Left-lateral thoracotomy for catheter ablation of scar-related ventricular tachycardia in patients with inaccessible pericardial access.

OBJECTIVES: We aimed to describe the feasibility of a surgical left thoracotomy for catheter ablation of scar-related ventricular tachycardia (VT) in patients with inaccessible pericardial access. BACKGROUND: Pericardial adhesion due to prior cardiac surgery or previous epicardial ablation procedures limits epicardial access in patients with drug-refractory VT originated from the epicardium. METHODS: Six patients who underwent a surgical left lateral thoracotomy epicardial access for catheter ablation of VT after failed subxiphoid percutaneous epicardial access were reviewed. Patients' baseline characteristics and procedural characteristics including epicardial access, mapping, and ablation were described. Epicardial access was successfully obtained in all patients by a surgical left lateral thoracotomy. RESULTS: The reasons of pericardial adhesion were prior cardiac surgery (n = 3, 50%) and previous epicardial ablation procedures (n = 3, 50%). Epicardial mapping of the lateral and inferior left ventricle was acquired, and a total of 15 different VTs originated from those regions were abolished. Unless one patient with ST elevation myocardial infarction due to periprocedural occlusion of the posterior descending artery no further complications occurred. All patients were discharged 10.2 ± 4 days after the procedure. VT recurred in 1 patient (17%) and was controlled with oral amiodarone therapy during follow-up (median follow-up: 479 days). CONCLUSIONS: A surgical left lateral thoracotomy is feasible and safe for selected patients. This approach provides epicardial ablation in patients with VT located at the infero-lateral left ventricle and pericardial adhesions due to previous cardiac surgery or previous ablation procedures.

High-Resolution Imaging of LA Anatomy Using a Novel Wide-Band Dielectric Mapping System: First Clinical Experience.

OBJECTIVES: This study presents the first report of high-resolution imaging of cardiac anatomy using a novel system. BACKGROUND: Recently, the wide-band dielectric mapping system Kodex was introduced. METHODS: This study included 20 consecutive patients with symptomatic atrial fibrillation or left atrial tachycardia who were scheduled for an ablation procedure and who underwent simultaneous left atrial mapping using the Kodex and CARTO 3 systems. Pulmonary vein angiograms served as a reference to compare the craniocaudal dimensions of the pulmonary vein ostia as depicted by either of the 2 mapping systems. RESULTS: Complete left atrial imaging was achieved within a median [first quartile; third quartile] of 9.7 [7.5; 12.8] min. Median procedure time was 97.5 [90; 112.5] min, and median total fluoroscopy time was 8.2 [5.7; 10.6] min, of which a median of 1.4 [1.1; 2.3] min were used during the creation of the left atrial map. High-resolution representations of left atrial anatomy were successfully created in all patients. Both the Kodex and CARTO measurements correlated well with fluoroscopy measurements, as reflected by Pearson's correlation coefficients (r) of 0.91 and 0.95, respectively. Bland-Altman plots revealed that, on average, Kodex measurements underestimated fluoroscopy measurements by 0.04 mm (95% limits of agreement of -5.72 and 5.64 mm), and CARTO measurements underestimated fluoroscopy measurements by 0.02 mm (95% limits of agreement of -3.61 and 3.57 mm). CONCLUSIONS: Anatomic mapping of the left atrium using Kodex shows the potential to create computed tomography-like images without the need for additional periprocedural imaging.

The best of two worlds? Pulmonary vein isolation using a novel radiofrequency ablation catheter incorporating contact force sensing technology and 56-hole porous tip irrigation.

