PT005 Presence of thrombus in left atrium in patients with atrium fibrillation anticoagulated with coumarin anticoagulants versus dabigatran

Abstract

O ST E R A B ST R A C T S theoretical and experimental studies, our group has shown that high bipolar electrogram Shannon entropy (ShEn) distinguishes the pivot and periphery of rotors. We hypothesised that ablation directed towards regions of high ShEn could slow or terminate AF. Objectives: The aim was to determine if directed ablation of regions of high ShEn would slow or terminate human persistent AF. Methods: The study enrolled 9 patients undergoing persistent AF ablation. (Left atrial diameter 45 6mm, LV ejection fraction 52 5%). Patients in spontaneous or induced AF were mapped with a 20-pole PentaRay catheter and NavX system. 8-second recordings of each mapped point were acquired, with endocardial contact verified by fluosocopy at each site. After mapping, mapped point electrophysiologic data and location data were exported to a PC where Shannon entropy (ShEn) was calculated for each mapped point. Points were ranked by entropy value, and colour-coded ShEn maps constructed. The top 10% of ShEn points were annotated on to the NavX map, and used to guide selection of regions for ablation. Ablation of pre-identified ShEn regions was performed after pulmonary vein antral isolation without CFAE or linear ablation. The study endpoints were: (i) AF cycle length change; and (ii) AF termination. Results: Mapping was able to be performed in all cases, with 621 26 points/pt acquired. AF termination occurred in 6/9 cases, with 3/9 cases requiring cardioversion. 5/9 cases showed AF termination co-localised with pre-specified regions of ShEn. In 3 of these cases, termination occurred at pre-specified regions of ShEn encountered during pulmonary vein antral isolation. In 2 cases,termination occurred at ShEn sites outside the pulmonary vein antra. Mean AFCL change post PV isolation was 11.8 13ms (p1⁄40.07), and AFCL change post-ShEn ablation was 29.1 26ms (p1⁄40.02). 6/9 cases remained in sinus rhythm at median follow-up 274 148 days . Sites of ShEn region termination included the base of LA appendage, right anterior wall, roof, posterior wall, and left superior PV ridge. Conclusion: The study demonstrates the feasibility of ablation of high ShEn regions, associated with termination of AF and/or AF cycle length slowing in selected AF patients, and requires further investigation in AF ablation. Disclosure of Interest: None Declared