Peak frequency annotation algorithm-guided slow pathway ablation enables lesion delivery farther from the His bundle in typical atrioventricular nodal reentrant tachycardia

BACKGROUND: Although slow pathway ablation is an established curative therapy for typical atrioventricular nodal reentrant tachycardia (AVNRT), lesion delivery is constrained by the anatomical proximity to the His bundle, limiting the procedural safety margin. Peak frequency mapping (PFM) is a novel physiology-based method that highlights regions of the slow pathway-related electrograms and may enable safer ablation at more annular sites. OBJECTIVE: To evaluate the reproducibility, procedural safety, and clinical efficacy of PFM-guided slow pathway ablation compared with the conventional anatomical approach. METHODS: Eighty-one consecutive patients with typical AVNRT were analyzed (39 conventional, 42 PFM-guided). Procedural characteristics, acute success, safety outcomes, and mid-term recurrence were assessed. RESULTS: PFM consistently localized the slow pathway around the 4-5 o'clock region of the tricuspid annulus and enabled effective ablation at significantly greater distances from the His bundle (22.8 ± 5.5 vs. 11.5 ± 3.2 mm, p < 0.0001). Acute success was achieved in all PFM-guided cases and in 97.4% of conventional cases. PFM-guided ablation required fewer RF applications and demonstrated earlier and slower junctional rhythm during energy delivery. During a mean follow-up of 822 ± 362 days, recurrence occurred in 2 conventional patients (5.1%) but in none of the PFM-guided patients. CONCLUSIONS: PFM-guided slow pathway ablation enables lesion delivery at annular sites farther from the His bundle while maintaining acute success and mid-term efficacy. By facilitating ablation at sites more distant from the His bundle, this physiology-based strategy may provide a wider procedural safety margin and represents a reproducible refinement of conventional AVNRT ablation.