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BACKGROUND Intracardiac electrogram data remain one of the primary diagnostic inputs guiding complex ablation procedures. However, the technology to collect, process, and display intracardiac signals has known shortcomings and has not advanced in several decades. OBJECTIVE The purpose of this study was to evaluate a new signal processing platform, the PURE EP™ system (PURE), in a multi-center, prospective study. METHODS Intracardiac signal data of clinical interest were collected from 51 patients undergoing ablation procedures with PURE, the signal recording system, and the 3D mapping system at the same time stamps. The samples were randomized and subjected to blinded, controlled evaluation by three independent electrophysiologists to determine the overall quality and clinical utility of PURE signals when compared to conventional sources. Each reviewer assessed the same (92) signal sample sets and responded to (235) questions using a 10-point rating scale. If two or more reviewers rated the PURE signal higher than the control, it was deemed superior. RESULTS A total of 93% of question responses showed consensus amongst the blinded reviewers. Based on the ratings for each pair of signals, a cumulative total of 164 PURE signals out of 218 (75.2%) were statistically rated as Superior for this data set (p

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 The creation of effective and permanent lesions is a crucial factor in determining the success rate of atrial fibrillation (AF) ablation. By increasing the efficacy of radiofrequency (RF) energy-mediated lesion formation, half-normal saline (HNS) as an irrigant for open-irrigated ablation catheters has the potential to reduce procedural times and improve acute and long-term outcomes. Methods This is a double-blind randomized clinical trial of 99 patients undergoing first-time RF catheter ablation for AF. Patients enrolled were randomly assigned in a 1:1 fashion to perform ablation using HNS or normal saline (NS) as an irrigant for the ablation catheter. Results The use of HNS is associated with shorter RF times (26 vs. 33 min; p = .02) with comparable procedure times (104 vs. 104 min). The rate of acute pulmonary vein reconnections (16% vs. 18%) was comparable, with a median of 1 vein reconnection in the HNS arm versus 2 in the NS arm. There was no difference in procedure-related complications, including the incidence of postprocedural hyponatremia when using HNS. Over the 1-year follow-up, there is no significant difference between the HNS and NS with respect to the recurrence of any atrial arrhythmia (off antiarrhythmic drugs [AAD]: 47% vs. 52%; hazard ratio [HR]: 1.17, 95% confidence interval [CI]: 0.66-2.06; off/on AAD: 66% vs. 66%, HR: 1.06, 95% CI: 0.53-2.12), with a potential benefit of using HNS when considering the paroxysmal AF cohort (on/off AAD 73% vs. 62%, HR: 0.72, 95% CI: 0.19-2.70). Conclusions In a mixed cohort of patients undergoing first-time AF ablation, irrigation of open-irrigated RF ablation catheters with HNS is associated with shorter RF times, with a comparably low rate of procedure-related complications. In the long term, there is no significant difference with respect to the recurrence of any atrial arrhythmia. Larger studies with a more homogeneous population are necessary to determine whether HNS improves clinical outcomes.

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.

INTRODUCTION 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. METHODS 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. RESULTS 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

Introduction This study reports the procedural findings and ablation outcome in AF patients referred after ≥2 failed PV isolation (PVI). Methods Three hundred and five consecutive AF patients referred after ≥2 PVI were included in the analysis. High-dose isoproterenol challenge was used to identify PV reconnection and non-PV triggers; the latter were ablated based on the operator's discretion during the index procedure. At the repeat procedure, non-PV triggers were ablated in all. Empirical isolation of LA appendage (LAA) and coronary sinus (CS) was performed if the PVs were silent and no non-PV triggers were detected. Results PV reconnection was detected in 226 and non-PV triggers were identified or empirically isolated in 285 patients during the index procedure. At follow-up, 182 (60%) patients were recurrence-free off-AAD; the success rate with and without non-PV ablation was 81% vs. 8% (P

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

Management of Tamponade Following AF Ablation With FXaIIntroduction Because of the absence of a dedicated reversal agent, the outcome of pericardial effusion (PE) following procedures performed with uninterrupted apixaban or rivaroxaban is unknown. We report the characteristics of PEs presenting with tamponade in patients undergoing AF ablation with uninterrupted factor Xa inhibition (FXaI) to understand their management and prognosis. Methods and Results We performed a multicenter cross-sectional survey in 10 centers across the United States. Patient data were obtained by chart review. In all patients the procedure was performed with uninterrupted FXaI. A total of 16 PEs requiring intervention were reported from 5 centers. Two patients were on apixaban 5 mg BD, the remaining on rivaroxaban 20 mg OD. Eleven PEs occurred in the periprocedural setting, and 5 PEs occurred from 1 to 28 days after the procedure. Pericardiocentesis and drainage were performed in all cases. Protamine and 4-factor prothrombin complex concentrate (4F-PCC) were given in all periprocedural cases. Two patients required surgery: in one case coagulation of the pericardial blood prevented effective drainage, and in the other bleeding was secondary to a steam pop-induced atrial tear. None of the postprocedural cases required FXaI reversal and the dose of rivaroxaban was temporarily reduced. No fatal outcomes or thromboembolic events were reported. Conclusion Pericardiocentesis and drainage with FXaI reversal proved effective in the management of acute PEs with tamponade occurring periprocedurally in patients undergoing AF ablation with uninterrupted FXaI. Early postprocedural effusions can be treated with pericardiocentesis without the need of a reversal agent.

