non-PV Trigger Ablation Research Articles

Catheter ablation for atrial fibrillation: indications and future perspective.

Recent advances in techniques, technologies and proven superiority over anti-arrhythmic drugs have made catheter ablation the cornerstone of management for atrial fibrillation (AF), which has shown a steady increase in prevalence in the ageing population worldwide. The aim of therapeutic interventions is to achieve stable sinus rhythm that would improve the quality of life and reduce the risk of AF-associated complications. Pulmonary veins (PVs) were first described as the source of initiation of ectopic triggers driving AF, which led to the establishment of PV isolation (PVI) as the most widely practiced procedure to treat AF. Antral PVI is still recognized as the stand-alone ablation strategy for newly diagnosed paroxysmal AF (PAF). However, in non-PAF patients, PVI seems to be inadequate and several adjunctive strategies, including ablation of left atrial posterior wall and non-PV triggers, AF mapping and ablation of rotors and drivers, ethanol infusion of vein of Marshall and renal denervation, etc. have been reported with mixed results. Recent trials have also documented the benefits of early rhythm control in preventing cardiovascular events in addition to slowing the progression of PAF to more persistent forms. Similarly, very late relapse of the arrhythmia after successful PVI has drawn attention to the critical role of non-PV triggers and highlighted their relevance as potential ablation targets during repeat procedures. Ablation technology is also under constant evolution with the introduction of non-thermal energy sources and new tools to create durable lesions. This review summarizes the indications, advancements, and future perspective of AF ablation.

Cryoballoon ablation of non-PV triggers in persistent atrial fibrillation.

Cryoballoon-based catheter ablation has emerged as an efficacious and safe therapeutic intervention for patients with paroxysmal atrial fibrillation (PAF). PAF is primarily associated with the triggers in the pulmonary vein (PV). However, persistent atrial fibrillation (PeAF) is a complex condition that involves changes in the atrial substrate and the presence of non-PV triggers. Therefore, a comprehensive treatment approach is necessary for patients with PeAF. Utilizing a 3D electroanatomical map, the radiofrequency-based ablation technique adeptly identifies and targets the atrial substrate and non-PV triggers. On the other hand, the cryoballoon-based AF ablation was initially designed for PV isolation. However, its single-shot feature makes it a great choice for electrophysiologists looking to address non-PV triggers. It is possible to target the left atrial appendage (LAA), superior vena cava (SVC), left atrial roof, and posterior wall using the apparatus's unique configuration and ablation abilities. This review focuses on the increasing literature regarding cryoballoon-based methods for non-PV trigger ablation. Specifically, it delves into the technical procedures used to isolate the LAA, SVC, and ablate the left atrial roof and posterior wall.

PO-03-100 A VALIDATION STUDY OF THE ACCURACY OF THE ATRIAL PACE MAP ASSESSED WITH INTRACARDIAC PATTERN MATCHING: POTENTIAL UTILITY OF NON-PULMONARY VEIN MAPPING

The elimination of all non-PV triggers is known to be an additional strategy for the PVI of AF. However, activation mapping of infrequent non-PV triggers is challenging. We hypothesized that pace mapping assessed by intracardiac pattern matching (ICPM) with the CARTO3 mapping system yields a good diagnostic performance to locate atrial premature complexes (APCs). Furthermore, we assessed whether the combined use of both atrial electrograms for the ICPM improved the accuracy as compared to using electrograms only in the LA. In 16 patients, atrial pacing at 21 sites (LA anterior: 5, LA posterior: 8, LA septum: 3, and RA lateral: 5) was arbitrarily determined as APC foci, and the intracardiac atrial sequence of the obtained APC was set as a reference. The matching ICPM score was assessed during pace mapping around the APC focus. ICPM was determined by CS electrograms (CS group) or those from both the CS and RA (CS-RA group). The surface area was measured for each matching score. The mean pace mapping number was 213±113 points and was similar between the CS and CS-RA groups (181±81 vs. 237±114 points, P=0.09). By pace mapping with ICPM, maximum matching scores of ≥90% were obtained at all pacing origins in both the CS and CS-RA groups. At least 1 site with a matching score ≥98% was more often obtained in the CS group than CS-RA group (14/21 APCs [67%] vs. 7/21 APCs [33%], P=0.03), but sites with matching scores ≥95% were similarly obtained between the CS and CS-RA groups (17/21 APCs [81%] vs. 19/21 APCs [90%], P=0.66). The sites with matching scores ≥90% were all APCs in both groups. The surface area of matching scores ≥98% was similar between the CS and CS-RA groups (0.2 [0.1, 1.3] vs. 0.35 [0.1, 5.5] cm2, P=0.23), but that ≥95% was smaller in the CS-RA group than CS group (0.2 [0.1, 0.4] vs. 0.6 [0.15, 4.8] cm2, P=0.03). Of LA origins, the surface area for matching scores ≥95% was equal between the CS and CS-RA groups (0.2 [0.1, 0.5] vs. 0.5 [0.1, 1.3] cm2, P=0.19), but for RA origins, it was smaller in the CS-RA group than CS group (0.2 [0.1, 2.3] vs. 8 [0.3, 13.0] cm2, P=0.05) (Figure). ICPM-guided pace mapping may be useful to locate infrequent non-PV APCs. A combined use of RA and CS electrograms may improve the mapping quality and may be essential for identifying origins of RA non-PV APCs. RF applications targeting the area with a matching score ≥95% may be reasonable for a non-PV trigger ablation.