AIMS: This study aimed to evaluate feasibility and safety as well as 1-year clinical outcome of pulmonary vein isolation (PVI) using a unique radiofrequency ablation catheter ("Thermocool SmartTouch SurroundFlow"; STSF) incorporating both, contact force (CF) sensing technology and enhanced tip irrigation with 56 holes, in one device. METHODS: A total of 110 patients suffering from drug-refractory atrial fibrillation underwent wide area circumferential PVI using either the STSF ablation catheter (75 consecutive patients, study group) or a CF catheter with conventional tip irrigation ("Thermocool SmartTouch", 35 consecutive patients, control group). For each ablation lesion, a target CF of ≥ 10-39 g and a force time integral (FTI) of > 400 g s was targeted. RESULTS: Acute PVI was achieved in all patients with target CF obtained in > 85% of ablation points when using either device. Mean procedure time (131.3 ± 33.7 min in the study group vs. 133.0 ± 42.0 min in the control group; p = 0.99), mean fluoroscopy time (14.0 ± 6 vs. 13.5 ± 6.6 min; p = 0.56) and total ablation time were not significantly different (1751.0 ± 394.0 vs. 1604.6 ± 287.8 s; p = 0.2). However, there was a marked reduction in total irrigation fluid delivery by 51.7% (265.52 ± 64.4 vs. 539.6 ± 118.2 ml; p < 0.01). The Kaplan-Meier estimate 12-month arrhythmia-free survival after the index procedure following a 3-month blanking period was 79.9% (95% CI 70.4%, 90.4%) for the study group and 66.7% for the control group (95% CI 50.2%, 88.5%). This finding did not reach statistical significance (p = 0.18). Major complications occurred in 2/75 patients (2.7%; one pericardial tamponade and one transient ischemic attack) in the study group and no patient in the control group (p = 18). CONCLUSION: PVI using the STSF catheter is safe and effective and results in beneficial 1-year clinical outcome. The improved tip irrigation leads to a significant reduction in procedural fluid burden.

Ten-Year Clinical Outcome After Circumferential Pulmonary Vein Isolation Utilizing the Hamburg Approach in Patients With Symptomatic Drug-Refractory Paroxysmal Atrial Fibrillation.

BACKGROUND: Circumferential pulmonary vein isolation (CPVI) is increasingly performed for the treatment of symptomatic drug-refractory paroxysmal atrial fibrillation. Long-term data for >10 years after CPVI are sparse. We investigated the long-term clinical outcome and progression of paroxysmal atrial fibrillation after double-lasso and 3-dimensional electroanatomical mapping-guided CPVI. METHODS AND RESULTS: From 2003 to 2004, 161 patients (mean age: 60±10 years) with symptomatic drug-refractory paroxysmal atrial fibrillation were prospectively enrolled and underwent electroanatomical mapping-guided CPVI. Right-sided and left-sided continuous circular lesions encircling the ipsilateral pulmonary veins were placed with irrigated radiofrequency energy. The procedural end point was the absence of pulmonary vein spikes 30 minutes after CPVI verified by 2 spiral catheters placed within the ipsilateral pulmonary veins (double-lasso technique). Major periprocedural complications occurred in 5 of 161 patients (3.1%). Follow-up was based on outpatient clinic visits, including Holter-ECGs and telephonic interviews. After a single procedure and median follow-up of 129.0 months (interquartile range, 124.7-133.1 months), stable sinus rhythm was present in 53 of 161 (32.9%) patients. Multiprocedural outcome after a mean of 1.73±0.9 procedures and a median follow-up of 123.4 months (interquartile range, 61.0-131.0 months) resulted in stable sinus rhythm in 101 of 161 patients (62.7%). Progression toward persistent atrial fibrillation was observed in 10 of 161 patients (6.2%). CONCLUSION: Ten-year single-procedural outcome of CPVI in patients with paroxysmal atrial fibrillation resulted in stable sinus rhythm in 32.9% and in 62.7% of patients after multiple procedures. The progression rate to persistent AF was remarkably low.

Five-year clinical outcomes of visually guided laser balloon pulmonary vein isolation for the treatment of paroxysmal atrial fibrillation.

BACKGROUND: Visually guided laser balloon (VGLB) ablation allows for pulmonary vein isolation (PVI) under direct endoscopic control. Short- and midterm clinical outcomes are in accordance with results of radiofrequency current (RFC) ablation for the treatment of paroxysmal atrial fibrillation (PAF). OBJECTIVE: The current study sought to assess the long-term clinical outcomes of VGLB-based PVI for PAF. METHODS: A total of 90 patients [60 ± 10 years; 33 (37%) female, left atrial diameter 42 ± 4 mm] with drug-refractory PAF underwent VGLB ablation. The median duration of PAF until VGLB ablation was 36 (interquartile range 12; 84) months. Follow-up was based on outpatient clinic visits including Holter ECGs and telephone interviews. Repeat ablation due to arrhythmia recurrences was performed using RFC ablation. RESULTS: After a single VGLB procedure, 5-year freedom from arrhythmia recurrence was 51% [95% confidence interval (CI) 39-62%]. Thirty-three patients underwent repeat RFC ablation procedures, resulting in multiple procedure freedom from arrhythmia recurrence of 78% (95% CI 68-88%). Major periprocedural complications occurred in four patients (4%). CONCLUSIONS: VGLB ablation for the treatment of drug-refractory PAF is safe and results in 5-year single and multiple procedure arrhythmia-free survival of 51 and 78%, respectively.

