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Objectives This study evaluated the long-term efficacy of a standard antithrombotic strategy versus half-dose direct oral anticoagulation (DOAC) after Watchman implantation. Background No consensus currently exists on the selection of the most effective antithrombotic strategy to prevent device-related thrombosis (DRT) in patients undergoing endocardial left atrial appendage closure. Methods After successful left atrial appendage closure, consecutive patients were prescribed a standard antithrombotic strategy (SAT) or long-term half-dose DOAC (hdDOAC). The primary composite endpoint was DRT and thromboembolic (TE) and bleeding events. Results Overall, 555 patients (mean age 75 ± 8 years, 63% male; median CHA2DS2-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 4 [interquartile range (IQR): 3-6]; median HAS-BLED [hypertension, abnormal renal or liver function, stroke, bleeding, labile international normalized ratio, elderly, drugs or alcohol] score 3 [IQR: 2-4]) were included. Patients were categorized into 2 groups (SAT: n = 357 vs hdDOAC: n = 198). Baseline clinical characteristics were similar between groups. The median follow-up duration was 13 months (IQR: 12-15 months). DRT occurred in 12 (2.1%) patients, all in the SAT group (3.4% vs 0.0%; log-rank P = 0.009). The risk of nonprocedural major bleeding was significantly more favorable in the hdDOAC group (0.5% vs. 3.9%; log-rank P = 0.018). The rate of the primary composite endpoint of DRT and TE and major bleeding events was 9.5% in SAT patients and 1.0% in hdDOAC patients (HR: 9.8; 95% CI: 2.3-40.7; P = 0.002). Conclusions After successful Watchman implantation, long-term half-dose DOAC significantly reduced the risk of the composite endpoint of DRT and TE and major bleeding events compared with a standard, antiplatelet-based, antithrombotic therapy.

Introduction Watchman FLX has been recently approved for left atrial appendage occlusion (LAAO) in the US. Intracardiac echocardiography (ICE) - which is already commonly used to guide trans-septal access - can serve as an alternative to TEE, simplifying the procedure and reducing associated costs. Herein, we report our experience with ICE-guided LAAO with Watchman FLX. Methods and results This cohort study included the first 190 consecutive patients who underwent LAAO with Watchman FLX in our center. LAAO was successful in all patients without significant peri-procedural, device-related complications in either group. Compared to TEE, we observed a significant reduction in procedural times when using ICE. In addition, there was a potentially clinically relevant reduction in fluoroscopy dose, mainly secondary to fewer cine acquisition runs. At follow-up, no cases of device embolism were noted, whereas the rate of device-related thrombosis and peri-device leaks were comparable between groups. Conclusion ICE-guided LAAO with Watchman FLX is safe and feasible, with a significant reduction in procedural time and potential reduction in fluoroscopy dose when compared to TEE.

BACKGROUND We evaluated the efficacy of a new method in identifying peri-device leak (PDL) using morphology of the thrombus formed inside the left atrial appendage (LAA) as seen on follow-up transesophageal echo (TEE). METHOD A total of 291 consecutive patients undergoing Watchman procedure were included in this analysis. TEE was performed at 45 days postprocedure. Based on the presence of the thrombus inside the LAA behind the device, patients were grouped as (1) white (W) group: LAA completely filled with thrombus (n = 101), 2) nonwhite (NW) group: LAA completely black or mixed (part black and part white; n = 190). Follow-up TEE was repeated at 6 and 12 months. RESULTS Baseline characteristics were comparable between groups except the device size, number of patients with chicken-wing morphology, and prevalence of left atrial "smoke" that were significantly higher in the NW group. Detection of black appearance was comparable between the pre-coil closure image and the NW population (26/36 [72.2%] vs 99/154 [64.3%], p = .37). After adjusting for clinically relevant covariates, NW appearance of the LAA was associated with the presence of significant leak (odds ratio: 47.96, 95% confidence interval: 2.91-790.2, p

Rhythm control of persistent atrial fibrillation (AF) patients represents a challenge for the modern interventional cardiac electrophysiologist; as a matter of fact, there is still divergence regarding the best ablative approach to adopt in this population. Different investigational endpoints, variability of techniques and tools, significant technological evolution, and the lack of universally accepted pathophysiological models engendered a considerable heterogeneity in terms of techniques and outcomes, so much that the treatment of persistent subtypes of AF commonly still relies mainly on pulmonary vein (PV) isolation. The purpose of the present review is to report the current experimental and clinical evidence supporting the importance of mapping and ablating non-PV triggers and describe our institutional approach for the ablation of nonparoxysmal AF.

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the authors. The authors inadvertently specified some ablation settings in the methods section that should not have been reported because they can be potentially linked to a specific pulsed field ablation technology that is currently under investigation for FDA approval. The Authors apologize for the inconvenience caused by this oversightinsert 'Reason' text (to be provided by the Editor-in-Chief or written by the Publisher and approved by the Editor-in-Chief and then approved by the RR panel). In case of (suspected) plagiarism, it is mandatory to refer to the plagiarized work here byAbbreviated Journal Title, volume (year) first page - last page, http://dx.doi.org/DOI of plagiarized work (in URL format) coded as inter-ref if possible.

