High-density open window mapping vs conventional mapping in accessory pathways ablation

Abstract

Abstract Background and purpose High density (HD) mapping is associated with a reduction in fluoroscopy time compared to conventional mapping in accessory pathway (AP) ablation. The Open Window (OW) technique (CARTO 3, Biosense Webster) is a new tool that automatically uses conventional electrophysiology criteria for AP location, as shorter local EGM AV interval (extended early meets late tool), earliest local activation time (LAT) and annotation at unipolar signal (wavefront annotation). However, no studies comparing its feasibility to conventional mapping have been conducted. Therefore, the aim of the present study was to assess the feasibility and the clinical implications of high-density OW mapping when compared to conventional HD mapping. Methods A prospective, unicentric cohort study was conducted that included consecutive patients which were referred to our institution for AP ablation with OW mapping technique and compared to a recent retrospective cohort of patients who underwent conventional HD mapping. Total fluoroscopy time, total mapping time and the rate of recurrence of the AP were compared between groups. A schematic step by step graphic of the workflow procedure is represented in figure 1. Results A total of 33 consecutive patients (32.28 ± 18 years, 58% males) were included in the OW group and compared with a cohort of 29 patients (29.6 ± 18 years, 52% males) who underwent conventional HD mapping. An example of Right Superior AP ablation is showed in figure 2. No differences in the location of the AP were observed (p=NS). OW mapping was associated to a lower mapping time (29.3 vs 37.8 min; p=0.04), lower fluoroscopy time (14.3 vs 21.3 min; p= 0.04) and lower radiofrequency time (p=0.007). After a median follow up of6 months, there were no differences in the rate of recurrence of the AP conduction between groups (p=NS). Conclusions In our experience, OW mapping was a feasible tool for AP location associated to a lower mapping time, lower radiofrequency time and lower X-ray exposure time with no differences in recurrence rate when compared to conventional HD mapping. However, more studies should be performed to corroborate these conclusions.Step by Step WorkflowRight Superior AP ablation