Comparison of advanced generation cryoballoon ablation and ablation index-guided pulmonary vein isolation with non-pulmonary vein trigger induction test and additional ablation in paroxysmal atrial fibrillation.

An ablation index (AI)-guided pulmonary vein isolation (PVI) or 2nd generation cryoballoon (CB)-PVI has been shown to reduce the atrial fibrillation (AF) burden by 99% despite the absence of ablation of non-pulmonary vein (PV) triggers in patients with paroxysmal AF. The purpose of this study was to investigate the effects of PVI alone strategy using 2nd generation CB compared with AI-guided PVI with an additional induction test and subsequent AF trigger ablation. We investigated 223 patients with symptomatic paroxysmal AF who underwent an initial PVI between August 2018 and August 2020. The study patients were divided into 2 groups: CB-PVI without an induction test (CB-PVI alone group, n = 82) and AI-guided PVI with an induction test and subsequent additional ablation of non-PV triggers (AI-PVI plus group, n = 141). In the AI-PVI plus group, a total of 62 non-PV triggers were induced in 38 patients, and non-PV triggers in 22 patients were completely ablated. The procedure time and left atrium dwell time were significantly shorter in the CB-PVI alone group than AI-PVI plus group. There were no significant differences in the incidence of procedural complications between the 2 groups (P = 0.650). The AF free survival rate in the CB-PVI alone group and AI-PVI plus group was 80% vs. 80% at 24months (P = 0.969). An PVI alone strategy using advanced generation CB did not differ in the clinical outcomes compared with an AI-guided PVI strategy with an induction test and subsequent ablation of non-PV triggers in the patients with paroxysmal AF.

Empirical superior vena cava isolation improves outcomes of radiofrequency re-ablation in pulmonary vein isolation non-responders: A 2-center retrospective study in China.

Pulmonary vein isolation (PVI) is the standard ablation strategy for treating atrial fibrillation (AF). However, the optimal strategy of a repeat procedure for PVI non-responders remains unclear. This study aims to investigate the incidence of PVI non-responders in patients undergoing a repeat procedure, as well as the predictors for the recurrence of repeat ablation. A total of 276 consecutive patients who underwent repeat ablation from August 2016 to July 2019 in two centers were screened. A total of 64 (22%) patients with durable PVI were enrolled. Techniques such as low voltage zone modification, linear ablation, non-PV trigger ablation, and empirical superior vena cava (SVC) isolation were conducted. After the 20.0 ± 9.9 month follow-up, 42 (65.6%) patients were free from atrial arrhythmias. A significant difference was reported between the recurrent and non-recurrent groups in non-paroxysmal AF (50 vs. 23.8%, p = 0.038), diabetes mellitus (27.3 vs. 4.8%, p = 0.02), and empirical superior vena cava (SVC) isolation (28.6 vs. 60.5%, p = 0.019). Multivariate regression analysis demonstrated that empirical SVC isolation was an independent predictor of freedom from recurrence (95% CI: 1.64-32.8, p = 0.009). Kaplan-Meier curve demonstrates significant difference in recurrence between empirical and non-empirical SVC isolation groups (HR: 0.338; 95% CI: 0.131-0.873; p = 0.025). About 22% of patients in repeat procedures were PVI non-responders. Non-paroxysmal AF and diabetes mellitus were associated with recurrence post-re-ablation. Empirical SVC isolation could potentially improve the outcome of repeat procedures in PVI non-responders.