Does Size Matter? Cryoballoon-Based Pulmonary Vein Isolation Using a Novel 25-mm Circular Mapping Catheter.

BACKGROUND: Real-time recording of pulmonary vein isolation (PVI) using a circular mapping catheter has become a key aspect of cryoballoon (CB) ablation. The aim of this study was to investigate the procedural safety, efficacy and rate of real-time pulmonary vein (PV) recording using a novel circular mapping catheter with a 25-mm loop size for CB-based PVI.Methods and Results:A total of 40 patients with symptomatic atrial fibrillation (AF) underwent PVI using a second-generation CB and a novel 25-mm circular mapping catheter. A total of 159 PV were identified and successfully isolated. Real-time PV recording was achieved in 80% of the PV. In 3 right inferior PV the circular mapping catheter had to be exchanged for a stiff guidewire due to insufficient mechanical support. Therefore, acute PVI using exclusively the circular mapping catheter was achieved in 156/159 PV (98%). Mean procedure and fluoroscopy times were 66±21 min and 15±6 min, respectively. Transient phrenic nerve palsy occurred in 1 patient as the only procedural complication. CONCLUSIONS: The exclusive use of a novel 25-mm circular mapping catheter for CB ablation of AF results in a real-time PV recording rate of 80% and isolation of 98% of targeted PV.

Catheter ablation of atrial fibrillation in very young adults: a 5-year follow-up study.

Aims: Catheter ablation is an established therapy for symptomatic atrial fibrillation (AF). However, outcome data on catheter ablation for AF in young adults is scarce. Methods and results: From 2005-2014, 85 consecutive young adults (mean age 31 ± 4 years; 69% men) with symptomatic paroxysmal AF (PAF, n = 52) and persistent (Pers) AF (n = 33) underwent pulmonary vein isolation (PVI) [±ablation of complex fractionated atrial electrograms/linear lesions in PVI non-responders] at our centre. Follow-up was based on outpatient visits including 24-h Holter-ECG at 3, 6 and, 12 months post ablation, and every 12 months thereafter. Recurrence was defined as any AF/atrial tachycardia episode >30s following a 3-month blanking period. Follow-up was available for 74/85 (87%) patients. After a median follow-up of 4.6 years (Q1: 2.6; Q3: 6.6) and a mean of 1.5 ± 0.6 (median 1, range 1-3) ablation procedures 84% [including 13% on previously ineffective antiarrhythmic drugs (AAD)] of patients were in stable SR. Single-procedural 1-year/5-year arrhythmia-free survival was 66% [95% confidence interval (CI): 56-78%]/44% (95% CI: 33-59%), respectively. Structural heart disease [SHD; hazard ratio (HR) 2.79 (95% CI 1.52-5.12), P = 0.001] and obesity [HR 1.10 (95% CI 1.00-1.21) per unit increase in body mass index >27 kg/m2, P = 0.05] independently predicted AF recurrence. Major complications occurred in 6/122 (4.9%) procedures (PV stenosis in 3, cardiac tamponade in 1, stroke in 1, and arterial-venous fistula in 1). Conclusion: In the majority of very young adults catheter ablation for AF is effective, and associated with an acceptable complication rate. SHD and obesity are predictors for AF recurrence in this population.

Significant reduction of radiation exposure in cryoballoon-based pulmonary vein isolation.

Aims: Procedure times and left atrial dwell times of cryoballoon (CB)-based ablation strategies for atrial fibrillation (AF) are shorter as compared to radiofrequency ablation, yet fluoroscopy times are longer and result in a higher radiation exposure. The objective of this study is to evaluate a modified fluoroscopy protocol aiming at reduction of radiation exposure in CB ablation. Methods and results: A total of 120 patients with symptomatic AF underwent pulmonary vein isolation (PVI) using the second generation CB and an ablation strategy considering the individual time-to-isolation. The first 60 patients (Group 1) underwent CB-based PVI with conventional fluoroscopy settings. An optimized approach was applied in the following 60 patients (Group 2) by (i) using fluoroscopy instead of filming for verification of pulmonary vein (PV) occlusion after contrast injection, (ii) reducing the frame rate, and (iii) pursuing maximal collimation on the region of interest. A total of 475 PVs were identified and successfully isolated. Median dose area product and fluoroscopy time were significantly shorter in Group 2 as compared to Group 1 [389 (285; 550) cGycm2 vs. 2168 (1355; 3490) cGycm2 (P < 0.0001) and 10 (8; 12) min vs. 14 (11; 19) min (P < 0.0001)]. Additionally, median time-to-isolation of the PVs was significantly shorter in Group 2 [44 (30; 65) s vs. 33 (20; 46) s (P < 0.0001)]. Conclusions: The implementation of an optimized fluoroscopy protocol significantly reduces radiation exposure in CB-based PVI without compromising acute efficacy and safety.

