We specifically evaluated unipolar, bipolar, and omnipolar voltage mapping during the stepwise creation of linear RF ablation lesions in an ex vivo perfused porcine heart model. By intentionally creating lesions in three stages—non-transmural discontinuous, transmural discontinuous, and fully transmural continuous—we were able to systematically assess how each mapping technique reflects lesion formation, continuity, and transmurality.

Our results show that all voltage modalities demonstrate a reduction in signal amplitude during ablation. However, the magnitude and interpretability of these changes differ substantially. Omnipolar voltage mapping showed the most pronounced and consistent decrease in voltage (up to 100% reduction), with nearly all signals within the lesion area falling below clinically relevant low-voltage thresholds after completion of a continuous transmural lesion. In contrast, unipolar voltages remained relatively high and variable, even in fully ablated tissue, limiting their usefulness for lesion assessment.

Importantly, we demonstrate that omnipolar mapping uniquely enables reliable identification of lesion gaps. During intermediate ablation stages, localized regions of higher voltage—indicative of conduction gaps—could be clearly visualized using omnipolar electrograms, whereas these gaps could not be consistently detected using unipolar mapping. Bipolar mapping, while useful, was significantly influenced by electrode orientation and wavefront direction, leading to variability in voltage measurements that complicates interpretation.

Our findings highlight that omnipolar mapping overcomes key limitations of both unipolar and bipolar techniques by providing direction-independent voltage measurements with higher spatial resolution. This allows for more accurate identification of incomplete lesions and improves the assessment of lesion continuity and transmurality—both critical factors for achieving durable conduction block and preventing arrhythmia recurrence.

Clinically, these insights are highly relevant. Incomplete or non-transmural lesions are a major cause of arrhythmia recurrence after ablation procedures. By enabling more accurate real-time assessment of lesion quality, omnipolar voltage mapping has the potential to guide more effective ablation strategies, reduce unnecessary energy delivery, and ultimately improve long-term patient outcomes.

With this work, we contribute to a more precise and mechanistic understanding of how ablation lesions should be evaluated, supporting the translation of advanced mapping technologies into clinical practice.