Background Fragmented QRS (fQRS) on 12-lead electrocardiography is a noninvasive marker of intramyocardial conduction delay due to ventricular scarring that has not previously been studied in atrial fibrillation. Objective The purpose of this study was to assess the association of fQRS with left atrial (LA) scarring in patients with persistent atrial fibrillation (PsAF) undergoing first catheter ablation. Methods A total of 376 patients with PsAF were enrolled. Severity of LA scarring was assessed using electroanatomic mapping. Narrow fQRS was defined by the presence of an additional R wave (R′) or notching in the nadir of the S wave, or the presence of >1 R′ in 2 contiguous leads corresponding to inferior, lateral, or anterior myocardial regions. Results Both any degree (97.3% vs 63.3%) and severe (42.2% vs 6.3%) LA scarring were higher in patients with fQRS. Age and fQRS were found to be independent predictors of severe LA scarring. At multiple ventricular regions, fQRS had diagnostic accuracy of 79.8% for prediction of severe LA scarring. Nonpulmonary vein triggers were more often detected and ablated in patients with fQRS and severe LA scarring (84.4% vs 70%; P = .001). Atrial tachyarrhythmia recurrence was observed in 131 patients (34.8%) during 18.9 ± 7.7 months of follow-up, which was significantly higher in patients with fQRS (53.2% vs 16.8%). In multivariate analysis, fQRS was found to be a significant predictor of recurrence (hazard ratio 4.65; 95% interval confidence 2.91–7.42; P Conclusion The study results showed that fQRS is a simple, available, and noninvasive marker, and that fQRS at multiple ventricular regions is significantly associated with the severity of LA scarring in PsAF patients.

Background Atrial fibrillation (AF) triggers within the coronary sinus (CS)/great cardiac vein (GCV) and the left atrial appendage (LAA) have been recognized as nonpulmonary vein triggers of AF. Objective The aim of this study was to describe an electrical connection between the LAA and CS/GCV and its importance in achieving LAA electrical isolation (LAAEI). Methods A total of 488 consecutive patients undergoing catheter ablation for persistent or long-standing persistent AF who showed firing from the LAA and/or from the CS/GCV were enrolled in this multicenter prospective study. In all patients, potential defragmentation of the CS/GCV to achieve isolation and LAAEI was attempted with both endocardial and epicardial ablation. Results In 7% (n = 34) of these patients, after attempting endocardial LAAEI, the LAA was isolated during epicardial ablation in the GCV. In 8% (n = 39) of patients after attempting endocardial LAA isolation, the LAA was isolated during ablation along the endocardial aspect of the GCV. The presence of a venous branch connecting the GCV with the LAA was found in all these patients. In 23% (n = 112) of patients, the isolation of the LAA also isolated the GCV. In all these patients, LAA dissociated firing was present together with the CS/GCV recordings. Conclusion These findings suggest the presence of a distinct electrical connection between the GCV and the LAA. The clinical relevance of our results requires further investigation. Ablation in the CS/GCV can result in inadvertent isolation of the LAA. Ablation of the GCV is relevant to achieve LAAEI. Considering the potential long-term implications, ablation in the distal CS/GCV should prompt assessment of LAA conduction.

Background An increasing number of adults with congenital heart disease (CHD) are undergoing catheter ablation for atrial fibrillation (AF). Data on ablation strategy and outcomes in CHD are limited. Rhythm control is often believed to be of greater importance among patients with complex CHD. Objective The purpose of this study was to examine the safety and efficacy of AF ablation in adult patients with CHD. Methods A multicenter retrospective analysis was performed of CHD patients undergoing AF ablation. Clinical data were collected, including AF and CHD type, procedural data, and outcomes. Patients were divided into 3 groups (simple, moderate, and severe) based on CHD complexity, as defined by the 2014 PACES/HRS (Pediatric and Congenital Electrophysiology Society/Heart Rhythm Society) consensus statement. One-year procedural success was defined as freedom from recurrent AF, off antiarrhythmic drugs (complete) or off/on previously failed antiarrhythmic drugs (partial). Results Overall, 84 CHD patients (mean age 51.5 ± 12.1 years; 65.5% male; 45.2% with paroxysmal AF) undergoing AF ablation (51 simple, 22 moderate, 11 severe complexity) were included. Pulmonary vein isolation was performed in 80 (95.2%), of whom 30 (35.7%) underwent pulmonary vein isolation alone. Overall, complete and complete/partial freedom was achieved at 1 year in 53.1% and 71.6%, respectively, with no significant differences between those with simple, moderate, or severe complexity. There were no major complications and 7 minor complications, and 2 patients died during follow-up. Conclusion There are dramatic differences in the degree of CHD complexity among patients referred for AF ablation. When performed at experienced centers, AF ablation is safe and effective even among patients with the most complex forms of CHD.

The optimal site of ablation of idiopathic left ventricular outflow tract (LVOT) ventricular arrhythmias (VAs) is challenging as activation mapping can reveal similar activation times in different anatomical sites, suggesting an intramural origin.We sought to assess whether in patients with intramural VAs and with multiple early activation sites (EASs), sequential ablation of all the early EASs could improve acute and long-term clinical outcomes.A total of 116 patients undergoing catheter ablation for symptomatic LVOT VAs were enrolled in this study. Thirty-nine patients (34%) were referred for a redo procedure, whereas the remaining presented for a first procedure. Mapping was performed manually in 86 cases (74%) and with a magnetic robotic system (Niobe, Stereotaxis, St. Louis, MO) in the remainder of the cases.Of the 116 patients, 15 (13%) were found to have multiple sites of equally early activation. In patients with multiple EASs, the mean pre-QRS activation time was significantly less than in patients with a single EASs (-26 ± 3 ms vs -38 ± 6 ms; P .005). Sequential ablation of all the EASs was possible in 14 patients (93%), resulting in complete arrhythmia suppression. After a mean follow-up of 21 ± 5 months, all patients with successful ablation of all multiple early EASs remained free from clinical VAs.Intramural LVOT VAs manifesting with multiple EASs require ablation at all sites to achieve acute and long-term success, particularly if none of the EASs is-30ms pre-QRS activation time.