Is less more? Impact of different ablation protocols on periprocedural complications in second-generation cryoballoon based pulmonary vein isolation.

Aims: Second-generation cryoballoon (CB2) based pulmonary vein isolation (PVI) has emerged as an effective treatment option for symptomatic atrial fibrillation (AF). The current study sought to assess the impact of different ablation protocols on the incidence and characteristics of procedural complications in a large patient cohort. Methods and results: A total of 563 consecutive patients with symptomatic AF who underwent CB2-based ablation between July 2012 and January 2016, were assessed. Three different ablation protocols were applied and characterized by (#1) a bonus-freeze following PVI, (#2) no bonus-freeze after PVI, and (#3) a 'time-to-effect'-guided strategy. Major complications occurred in 30/563 patients (5.3%) with phrenic nerve palsy (PNP) as the most frequent complication occurring in 2.7% of the cases. The overall incidence of complications was significantly lower in patients treated with a 'time-to-effect' guided ablation strategy compared with the other ablation protocols (8.1% [17/211] (protocol #1+#2) vs. 3.7% [13/352] (protocol #3), respectively; P = 0.026). The 'time-to-effect' guided ablation protocol was associated with less applied freeze-cycles and shorter freeze-cycle durations. Additionally, shorter procedure times, radiation exposures and lower volumes of contrast medium needed were assessed for the 'time-to-effect' guided protocol as compared with the other ablation protocols. Conclusion: The overall incidence of complications was 5.3% in our analysis. The most frequent complication was PNP. The use of a time-to-effect guided ablation protocol was associated with a lower incidence of major complications compared with a bonus-freeze and no bonus-freeze protocol.

Antegrade-transseptal approach for left ventricular tachyarrhythmia in patients with previous Mitraclip implantation.

Aims: Antegrade-transseptal approach to treat left ventricular tachyarrhythmia (LVT) is useful and widespread. Meanwhile, Mitraclip has been recently introduced as an alternative to mitral valve surgery for severe mitral regurgitation, usually coexisting with ventricular arrhythmias. However, data on the antegrade approach for mapping and ablating LVT in these patients are insufficient. We evaluated the feasibility and clinical impact of the antegrade approach for LVT after Mitraclip implantation. Methods and results: We included five patients (all men; age 72.6 ± 10.5 years) with Mitraclip implantation who underwent catheter ablation for LVT and employed the antegrade approach. Post-ablation mitral valve function was systematically evaluated by transthoracic echocardiography. Six procedures with the antegrade approach were performed on the five patients; three of these patients developed electrical storm. The number of implanted Mitraclip was 1 in two patients, 2 in two patients, and 3 in one patient, for a mean duration of 417 ± 324 days before ablation. After 117-day median follow-up, there was no recurrence of electrical storm, but ventricular tachyarrhythmia recurred and required implantable cardioverter defibrillator therapy in one patient (only sporadic anti-tachycardia pacing); two patients died because of reasons other than ventricular arrhythmia. There was no procedure-related injury on the mitral valve immediately and 3 months after ablation. Conclusions: Antegrade ablation of LVT after Mitraclip implantation may be feasible. Non-arrhythmic death during follow-up suggested the need for comprehensive evaluation before and after ablation.

Catheter Ablation of the Superolateral Mitral Isthmus Line: A Novel Approach to Reduce the Need for Epicardial Ablation.

