Unipolar electrograms are voltage signals that reflect time-varying extracellular currents. Bipolar electrograms provide differential extracellular voltages along an axis and resemble a local directional derivative. Both are based on the fundamental concept of electric fields in tissues. Omnipolar electrograms are derived from a clique, a group of nearby electrodes that generate bipolar signals from multiple directions. They are electrode and catheter-orientation independent.

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Omnipolar electrograms provide wavefront characteristics, such as amplitude, timing, direction, and speed, in physiologically relevant directions located at the center of the electrode clique. This enables determinations of a maximal bipolar voltage amplitude termed OT Vmax, the generalization of peak-to-peak in the presence of directionality, and is not affected by catheter orientation and is less sensitive to electrode distance for small cliques.

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Specialized catheters and three-dimensional mapping system software enable omnipolar electrograms and derived quantities to be generated and displayed in real-time.

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Omnipolar electrograms during atrial fibrillation are significantly less influenced by directional factors, allowing for robust and consistent substrate assessment.

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Mapping the ventricles using an equispaced electrode grid catheter and omnipolar electrograms can provide reliable substrate assessment within infarcted and noninfarcted regions of the ventricles to aid in determining ablation targets, such as a lesion gap or an isthmus.