on the risk of electrical storms (ES) in CMP has never been evaluated. Purpose To describe our multicenter experience with CSD in CMP patients with refractory VAs, with a specific focus on ES incidence. Methods Thirty patients with CMP and refractory VAs underwent either LCSD or BCSD between April 2016 and June 2022. Among them, one patient received first LCSD and then right-side CSD due to ES recurrence after LCSD: to properly assess the risk of ES after LCSD and BCSD he was included in both groups, leading to 5 cases of LCSD and 26 cases of BCSD. All patients had a Video-Assisted Thoracoscopic Surgery, in 8 cases with the robotic technique. The main reason (3/5 cases, 60%) to perform LCSD instead of BCSD since the beginning was sinus bradycardia in single ICD lead recipients. Results 87% of pts were male, mean age was 56 ± 16 yrs and mean LVEF 31± 12%; most (n=26, 85%) suffered non-ischemic CMP and 37% were in NYHA class ≥3. Main indications for CSD were refractory polymorphic/fast VAs in 60% of pts and refractory monomorphic VAs in the rest. Except for 5 patients (17%) with previous thyrotoxicosis, the majority were either on amiodarone (n=19, 63%) or on sotalol (n=3, 10%) and 53% had previously undergone ≥1 catheter ablation for VAs. The median follow-up (FU) after CSD was 16 months (IQR 6-42 months). No major complications occurred. Eleven patients (37%) either died during FU (n=8, 27%), mostly due to end-stage heart failure, or underwent heart transplant (n=3, 10%). After CSD, the percentage of patients with ES decreased from 77% to 40% (p&amp;lt;0.01), while patients with appropriate shocks decreased from 100% to 60%. The figure shows the significant impact of CSD on VT burden. The antiarrhythmic benefit was more pronounced after BCSD: ES incidence decreased from 85% to 39% (p&amp;lt;0.01), ICD shock incidence from 100% to 54% (p&amp;lt;0.01), while no significant changes in ES and ICD shock incidence were observed after the few LCSD procedures (n=5). Survival free from ICD shock at 1 year was better among patients with a NYHA class &amp;lt;3 (73% versus 15%, p&amp;lt;0.001). Conclusions Our case series of CSD in CMP represents the largest reported in Europe and the first one to evaluate the impact of CSD on electrical storms. The occurrence of electrical storms was more than halved by BCSD confirming the powerful protective effect also on this ominous phenomenon. The greater antiarrhythmic benefit observed among patients with better functional class suggests the opportunity to perform this procedure earlier on in the trajectory of patients with progressive heart failure.

Characteristics and outcomes of catheter ablation of ventricular arrhythmias originating from the left ventricular summit

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Catheter ablation (CA) of the left ventricular summit (LVS) arrhythmias is a challenging procedure due to the inherent complexity anatomy of that region. Different anatomical approaches are usually performed for mapping this area including deep intramural location. The objective of this study is to investigate the procedural outcomes of ablation of LVS arrhythmias. Methods Retrospective analysis of 32 consecutive patients (mean age 58±12 years old) who underwent CA of LVS arrhythmia in a single center. Baseline characteristics, procedural parameters and clinical outcomes were analyzed. Results All LVS arrhythmias had inferior and vertical axis (positive inferior leads with negative aVR and aVL leads). LBBB pattern was found in 25/32 (78%) and RBBB pattern in 7/32 (22%). 14/32 (44%) patients presented a "w" morphology in DI lead. 18/32 (56%) cases showed abrupt V3 transition. 13/32 (41%) patients had a previous failed ablation. Direct mapping of the intramural septum, through the septal perforator veins, was performed using a wire or a multipolar 2Fr catheter in 19 patients (59%). The earliest activation area was recorded in LCC-RCC in 13 patients (41%) followed by a septal perforator vein in 9 patients (28%). Most patients required multisite sequential ablation for achieving success (20 patients, 62%). Acute arrhythmia suppression was achieved in 22 patients (69%) and only 1 patient presented a complication (pericardial tamponade). Late success was noted in 3 patients (9%). During a median follow up of 9,79±8,6 months, 23 patients (72%) maintained a sustained acute success (80% reduction of PVC burden at least) None of the 9 patients without sustained acute success needed to repeat ablation. Conclusions Ablation of LVS arrhythmias is a challenging procedure with frequent previous ablation attempts. The earliest activation area is commonly found between LCC-RCC junction and in the intramural septum. Multisite non-conventional anatomical mapping and ablation steps are required to obtain a sustained success.