BACKGROUND: The mitral isthmus is a critical part of perimitral reentrant tachycardia, as well as an important substrate of persistent atrial fibrillation. Deployment of an endocardial mitral isthmus line (MIL) with the end point of bidirectional block may be challenging and often requires additional epicardial ablation within the coronary sinus. METHODS AND RESULTS: The study population comprised 114 patients with perimitral flutter who underwent de novo ablation of an MIL. The initial 57 patients (group A) underwent catheter ablation using a novel superolateral MIL design, connecting the left-sided pulmonary veins with the mitral annulus along the posterior base of the left atrial appendage visualized by selective angiography. The next 57 patients (group B) served as a control group and underwent ablation using a conventional MIL design, connecting the left inferior pulmonary vein with the mitral annulus. Bidirectional block was achieved in 56 of 57 patients in group A (98.2%) and 50 of 57 patients in group B (87.7%; P=0.06). Deployment of a superolateral MIL required significantly less ablation from within the coronary sinus (7.0% versus 71.9%; P<0.01). Predictors for unsuccessful bidirectional mitral isthmus blockade were the need for epicardial ablation from within the coronary sinus (P<0.01) and the total length of the MIL (29.3±6.35 mm versus 40.8±7.29 mm; P=0.005). A higher rate of pericardial tamponade was observed in group A (5.2% versus 0%; P=0.24). CONCLUSIONS: The superolateral MIL is associated with a high acute success rate to achieve bidirectional block using endocardial ablation only with minimal need for epicardial ablation from within the coronary sinus.

Stand-Alone Pulmonary Vein Isolation Versus Pulmonary Vein Isolation With Additional Substrate Modification as Index Ablation Procedures in Patients With Persistent and Long-Standing Persistent Atrial Fibrillation: The Randomized Alster-Lost-AF Trial (Ablation at St. Georg Hospital for Long-Standing Persistent Atrial Fibrillation).

BACKGROUND: Pulmonary vein isolation (PVI) for persistent atrial fibrillation is associated with limited success rates and often requires multiple procedures to maintain stable sinus rhythm. In the prospective and randomized Alster-Lost-AF trial (Ablation at St. Georg Hospital for Long-Standing Persistent Atrial Fibrillation), we sought to assess, in patients with symptomatic persistent or long-standing persistent atrial fibrillation, the outcomes of initial ablative strategies comprising either stand-alone PVI (PVI-only approach) or a stepwise approach of PVI followed by complex fractionated atrial electrogram ablation and linear ablation (Substrate-modification approach). METHODS AND RESULTS: Patients were randomized 1:1 to stand-alone PVI or PVI plus substrate modification. The primary study end point was freedom from recurrence of any atrial tachyarrhythmia, outside a 90-day blanking period, at 12 months. A total of 124 patients were enrolled, with 118 patients included in the analysis (61 in the PVI-only group, 57 in the Substrate-modification group). Atrial tachyarrhythmias recurred in 28 PVI-only group patients and 24 Substrate-modification group patients, for 1-year freedom from tachyarrhythmia recurrence after a single ablation procedure of 54% (95% confidence interval, 43%-68%) in the PVI-only and 57% (95% confidence interval, 46%-72%) in the Substrate-modification group (P=0.86). Twenty-four patients in the PVI-only group (39%) and 18 in the Substrate-modification group (32%) were without arrhythmia recurrence and off antiarrhythmic drug therapy at the end of the 12-month follow-up. CONCLUSIONS: In patients with persistent and long-standing persistent atrial fibrillation, no significant difference was observed in 12-month freedom from atrial tachyarrhythmias between an index ablative approach of stand-alone PVI and a stepwise approach of PVI plus complex fractionated atrial electrogram and linear ablation. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00820625.

Significant reduction in procedure duration in remote magnetic-guided catheter ablation of atrial fibrillation using the third-generation magnetic navigation system.

PURPOSE: The magnetic navigation system (MNS) has shown to be safe and effective for catheter ablation of atrial fibrillation (AF). However, longer procedure duration as compared to manual catheter ablation may limit its widespread use. This study aimed to assess the impact of the newest generation MNS using an optimized mapping and ablation protocol on the efficacy and safety of remote magnetic catheter (RMC)-guided pulmonary vein isolation (PVI). METHODS: This observational study included 52 patients with symptomatic AF who underwent RMC-guided PVI using the second-generation MNS Niobe II (initial 28 patients, group I) or the third-generation MNS Niobe ES in combination with an optimized mapping and ablation protocol (24 patients, group II). RESULTS: Acute PVI was achieved in 26/28 (93%) patients in group I and 24/24 patients (100%) in group II. Mean procedure time was 263.9 ± 81.9 min in group I and significantly lower in group II (139.7 ± 22.6 min, p < 0.01). Mean fluoroscopy time was 18.8 ± 8.7 min in group I and decreased to 7.9 ± 2.6 in group II (p < 0.01). After a median follow-up of 640.5 days (Q1 460.75; Q3 766.5), 16/24 (67%) patients undergoing RMC-guided PVI in group II remained in stable SR. No periprocedural complications were noted for either group. CONCLUSIONS: Use of the third-generation MNS for RMC-guided PVI is safe, effective, and drastically reduced procedure times.