Comparing the efficacy of catheter ablation strategies for persistent atrial fibrillation: a Bayesian analysis of randomized controlled trials.

Catheter ablation has been recommended as the first-line treatment option for selected patients with atrial fibrillation (AF). However, a widely accepted ablation strategy for persistent AF (perAF) has not yet been established. The benefits of ablation strategies are not conclusive for perAF. There is an urgent need to systematically analyze the results of previous studies and rank these treatment strategies to guide clinical practice. Randomized controlled trials (RCTs) on ablation for perAF were included. The primary outcome was recurrence of atrial tachyarrhythmia (AT) after a single ablation procedure. A Bayesian random-effects network meta-analysis model was fitted. Twenty-three studies were included in the analysis. A total of 3394 patients and 22 ablation strategies were found in the involved studies. The ablation strategy of pulmonary vein isolation (PVI) + electrical box isolation of the left atrial posterior wall (PBOX) + non-PV trigger ablation (NPV) showed the best treatment effect in terms of the primary outcome. The individualized ablation strategies of mapping and ablation combined with PVI, such as PVI + rotors, PVI + dispersion areas, and PVI + low voltage zone (LVZ) also showed a better ablation effect in perAF. PVI ablation is a widely used strategy in perAF and is recognized as a cornerstone procedure for perAF. The PVI + PBOX + NPV strategy showed the highest rank in our analysis. Mapping and ablation strategies that could provide individualized substrate modification also showed a better rank in our analysis and are believed to be a promising direction for the treatment of perAF.

Intra-atrial activation pattern is useful to localize the areas of non-pulmonary vein triggers of atrial fibrillation

Pulmonary vein isolation (PVI) is an established ablation procedure for atrial fibrillation (AF), however, PVI alone is insufficient to suppress AF recurrence. Non-pulmonary vein (non-PV) trigger ablation is one of the promising strategies beyond PVI and has been shown to be effective in refractory/persistent AF cases. To make non-PV trigger ablation more standardized, it is essential to develop a simple method to localize the origin of non-PV triggers. We retrospectively analyzed 37 non-PV triggers in 751 ablation sessions for symptomatic AF from January 2017 to December 2020. Regarding non-PV triggers, intra-atrial activation interval from the earliest in right atrium (RA) to proximal coronary sinus (CS) (RA-CSp) and that from the earliest in RA to distal CS (RA-CSd) obtained by a basically-positioned duodecapolar RA-CS catheter were compared among 3 originating non-PV areas [RA, atrial septum (SEP) and left atrium (LA)]. RA-CSp of RA non-PV trigger (56.4 ± 23.4 ms) was significantly longer than that of SEP non-PV (14.8 ± 25.6 ms, p = 0.019) and LA non-PV (-24.9 ± 27.9 ms, p = 0.0004). RA-CSd of RA non-PV (75.9 ± 32.1 ms) was significantly longer than that of SEP non-PV (34.2 ± 32.6 ms, p = 0.040) and LA non-PV (-13.3 ± 41.2 ms, p = 0.0008). RA-CSp and RA-CSd of SEP non-PV were significantly longer than those of LA non-PV (p = 0.022 and p = 0.016, respectively). Sensitivity and specificity of an algorithm to differentiate the area of non-PV trigger using RA-CSp (cut-off value: 50 ms) and RA-CSd (cut-off value: 0 ms) were 88% and 97% for RA non-PV, 81% and 73% for SEP non-PV, 65% and 95% for LA non-PV, respectively. The analysis of intra-atrial activation sequences was useful to differentiate non-PV trigger areas. A simple algorithm to localize the area of non-PV trigger would be helpful to identify non-PV trigger sites in AF ablation.

Optimal single procedure strategy of pulmonary vein isolation with cryoballoon or radiofrequency and non-pulmonary vein triggers ablation for non-paroxysmal atrial fibrillation.