Background We evaluated long‐term outcome of isolation of pulmonary veins, left atrial posterior wall, and superior vena cava, including time to recurrence and prevalent triggering foci at repeat ablation in patients with paroxysmal atrial fibrillation with or without cardiovascular comorbidities. Methods and Results A total of 1633 consecutive patients with paroxysmal atrial fibrillation that were arrhythmia‐free for 2 years following the index ablation were classified into: group 1 (without comorbidities); n=692 and group 2 (with comorbidities); n=941. We excluded patients with documented ablation of areas other than pulmonary veins, the left atrial posterior wall, and the superior vena cava at the index procedure. At 10 years after an average of 1.2 procedures, 215 (31%) and 480 (51%) patients had recurrence with median time to recurrence being 7.4 (interquartile interval [IQI] 4.3–8.5) and 5.6 (IQI 3.8–8.3) years in group 1 and 2, respectively. A total of 201 (93.5%) and 456 (95%) patients from group 1 and 2 underwent redo ablation; 147/201 and 414/456 received left atrial appendage and coronary sinus isolation and 54/201 and 42/456 had left atrial lines and flutter ablation. At 2 years after the redo, 134 (91.1%) and 391 (94.4%) patients from group 1 and 2 receiving left atrial appendage/coronary sinus isolation remained arrhythmia‐free whereas sinus rhythm was maintained in 4 (7.4%) and 3 (7.1%) patients in respective groups undergoing empirical lines and flutter ablation ( P Conclusions Very late recurrence of atrial fibrillation after successful isolation of pulmonary veins, regardless of the comorbidity profile, was majorly driven by non‐pulmonary vein triggers and ablation of these foci resulted in high success rate. However, presence of comorbidities was associated with significantly earlier recurrence.

Objectives This study sought to report the incidence of device-related thrombosis (DRT) and thromboembolic (TE) events when an alternative to clopidogrel is prescribed in loss-of-function (LOF) allele carriers of the cytochrome P450 2C19 (CYP2C19) gene. Background LOF polymorphisms of the CYP2C19 gene are associated with reduced hepatic bioactivation of clopidogrel. Methods One thousand two Watchman patients were included. Six hundred forty-five patients underwent CYP2C19 genetic testing; among patients with clopidogrel resistance, clopidogrel was replaced by either prasugrel (pilot cohort) or half dose direct oral anticoagulant ((DOAC)/Group 1), both in combination with aspirin. We compared the incidence of DRT/TE events among genotyped patients and a control group which received standard dual antiplatelet therapy (DAPT) (Group 2; n = 357). All reported events occurred during a timeframe between 45- and 180-day follow-up transesophageal echocardiograms, when the 2 different antithrombotic strategies (genotype-guided vs standard DAPT) were adopted. Results In the pilot cohort (n = 244), bleeding events occurred in 10.2% of patients who received aspirin plus prasugrel, leading to early discontinuation of the prasugrel-based protocol. DOAC Group 1 patients (n = 401), 25.7% were reduced metabolizers, and clopidogrel was replaced by half dose direct oral anticoagulant. DRT was documented in 1 (0.2%) patient of Group 1 and 7 (1.96%) patients of Group 2 (log-rank P value = 0.021). The composite endpoint of DRT/TE events was significantly lower among patients receiving a genotype-guided antithrombotic strategy (0.75% vs 3.1%; log-rank P value = 0.017). Conclusions In Watchman patients, a genotype-based antithrombotic strategy with aspirin plus half dose DOAC in reduced clopidogrel metabolizers was superior to standard DAPT with respect to DRT/TE events.

This study sought to compare the effect of high-dose dobutamine (DBT) with that of high-dose isoproterenol (IPN) in eliciting triggers during atrial fibrillation (AF) ablation.High-dose IPN is commonly used to elicit triggers during AF ablation. However, it is not available worldwide and, in the United States, its cost per dose has significantly increased. DBT is a similarly nonselective β-agonist and, as such, is a potential alternative.This was a prospective, randomized 2×2 crossover study of patients undergoing AF ablation. Patients were assigned to receive IPN (20 to 30 μg/min for 10 min) followed by DBT (40 to 50 μg/kg/min for 10 min) or vice versa in a 1:1 fashion. The type, number, and location of triggers as well as heart rate, blood pressure, and side effects were noted.Fifty patients were included in the study. Both drugs caused a significant increase in heart rate, with a consistently lower peak for DBT. Blood pressure significantly increased with DBT, while there was a significant reduction with IPN, despite phenylephrine support. Atrial arrhythmias induced during DBT were comparable to that induced during IPN. In patients with IPN-inducible outflow tract premature ventricular contractions, a similar effect was noted with DBT. No major complications occurred during either drug challenge.High-dose DBT is safe and comparable to high-dose IPN in respect of eliciting AF triggers, with the advantage to maintain systemic pressure without the need of additional vasopressor support. This study supports the use of high-dose DBT in electrophysiology laboratories in which IPN is not readily available and for those patients in whom hypotension is a concern.