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

Administration of Isuprel/Adenosine After PulmonaryVein Antrum IsolationBackground Pulmonary vein antrum isolation (PVAI) remains associated with atrial fibrillation (AF) recurrence. We administered adenosine and isoproterenol (ISP) after PVAI to uncover non-PV atrial triggers and PV reconnection, potentially increasing ablation success rate. Methods One hundred and ninety-two consecutive patients with symptomatic AF presenting for PVAI were prospectively studied (group 1). Following PVAI, adenosine (18–24 mg) and ISP (20–30 mcg/min) were administered intravenously. Supplemental ablation was performed in patients with non-PV triggers that induced AF (group 1A). Other subgroups included patients with (group 1B) or without (group 1C) consistent non-PV atrial foci that did not induce AF. A cohort of 196 matched control patients undergoing PVAI without drug challenge was used for comparison (group 2). Results A total of 132 atrial non-PV foci were revealed (31 inducing AF). The majority of atrial foci were observed with ISP (113/132, 86%). Less than 5% of patients had persistent PV recovery during the drug challenge. During a mean follow-up of 22 ± 8 months, PVAI was successful in 110/192 (57%, group 1) versus 100/196 (52%, group 2), P = 0.038. Furthermore, the success rate was statistically different between group 1A (25/32, 78%), group 1B (28/83, 34%), and group 1C (57/74, 74%), P < 0.001. Conclusion After PVAI, ablation guided by the administration of adenosine and ISP to target non-PV triggers inducing AF increased AF ablation outcomes. Patients with non-PV foci that did not induce AF had no further ablation, with the lowest ablation success rate. This group may likely benefit from further ablation after PVAI.

AF Ablation in Patients with Large LA Introduction The effect of catheter ablation on severe left atrial enlargement especially in nonparoxysmal atrial fibrillation (NPAF) patients is not well understood. Whether reverse remodelling may occur after ablation has not been evaluated in this setting. Methods and results Fifty consecutive patients with left atrial diameter (LAD) ≥50 mm, and LA volume >200 cc undergoing catheter ablation for drug-refractory NPAF were included in this study. Transthoracic echocardiographic measurements were performed at baseline and at 12-months postprocedure. Left ventricular end-diastolic and end-systolic dimensions were indexed by body surface area (LVEDDI, LVESDI). Electroanatomic mapping system (Carto or NavX system) and computed tomography (CT) were used for 3-dimensional reconstruction of the LA. All patients underwent posterior wall isolation and pulmonary vein (PV) antrum and extra PV trigger ablations. Long-term follow-up was monitored by event recordings, 7-day Holter monitors and office visits. The mean age was 65 ± 10 years, 78% male, persistent AF 22 (44%), longstanding AF 28 (56%), LAD diameter 56.9 ± 7.8 mm, left ventricular ejection fraction (LVEF) 53 ± 14 and median AF duration 72 (49–96) months. At 12-month follow-up, 27 patients (54%) remained arrhythmia-free off antiarrhythmic drugs. Significant reduction in LAD at follow-up (≥10% reduction) was observed in 52% (26/50) of the total population and among the 63% (17/27) of recurrence-free patients. Magnitude of LA reduction was identically distributed among the persistent and longstanding persistent AF cohorts (16 ± 12% vs 14 ± 16%, respectively, P = 0.15). A significant 20% improvement in LVEF (from 53 ± 14 to 58 ± 9, P = 0.03) was found in the overall population. Improvement was noted in recurrence-free patients. No significant change in LVEDDI and LVESDI was noted. After adjusting for baseline risk factors in a multivariable model, a reduction in LAD was identified as a strong predictor of long-term success (beta = –11.1, P = 0.013). Preexisting LA scarring was associated with increased LAD (beta = 2.7, P = 0.023). No periprocedural or long-term complications were reported. Conclusion Our results show that atrial fibrillation ablation is effective in NPAF patients with severe LA enlargement and is associated with LA reverse remodeling and improvement in LVEF.