BackgroundLimited data exist on pulmonary vein isolation (PVI) using cryoballoon (CB) or radiofrequency (RF) ablation and additional non-pulmonary vein trigger ablation for non-paroxysmal atrial fibrillation (non-PAF). We aimed to assess the outcomes of first-stage catheter ablation for non-PAF patients.MethodsInitial PVI was performed on 734 non-PAF patients (age: 64 ± 10 years; male: 584 (80%)) between September 2014 and June 2018 [315 (43%), CB ablation; 419 (57%), RF catheter]. A logistic regression model was used to match 257 pairs (514 patients) according to the propensity scores (CB or RF group). After PVI, additional non-PV trigger ablation was performed if induced by isoproterenol. We analysed the clinical outcomes of both groups.ResultsThe mean procedural time was significantly shorter in the CB group (125 [range, 89–165] min) than in the RF group (190 [160–224] min; P < 0.001). The 1-year Kaplan-Meier event rate revealed similar atrial fibrillation-free survival rates between the two groups (CB: 77.9%, RF: 82.3%; log-rank P = 0.111). The additional ablation percentage for non-PV foci (CB: 39%, RF: 41%; P = 0.653) and complication incidence (CB: 5%, RF: 4%; P = 0.670) were also similar.ConclusionsIn non-PAF patients, the combination strategy of PVI using CB or RF ablation and non-PV trigger ablation achieved comparable outcomes.

Outcomes of a comprehensive strategy during repeat atrial fibrillation ablation.

Atrial fibrillation (AF) recurs post-ablation in 30-40% of patients. The approach to a repeat ablation, beyond isolation of reconnected pulmonary veins (PVs), is not well established. We sought to prospectively assess outcomes and predictors of recurrence among consecutive patients who underwent repeat AF ablation with a standardized approach. This was a single-center prospective study of consecutive patients who underwent repeat AF ablation. Our protocol consisted of six steps: PV re-isolation, ablation of left atrial low-voltage areas (LVAs), ablation of isoproterenol-induced non-PV triggers, electrophysiology study (EPS) and ablation of induced AVNRT/AVRT, ablation of induced clinical atrial flutters, and lastly empiric ablation as per operator discretion if no other ablation was performed. Among 725 AF ablations performed during the study period, 74 were repeat ablations. Of those undergoing repeat ablation, 53 (72%) had PV reconnection, 30 (41%) had LVAs, seven (10%) had non-PV triggers, five (7%) had AVNRT, and 15 (20%) had typical atrial flutter. Following repeat ablation, arrhythmia-free survival was 65% at 1year. The absence of PV reconnection was the only factor independently associated with recurrence after repeat ablation (recurrence rate 71%, adjusted OR 7.91, 95% CI 2.31-27.16, p = 0.001). A comprehensive approach to repeat AF ablation including PV re-isolation, LVA ablation, non-PV trigger ablation, EPS, and flutter ablation was associated with a 65% 1-year arrhythmia-free survival. The absence of PV reconnection was the only independent predictor of arrhythmia recurrence. Further research is needed to identify therapies beyond PV isolation for patients undergoing repeat ablation.

