Right atrial appendage firing in atrial fibrillation.

Background: The role of atrial fibrillation (AF) drivers located at the left atrium, superior vena cava, crista terminalis and coronary sinus (CS) is well established. While these regions are classically targeted during catheter ablation, the role of right atrial appendage (RAA) drivers has been incompletely investigated. Objective: To determine the prevalence and electrophysiological characteristics of AF driver's arising from the RAA. Materials and methods: We conducted a retrospective analysis of clinical and procedural data of 317 consecutive patients who underwent an AF ablation procedure after bi-atrial mapping (multipolar catheter). We selected patients who presented with a per-procedural RAA firing (RAAF). RAAF was defined as the recording of a sustained RAA EGM with a cycle length shorter than 120 ms or 120 < RAAF CL ≤ 130 ms and ratio RAA CL/CS CL ≤ 0.75. Results: Right atrial/atrium appendage firing was found in 22 patients. The prevalence was estimated at 7% (95% CI, 4-10). These patients were mostly men (72%), median age: 66 yo ± 8 without structural heart disease (77%). RAAFs were predominantly found in paroxysmal AF patients (63%, 32%, and 5% for paroxysmal, short standing and long-standing AF, respectively, p > 0.05). RAAF median cycle length was 117 ms ± 7 while CS cycle length was 180 ms ± 10 (p < 0.01). Conclusion: In 317 consecutive AF ablation patients (22 patients, 7%) the presence of a high-voltage short-cycle-length right atrial appendage driver (RAAF) may conclusively be associated with AF termination. This case series exemplifies the not-so-uncommon role of the RAA in the perpetuation of AF.

Localized Atrial Tachycardia and Dispersion Regions in Atrial Fibrillation: Evidence of Spatial Concordance.

INTRODUCTION: During atrial fibrillation (AF) ablation, it is generally considered that atrial tachycardia (AT) episodes are a consequence of ablation. Objective: To investigate the spatial relationship between localized AT episodes and dispersion/ablation regions during persistent AF ablation procedures. Methods: We analyzed 72 consecutive patients who presented for an index persistent AF ablation procedure guided by the presence of spatiotemporal dispersion of multipolar electrograms. We characterized spontaneous or post-ablation ATs' mechanism and location in regard to dispersion regions and ablation lesions. RESULTS: In 72 consecutive patients admitted for persistent AF ablation, 128 ATs occurred in 62 patients (1.9 ± 1.1/patient). Seventeen ATs were recorded before any ablation. In a total of 100 ATs with elucidated mechanism, there were 58 localized sources and 42 macro-reentries. A large number of localized ATs arose from regions exhibiting dispersion during AF (n = 49, 84%). Importantly, these ATs' locations were generally remote from the closest ablation lesion (n = 42, 72%). CONCLUSIONS: In patients undergoing a persistent AF ablation procedure guided by the presence of spatiotemporal dispersion of multipolar electrograms, localized ATs originate within dispersion regions but remotely from the closest ablation lesion. These results suggest that ATs represent a stabilized manifestation of co-existing AF drivers rather than ablation-induced arrhythmias.

MAPT (Mono Antiplatelet Therapy) as Regular Regimen After COBRA PzF™ NanoCoated Coronary Stent (NCS) Implantation.

