Orientation-Independent Catheter-Based Characterization of Myocardial Activation

Objective: We describe a novel method to map cardiac activation that resolves signals into meaningful directions and is insensitive to electrode directional effects.

Methods: Multielectrode catheters that span 2- and 3-D space are used to derive local electric field (E-field) signals. A traveling wave model of local EGM propagation motivates a new "omnipolar" reference frame in which to understand EGM E-field signals and provide bipolar component EGMs aligned with these anatomic and physiologic directions. We validate the basis of this technology and determine its accuracy using a saline tank in which we simulate physiologic propagation.

Results: Omnipole signals from healthy tissue are nearly free of catheter orientation effects and are constrained by biophysics to consistent morphologies and thus consistent measured amplitudes and timings. Using a 3-D EP mapping system, traveling wave treatment, and omnipolar technology (OT) E-field loops, we derived a new and nearly instantaneous means to determine conduction velocity and activation direction.

Conclusion: We describe the basis of OT and validate it with ablation and mapping catheters in a saline tank. Finally, we illustrate OT with signals from live subjects.

Significance: OT's novel approach with signal processing and real-time visualization allows for a newly detailed characterization of myocardial activation that is insensitive to catheter orientation.