482 Dressler’s syndrome following catheter ablation of atrial fibrillation: a case series

Abstract Aims Dressler’s syndrome is a secondary form of pleuro-pericarditis caused by an immune system response to heart damage. The onset of Dressler’s syndrome following catheter ablation has been previously described in rare case reports. We sought to report clinical manifestations, management, and outcomes of Dressler’s syndrome after atrial fibrillation (AF) catheter ablation. Methods and results Data from five AF patients who underwent radiofrequency ablation that was complicated by the development of Dressler’s syndrome were extracted from a prospective, single-centre database. Five out of 12 747 patients (0.04%) developed Dressler’s syndrome post AF ablation, 100% of which were females, with a mean age of 75.8 ± 3.4 years. All patients had persistent AF, and had pulmonary vein (PV) antrum, plus posterior wall isolation, plus non-PV trigger ablation. The mean procedure, fluoroscopy, and radiofrequency times were 183.20 ± 48.0, 50.3 ± 24.0, and 78.03 ± 27.9 min, respectively. All procedures were uncomplicated, and patients were discharged after overnight observation. Hospital re-admission was required in all after an average of 13.2 ± 5.2 days, due to worsening dyspnoea, pleuritic pain, and low-grade fever. At re-admission, all five patients had moderate-severe leucocytosis with neutrophilia, as well as bilateral rales and pericardial friction rub. Transthoracic echocardiography showed a mean pericardial circumferential effusion of 8 ± 2 mm, and chest X-ray was suggestive of bilateral mild pleural effusion in all. Corticosteroids were prescribed in three and NSAIDs plus colchicine in two patients. Pericardial drain placement was required in three patients after a median of 3 days, due to increasing pericardial effusion with hemodynamic impairment. The drainage tube was removed after a median of 2 days. All patients had complete resolution of symptoms and remained free from pericardial/pleural effusion within 1-month post-admission. Four of five patients had repeat ablation without recurrent Dressler’s syndrome. Conclusions Dressler’s syndrome occurred in older female patients, who underwent extensive ablation for AF. If promptly treated, its clinical course appears favourable with complete resolution of symptoms and pleuro-pericardial involvement.

Impact of the sinus node recovery time after termination of atrial fibrillation during catheter ablation on clinical outcomes in patients with persistent atrial fibrillation.

BackgroundAlthough long sinus arrest is occasionally observed during atrial fibrillation (AF) catheter ablation when the fibrillation was terminated, its meaning and prognosis have not yet been clearly elucidated. We hypothesized that sinus node recovery time (SNRT) after termination of AF (time from termination of AF to the earliest sinus node activation) could reflect the extent of atrial remodeling, influencing the formation of non-pulmonary vein (non-PV) triggers and post-ablation outcomes.MethodThe participants were 157 consecutive patients with persistent AF (male: 77.1%, age: 63.3±11.2 years) who underwent catheter ablation. We recorded SNRT after terminating AF by radiofrequency delivery or electrical cardioversion during the first ablation and evaluated the relationships between SNRT and atrial tachyarrhythmia recurrence and between SNRT and non-PV triggers after repeat ablation.ResultsForty-five patients (28.7%) experienced recurrence of atrial tachyarrhythmias. Patients with recurrence had longer SNRTs (1738 ms vs. 1394 ms, p = 0.012). In the multivariate logistic regression analysis, only SNRT ≥2128ms was a significant independent predictor of clinical AF recurrence (hazard ratio 7.48; 95% confidence interval 2.94–19.00; P<0.001). Kaplan–Meier estimator showed that the recurrence-free rate was significantly lower if ≥ 2128ms (log-rank, p<0.001). Thirty-five patients (77.8%) underwent a second ablation. Although there was no difference in the rate of pulmonary vein reconnections (78.6% vs. 71.4%, p = 0.712), non-PV triggers were observed more frequently in the longer SNRT group (57.1% vs. 14.3%, p = 0.012).ConclusionsPatients with a prolonged SNRT had a higher prevalence of AF recurrence after the first ablation and higher inducibility of non-PV triggers. Measuring SNRT might be used for the stratification of patients with persistent AF.

Optimal ablation targets during second catheter ablation in patients with persistent AF

Abstract Introduction Pulmonary vein isolation (PVI) is the cornerstone of ablative therapy in atrial fibrillation (AF). However, the one-year success rate after single ablation procedure is known to be up to 60%, necessitating repeat procedures in many. Purpose We evaluated the impact of different ablation strategies on procedural success at the second ablation in patients with persistent AF (PerAF). Methods Consecutive PerAF patients scheduled to undergo their second ablation were screened and only those that have received PVI plus isolation of left atrial posterior wall (PWI) and superior vena cava (SVC) at the first procedure (n=1390), were included in the analysis. At the second ablation, all reconnected structures were ablated. Additionally, based on operators' decision, non-PV triggers were targeted for ablation. Patients were classified into two groups based on the ablation strategy: group 1: Re-isolation of reconnected PVs, PW, SVC and group 2: additional ablation of non-PV triggers (from inter-atrial septum, coronary sinus (CS), left atrial appendage (LAA) and crista terminalis). Arrhythmia-monitoring was performed quarterly for 1 year and biannually afterwards. Ablation success was assessed off-antiarrhythmic drugs (AAD). Results Of the 1390 patients included in the analysis, 698 were in group 1 and 692 were in group 2. In group 1, reconnected PV, PW and SVC were re-isolated in 98 (14%), 311 (44.5%) and 173 (24.8%) respectively. In 131 (18.7%) patients, in the absence of any reconnection, CS was empirically isolated. In group 2, PV, PW and SVC were re-isolated in 83 (12%), 270 (39%) and 113 (16.3%) patients respectively. Additionally, non-PV triggers were ablated in 505 (73%) and empirical isolation of LAA and CS in the absence of detectable triggers and PV reconnection was performed in 187 (27%). At 2 years of follow-up, 425 (61%) and 602 (87%) from group 1 and 2 were arrhythmia-free off-AAD (p&amp;lt;0.001). Conclusion Including non-PV triggers as targets for ablation at the repeat procedure was associated with significantly higher success rate in persistent AF. Funding Acknowledgement Type of funding sources: None.