Acute efficacy, safety, and long-term clinical outcomes using the second-generation cryoballoon for pulmonary vein isolation in patients with a left common pulmonary vein: A multicenter study.

BACKGROUND: Second-generation cryoballoon (CB2)-based pulmonary vein isolation (PVI) has demonstrated encouraging clinical results in the treatment of paroxysmal (PAF) and persistent atrial fibrillation (PersAF). However, the CB2 features a maximal diameter of 28 mm, and its adaptability to anatomic variations of the pulmonary veins (PVs) might be challenging. OBJECTIVE: The purpose of this study was to assess the acute efficacy, safety, and long-term clinical results of CB2-based PVI in patients with a left common pulmonary vein (LCPV). METHODS: Six hundred seventy consecutive patients underwent CB2-based PVI in 3 electrophysiology centers. In 74 patients (11%), an LCPV was identified (LCPV group). The data were compared to those from matched patients (n = 74) with normal PV anatomy and comparable baseline characteristics (control group). An antral occlusion of the complete LCPV ostium was feasible in 50% of patients in the LCPV group. If an antral occlusion could not be obtained, a sequential isolation of the first superior and inferior branches was applied. RESULTS: All 74 LCPVs were successfully isolated. A total of 64% patients (LCPV group) and 66% patients (control group) remained in sinus rhythm after mean follow-up of 1.9 ± 0.9 years (P = .820). In 18 of 26 patients (69%) with atrial tachyarrhythmia recurrence, a repeat procedure using radiofrequency energy was performed, and a total of 56% LCPVs were found to be persistently isolated (control group: 61% of left-sided PVs, P = .801). CONCLUSION: Patients with an LCPV undergoing CB2-based PVI demonstrate a high acute success rate. Comparable results with regard to clinical success and durability of PVI were shown when comparing patients of the LCPV group and the control group.

Three-Year Clinical Outcome After 2nd-Generation Cryoballoon-Based Pulmonary Vein Isolation for the Treatment of Paroxysmal and Persistent Atrial Fibrillation　- A 2-Center Experience.

BACKGROUND: Pulmonary vein isolation (PVI) using the 2nd-generation cryoballoon (CB2) for the treatment of atrial fibrillation (AF) has demonstrated encouraging acute and mid-term results. However, follow-up data on outcomes beyond 1 year are sparse. We investigated the 3-year outcome after PVI using the CB2.Methods and Results:100 patients with paroxysmal (PAF, 70/100 [70%] patients) or persistent AF (pAF, 30/100 [30%] patients) underwent CB2-based PVI in 2 experienced centers in Germany. Freeze-cycle duration was 240 s. After successful PVI a bonus freeze-cycle of the same duration was applied in the first 71 patients but was omitted in the following 29 patients. Phrenic nerve palsy occurred in 3 patients (3%); 2 patients were lost to follow-up. After a median follow-up of 38 (29-50) months, 59/98 (60.2%) patients remained in stable sinus rhythm (PAF: 48/70 (69%), pAF: 11/28 (39%) P=0.0084). In 32/39 (77%) patients with arrhythmia recurrence, a second ablation procedure using radiofrequency energy was conducted. Persistent PVI was noted in 76/125 (61%) PVs. After a mean of 1.37±0.6 procedures and a median follow-up of 35 (25-39) months, 77/98 (78.6%) patients remained in stable sinus rhythm (PAF: 56/70 (80%), pAF: 20/28 (71%), P=0.0276). CONCLUSIONS: CB2-based PVI resulted in a 60.2% single-procedure and a 78.6% multiple-procedure success rate after 3 years. Repeat procedures demonstrated a high rate of durable PVI.

First insights into cryoballoon-based pulmonary vein isolation taking the individual time-to-isolation into account.

