Use of a novel, mode-switching electroanatomic mapping function and its effect on procedure and fluoroscopy duration in de novo AF procedures
Authors: Lo M , Loguidice M , Nilsson K , Huegl B , Deisenhofer I , Arumugam D , Burns M , Wenzel E , Gaeta L 
Published: May 2024

Abstract

Background
Electroanatomical mapping systems utilize either an impedance-primary (IP) or magnetic-primary (MP) coordinate system for navigation. IP systems allow visualization of metal within the impedance field and can be scaled with supplemental magnetic information. MP systems collect information from catheters with a magnetic sensor, and supplementary impedance information is used to visualize catheters without a sensor. One commercially available mapping system offers both IP and MP navigation modes; however, operators must select a mode at procedure start. A novel software function allowing for near-instant transition between modes was recently introduced; its impact on procedural metrics has not yet been quantified.

Objective
Assess the impact of a mode-switching software function (MS) on acute procedural metrics in de novo paroxysmal atrial fibrillation (PAF) cases in which both the IP and MP modes were used, compared to procedures in which IP or MP was used alone.

Methods
Observational data was collected from 309 de novo PAF cases performed at 63 centers in Europe, the US, and Australia. Ablation technology used, procedure duration, fluoroscopy time, and acute outcomes were collected.

Results
Of 309 cases analyzed, 157 (50.8%) used MS, 97 (31.4%) used MP alone, and 55 (17.8%) used IP alone. Radiofrequency ablation (RFA) was used in 291 (94.2%) cases, while the remaining 18 (5.8%) used cryoablation. Irrigated, contact force sensing RFA catheters were used in 153 (97.4%) MS, 89 (91.8%) MP, and 29 (52.7%) IP cases.
Mean procedure durations for MS and MP cases were similar: 106.2±51.6 min and 106.8±53.0 min, respectively (p=0.93). However, IP cases were significantly longer than both MS and MP cases, 134.2±53.8 min (p=0.002). Fluoroscopy time was significantly less in the MS group compared to MP and IP groups: 3.9±5.5, 6.1±5.2, and 7.8±6.4 min, respectively (p&lt;0.001). No fluoroscopy was used in significantly more MS compared to MP or IP cases: 72 (45.9%) MS, 10 (10.3%) MP, and 8 (14.5%) IP cases (p&lt;0.001). When these 90 cases were excluded, mean fluoroscopy times were similar between MS, MP, and IP cases (7.1±5.6, 6.8±5.0, and 9.2±5.9 min, respectively (p=0.05)). Acute success rates were not significantly different between modes: 98.6% MS, 100% MP, and 100% IP (p=0.49).

Conclusions
In this analysis of international usage of a novel software function, cases utilizing MS had significantly shorter fluoroscopy durations with similar acute success rates and procedure durations than those using MP or IP. When zero fluoroscopy cases were excluded, there was no significant difference in fluoroscopy times; however, there were significantly more zero fluoroscopy cases in the MS group, indicating that, while MS supports and may encourage low-fluoroscopy workflows, differences in procedural metrics seen may be biased by operator preference. Future analyses are warranted to provide insight into operator-specific metrics when using MS.Fluoroscopy Duration Comparison