Objectives This study sought to characterize ventricular tachycardia (VT) ablation outcomes across nonischemic cardiomyopathy (NICM) etiologies and adjust these outcomes by patient-related comorbidities that could explain differences in arrhythmia recurrence rates. Background Outcomes of catheter ablation of VT in patients with NICM could be related to etiology of NICM. Methods Data from 2,075 patients with structural heart disease referred for catheter ablation of VT from 12 international centers was retrospectively analyzed. Patient characteristics and outcomes were noted for the 6 most common NICM etiologies. Multivariable Cox proportional hazards modeling was used to adjust for potential confounders. Results Of 780 NICM patients (57 ± 14 years of age, 18% women, left ventricular ejection fraction 37 ± 13%), underlying prevalence was 66% for dilated idiopathic cardiomyopathy (DICM), 13% for arrhythmogenic right ventricular cardiomyopathy (ARVC), 6% for valvular cardiomyopathy, 6% for myocarditis, 4% for hypertrophic cardiomyopathy, and 3% for sarcoidosis. One-year freedom from VT was 69%, and freedom from VT, heart transplantation, and death was 62%. On unadjusted competing risk analysis, VT ablation in ARVC demonstrated superior VT-free survival (82%) versus DICM (p ≤ 0.01). Valvular cardiomyopathy had the poorest unadjusted VT-free survival, at 47% (p Conclusions Catheter ablation of VT in NICM is effective. Etiology of NICM is a significant predictor of outcomes, with ARVC, myocarditis, and DICM having similar but superior outcomes to hypertrophic cardiomyopathy, valvular cardiomyopathy, and sarcoidosis, after adjusting for potential covariates.

The Purkinje network (PN) is the distal part of the ventricular conduction system, which has shown to play a central role in the pathophysiology of ventricular fibrillation (VF). Abnormal automaticity and triggered activity are commonly seen in the PN, and the resulting premature ventricular complexes (PVCs) are frequently recognized as triggers of this life-threatening arrhythmia. Catheter ablation targeting PN-related PVCs can be successfully performed in patients with medically refractory VF in a variety of arrhythmic substrates.

The purpose of this study was to evaluate the characteristics and outcome of patients undergoing ablation after electrical storm (ES).Clinical and procedural characteristics, ventricular tachycardia (VT) recurrence, and mortality rates from 1940 patients undergoing VT ablation were compared between patients with and without ES.The group of 677 patients with ES (34.9%) were older, were more frequently men, and had a lower ejection fraction, more advanced heart failure, and a higher prevalence of cardiovascular comorbidities as compared with those without ES (86.1% patients with ES had ≥2 comorbidities vs 71.4%; P.001). Patients with ES had more inducible VTs (2.5 ± 1.8 vs 1.9 ± 1.9; P.001), required longer procedures (296.1 ± 119.1 minutes vs 265.7 ± 110.3 minutes; P.001), and had a higher in-hospital mortality (42 deaths [6.2%] vs 18 deaths [1.4%]; P.001). At 1-year follow-up, patients with ES experienced a higher risk of VT recurrence and mortality (32.1% vs 22.6% and 20.1% vs 8.5%; long-rank, P.001 for both). Among patients with ES, those without any inducible VT after ablation had a higher survival rate (86.3%) than did those with nonclinical VTs only (72.9%), those with clinical VTs inducible at programmed electrical stimulation (51.2%), and not-tested patients (65.0%) (long-rank, P.001 for all). In multivariate analysis, ES remained an independent predictor of in-hospital mortality, VT recurrence, and 1-year mortality (P.001).Patients with ES have a high risk of VT recurrence and mortality. Patient and procedure characteristics are consistent with advanced cardiac disease and longer and more complex procedures. In patients with ES, acute procedural success is associated with a significant reduction in VT recurrence and improved 1-year survival.

In patients with the Brugada syndrome, radiofrequency ablation targeting the right ventricular outflow tract epicardium is helpful in normalizing the ECG and reducing arrhythmia burden.

Outflow tract PVCs can be accessible in the majority of cases. PVCs that originate in the left ventricular summit may be difficult to target with ablation directly. Ablation in the pulmonary cusp is feasible but should be carefully performed.

Wide complex tachycardia (WTC) is an electrocardiographic (ECG) descriptor encompassing all tachycardias (i.e., rhythms with a rate ≥ 100 bpm) with a QRS complex ≥120 msec. The approach to a WTC is frequently challenging, as a wide QRS complex can result from a variety of mechanisms and clinical conditions with very different prognostic and therapeutic implications. In this chapter, we will review the clinical, ECG, and electrophysiology study criteria used in the differential diagnosis of WTC, with a focus on identifying ventricular tachycardia (VT) versus other causes of WCT.

INTRODUCTION Patients with prior cardiac surgery may represent a subgroup of patients with ventricular tachycardia (VT) that may be more difficult to control with catheter ablation. METHODS We evaluated 1901 patients with ischemic and nonischemic cardiomyopathy who underwent VT ablation at 12 centers. Clinical characteristics and VT radiofrequency ablation procedural outcomes were assessed and compared between those with and without prior cardiac surgery. Kaplan-Meier analysis was used to estimate freedom from recurrent VT and survival. RESULTS There were 578 subjects (30.4%) with prior cardiac surgery identified in the cohort. Those with prior cardiac surgery were older (66.4 ± 11.0 years vs. 60.5 ± 13.9 years, p