AIMS: Cryoballoon (CB)-based pulmonary vein isolation (PVI) is an established treatment for symptomatic atrial fibrillation (AF). In the present study, we sought to assess the efficacy and safety of CB-based PVI taking the individual time-to-isolation (TTI) into account. METHODS AND RESULTS: Sixty consecutive patients with drug-refractory paroxysmal atrial fibrillation [n = 49 (82%)] or short-standing persistent atrial fibrillation [n = 11 (18%)] underwent ablation with a 28-mm second-generation CB. The TTI was assessed by spiral mapping-catheter recordings and subsequently followed by an additional freeze-time of 120 s. No bonus freeze-cycle was applied. If the TTI could not be assessed, a fixed freeze-cycle duration of 240 s was applied and successful PVI confirmed thereafter. Clinical follow-up (FU) included 12-lead ECGs and 24 h Holter-ECGs at 3, 6, and 12 months. A blanking period of 3 months was defined. A total of 239 pulmonary veins (PVs) were identified and successfully isolated. The mean TTI assessed in 170/239 (71%) PVs was 52 ± 32 s. The mean number of CB applications was 1.2 ± 0.5; mean freeze-cycle duration was 192 ± 41 s. Mean procedure and fluoroscopy times were 80 ± 24 min and 16 ± 7 min, respectively. Transient phrenic nerve palsy occurred in one patient (2%). During a mean FU of 405 ± 67 days, 43 patients (72%) remained in stable sinus rhythm. CONCLUSIONS: Integrating an individual TTI protocol to CB-based PVI results in shorter freeze-cycle applications in a substantial portion of targeted PVs and an arrhythmia-free survival comparable to conventional ablation protocols. The complication rate is low.

Direct Comparison of Point-by-Point and Rapid Ultra-High-Resolution Electroanatomical Mapping in Patients Scheduled for Ablation of Atrial Fibrillation.

INTRODUCTION: Three-dimensional electroanatomical mapping (EAM) is an established tool facilitating catheter ablation. In this context, the novel Rhythmia system sets a new bar in fast high-resolution mapping. The aim of this study was to directly compare point-by-point versus rapid ultra-high-resolution EAM in patients scheduled for ablation of atrial fibrillation (AF) with focus on procedural data, acute success, and midterm clinical outcome. METHODS AND RESULTS: A total number of 74 consecutive patients (48/74 male) with symptomatic AF were scheduled to undergo pulmonary vein isolation (PVI) using either Carto or Rhythmia. The Carto-guided procedures were performed using point-by-point acquisition according to our routine approach, whereas for Rhythmia, fast anatomical mapping was utilized. Comparing Rhythmia- versus Carto-guided ablation approaches, we observed a significantly longer total mapping time (P = 0.001), longer total fluoroscopy time (P = 0.001), more delivered RF-applications (P = 0.019), and longer total RF-duration (P = 0.002). There was no difference regarding total ablation time (P = 0.707), total procedure duration (P = 0.99), and acute procedural success. During follow-up, 84.8% of patients remained free from any AF/AT-recurrence using Carto versus 88.2% when using Rhythmia (P = 0.53). From Kaplan-Meier analysis, the event rate estimations were 15% versus 13.5%, respectively. CONCLUSION: The present study reports our first clinical experience using Rhythmia in direct comparison with the established Carto system for AF ablation. Our data clearly demonstrate that Rhythmia was proved to be effective and well applicable but more data will be mandatory before final conclusions can be drawn.

Endocardial voltage mapping of pulmonary veins with an ultra-high-resolution system to evaluate atrial myocardial extensions.

INTRODUCTION: Atrial fibrillation (AF) is mainly triggered by arrhythmogenic foci originating from atrial myocardial extensions (MEs) into the pulmonary veins (PVs). Aim of the study was to evaluate endocardial voltage maps of PVs as a surrogate parameter for the extent of MEs in subjects with AF through a ultra-high-density mapping system. METHODS: Sixty-four bipolar electrograms were recorded simultaneously from the Orion mini-basket catheter placed in 72 PVs of 18 consecutive patients with paroxysmal/persistent AF undergoing PV isolation (PVI). The Rhythmia system in conjunction with the Orion mini-basket catheter was utilized to create a bipolar electro-anatomic reconstruction of the left atrium and PVs. RESULTS: Mean patients' age was 61 ± 10 years, 56% had paroxysmal and 44% persistent AF. Mean endocardial bipolar voltages in the PVs were as follows: 1.06 ± 0.34 mV in right superior PV, 1.14 ± 0.52 mV in right inferior PV, 1.15 ± 0.44 mV in left superior PV and 0.94 ± 0.44 in left inferior PV. PVs had no detectable endocardial signals in 7 out of 72 PVs (9%); a total of 29/72 PVs (40%) revealed a non-uniform arrangement of MEs. The area of MEs was significantly larger in the superior PVs compared to the inferior PVs (9.3 ± 4.7 vs 6.7 ± 4 cm2, p = 0.002). No statistical differences in terms of MEs length were found among PVs and according to type of AF. CONCLUSION: In this pilot study using a ultra-high-resolution electro-anatomical mapping system, endocardial voltage maps of PVs as a surrogate parameter of MEs among patients with AF well correspond to previous data from histopathological studies.

