Abstract
Abstract Background Wolff–Parkinson–White (WPW) syndrome is characterized by the presence of an accessory pathway (AP) that predisposes patients to tachyarrhythmias. Accurate localization of the AP is critical for successful catheter ablation. Traditional mapping techniques may be limited by poor signal resolution or anatomical complexity. Open window mapping (OWM) is an emerging technique that allows for detailed, high-resolution visualization of activation patterns across the atrioventricular (AV) ring. Objective To demonstrate the feasibility and effectiveness of OWM for accessory pathway localization and ablation in WPW syndrome based on a first reported case series. Methods A case series of three pediatric patients (mean age 15 years; 66.7% female) diagnosed with WPW syndrome who underwent catheter ablation using the OWM technique was analyzed. Activation mapping was performed during sinus rhythm or retrograde pacing with high-density electroanatomical mapping systems. The timing and location of earliest atrioventricular conduction were analyzed to guide ablation. Results OWM enabled precise localization of the accessory pathway in all cases. Successful ablation was achieved in 3/3 patients (100%): one with a left posteroseptal AP, one with a right posteroseptal AP, and one with a left posterolateral AP. The mean fluoroscopy time was 3 ± 2 minutes. No recurrence of arrhythmia was observed during a 1-year follow-up. In cases with complex or anatomically challenging pathways, OWM provided critical spatial resolution beyond that of conventional mapping. Conclusion This is the first reported experience with OWM for WPW syndrome in a single tertiary center. The findings suggest that OWM is a highly effective and safe method for accessory pathway localization and ablation. Its integration into routine electrophysiology practice may improve procedural success rates, particularly in centers with developing EP programs.