Abstract 19176: Mapping of Electrogram Morphology Recurrence Patterns during Atrial Fibrillation
Introduction: Electrograms during atrial fibrillation (AF) are complex and seemingly chaotic. It is still unknown how to best analyze and utilize AF electrograms.
Hypothesis: We hypothesize that the frequency and patterns of AF electrogram morphology recurrence determined by a modified recurrence plot (RP) analysis will show differences based on region in this pilot study.
Methods: AF electrograms (>16 s) recorded from documented left atrial (LA) and right atrial (RA) sites in 13 patients (10 male, 59±10 years old) prior to AF ablation were analyzed. A 100 ms window for each automatically detected activation was extracted and cross-correlated with every other activation in a 30-sec recording. The result was a set of NxN cross-correlation (CC) values, where N is the number of detected activations. These values were displayed in a two-dimensional RP. A recurrence index (RI), the percentage of the most common morphology, was also computed. A high RI likely indicates consistent activation directions at the site of bipolar electrogram recording.
Results: Figure A is a RP example. The checker board pattern of alternating high and low CC values indicates periodic recurrences in morphologies (RI=70% for this example). The mean RI for all sites and all patients was 38±25%. The highest RI was found in the left superior LA in all 4 paroxysmal AF patients (85±18%, see Figure B). For 9 persistent AF patients, the highest RI was found in the RA (91±10%) in 5 patients and in the left superior LA (95±6%) in 4 patients. The persistent AF patients had higher maximum RIs in the RA than the paroxysmal AF patients (87±16 vs. 51±15%, p=0.01).
Conclusion: Electrogram morphology with highest recurrence rates were most frequently found in the left superior LA, a common location for AF triggers. Further work is needed to determine whether high electrogram repeatability reflects AF driver activity and whether RPs could be used as part of an ablation strategy.
- © 2012 by American Heart Association, Inc.