Confirmation of Pulmonary Vein Isolation with High-Density Mapping: Comparison to Traditional Workflows

Abstract

Pulmonary vein isolation (PVI) is the cornerstone of atrial fibrillation (AF) ablation. Yet tools and techniques used for confirmation of PVI vary greatly, and it is unclear whether the use of any particular combination of tools and techniques provides greater sensitivity for identifying gaps periprocedurally. It has been suggested the use of a high-density mapping catheter, which enables simultaneous recording of adjacent bipolar EGMs in two directions, may provide improved sensitivity for gap identification. Anonymized, acute procedural data was prospectively collected in AF ablation cases utilizing various workflows for confirmation of PVI. Post-hoc analysis was performed to evaluate the incidence of gaps detected by different diagnostic catheter technologies, including a high-density mapping catheter and circular mapping catheters (CMCs), and common techniques such as pacing the ablation lines. A total of 139 cases were included across three subgroup analyses: 99 cases were included in an indirect comparison of three mapping catheter technologies, revealing gaps in 36.7%, 38.9%, and 81.8% of cases utilizing a 10-pole CMC, 20-pole CMC, and a high-density mapping catheter, respectively; a direct comparison of diagnostic catheter technologies in 18 cryoballoon ablation cases revealed residual gaps in 22.2% of patients identified by high-density mapping which were missed previously with the use of a 3.3F CMC; in 22 cases utilizing a technique of pacing the ablation lines, high-density mapping identified residual gaps in 68.2% of patients. This proof of concept analysis demonstrated that the use of a high-density catheter which records orthogonal bipoles simultaneously, appears to improve acute detection of gaps in PVI lines relative to other commonly utilized techniques and technologies. The long-term impact of ablating these concealed gaps remains unclear. Further study, including direct comparison of diagnostic catheter technologies in a randomized setting with long-term followup, is warranted.

Keywords: Atrial fibrillation; High density mapping; Pulmonary vein isolation (PVI).

Figure 1.. Advisor HD Grid Mapping Catheter, Sensor Enabled (left) and an example HD Wave Solution configuration which records bipolar electrograms in two directions, simultaneously (right).

Figure 2.. Incidence and location of gaps identified by three diagnostic catheter technologies (percentage of total gaps detected by each technology) HD Grid identified significantly more gaps than the other two technologies (p = 0.015), identifying an average of 49.0% and 139.1% more gaps per patient than CMC20 and CMC10, respectively (HD Grid: 2.15/patient; CMC20: 1.44/patient; CMC10: 0.9/patient).

Figure 3.. Incidence and location of residual gaps (across all cryoablation patients in which gaps were recorded) identified by Advisor HD Grid, which were not identified by the Achieve. The Achieve catheter was used to confirm isolation after cryoablation followed by the use of the HD Grid to recomfrim isolation. The HD Grid identified a total of 12 gaps in 4 (22.2%) patients, which were missed by the Achieve catheter. All except for one gap were in the right pulmonary veins. The majority of the gaps identified in the right pulmonary veins were located in the inferior regions.

Figure 4.. Incidence and location of residual gaps (across all pacing-cohort patients in which gaps were recorded) identified by Advisor HD Grid, which were not identified by pacing the ablation line. PVI was confirmed by pacing along the ablation line with subsequent PVI assessment using HD Grid and the HD Wave configuration. The HD Grid identified a total of 30 gaps in 15 (68.2%) patients, which were initially missed by pacing along the ablation lines.