Arrhythmia profile and ablation-outcome in elderly women with atrial fibrillation undergoing first catheter ablation.

This study evaluated the arrhythmia profile and ablation outcome in women with atrial fibrillation (AF) aged ≥75 years. A total of 573 consecutive female patients undergoing first AF ablation were classified into group 1: ≥75 years (n=221) and group 2:<75 years (n=352). Isolation of PVs, posterior wall and superior vena cava was performed in all. Non-PV triggers from other areas were ablated based on operator's discretion. Group 1 had higher prevalence of hypertension (154 (69.7%) vs. 188 (53.4%), p<.001) and non-paroxysmal AF (136 (61.5%) vs. 126 (35.8%), p<.001). Non-PV triggers were detected in 194 (87.8%) patients from group 1 and 143 (40.6%) from group 2 (p<.001) and were ablated in 152 (68.8%) and 114 (32.4%) from group 1 and 2 respectively. Remaining patients (group 1: 69/221 and group 2: 238/352) received no additional ablation. At 4 years, 109 (49.3%) and 185 (52.6%) from group 1 and 2, respectively, were arrhythmia-free, p=.69. When stratified by ablation-strategy, success-rate was similar across groups in patients receiving non-PV trigger ablation (96 (63.2%) in group 1 and 76 (66.7%) in group 2, p=.61), whereas it was significantly lower in group 1 patients not receiving additional ablation compared to those from group 2 (13 (18.8%) vs. 109 (45.8%), p<.001). Non-paroxysmal AF was more common in women aged ≥75 years. Furthermore, significantly higher number of non-PV triggers were detected in elderly women and ablation of those provided similar ablation success as that in women aged<75 years.

Risk factors and effective ablation strategy in patients presenting with left atrial flutter with no previous ablation for atrial fibrillation

Abstract Background A typical left atrial flutter (LAFL) may occur as a proarrhythmic complication of ablation for atrial fibrillation (AF). Objective We evaluated the risk factors and the best ablation strategy for LAFL in patients with no prior AF ablation. Methods Consecutive patients undergoing first catheter ablation for AFL with no prior procedure for AF were included in this prospective analysis. Based on the ablation strategy, patients were divided into, Group 1: PVI+ Flutter ablation (ablation of re-entry circuits) and Group 2: PVI+ Non-PV trigger ablation (targeting areas of focal activity as triggers). 3-D mapping of the LA was performed during tachycardia to identify the reentrant circuit. PV isolation was performed in all patients. In group 1, ablation line was chosen to transect the area critical for the circuit (roof and mitral line). In group 2, ectopic beats arising from extra-PV foci detected by isoproterenol challenge were ablated. Off-drug success rate was assessed in all. Results A total of 92 and 90 patients were included in group 1 and 2 respectively. Baseline characteristics are provided in table 1. Pre-existent LA scar was detected in 91.3% and 90% of patients in group 1 and 2 respectively. At 2 years of follow-up, 11/92 (12%) from group 1 and 60/90 (66.7%) from group 2 remained arrhythmia-free off-drugs (p&amp;lt;0.001). In the multivariate analysis, PVI +flutter ablation was detected to be associated with significantly high risk of recurrence [HR: 3.92 (95% CI: 2.52–6.1, p&amp;lt;0.001)] Conclusion In this series of patients presenting with LAFL with no earlier AF ablations, pre-existent left atrial scar was detected in majority of cases and PVI+ non-PV trigger ablation provided significantly better success rate than PVI+ flutter ablation. Funding Acknowledgement Type of funding source: None

Approach to recurrent atrial fibrillation with isolated pulmonary veins.

