Abstract 15023: Minimum Electrode Spatial Resolution for Arrhythmia Rotor Detection and Localization

Introduction: Efficacy of electrotherapy or ablation therapy for treatment of arrhythmias is dependent on accurate detection of arrhythmia focal or reentrant drivers. However, success rates have been inconsistent, with frequent arrhythmia recurrence. A likely reason is the limited current spatial resolution of mapping devices, which averages 4 mm. The goal of this study was to determine the minimum spatial resolution necessary to identify and localize arrhythmia reentrant drivers (rotors). Methods: We conducted dual-sided (epicardial and endocardial) optical mapping studies in 12 donor human right ventricular wedge preparations subjected to arrhythmia induction protocol (S1S1 restitution and/or 50Hz burst pacing). The resulting arrhythmia data (0.7mm spatial resolution) was down sampled to different spatial resolutions (1.4-7mm) and up sampled back to full resolution. Rotors were tracked for each sub-resolution and compared to the rotors in the original data. Further comparisons were made according to arrhythmia type, sex, anatomical region, and mapped surface. Results: Rotor detection accuracy for currently used mapping devices was found to be 57±4%. Localization accuracy was 61±7%. For the current average spatial resolution, clinical rotor detection and localization accuracies can be expected to fall within a confidence interval of 47-67% and 46-75%, respectively. For the spatial resolutions tested, detection accuracy was above 80% only for a resolution of 1.4 mm, while localization accuracy reached that value at 2.1 mm. Moreover, the arrhythmia type affected detection and localization accuracies, which decreased consistently with loss of spatial resolution for unstable arrhythmias and had steadier values for stable arrhythmias. When comparing mapped surfaces, rotor incidence was higher in the endocardium, likely due to the presence of adipose tissue on the epicardial surface. Differences in sex and anatomical region had no statistically significant impact. Conclusions: The spatial resolution of current devices is insufficient to map rotors accurately, especially for unstable arrhythmias. For both detection and localization accuracies to be above 80%, a resolution of at least 1.4 mm is required.