Regions of Highly Recurrent Electrogram Morphology With Low Cycle Length Reflect Substrate for Atrial Fibrillation

Abstract

Traditional anatomically guided ablation and attempts to perform electrogram-guided atrial fibrillation (AF) ablation (CFAE, DF, and FIRM) have not been shown to be sufficient treatment for persistent AF. Using biatrial high-density electrophysiologic mapping in a canine rapid atrial pacing model of AF, we systematically investigated the relationship of electrogram morphology recurrence (EMR) (Rec% and CL_R) with established AF electrogram parameters and tissue characteristics. Rec% correlates with stability of rotational activity and with the spatial distribution of parasympathetic nerve fibers. These results have indicated that EMR may therefore be a viable therapeutic target in persistent AF.

Keywords: AF, atrial fibrillation; AI, anisotropy index; CFAE, complex fractionated atrial electrogram; CLR, cycle length of the most recurrent electrogram morphology; DF, dominant frequency; EGM, electrogram; EMR, electrogram morphology recurrence; FFT, fast Fourier transform; FI, fractionation interval; FIRM, focal impulse and rotor mapping; LAA, left atrial appendage; LAFW, left atrial free wall; LAT, local activation time; OI, organization index; PLA, posterior left atrium; PV, pulmonary vein; RAA, right atrial appendage; RAFW, right atrial free wall; RAP, rapid atrial pacing; Rec%, recurrence percentage; ShEn, Shannon’s entropy; arrhythmias; atrial fibrillation; fibrosis; mapping.