BackgroundStereotactic radiosurgery is a form of radiotherapy that is performed in a single session and focuses high-dose ionizing radiation beams from a collimated radiation source to a small, localized area of the body. Recently, stereotactic radiosurgery has been applied to arrhythmias (stereotactic arrhythmia radioablation - STAR), with promising results reported in patients with refractory, scar-related ventricular tachycardia (VT), a cohort with known high morbidity and mortality.ObjectiveHerein, we describe our experience with the use of CyberKnife, a frameless image-guided linear accelerator stereotactic radiosurgery system, in conjunction with CardioPlan, a cardiac specific radiotherapy planning software, to treat patients with scar-related VT, detailing its early and mid-to long-term results.MethodsThis is a pilot, prospective study of patients undergoing STAR for refractory VT. The anatomical target for radioablation was defined based on the clinical VT morphology, electroanatomical mapping, and study-specific pre-procedural imaging with cardiac computed tomography. The target volume delineated with the aid of CardioPlan was treated with a prescription radiation dose of 25 Gy delivered in a single fraction by CyberKnife in an outpatient setting. Ventricular arrhythmias and radiation-related adverse events were monitored at follow-up to determine STAR efficacy and safety.ResultsFive patients (100 % male, 63 ± 12 years old, 80 % ischemic cardiomyopathy, left ventricular ejection fraction 34 ± 15 %) with refractory VT underwent STAR between January and June 2018. Radioablation was delivered in 82 ± 11 minutes without acute complications. During a mean follow-up of 12 ± 2 months, all patients experienced clinically significant mid-to late-term ventricular arrhythmia recurrence; two patients died of complications associated with their advanced heart failure. There were no clinical or imaging evidence of radiation necrosis or other radiation-induced complications in the organs at risk surrounding the scar targeted by radioablation.ConclusionDespite good initial results, STAR did not result in effective ventricular arrhythmia control in the long term in a selected, high-risk population of patients with scar-related VT. The safety profile was confirmed to be favorable, with no radiation-related complications observed during follow-up. Further studies are needed to explain these disappointing results.

This study describes the technique and outcomes of atrial fibrillation (AF) ablation via a superior approach in patients with interrupted or absent inferior vena cavas (IVCs).In patients with interrupted or absent IVCs, transseptal access cannot be obtained via standard femoral venous access. In these patients, alternative strategies are necessary to permit catheter ablation in the left atrium (LA). This study reports on the outcomes of AF ablation from a superior venous access with a radiofrequency (RF)-assisted transseptal puncture (TSP) technique.This study identified patients with interrupted or absent IVCs who underwent AF ablation via a superior approach at 2 ablation centers from 2010 to 2019.Fifteen patients (mean age: 50.8 ± 11.2 years; 10 men; 10 with paroxysmal AF) with interrupted or absent IVCs underwent AF ablation with transseptal access via a superior approach. Successful TSP was performed either with a manually bent RF transseptal needle (early cases: n = 4) or using a RF wire (late cases: n = 11); this approach permitted LA mapping and ablation in all patients. Mean time required to perform single (n = 8) or double (n = 7) TSP was 16.1 ± 4.8 min, and mean total procedure time was 227.9 ± 120.7 min (fluoroscopy time: 57.0 ± 28.5 min). LA mapping and ablation were successfully performed in all patients.In patients with AF undergoing catheter ablation and who had a standard transseptal approach via femoral venous approach is impossible due to anatomic constraints, RF-assisted transseptal access via a superior approach can be an effective alternative strategy to permit LA mapping and ablation.

Patients with ischemic cardiomyopathy (ICM) are prone to scar-related ventricular tachycardia (VT). The success of VT ablation depends on accurate arrhythmogenic substrate localization, followed by optimal delivery of energy provided by constant electrode-tissue contact. Current manual and remote magnetic navigation (RMN)-guided ablation strategies aim to identify a reentry circuit and to target a critical isthmus through activation and entrainment mapping during ongoing tachycardia. The MAGNETIC VT trial will assess if VT ablation using the Niobe™ ES magnetic navigation system results in superior outcomes compared to a manual approach in subjects with ischemic scar VT and low ejection fraction. This is a randomized, single-blind, prospective, multicenter post-market study. A total of 386 subjects (193 per group) will be enrolled and randomized 1:1 between treatment with the Niobe ES system and treatment via a manual procedure at up to 20 sites. The study population will consist of patients with ischemic cardiomyopathy with left ventricular ejection fraction (LVEF) of ≤35% and implantable cardioverter defibrillator (ICD) who have sustained monomorphic VT. The primary study endpoint is freedom from any recurrence of VT through 12 months. The secondary endpoints are acute success; freedom from any VT at 1 year in a large-scar subpopulation; procedure-related major adverse events; and mortality rate through 12-month follow-up. Follow-up will consist of visits at 3, 6, 9, and 12 months, all of which will include ICD interrogation. The MAGNETIC VT trial will help determine whether substrate-based ablation of VT with RMN has clinical advantages over manual catheter manipulation. Clinicaltrials.gov identifier: NCT02637947

Aims Left atrial (LA) scarring, a consequence of cardiac fibrosis is a powerful predictor of procedure-outcome in atrial fibrillation (AF) patients undergoing catheter ablation. We sought to compare the long-term outcome in patients with paroxysmal AF (PAF) and severe LA scarring identified by 3D mapping, undergoing pulmonary vein isolation (PVAI) only or PVAI and the entire scar areas (scar homogenization) or PVAI+ ablation of the non-PV triggers. Methods and results Totally, 177 consecutive patients with PAF and severe LA scarring were included. Patients underwent PVAI only ( n = 45, Group 1), PVAI+ scar homogenization ( n = 66, Group 2) or PVAI+ ablation of non-PV triggers ( n = 66, Group 3) based on operator’s choice. Baseline characteristics were similar across the groups. After first procedure, all patients were followed-up for a minimum of 2 years. The success rate at the end of the follow-up was 18% (8 pts), 21% (14 pts), and 61% (40 pts) in Groups 1, 2, and 3, respectively. Cumulative probability of AF-free survival was significantly higher in Group 3 (overall log-rank P

Background: Longstanding persistent (LSP) atrial fibrillation (AF) is the most challenging type of AF. In addition to pulmonary vein isolation, substrate modification and triggers ablation ...

