VERSA: Omnipolar Vector Mapping from Arbitrarily Positioned Electrodes.
Academic Article
Overview
abstract
BACKGROUND: Accurate assessment of arrhythmia propagation can help identify ablation targets, but current methods are limited by local activation time (LAT) variability, catheter orientation dependence, and inconsistent sampling density. OBJECTIVE: To extend LAT-independent omnipolar technology (OT) to catheters with arbitrary electrode arrangements, compare estimates to LAT-derived equivalents, and demonstrate a weighted resampling algorithm that produces clear and robust visualizations of wavefront propagation. METHODS: Omnipolar estimates of conduction velocity (CV), activation direction (AD), and voltage were computed from electroanatomic mapping data from 34 scar-related reentrant atrial tachycardias (ATs) and one ventricular tachycardia mapped with PENTARAY and OCTARAY catheters. Estimates were compared with conventional analogs to assess concordance, both globally and after stratification by anatomic region. To overcome sampling non-uniformity, a distance-weighted vector estimation, resampling and smoothing algorithm (VERSA) was devised to render propagation metrics (CV and AD) into intuitive visualizations. Resulting VERSA maps were assessed qualitatively for their ability to convey local propagation and their agreement with conventional activation maps. RESULTS: Across all cases, omnipolar CV was higher than LAT-based CV, while differences in AD were negligible. Omnipolar voltages were significantly higher than corresponding maximum bipolar voltages. The proposed VERSA maps intuitively depicted wavefront propagation, agreed broadly with activation maps, and illustrated conduction block, conduction breakthrough, and overall patterns of reentry. CONCLUSION: Extending OT to arbitrary electrode arrangements and visualizing measurements in VERSA maps can elucidate wavefront propagation in reentrant tachycardias without the need for LAT annotation. These methods could facilitate better interpretation of complex arrhythmia patterns and more effective ablation.
