Dominant Frequency Mapping as a Functional Tool for Substrate-Guided Ventricular Tachycardia Ablation.

INTRODUCTION

Accurate identification of arrhythmogenic substrate is essential for successful ventricular tachycardia (VT) ablation, yet existing electrogram-based methods are limited by far-field interference and operator dependence. Dominant frequency (DF) mapping offers a stimulus-independent alternative, but existing implementations lack anatomically integrated workflows with quantitative assessment of spatial concordance.

METHODS

The objective of this study is to develop and evaluate a computational workflow for DF mapping with three-dimensional anatomical integration in patients undergoing substrate-guided VT ablation. We retrospectively analyzed 12 patients (mean age 57.5 ± 18.0 years; 75% male) with ischemic or non-ischemic cardiomyopathy. Intracardiac electrograms from SmartTouch or Pentaray catheters were segmented, transformed into the frequency domain, and thresholded using case-specific histograms. DF activity was projected onto patient-specific ventricular meshes, and spatial correspondence with operator-defined ablation sites was quantified using continuous proximity metrics (soft recall, soft precision) and receiver operating characteristic (ROC) analysis.

RESULTS

DF analysis was successful in all cases, with projection errors < 4 mm. DF activity showed high soft recall (0.776-0.999) and variable soft precision (0.025-0.754). ROC AUC values ranged from 0.622 to 0.953, exceeding baseline in all cases. SmartTouch data generally yielded higher recall and greater separation between ablation and non-ablation points.

CONCLUSION

DF mapping with anatomical integration is feasible across catheter types and demonstrates consistent spatial concordance with operator-defined VT ablation targets. This stimulus-independent workflow can be applied to routine mapping data and provides a framework for quantitative assessment of spatial relationships with procedural targets. DF values were case-specific and not comparable across patients, catheter types, or institutions. Prospective evaluation in larger cohorts is warranted.