Durability of wide-area left atrial appendage isolation: Results from extensive catheter ablation for treatment of persistent atrial fibrillation.

BACKGROUND: Extensive ablation strategies are currently performed in addition to pulmonary vein isolation (PVI) to improve the clinical outcome of patients with drug-refractory persistent atrial fibrillation (AF). Ablation of complex fractionated atrial electrograms (CFAEs), linear lesions, and/or isolation of the left atrial appendage (LAA) are thought to improve arrhythmia-free survival. OBJECTIVE: The purpose of this study was to assess the durability of wide-area left atrial appendage isolation (LAAI) achieved by PVI, an anterior line, and a mitral isthmus line. METHODS: Seventy-one patients with intentional or incidental LAAI during repeat catheter ablation for treatment of persistent AF were included. The initial ablation strategy was PVI. Additional ablation strategies were performed only if PVI failed to maintain stable sinus rhythm. Durability of LAAI was assessed during a subsequent ablation procedure for arrhythmia recurrences (n = 23) or a subsequent percutaneous LAA closure (n = 48). RESULTS: LAAI was performed after a mean of 3 ± 1 procedures. Ablation strategies included circumferential PVI in 71 patients (100%), mitral isthmus line in 64 (90%), anterior line in 60 (85%), CFAE in 27 (38%), and roof line in 13 (18%). LAAI occurred after ablation and bidirectional block of LA linear lesions in 63 patients (89%) and during extensive CFAE ablation in 8 patients (11%). After a median of 105 [61;426] days, the LAA remained electrically isolated in 52 of 71 patients (73%). CONCLUSION: Wide-area LAAI after extensive catheter ablation for persistent AF is durable in the majority of patients. The potential clinical benefit of LAAI for maintaining stable sinus rhythm requires further investigation.

Prognostic Impact of the Timing of Recurrence of Infarct-Related Ventricular Tachycardia After Catheter Ablation.

BACKGROUND: Recurrence of ventricular tachycardia (VT) after ablation in patients with previous myocardial infarction is associated with adverse prognosis. However, the impact of the timing of VT recurrence on outcomes is unclear. METHODS AND RESULTS: We analyzed data from a multicenter collaborative database of patients who underwent catheter ablation for infarct-related VT. Multivariable Cox regression analyses investigated the effect of the timing of VT recurrence on the composite outcome of death or heart transplantation using VT recurrence as a time-varying covariate. A total of 1412 patients were included (92% men; age: 66.7±10.7 years), and 605 patients (42.8%) had a recurrence after median 116 days (188 [31.1%] within 1 month, 239 [39.5%] between 1 and 12 months, and 178 [29.4%] after 12 months). At median follow-up of 670 days, 375 patients (26.6%) experienced death or heart transplantation. The median time from recurrence to death or heart transplantation was 65 and 198.5 days in patients with recurrence ≤30 days and >30 days post ablation, respectively. The adjusted hazard ratio (95% confidence interval) for the effect of VT recurrence occurring immediately post ablation on death or heart transplantation was 3.45 (2.33-5.11) in reference to no recurrence. However, the magnitude of this effect decreased statistically significantly (P<0.001) as recurrence occurred later in the follow-up period. The respective risk estimates for VT recurrence at 30 days, 6 months, 1 year, and 2 years were 3.36 (2.29-4.93), 2.94 (2.09-4.14), 2.50 (1.85-3.37), and 1.81 (1.37-2.40). CONCLUSIONS: VT recurrence post ablation is associated with a mortality risk that is highest soon after the ablation and decreases gradually thereafter.