2381/41403 Tiago P. Almeida Tiago P. Almeida GS Chu GS Chu Michael J. Bell Michael J. Bell Xin Li Xin Li JL Salinet JL Salinet N Dastagir N Dastagir JH Tuan JH Tuan PJ Stafford PJ Stafford G André Ng G André Ng Fernando S. Schlindwein Fernando S. Schlindwein The temporal behavior and consistency of bipolar atrial electrograms in human persistent atrial fibrillation University of Leicester 2018 Atrial fibrillation Catheter ablation Electrophysiology mapping Fractionation Stability 2018-03-27 13:34:17 Journal contribution https://figshare.le.ac.uk/articles/journal_contribution/The_temporal_behavior_and_consistency_of_bipolar_atrial_electrograms_in_human_persistent_atrial_fibrillation/10209959 The unstable temporal behavior of atrial electrical activity during persistent atrial fibrillation (persAF) might influence ablation target identification, which could explain the conflicting persAF ablation outcomes in previous studies. We sought to investigate the temporal behavior and consistency of atrial electrogram (AEG) fractionation using different segment lengths. Seven hundred ninety-seven bipolar AEGs were collected with three segment lengths (2.5, 5,and 8 s) from 18 patients undergoing persAF ablation. The AEGs with 8-s duration were divided into three 2.5-s consecutive segments. AEG fractionation classification was applied off-line to all cases following the CARTO criteria; 43% of the AEGs remained fractionated for the three consecutive AEG segments, while nearly 30% were temporally unstable. AEG classification within the consecutive segments had moderate correlation (segment 1 vs 2: Spearman's correlation ρ = 0.74, kappa score κ = 0.62; segment 1 vs 3: ρ = 0.726, κ = 0.62; segment 2 vs 3: ρ = 0.75, κ = 0.68). AEG classifications were more similar between AEGs with 5 and 8 s (ρ = 0.96, κ = 0.87) than 2.5 versus 5 s (ρ = 0.93, κ = 0.84) and 2.5 versus 8 s (ρ = 0.90, κ = 0.78). Our results show that the CARTO criteria should be revisited and consider recording duration longer than 2.5 s for consistent ablation target identification in persAF.