C3 OUTCOME OF CARDIAC SYMPATHETIC DENERVATION IN CARDIOMYOPATHIES AND PREDICTORS OF RECURRENCES

Abstract Background Cardiac Sympathetic Denervation (CSD) has been recently proposed for the treatment of refractory ventricular arrhythmias (VAs) in patients with cardiomyopathy (CMP). Long–term outcome and predictors of recurrences after the procedure are still poorly defined. Aim: To describe our multicenter Italian experience with CSD in CMP patients with refractory VAs. Methods 32 patients with CMP and refractory VAs underwent either left CSD (n=4) or BCSD (n=28). All patients had a Video Assisted Thoracoscopic Surgery, in 8 cases with the robotic technique. The main reason (3/4 cases, 75%) to perform LCSD instead of BCSD was sinus bradycardia in single ICD lead recipients. Results 84% of patients were male, mean age was 55 ± 16 yrs and mean LVEF was 32± 12%; most (n=26, 81%) had non–ischemic CMP (including 3 with hypertrophic CMP and 2 with cardiolaminopathy) and 34% were in NYHA class ≥3. Main indications for CSD were refractory polymorphic/fast VAs (&amp;gt;200 bpm) in 56% of pts and refractory monomorphic VAs in the rest. Except for 5 patients (15%) with previous thyrotoxicosis, the majority were either on amiodarone (n=20, 63%) or on sotalol (n=3, 9%) and 53% had previously undergone ≥1 catheter ablation for VAs. The median follow–up (FU) after CSD was 16 months (IQR 5–45 months). No major complications occurred. Eleven patients (34%) either died during FU (n=8, 25%), mostly due to end–stage heart failure, or underwent heart transplant (n=3, 9%). After CSD, the percentage of patients with ES decreased from 78% to 40% (p&amp;lt;0.01), while patients with appropriate ICD shocks decreased from 100% to 62%. The mean number of ICD shocks was reduced from 6 (IQR 3–16) in the 6 months before CSD to 0 (IQR 0–2) in the 6 months after (p=0.001). Overall, 69% of patients experienced a 6–months reduction in ICD shocks ≥ 75%, 81% a reduction ≥ 50%. At the univariate Kaplan Meier survival analysis, NYHA class ≥ 3 (p&amp;lt;0.001), VT heart rate &amp;lt; 180 bpm (p=0.02) and left ventricular ejection fraction (LVEF) ≤ 25% (p=0.02) were associated with ICD shock recurrences. Conclusions Our case series of CSD in CMP represents the largest reported in Europe and the one with the longest follow–up. The occurrence of electrical storms was almost halved by CSD, and most patients had a reduction in ICD shocks at 6 months larger than 75%. Patients with better functional class, better LVEF and faster VAs benefited more from CSD, suggesting the opportunity of an earlier referral of these patients.

Predictors for major in-hospital complications after catheter ablation of ventricular arrhythmias: validation and modification of the Risk in Ventricular Ablation (RIVA) Score.

Catheter-based treatment of patients with ventricular arrhythmias (VA) reduces VA and mortality in selected patients. With regard to potential risks of catheter ablation, a benefit-risk assessment should be carried out. This can be performed with risk scores such as the recently published "Risk in Ventricular Ablation (RIVA) Score". We sought to validate this score and to test for possible additional predictors in a large database of VT ablations. We analyzed 1964 catheter ablations for VA in patients with (1069; 54.4%) and without (893, 45.6%) structural heart disease (SHD) and observed an overall major adverse event rate of 4.0% with an in-hospital mortality of 1.3% with significantly less complications occurring in patients without structural heart disease (6.5% vs. 1.1%; p ≤ 0.01). The RIVA Score demonstrated to be a valid predictive tool for major in-hospital complications (OR 1.18; 95% CI 1.12, 1.25; p ≤ 0.001). NYHA Class ≥ III (OR 2.5; 95% CI 1.5, 4.2; p < 0.001) and age (OR 1.04; 95% CI 1.02, 1.07; p ≤ 0.001) proved to be additional predictive parameters. Hence, a modified RIVA Score (mRIVA) model was analyzed with a subset of established predictors (SHD, eGFR, epicardial puncture) as well as new predictive parameters (age, NYHA Class ≥ III), that achieved a higher predictive value for major complications compared with the model based on all RIVA variables. Adding age and functional heart failure status (NYHA class) as simple clinical parameters to the recently published RIVA Score increases the predictive value for ablation-associated complications in a large VT ablations registry.