The aim of this study was to evaluate the incidence and clinical implications of leaks (acute incomplete occlusion, early and late reopenings) following LAA ligation with the LARIAT device.Percutaneous LAA ligation with the LARIAT device may represent an alternative for stroke prevention in high-risk patients with atrial fibrillation with contraindications to oral anticoagulation.This was a retrospective, multicenter study of 98 consecutive patients undergoing successful LAA ligation with the LARIAT device. Leaks were defined as the presence of flow as evaluated by transesophageal echocardiography (TEE). TEE was performed during the procedure, at 6 and 12 months, and after thromboembolic events.Leaks were detected in 5 (5%), 14 (15%), and 19 (20%) patients at the 3 time points. During follow-up, 5 patients developed neurological events (4 strokes and 1 transient ischemic attack). Two occurred early (1 fatal stroke and 1 stroke with multiple recurrences in the following months), and TEE was not repeated after the events. The remaining 3 occurred late (after 6 months) and were associated with small leaks (5 mm). In 2 of 3 cases, such a small leak was missed by the standard evaluation on 2-dimensional TEE, being evident only with the aid of 3-dimensional imaging.Incomplete occlusion of the LAA after LARIAT ligation is relatively common and may be associated with thromboembolic events. Proper long-term surveillance with careful TEE should be considered to detect leaks, which can be managed with either resumption of oral anticoagulation or percutaneous transcatheter closure.

Background Focal impulse and rotor modulation (FIRM)-guided ablation targets sites that are thought to sustain atrial fibrillation (AF). Objective The purpose of this study was to evaluate the acute and mid-term outcomes of FIRM-guided only ablation in patients with nonparoxysmal AF. Methods We prospectively enrolled patients with persistent and long-standing persistent (LSP) AF at three centers to undergo FIRM-guided only ablation. We evaluated acute procedural success (defined as AF termination, organization, or ≥10% slowing), safety (incidence of periprocedural complications), and long-term success (single-procedure freedom from atrial tachycardia [AT]/AF off antiarrhythmic drugs [AAD] after a 2-month blanking period). Results Twenty-nine patients with persistent (N = 20) and LSP (N = 9) AF underwent FIRM mapping. Rotors were presents in all patients, with a mean of 4 ± 1.2 per patient (62% were left atrial); 1 focal impulse was identified. All sources were successfully ablated, and overall acute success rate was 41% (0 AF termination, 2 AF slowing, 10 AF organization). There were no major procedure-related adverse events. After a mean 5.7 months of follow-up, single-procedure freedom from AT/AF without AADs was 17%. Conclusion In nonparoxysmal AF patients, targeted ablation of FIRM-identified rotors is not effective in obtaining AF termination, organization, or slowing during the procedure. After mid-term follow-up, the strategy of ablating FIRM-identified rotors alone did not prevent recurrence from AT/AF.

Gianni, Carola/0000-0002-8174-7207; Rocca, Domenico Della/0000-0003-3837-3462; /0000-0002-5487-0728 WOS: 000459889100007 PubMed: 30312757 BACKGROUND Spontaneous echocardiographic contrast ("smoke") within the left atrial cavity on transesophageal echocardiography (TEE) suggests low blood flow velocities in the heart that may lead to thromboembolic (TE) events. OBJECTIVE The purpose of this study was to evaluate the risk of TE events in the periprocedural period and at long-term follow-up in atrial fibrillation (AF) patients having dense smoke on preprocedural TEE. METHODS A total of 2511 patients undergoing AF ablation were included in this analysis. They were classified as group 1 (dense smoke detected on TEE at baseline; n = 234) and group 2 (no smoke on baseline TEE; n = 2277). Patients were followed up for TE events, which included both stroke and transient ischemic attacks (TIAs). In order to attenuate the observed imbalance in baseline covariates between the study groups, a propensity score matching technique was used (covariates were age, sex, AF type, diabetes, and CHADS(2)-VASc score). RESULTS In the periprocedural period, no TE events were reported in group 1 and 3 events (0.13%) were reported in group 2. At follow-up of 6.62 +/- 62.01 years, 6 (2.6%) TE complications (2 TIA, 4 stroke) occurred in group 1 and 16 (0.70%) TE complications (6 TIA, 10 stroke) in group 2 (P = .004). In the propensity-matched population, 6 (2.56%) TE complications occurred in group 1 and 1 (0.2%) in group 2 (P = .007). CONCLUSION In our study population, the presence of dense left atrial smoke did not show any correlation with periprocedural TE events in patients undergoing catheter ablation with uninterrupted anticoagulation. However, significant association was observed with late stroke/TIA, irrespective of CHA(2)DS(2)-VASc score.

Background: Several distinct risk factors for arrhythmia recurrence and mortality following ventricular tachycardia (VT) ablation have been described. The effect of concurrent risk factors has not been assessed so far; thus, it is not yet possible to estimate these risks for a patient with several comorbidities. The aim of the study was to identify specific risk groups for mortality and VT recurrence using the Survival Tree (ST) analysis method. Methods: In 1251 patients 16 demographic, clinical and procedure-related variables were evaluated as potential prognostic factors using ST analysis using a recursive partitioning algorithm that searches for relationships among variables. Survival time and time to VT recurrence in groups derived from ST analysis were compared by a log-rank test. A random forest analysis was then run to extract a variable importance index and internally validate the ST models. Results: Left ventricular ejection fraction, implantable cardioverter defibrillator/cardiac resynchronization device, previous ablation were, in hierarchical order, identified by ST analysis as best predictors of VT recurrence, while left ventricular ejection fraction, previous ablation, Electrical storm were identified as best predictors of mortality. Three groups with significantly different survival rates were identified. Among the high-risk group, 65.0% patients were survived and 52.1% patients were free from VT recurrence; within the medium- and low-risk groups, 84.0% and 97.2% patients survived, 72.4% and 88.4% were free from VT recurrence, respectively. Conclusions: Our study is the first to derive and validate a decisional model that provides estimates of VT recurrence and mortality with an effective classification tree. Preprocedure risk stratification could help optimize periprocedural and postprocedural care.

