Towards application of complexity measures of atrial electrograms to predict outcome of the ablation procedure

The aim of this study was to assess the reliability of the complexity analysis of a single electrogram as a predictor of spontaneous termination of Atrial Fibrillation (AF) during ablation procedure. Left and right atrial endocardial bipolar electrograms from two locations (High Right Atrium - HRA and Coronary Sinus - CS) were recorded before ablation treatment of AF (at baseline) in 36 patients. Information about the ablation outcome (cardioversion - CV or spontaneous termination - TEKM) was collected. For each electrogram, algorithmic complexity (AC) and Shannon entropy was calculated. Baseline electrograms from electrodes located in HRA had significantly lower algorithmic complexity than from electrodes located in Cs. Only the Shannon Entropy of electrogram measured at CS showed significant diference between CV and TERM (p=0.03), while in case of algorithmic complexity only a trend towards significance was found (p=0. 08). Electrogram complexity parameters used in clinical practice did not distinguish the ablation outcome groups, with Shannon entropy showing the most significant diference.