Comparative performance of open-window mapping catheters for accessory pathway ablation

Background Open-window mapping (OWM) is a contemporary technique used to enhance the localization of accessory pathways (AP) during catheter ablation in patients with Wolff–Parkinson–White (WPW) syndrome. Advances in diagnostic catheter technology may further improve mapping accuracy and procedural outcomes. Objective To compare the performance of the Pentaray and HD Grid diagnostic catheters during OWM using different mapping catheters in patients with WPW syndrome. Methods One hundred patients (mean age 35±14 years; 64 men) with APs located in the mitral (n=72) or tricuspid annulus (n=28) were randomly assigned to undergo mapping with either a Pentaray catheter (n=50) or an HD Grid catheter (n=50). All procedures incorporated the extended early-meets-late (EEML) algorithm. Mapping density, mapping time, AP width, and first-attempt ablation success were compared between groups. Results The HD Grid group demonstrated significantly higher mapping density (8,597 vs. 3,545 points; P<0.001), shorter mapping time (15 vs. 30 min; P<0.001), and narrower AP width (6.4 vs. 9.8 mm; P<0.0335) compared with the Pentaray group. First-attempt AP elimination was achieved in 92% of patients in the HD Grid group versus 78% with Pentaray. Conclusion HD Grid mapping provides superior efficiency and precision during OWM, resulting in improved first-attempt ablation success in patients with WPW syndrome. It may serve as a more effective diagnostic option than the traditional Pentaray catheter for AP localization.