The effectiveness of radiofrequency catheter ablation (RFCA) in atrial tachyarrhythmias correlates with lesion transmurality. Ablation Index (AI) is an index that incorporates contact force, time, and radiofrequency power simultaneously and is able to predict lesion size and outcomes in RFCA of atrial fibrillation.The purpose of this study was to assess whether AI could be an acute and long-term success predictor in RFCA of premature ventricular complexes (PVCs).One hundred forty-five patients with idiopathic outflow tract PVCs undergoing RFCA were retrospectively enrolled. The maximum and maximum AI values were calculated for each ablation site. Acute and 6-month outcomes were analyzed. Patients were divided into 3 outcome subgroups-success, acute failure, and 6-month failure-and the maximum and mean AI values were compared.Acute and 6-month success rates were 95% and 77%, respectively. The maximum and mean AI values were statistically higher in the success group (median of the maximum AI 630 [IQR 561-742]; median of the mean AI 489 [IQR 411-560]) than in the acute failure group (median of the maximum AI 487 [IQR 445-583]; median of the mean AI 372 [IQR 332-434]; P .0001 for both) and the 6-month failure group (median of the maximum AI 519 [IQR 476-568]; median of the mean AI 410 [IQR 368-472]; P .0001 for both). Both maximum and mean AI values were confirmed to be statistically higher in the success group than in the failure/6-month failure group (P = .001 and P = .04, respectively) and right ventricular free wall (P = .007 and P = .01, respectively) PVC origin subgroups.Our data support the concept that AI could be a long-term success predictor in RFCA of PVCs. However, further prospective studies are required to assess the feasibility of the AI-guided PVC ablation approach.

Hybrid versus Endocardial Ablation for LSPAFIntroduction Ablation of longstanding persistent atrial fibrillation (LSPAF) is the most challenging procedure in the treatment of AF, either by surgical or by percutaneous approach. Objective We investigated the difference in success and complication rates between combined surgical epicardial and endocardial catheter ablation procedure and our standard endocardial ablation procedure. Methods and Results Twenty-four consecutive patients (group 1) with LSPAF and enlarged left atrium (>4.5 cm) underwent a combined procedure, consisting of surgical, closed-chest, epicardial, radiofrequency ablation (nContact, NC, USA) via pericardial access, and concomitant endocardial ablation (hybrid procedure). Procedural complications and long-term outcomes were compared to those of 35 consecutive patients who refused the hybrid procedure and underwent standard endocardial only ablation (group 2). Baseline characteristics were comparable. In group 1, 1 patient (4.2%) developed post-procedural cardio-embolic stroke and 3 (12.5%) died (1 atrio-esophageal fistula, 1 fatal stroke, 1 of unknown cause in early follow-up), while no strokes or deaths occurred in group 2. Overall complication rates were higher for group 1 (P = 0.036). At 24-month follow-up, 4 (19%) patients in group 1 and 19 (54.3%) in group 2 were arrhythmia-free after a single procedure, on or off antiarrhythmic drugs (P

It is unclear whether isolation of the left atrial posterior wall (LAPW) offers additional benefits over pulmonary vein antrum isolation (PVAI) alone in patients with persistent atrial fibrillation (AF).We sought to determine the impact of PVAI and LAPW isolation (PVAI+LAPW) versus PVAI alone on the outcome of ablation of persistent AF.During the first procedure, PVAI was performed in 20 patients (group 1), whereas in 32 patients (group 2), PVAI was extended to the left atrial (LA) septum and coronary sinus (CS), and isolation of the LAPW was targeted (ePVAI+LAPW). Isolation of the superior vena cava was achieved in both groups. All patients, regardless of arrhythmia recurrence, underwent a second procedure 3 months after the first procedure. In patients with reconnection of pulmonary veins or LAPW, reisolation was performed, and a third procedure was performed 3 months later to verify isolation. Patients entered follow-up only after PVAI (group 1) or PVAI+LAPW (group 2) isolation was proven.At the 1-, 2-, and 3-year follow-up examinations, the rates of freedom from atrial tachyarrhythmia without use of an antiarrhythmic drug were 20%, 15%, and 10% in group 1 and 65%, 50%, and 40% in group 2, respectively (log-rank P.001). The median recurrence-free survival time was 8.5 months (interquartile range 6.5-11.0) in group 1 and 28.0 months (interquartile range 8.5-32.0) in group 2.Proven isolation of the LAPW provides additional benefits over PVAI alone in the treatment of persistent AF and improves procedural outcome at follow-up. However, the ablation strategy of ePVAI+LAPW is still associated with a significant high incidence of very late recurrence of atrial tachyarrhythmia."Outcome of Atrial Fibrillation Ablation After Permanent Pulmonary Vein Antrum Isolation With or Without Proven Left Atrial Posterior Wall Isolation" (LIBERATION). ClinicalTrials.gov Identifier: NCT01660100.

