A New Approach for Mapping Slow Electrical Conduction Areas in Atypical Atrial Flutter

Detection of slow electrical conduction areas is crucial for providing an effective ablation therapy in atypical atrial flutter. To this aim local atrial activations and their duration should be accurately identified. Currently mapping systems identify the precocity or lateness of a local activation with respect to a fixed reference without considering its duration. In this study we developed an automatic approach to compute local activation durations from electrograms (EGMs). EGMs were acquired with two different commercial mapping catheters (Advisor™ FL Circular and HD Grid) in two patients. Signals were passband filtered before processing and the analysis was based on the EGMs histogram and similarity techniques. The proposed approach was validated against 3875 activations manually annotated (GS) by an expert electrophysiologist. The mean error in the computation of the activation durations over each signal for each patient was 0.05±1.3ms (GS activation duration: 49.5±8.6ms) and - 0.37±1.87ms (GS activation duration: 45.9±10.1ms) for the FL Circular and -5.3±0.8ms (GS activation duration: 65.8±7.5ms) and -0.1±9.7ms (GS activation duration: 55.8±11.0ms)for the HD Grid. The developed algorithm is accurate, and the 3D maps showing slow electrical conduction areas may represent a useful tool to be integrated with activation and voltage maps to plan and assist therapeutic interventions in atypical atrial flutter.