New peak frequency maps' usefulness to enhance localization and ablation of premature ventricular contractions

Abstract Background Premature ventricular contractions (PVCs) are a common type of idiopathic ventricular arrhythmia. Catheter ablation has emerged as a first-line therapy with a high success rate and few complications. Traditional ablation targets the earliest local activation time (LAT) with typical QS signal morphology on unipolar electrogram, but often manual signals reannotation is needed to identify the best target for ablation. Peak frequency (PF) map is a new mapping tool that help to discriminate ‘far-field’ from ‘near-field’ signals thanks to the analysis of the electrograms’ sharpness. Several studies investigated its usefulness for signal detection and for identification of 3-dimensional critical isthmus during ventricular tachycardia ablation. In this regard, there are no studies that evaluated the role of PF mapping in PVC ablation Purpose To evaluate the concordance between earliest LAT and highest PF signals in PVC ablation and assess the potential of PF mapping to improve procedural targeting. Methods Patients who underwent monomorphic PVCs catheter ablation using the Ensite X mapping system at 7 different Italian hospitals between 2023 and 2024 were retrospectively included. Patients were excluded if no ablation was performed or the map had fewer than 50 points in the region of interest. Electroanatomical activation maps were created using a 16-pole grid catheter (Advisor HD Grid) with Omnipolar technology and PF maps were overlapped to local activation maps to emphasize a visual target within the earliest signal area (Figure 1). Acute success was defined as suppression of the targeted PVC at the end of the procedure. ROC analysis curve assessed PF’s predictive value for earliest reannotated LAT (rLAT) point where radiofrequency ablation was deployed. Results Sixty patients (44 men [73%]; mean age 52 ± 11 years) were included. An average of 656±553 electrograms for patient were acquired. The frequency distribution across different PVC origin sites are reported in Figure 2A. The highest frequencies were located close to the tricuspid valve (TV) and aortomitral continuity (AMC) with 420 and 415 Hz respectively, while the lowest were found in PVC originating from left anterior fascicle and Moderator band (MB) with an average of 265 Hz. In 95% of cases (57/60), the earliest rLAT and highest PF signals were concordant. The discordance was found in two cases of RVOT and one PVC located on the left anterior fascicle. As shown in Figure 2B, the ROC curve (AUC = 0.789, p<0.001) demonstrates the predictive value of PF and rLAT concordance. The acute success of ablation was achieved in 57 (95%) procedures. In these unsuccessful 3 cases there was an overlapping between PF and rLAT maps. Conclusion PF mapping offers an effective method to enhance PVC ablation target by identifying high-frequency sites that correlate with successful suppression. Site-specific frequency mapping cutoff should be delineated to enhance procedural success.RVOT-LVOT PVC with PF-LAT maps overlap PF average and ROC curve