Open window mapping with extended early meets late algorithm vs. conventional mapping for accessory pathway ablation.

Abstract

Background: Catheter ablation of accessory pathway is the treatment of choice for patients with symptomatic Wolff-Parkinson-White (WPW) syndrome. Accessory pathway (AP) identification relies on point-by-point mapping, raising the need for more precise and efficient methods. High-density open window mapping (OWM) combined with the extended early meets late (EEML) algorithm, utilizing 3D electroanatomic mapping systems, is a promising alternative. However, its role in clinical practice lacks comprehensive investigation, necessitating a comparison with conventional mapping.

Methods: A prospective cohort study of patients referred for AP ablation evaluated the OWM strategy, comparing it with a retrospective cohort using conventional mapping. Procedure variables, including radiofrequency (RF), fluoroscopy, mapping and procedure times along with total mapping points were compared. Long-term recurrence rates were assessed.

Results: 42 patients in the OWM group and 34 in the conventional group were included. The OWM strategy exhibited a significantly lower total mapping time (p = 0.030) despite acquiring more points (p < 0.001) than the conventional group. OWM was associated with reduced fluoroscopy time (12.0 (9.0-16) vs. 19 (11-30) minutes, p = 0.009) and RF time (p = 0.021). Long-term recurrence rates were comparable between groups (7.1% OWM vs. 17.7% conventional mapping, p = 0.284). At a median follow-up of 16.2 (4.6-39.4) months there were not significant differences in recurrence-free survival (p = 0.509).

Conclusion: OWM with the EEML algorithm is a feasible tool for precise AP location and ablation, associated with less fluoroscopy time, RF time, and total mapping time. Long-term recurrence rates were similar to conventional mapping. Prospective studies are warranted for further validation.