Incomplete LAA Occlusion by WATCHMAN Device. Introduction: Transcatheter left atrial appendage (LAA) closure with the WATCHMAN device has become one of the therapeutic options in atrial fibrillation (AF) patients who are at high risk for ischemic stroke. However, the incidence and evolution of incomplete occlusion of the LAA during and after placement of the WATCHMAN device has not been reported. Methods and Results: Fifty-eight consecutive patients who had undergone WATCHMAN device implant were included in the study. Intraprocedural, 45-day and 12-month transesophageal echocardiogram images were reviewed and analyzed. Peridevice gap was noted in 16 (27.6%), 17 (29.3%), and 20 (34.5%) patients across the 3 time points. Intraprocedural gaps are more likely to be persistent until 12 months and become larger in size over time. New gap also occurs during follow-up even if the LAA was completely sealed at implantation. One patient had an ischemic stroke 4.7 months after implant; another patient developed a left atrial thrombus over the device 21.6 months after implant. Both patients had intraprocedural gap and discontinued warfarin therapy after the 45-day evaluation. Conclusion: Incomplete LAA occlusion with a gap between the WATCHMAN device surface and the LAA wall is relatively common. Intraprocedural gaps are more likely to become bigger over time and persist, while new gaps also occur during follow-up. Further studies are warranted to verify whether the presence and persistence of a peridevice gap is associated with increased risk of thromboembolic event in AF patients implanted with a WATCHMAN device. (J Cardiovasc Electrophysiol, Vol. 23, pp. 455-461, May 2012)

MVI Block vs Trigger Ablation in PMFL. Introduction: Patients with previous ablation for atrial fibrillation (AF) may experience recurrence of perimitral flutter (PMFL). These arrhythmias are usually triggered from sources that may also induce AF. This study aims at determining whether ablation of triggers or completing mitral valve isthmus (MVI) block prevents more arrhythmia recurrences. Methods and Results: Sixty-five patients with recurrent PMFL after initial ablation of long standing persistent AF were included in this study. Thirty-two patients were randomized to MVI ablation only (Group 1) and 33 were randomized to cardioversion and repeat pulmonary vein (PV) isolation plus ablation of non-PV triggers (Group 2). MVI bidirectional block was achieved in all but 1 patient from Group 1. In Group 2, reconnection of 17 PVs was detected in 14 patients (42%). With isoproterenol challenge, 44 non-PV trigger sites were identified in 28 patients (85%, 1.57 sites per patient). At 18-month follow-up, 27 patients (84%) from Group 1 had recurrent atrial tachyarrhythmias, of whom 15 remained on antiarrhythmic drug (AAD); however, 28 patients from Group 2 (85%, P < 0.0001 vs Group 1) were free from arrhythmia off AAD. The ablation strategy used in Group 2 was associated with a lower risk of recurrence (hazard ratio = 0.10, 95% CI 0.04–0.28, P < 0.001) and an improved arrhythmia-free survival (log rank P < 0.0001). Conclusion: In patients presenting with PMFL after ablation for longstanding persistent AF, MVI block had limited impact on arrhythmia recurrence. On the other hand, elimination of all PV and non-PV triggers achieved higher freedom from atrial arrhythmias at follow-up. (J Cardiovasc Electrophysiol, Vol. 23, pp. 137-144, February 2012)

Relationship Between the Non-PV Triggers and the Critical CFAE Sites. Background: Complex fractionated atrial electrograms (CFAE) ablation has been performed in addition to pulmonary veins (PV) isolation to increase the success rate of atrial fibrillation (AF) ablation in patients with longstanding (LS) persistent AF. The mechanism underlying the clinical benefit of CFAE ablation remains, however, poorly understood. Objective: We compared the impact of CFAE ablation on the prevalence of non-PV atrial triggers inducing AF in 2 groups of patients with LS persistent AF. One group underwent PVAI alone, and the other group underwent PVAI plus CFAE ablation. In addition, we correlated the site of non-PV triggers with the presence of CFAE. Methods: A total of 98 consecutive patients with symptomatic drug refractory LS persistent AF presenting for ablation had a preablation electroanatomic CFAE map. Patients randomized to either isolation of the PVs and posterior wall (PVAI) (group I, n = 48 pts) or PVAI and biatrial ablation of CFAEs (group II, 50 pts). After ablation, infusion of isoproterenol up to 30 mcg/min was given to reveal non PV foci inducing AF. Those foci were mapped and correlated with CFAE regions and ablated. Results: A total of 19 patients (76%) with PV foci inducing AF were associated with either stable or transient CFAE after PVAI, respectively, in 12 patients (48%) and 7 patients (28%). A total of 20 (42%) non-PV triggers were observed in group I versus 5 (10%) in group II (P < 0.001) in 18 and 5 patients, respectively. After a mean f/u of 17.2 ± 5.2 months, 33 (69%) patients in group I and 36 (72%) patients in group II were in SR (P = NS). Conclusion: Non-PV triggers inducing AF post-PVAI were associated with the presence of stable or transient CFAE in 48% and 28% of cases, respectively, in LS persistent AF. CFAE ablation after PVAI was associated with a significantly higher elimination of those non-PV triggers. This suggests that at least part of the beneficial effect achieved by CFAE ablation reflects elimination of non-PV AF triggers. (J Cardiovasc Electrophysiol, Vol. pp. 1-7)