Characteristics of Complex Fractionated Electrograms in Nonpulmonary Vein Ectopy Initiating Atrial Fibrillation/Atrial Tachycardia

Abstract

Complex Fractionated Electrograms from Nonpulmonary Vein Ectopy. Background: Nonpulmonary vein (PV) ectopy initiating atrial fibrillation (AF)/atrial tachycardia (AT) is not uncommon in patients with AF. The relationship of complex fractionated atrial electrograms (CFAEs) and non-PV ectopy initiating AF/AT has not been assessed. We aimed to characterize the CFAEs in the non-PV ectopy initiating AF/AT. Methods: Twenty-three patients (age 53 ± 11 y/o, 19 males) who underwent a stepwise AF ablation with coexisting PV and non-PV ectopy initiating AF or AT were included. CFAE mapping was applied before and after the PV isolation in both atria by using a real-time NavX electroanatomic mapping system. A CFAE was defined as a fractionation interval (FI) of less than 120 ms over 8-second duration. A continuous CFAE (mostly, an FI < 50 ms) was defined as electrogram fractionation or repetitive rapid activity lasting for more than 8 seconds.Results: All patients (100%) with non-PV ectopy initiating AF or AT demonstrated corresponding continuous CFAEs at the firing foci. There was no significant difference in the FI among the PV ostial or non-PV atrial ectopy or other atrial CFAEs (54.1 ± 5.6, 58.3 ± 11.3, 52.8 ± 5.8 ms, P = 0.12). Ablation targeting those continuous CFAEs terminated the AF and AT and eliminated the non-PV ectopy in all patients (100%). During a follow-up of 7 months, 22% of the patients had an AF recurrence with PV reconnections. There was no recurrence of any ablated non-PV ectopy during the follow-up.Conclusion: The sites of the origin of the non-PV ectopies were at the same location as those of the atrial continuous CFAEs. Those non-PV foci were able to initiate and sustain AF/AT. By limited ablation targeting all atrial continuous CFAEs, the AF could be effectively eliminated.

Functional Nature of Electrogram Fractionation Demonstrated by Left Atrial High-Density Mapping

“…This observation has been described previously (11;22). Interestingly, pulmonary vein isolation during the ablation of PsAF results in an altered distribution and a significant reduction in left atrial pre-ablation fractionation without termination (23), suggesting in turn that much of the pre-ablation fractionation in the left atrium may play a passive role.…”

Effects of inter-electrode spacing on complex fractionated atrial electrograms and dominant frequency detection

“…The settings included a refractory period of 40 ms, peak-to-peak sensitivity between 0.05 and 0.1 mV, and duration of 10 ms. Continuous CFAEs were defined as having a mean fractionation interval (FI) of <50 ms and variable CFAEs as having an FI of 50-120 ms [8,9].…”

Three-Dimensional Electroanatomic Mapping Systems in Catheter Ablation of Atrial Fibrillation

“…The system can also provide simultaneous visualization of epicardial and endoscopic views of the LA and enable the ablation application to be performed more accurately and easily (Figure 3). 27 Udyavar et al reported that after 1 round of PV isolation, successful elimination of PV potentials was achieved in only approximately 60% of the patients. 33 A PV carina ablation is advisable to substantially increase the elimination rate of PV potentials to 100%.…”

“…26 Lo et al also reported that the origin of the non-PV ectopies was the same location as that of the atrial continuous CFEs; AF could be effectively eliminated by limited ablation targeting those atrial continuous CFEs. 27 Persistent CFE sites play an important role in the maintenance of AF and the 3D mapping system is a useful tool for substrate mapping during AF. …”