With the advent of contact force catheters, encountering isolated pulmonary veins (PV) at the time of redo AF ablation is increasingly common, particularly in patients with persistent forms of AF. The ablation procedure in a patient with isolated PVs is typically based on mapping and ablation of non-PV triggers, any inducible flutters, and some empiric ablation of the most likely AF trigger/driver sites. This article is protected by copyright. All rights reserved.

One-year outcomes after pulmonary vein isolation plus posterior wall isolation and additional non-pulmonary vein trigger ablation for persistent atrial fibrillation with or without contact force sensing: a propensity score-matched comparison.

Whether or not pulmonary vein isolation (PVI) plus left atrial posterior wall isolation (PWI) using contact force (CF) sensing improves the ablation outcome for persistent atrial fibrillation (AF) is unclear. This study compared the outcome of PVI plus PWI and additional non-PV trigger ablation for persistent AF with/without CF sensing. This retrospective cohort study analyzed 148 propensity score-matched persistent AF patients (median duration of persistent AF, 8months (interquartile range, 3-24months); left atrial diameter, 43 ± 7mm) undergoing PVI plus PWI and ablation of non-PV triggers provoked by high-dose isoproterenol, including 74 with CF-sensing catheters (CF group) and 74 with conventional catheters (non-CF group). PVI plus PWI with no additional ablation but cavotricuspid isthmus ablation was performed without non-PV triggers in 48 CF patients (65%) and 54 non-CF patients (73%) (P = 0.38). In all other patients, we performed additional ablation of provoked non-PV triggers. The Kaplan-Meier estimate of the rate of freedom from atrial tachyarrhythmia recurrence off antiarrhythmic drugs at 12months after the single procedure was higher in the CF group than in the non-CF group (85 vs. 70%, log-rank P = 0.030). A multivariable analysis revealed that using CF sensing and non-inducibility of AF from a non-PV trigger after PVI and PWI were significantly associated with a reduced rate of atrial tachyarrhythmia recurrence. Compared with non-CF sensing, PVI plus PWI and additional non-PV trigger ablation using CF-sensing catheters for persistent AF can reduce the rate of atrial tachyarrhythmia recurrence.

P4761Impact of focal ablation versus isolation of the coronary sinus in patients undergoing repeat radiofrequency catheter ablation of persistent atrial fibrillation

Abstract Introduction Non-pulmonary vein (PV) triggers originating from the coronary sinus (CS) are a common finding in atrial fibrillation (AF) patients. To date, no studies have investigated the clinical impact of focal ablation versus isolation of the CS in patients presenting triggers from this area. Purpose This study analyzed the effectiveness of two different approaches for CS ablation (total isolation vs focal ablation) in persistent AF patients undergoing repeat AF ablation. Methods Consecutive persistent AF patients undergoing repeat ablation were enrolled in this prospective analysis. All patients had triggers from the CS documented during high-dose isoproterenol. Pulmonary vein antrum isolation (PVAI) extended to the posterior wall (PW) plus superior vena cava (SVC) isolation was performed in all patients at first procedure. At repeat procedure, PV, PW, and SVC were re-isolated, if needed. Focal ablation or isolation of the CS was performed based on operator's choice either at first and/or repeat procedure, along with ablation of other non-PV triggers. Patients with triggers from left atrial appendage were excluded from the study. Results Overall, 628 consecutive patients (73.4% male, age 66.9±9.0 years) were enrolled. On the basis of the CS ablation strategy, patients were categorized into two groups: Group I received CS isolation (n=389) and Group II received CS focal ablation (n=239). Major clinical characteristics were not different between groups. PV reconnection was documented in 55 (14.1%) patients of Group I and 33 (13.8%) of Group II. The incidence of procedure-related complications was similar between the two groups (10 [2.6%] in Group I vs 6 [2.5%] in Group II; p=0.9). After a follow-up of 18±8 months, 276 (71%) patients in Group I and 115 (48%) in Group II remained arrhythmia-free (p&lt;0.001, figure.1). After adjusting for age, gender and clinically relevant variables, CS isolation was associated with a significantly higher arrhythmia-free survival rate (HR: 0.47; 95% CI: 0.37–0.61, p-value&lt;0.001). Conclusions In patients with documented triggers from the CS undergoing repeat ablation of persistent AF, isolation rather than focal ablation of the CS significantly increased freedom from atrial tachyarrhythmias in the long term.