PO-01-021 VASCULAR ACCESS COMPLICATIONS DURING CATHETER ABLATION OF VENTRICULAR ARRHYTHMIAS: IMPACT OF VASCULAR CLOSURE DEVICE

In patients (pts) with ventricular arrhythmias (VAs) undergoing catheter ablation (CA), the need for multiple vascular access points with large bore sheaths predisposes to vascular complications. Whether arterial/venous vascular closure devices prevent vascular complications is unknown. We investigated the benefit of vascular closure devices in pts undergoing CA of VAs. Consecutive pts undergoing CA of VAs between 2018-2020 were included. Vascular accesses were obtained with ultrasound guidance. At the discretion of the operator, arterial (Perclose or AngioSeal) and/or venous (Vascade or figure-of-eight suture) were used. Pts were divided into 3 groups: no use of vascular closure devices for any of the arterial/venous accesses (No-Closure), use of vascular closure devices for some but not the all of the arterial/venous accesses (Partial-Closure), use of vascular closure devices for all of the arterial/venous accesses (Complete-Closure). Vascular complications were defined minor if they didn’t require intervention or major if they required intervention (transfusion, percutaneous/surgical repair). 522 pts (62±13 years, BMI 30±6 kg/m2, 26% female) underwent ablation of VT (41%) or PVCs (59%) during the study period. 134 (34%) were on oral anticoagulation before the procedure (interrupted in 129, uninterrupted in 5). 477 arterial accesses were obtained in 471 (90%) pts (single access in 465 pts – 7.5±1.4 Fr size, two accesses in 6 – 7±1.5 Fr and 7±4 Fr). 1258 venous accesses were obtained in 520 (99.6%) pts (unilateral in 24%, bilateral in 75.6%, N. of accesses 2.4±0.7/pt, size 8.4±1.33 Fr). 142 (27%) pts received No-Closure, 201 (39%) Partial-Closure and 179 (34%) Complete-Closure. A vascular access-related complication occurred in 31 (5.9%) pts, including a minor hematoma in 4.6% and a major complication in 1.3%. The rate of vascular complications was 7% (5.6% minor and 1.4% major) in the No-Closure group, 6.9% (5% minor and 1.9% major) in the Partial-Closure group, and 3.9% (3.4% minor and 0.5% major, P=0.15 for comparison) in the Complete-Closure group. In pts undergoing CA of VAs, Complete-Closure using dedicated arterial/venous closure devices/sutures appeared associated with lower absolute rates of minor and major vascular-related complications compared to No-Closure or Partial-Closure. Although the differences did not reach statistical significance, they suggest a potential benefit of Complete-Closure and require further investigation in larger cohorts.

Combination of Intracardiac Echocardiography and Contact Force Sensing for Left Ventricular Papillary Muscle Arrhythmias.

The catheter ablation of ventricular arrhythmias (VAs) arising from the left ventricular (LV) papillary muscles (PMs) is challenging. This study sought to address whether the combination of intracardiac echocardiography (ICE) and contact force sensing (CFS) can improve the acute and long-term ablation outcomes of left ventricular papillary muscle arrhythmias. From May 2015 to August 2022, a total of thirty-three patients underwent catheter ablation for LV PM arrhythmias: VAs were located in anterolateral PMs in 11 and posteromedial PMs in 22. A combination of intracardiac echocardiography (ICE) and contact force sensing (CFS) was used in 21 of the 33 procedures. A mean of 6.93 ± 4.91 for lesions was used per patient, comparable between the CFS/ICE and no ICE/CFS (4.90 ± 2.23 vs. 10.17 ± 5.89; p = 0.011). The mean CF achieved in the ICE/CFS group was 7.52 ± 3.31 g. Less X-ray time was used in the combination group (CFS/ICE: 165.67 ± 47.80 S vs. no ICE/CFS: 365.00 ± 183.73 S; p < 0.001). An acute success rate of 100% was achieved for the ICE/CFS group (n = 22) and 66.67% for the no ICE/CFS group (n = 8). VA recurrence at the 11.21 ± 7.21-month follow-up was 14.2% for the ICE/CFS group and 50% for the no ICE/CFS group (p = 0.04). No severe complications occurred in all patients. The combination of intracardiac echocardiography (ICE) and contact force sensing (CFS) could provide precise geometries of cardiac endocavitary structures and accurate contact information for the catheter during ablation, which improved acute and long-term ablation outcomes. The routine adoption of this strategy should be considered to improve the outcomes of LV PM VA ablation.