AIMS: To report procedural and 1-year outcomes following COBRA PzF NCS implantation in a routine daily setting with high bleeding risk (HBR) patients treated with clopidogrel as mono antiplatelet therapy (MAPT). METHODS: This is a prospective, consecutive, observational study in HBR patients who underwent PCI with COBRA PzF NCS and treated with clopidogrel alone at discharge. The primary endpoint was definite stent thrombosis at one month. The secondary endpoint was MACE (Cardiac Death, myocardial infarction (MI), target lesion revascularization (TLR)) at 12 months. RESULTS: From October 2015 to December 2018, 77 patients with 120 lesions were enrolled and treated. Mean age was 78.7 ±â€¯8.89 years, 58.5% men and 18.2% had ACS. Patients included had a minimum of 2.0 inclusion LEADERS FREE criteria. Angiographic success was achieved in all cases. The primary endpoint occurred in 0%, no stent thrombosis was occurred. MACE at 12-months (available for 52 patients) was 3.8% including cardiac death 0%, MI 0% and TLR 3.8%. No severe bleeding events (BARC3-5) or stroke or late stent thrombosis were noted. CONCLUSION: Clopidogrel as MAPT after COBRA PzF NCS implantation in HBR patients is feasible and an attractive option. One-year follow-up was associated with excellent clinical outcomes and should be confirmed with large randomised study. CONDENSED ABSTRACT: This is prospective registry of high bleeding risk patients treated with the COBRA PzF NCS and MAPT at discharge. The primary end point demonstrated no stent thrombosis. The rate of major cardiac adverse events (a composite of cardiovascular death, myocardial infarction and target lesion revascularisation) at 1 year was 3.8%. No severe bleeding events, stroke or late stent thrombosis were noted. One-year follow-up was associated with good clinical outcomes and compared favorably with current devices.

A comparison between multipolar mapping and conventional mapping of atrial tachycardias in the context of atrial fibrillation ablation.

BACKGROUND: Activation mapping can be challenging and time-consuming in patients with multiple atrial tachycardias (ATs). AIMS: To compare multielectrode mapping using a dedicated mapping catheter - PentaRay (Biosense Webster Inc.) - and the conventional technique for mapping ATs in the context of atrial fibrillation (AF) ablation. METHODS: All procedures where PentaRay mapping of AT were used - after or during persistent AF ablation - were analysed. These were compared to a historical group - using conventional mapping. RESULTS: A mean of 449±520 points within 14±6min were acquired per AT in the PentaRay group (n=17) versus 42±18 points (P<0.0001) within 33±25min (P=0.04) in the conventional group (n=17). All 25 AT isthmuses were easily identified and ablated in the PentaRay group (100%) versus 20/23 (87%) in the conventional group (P=0.056). The ablation time was shorter in the PentaRay group (760±540 vs 1347±962 s; P=0.037). However, procedure and fluoroscopy times were not significantly different between the PentaRay and conventional groups: 253±77 vs 267±73min (P=0.80) and 13.1±8.0min vs 15.1±10.0min (P=0.98), respectively. Recurrence occurred in less patients in the PentaRay group (0 vs 23.5%; P=0.033) during a mean follow-up of nearly 1 year. CONCLUSION: In patients with multiple ATs, multielectrode PentaRay mapping was faster than the conventional technique, with less radiofrequency delivery and a better mid-term outcome.

Radiofrequency catheter ablation of atrial fibrillation: Electrical modification suggesting transmurality is faster achieved with remote magnetic catheter in comparison with contact force use.

BACKGROUND: Remote magnetic navigation (RMN) and contact force (CF) sensing catheters are available technologies for radiofrequency (RF) catheter ablation of atrial fibrillation (AF). Our purpose was to compare time to electrogram (EGM) modification suggesting transmural lesions between RMN and CF-guided AF ablation. METHODS AND RESULTS: A total of 1,008 RF applications were analyzed in 21 patients undergoing RMN (n = 11) or CF-guided ablation (n = 10) for paroxysmal AF. All procedures were performed in sinus rhythm during general anesthesia. Time to EGM modification was measured until transmurality criteria were fulfilled: (1) complete disappearance of R if initial QR morphology; (2) diminution > 75% of R if initial QRS morphology; (3) complete disappearance of R' of initial RSR' morphology. Impedance drop as well as force time integral (FTI) were also assessed for each application. Mean CF at the beginning of each RF application in the CF group was 11 ± 2 g and mean FTI per application was 488 ± 163 gs. Time to EGM modification was significantly shorter in the RMN group (4.52 ± 0.1 seconds vs. 5.6 ± 0.09 seconds; P < 0.00001). There was no significant difference between other procedural parameters. CONCLUSION: Remote magnetic AF ablation is associated with faster EGM modification suggesting transmurality than optimized CF and FTI-guided catheter ablation.