Local impedance and ultra-high density 3-dimensional mapping results in
improved ablation metrics for cavotricuspid isthmus dependent atrial
flutter compared with conventional ablation and contact force-guided
ablation with 3-dimensional mapping
Abstract
Introduction Multiple contact-based ablation technologies have been
developed to allow real-time judgement of lesion effectiveness; local
impedance (LI) guided ablation and the role of ultra-high density (UHD)
mapping have not yet been evaluated for cavotricuspid isthmus dependent
atrial flutter (CTI-AFL). Methods This non-randomised observational
study evaluated patients undergoing CTI-AFL ablation using conventional,
contact force (CF) and LI guided strategies. Ablation metrics were
collected, and in the LI cohort, the use of UHD mapping for breakthrough
was evaluated. Results 30 patients were included, 10 in each group. Mean
total ablation time was significantly shorter with LI (3.2±1.3min) vs
conventional (5.6±2.7min) and CF (5.7±2.0min, p=0.0042). Time from start
of ablation to CTI block was numerically shorter with LI (14.2±8.0min)
vs conventional and CF (19.7±14.1 and 22.5±19.1min, p=0.4408). There
were no differences in the number of lesions required to achieve block,
procedural success, complication rates or recurrence. 15/30 patients did
not achieve block following first-pass ablation. UHD mapping rapidly
identified breakthrough in the 5 LI patients, including
epicardial-endocardial breakthrough (EEB) away from the line. Conclusion
The use of LI for real-time assessment of lesion formation resulted in
significantly less ablation requirement. UHD mapping rapidly identified
breakthrough, including EEB, which would likely have been difficult to
identify otherwise and possibly require extensive ablation, contributing
towards shortening of time to CTI block with LI.