OTNF identified VT diastolic isthmus at PF >250 Hz in all patients with VT isthmus sites showing PF >315 Hz (AUC=0.781, 78.1% accuracy), aiding critical substrate detection.
Does the OTNF algorithm integrated with vector field disarray improve the identification of critical isthmus sites in patients with ventricular tachycardia?
The OTNF algorithm combined with vector field disarray can accurately identify critical VT isthmus sites, offering a novel approach to enhance substrate-based ablation strategies.
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Abstract Background Mapping and ablation of ventricular tachycardia (VT) integrate data from multiple procedural steps, including substrate and activation mapping. Purpose We applied the Omnipolar Technology Near Field (OTNF) algorithm with the goal of integrating it with traditional substrate metrics, areas of vector field disarray (VFD), and location of VT critical isthmus sites. Methods This single-center retrospective study analyzed 34 patients using the EnSite X System with the Advisor HD Grid catheter for mapping and FlexAbility, TactiCath, or TactiFlex ablation catheters. The analysis integrated the OTNF algorithm with traditional substrate metrics and VFD. Offline analysis was performed through comparison of Emphasis maps. Results The cohort (median age 70.5 years, 52.9% ischaemic) predominantly presented with electrical storm or sustained VT (70.6%). Median left ventricular ejection fraction (EF) was 31% (IQR 24-50), with 22 patients (63%) exhibiting severely reduced EF. Twenty-eight (80%) patients were ICD carriers. Median PF during VT was 435 (IQR 358-510) Hz. In 13 patients (2 female, 15.4%), complete high-density bipolar and omnipolar maps during sinus rhythm, activation maps during VT, and post-radiofrequency maps were available. The median low-voltage area in these patients was 15.6 (IQR 7.40-30.2) cm2. After offline analysis of 39 maps using the "Emphasis" tool (Figure 2), the VT diastolic isthmus was found to match areas of PF 250 Hz in all patients, whereas it matched areas of increased VFD in 12 of the 13 subjects. Median PF during VT was 435 (IQR 358-510) Hz. VT isthmus sites demonstrated higher baseline PF than non-isthmus locations, with a predictive threshold of 315 Hz (AUC=0.781, 78.1% accuracy). Post-ablation tissue showed significantly reduced PF compared to baseline and VT measurements (123 ± 42 Hz, 372 ± 96 Hz, and 450 ± 99 Hz, respectively). Conclusion OTNF and VFD may enhance the identification of critical VT substrates by detecting wavefront collision zones in low-voltage areas, potentially predicting isthmus locations, and complementing conventional mapping strategies to improve ablation outcomes.Diagnostic performance of OTNF analysis
Giordano et al. (Sat,) reported a other. OTNF identified VT diastolic isthmus at PF >250 Hz in all patients with VT isthmus sites showing PF >315 Hz (AUC=0.781, 78.1% accuracy), aiding critical substrate detection.