P-wave morphology and multipolar intracardiac atrial activation to facilitate nonpulmonary vein trigger localization.

Nonpulmonary vein (non-PV) triggers of atrial fibrillation (AF) are targets for ablation but their localization remains challenging. The aim of this study was to describe P-wave (PW) morphologic characteristics and intra-atrial activation patterns and timing from multipolar coronary sinus (CS) and crista terminalis (CT) catheters that localize non-PV triggers. Selective pacing from six right and nine left atrial common non-PV trigger sites was performed in 30 consecutive patients. We analyzed 12 lead ECG features based on PW duration, amplitude and morphology, and patterns and timing of multipolar activation for all 15 sites. Regionalization and then precise localization required criteria present in at least 70% of assessments at each pacing site. The algorithm was then prospectively evaluated by four blinded observers in a validation cohort of 18 consecutive patients undergoing the same pacing protocol and 60 consecutive patients who underwent successful non-PV trigger ablation. The algorithm for site regionalization included 1) negative PW in V1, ≥30 µV change in PW amplitude across the leads V1-V3, and PW duration ≤100 milliseconds in lead 2 and 2) unique intra-atrial activation patterns and timing noted in the multipolar catheters. Specific ECG and intra-atrial activation timing characteristics included in the algorithm allowed for more precise site localization after regionalization. In the prospective evaluation, the algorithm identified the site of origin for 72% of paced and 70% of spontaneous non-PV trigger sites. An algorithm based on PW morphology and intra-atrial multipolar activation pattern and timing can help identify non-PV trigger sites of origin.

Arrhythmogenecity and thrombogenicity of the residual left atrial appendage stump following surgical exclusion of the appendage in patients with atrial fibrillation.

It is common to find residual stump after the amputation or clip exclusion of the left atrial appendage (LAA). We evaluated the arrhythmogenic and thrombogenic potential of LAA stumps in atrial fibrillation (AF) patients. Consecutive patients undergoing catheter ablation for AF recurrence with LAA stump detected at baseline transesophageal echocardiogram (TEE) were included in the analysis. Nonpulmonary vein (non-PV) triggers were ablated based on operator's discretion. A total of 213 patients with LAA stump were included in the analysis. Firing from the LAA stump was detected in 186 cases, of which 145 received stump isolation (group I) and the stump was not targeted for isolation in 41 (group II) patients. In 27 patients with no firing from the stump (group III) only non-PV triggers from sites other than the LAA stump were targeted for ablation. At 16.7 ± 8.5 months of follow-up, 126 (86.9%) patients from group I, eight (19.5%) from group II, and eight (33.3%) from group III remained arrhythmia-free off antiarrhythmic drugs (AAD) (P < 0.001). Sixty out of 70 patients underwent redo procedure; electrical isolation of the stump and ablation of other non-PV triggers was done in all 60 cases. At 1 year after the repeat procedure, 55 (91.7%) patients remained arrhythmia-free off-AAD. A total of four (1.88%) thromboembolic (TE) events reported, three of which were transient ischemic attacks and all three patients had "smoke" detected in the left atrium. LAA stump is arrhythmogenic and electrical isolation improves clinical outcome. TE events are rare and mostly associated with left atrial smoke in this subset of AF population.

Novel concepts and approaches in ablation of atrial fibrillation: the role of non-pulmonary vein triggers.

Ablation of non-pulmonary vein (PV) triggers is an important step to improve outcomes in atrial fibrillation ablation. Non-pulmonary vein triggers typically originates from predictable sites (such as the left atrial posterior wall, superior vena cava, coronary sinus, interatrial septum, and crest terminalis), and these areas can be ablated either empirically or after observing significant ectopy (with or without drug challenge). In this review, we will focus on ablation of non-PV triggers, summarizing the existing evidence and our current approach for their mapping and ablation.