The Influence of Cardiac Ablation on the Electrophysiological Characterization of Rat Isolated Atrium: Preliminary Analysis

Abstract

Atrial fibrillation (AF) is the most common cardiac arrhythmia seen in clinical practice and its treatment by antiarrhythmic drugs is still non-effective. Radiofrequency catheter ablation (RFA) has been widely accepted as a strategy to prevent AF by creating myocardial lesions to block the AF electrical wavefront propagation and eliminate arrhythmogenic tissue. In this study, we analyzed the electrophysiological impact of different RFA time duration strategies through a controlled animal protocol. Electrical activity of the isolated right atrium of rats, under different RFA time strategies on the epicardium, was acquired during 4 s on the endocardium by electrical Mapping (EM) and simultaneously on the endocardium by Optical Mapping (OM), respectively. Analyses were concentrated on both time and frequency domain, through analysis of sig-nal's morphology, local activation time, conduction velocity, dominant frequency (DF), and organization index (OI). The morphology of the optical and electrical signals was altered as the ablation time increased, making it difficult to identify activation times. Moreover, DF and OI decreased with increasing ablation time implied in fragmented electrograms. Through the characterization of traditional metrics applied to the electrical and optical data, it was possible to identify important changes, in time and frequency, inside the ablated regions.