Toward Sequential Omnipolar Mapping: Effect of Inter-Beat Variability in a 2D Simulation Study

The omnipolar mapping technology (OT) was introduced to overcome the sensitivity of bipolar recordings to catheter orientation and relies on electrodes arranged in regular geometries, such as squares or triangles. Recent studies demonstrated that OT can be applied without the need for specialized catheter geometries. However, whether OT can be effectively applied in sequential mapping without specialized catheter designs remains an open question. In this study, we proposed a variant of OT which could be applied in sequential mapping. A key challenge of this approach is that the electrical field has to be reconstructed from multiple wavefronts recorded across different beats rather than from a single wave as in standard OT, with electrodes arbitrarily positioned. Despite OT was found sufficiently tolerant to the spatial variability of the electrodes, the temporal variability may play an important role. Therefore, to test the efficacy of the algorithm, we investigated the impact of physiological inter-beat variability on the proposed algorithm, with a particular focus on changes in conduction velocity (CV). We performed multiple two-dimensional planar wave simulations with CV values spanning physiological ranges to emulate multiple atrial beats. For each simulation, two bipolar signals were randomly sampled within a circular region of radius 5 mm around a fixed reference point and used to apply OT. Three experimental conditions were considered: i) all bipolar signals were generated from a wavefront with fixed maximum CV, ii) all bipolar signals originated from a single wavefront with a randomly selected CV per simulation, and iii) each bipolar signal originated from a wavefront with an independently selected random CV. Results showed that sequential OT consistently outperformed standard bipolar mapping across all experimental conditions for the characterization of the voltage, exhibiting higher median values (e.g., 5.04 vs 4.62 in Experiment 1 and 4.18 vs 3.68 in Experiment 3). Wavefront direction estimation remained accurate in all cases, with a maximum error of 0, (-3.05,, 3.25)° in Experiment 3. CV estimation of both standard and sequential OT showed a systematic positive bias in Experiment 1 (median 0.99 vs reference 0.9 m/s) and increased variability in Experiments 2 and 3. Sequential OT improved voltage estimation compared with conventional bipolar mapping and enabled reliable wavefront direction assessment. Although the promising results, some limitations persisted, such as a positive bias in CV estimation and incomplete recovery of the reference voltage.