Abstract:

Atrial fibrillation (AF) is the most common cardiac ar- rhythmia seen in clinical practice and its treatment by an- tiarrhythmic 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 elimi- nate 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 dur- ing 4 s on the endocardium by electrical Mapping (EM) and simultaneously on the endocardium by Optical Map- ping (OM), respectively. Analyses were concentrated on both time and frequency domain, through analysis of sig- nal’s morphology, local activation time, conduction veloc- ity, 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 elec- trograms. Through the characterization of traditional met- rics applied to the electrical and optical data, it was pos- sible to identify important changes, in time and frequency, inside the ablated regions.