Background Catheter ablation reduces ventricular tachycardia (VT) recurrence and implantable cardioverter defibrillator shocks in patients with VT and ischemic cardiomyopathy. The most effective catheter ablation technique is unknown. Objectives This study determined rates of VT recurrence in patients undergoing ablation limited to clinical VT along with mappable VTs (“clinical ablation”) versus substrate-based ablation. Methods Subjects with ischemic cardiomyopathy and hemodynamically tolerated VT were randomized to clinical ablation (n = 60) versus substrate-based ablation that targeted all “abnormal” electrograms in the scar (n = 58). Primary endpoint was recurrence of VT. Secondary endpoints included periprocedural complications, 12-month mortality, and rehospitalizations. Results At 12-month follow-up, 9 (15.5%) and 29 (48.3%) patients had VT recurrence in substrate-based and clinical VT ablation groups, respectively (log-rank p Conclusions An extensive substrate-based ablation approach is superior to ablation targeting only clinical and stable VTs in patients with ischemic cardiomyopathy presenting with tolerated VT. (Ablation of Clinical Ventricular Tachycardia Versus Addition of Substrate Ablation on the Long Term Success Rate of VT Ablation (VISTA); NCT01045668 )

Although cardiac resynchronization therapy (CRT) is an important treatment of symptomatic heart failure patients in sinus rhythm with low left ventricular ejection fraction and ventricular dyssynchrony, its role is not well defined in patients with atrial fibrillation (AF). CRT is not as effective in patients with AF because of inadequate biventricular capture and loss of atrioventricular synchrony. Both can be addressed with catheter ablation of AF. It is still unclear if these therapies offer additive benefits in patients with ventricular dyssynchrony. This article discusses the role and techniques of catheter ablation of AF in patients with heart failure, and its application in CRT recipients.

Benefits of PVI in Patients with Atrial Flutter Background This study examined incidence of AF following cavotricuspid isthmus (CTI) ablation alone or CTI plus prophylactic pulmonary vein isolation (PVI) in patients presenting with isolated atrial flutter (AFL) with no history of AF. Methods and Results We enrolled 216 patients with isolated typical atrial flutter and randomized them to CTI alone (group 1, n = 108, 61.2 ± 9.7 year, 75% male) or CTI+PVI ablation (group 2, n = 108, 62.4 ± 9.3 year, 73% male). Insertible loop recorder (ILR) was implanted in 21 and 19 patients from groups 1 and 2, respectively. Remaining patients were monitored with event recorders, ECG, 7-day Holter. Follow-up period was for 18 ± 6 months. Compared to group 1, group 2 had significantly longer procedural duration (75.9 ± 33 min vs. 161 ± 48 min [P < 0.001]) and fluoroscopy time (15.9 ± 12.3 min vs. 56.4+21 min [P < 0.001]). At the end of follow-up, 65 (60.2%) in group 1 and 77 (71.3%) in group 2 were arrhythmia free off-AAD (log-rank P = 0.044). A subgroup analysis was performed with 55 year age cut-off. In the

AIMS This study investigated the impact of weight loss in longstanding persistent (LSPAF) patients undergoing catheter ablation (CA). METHODS Ninety consecutive obese LSPAF patients were approached; 58 volunteered to try weight loss interventions for up to 1 year (group 1), while 32 patients declined weight loss interventions and were included as a control (group 2). Both groups remained on antiarrhythmic drugs. If they continued to experience AF, CA was performed. Body weight was measured at 6-month intervals and arrhythmia status was assessed by event recorder, electrocardiogram (ECG), and Holter monitoring. Symptom severity and quality of life (QoL) were evaluated by AFSS and SF-36 survey, respectively. A scoring algorithm with two summary measures, physical component score (PCS) and mental component score (MCS), was prepared for QoL analysis. RESULTS Significant reduction in body weight (median -24.9 (IQR -19.1 to -56.7) kg, P

This article discusses how ventricular tachycardia ablation should be used, discusses which patients may derive benefit from this treatment, and highlights the best means of implementing it.

This article reviews novel techniques in stroke prevention based on epicardial closure of the left atrial appendage, illustrating the features of the first endo-epicardial device currently available and those of devices still in development. It also provides further information about early clinical experience with the endo-epicardial device.

Background Successful ventricular tachycardia (VT) ablation is associated with improved survival in patients with heart failure. However, the safety and efficacy of VT ablation in the elderly, a population with higher competing nonsudden death risk and comorbidities, have not been well defined. Methods and Results The International Ventricular Tachycardia Center Collaborative Study Group registry of 2061 patients who underwent VT ablation at 12 international centers was analyzed. Kaplan–Meier analysis was used to estimate survival of patients ≥70 years with and without VT recurrence. Of the 2049 patients who met inclusion criteria, 681 (33%) patients were ≥70 years of age (mean age, 75±4 years). Among these, 92% were men, 71% had ischemic VT, and 42% had VT storm at presentation. Mean (±SD) left ventricular ejection fraction was 30±11%. Compared with patients P =0.01) and 1-year mortality (15% versus 11%; P =0.002) but a similar incidence of VT recurrence at 1 year (26% versus 25%; P =0.74) and time to VT recurrence (280 versus 289 days; P =0.20). Absence of VT recurrence during follow-up was strongly associated with improved survival in patients ≥70 years. Conclusion VT ablation in the elderly is feasible and reasonably safe with a modestly higher in-hospital and 1-year mortality, with similar rates of VT recurrence at 1 year compared with younger patients. Successful VT ablation, that is, lack of VT recurrence, is strongly associated with improved survival even in this elderly subgroup.