Impact of fluoroscopy unit on the accuracy of a magnet-based electroanatomic mapping and navigation system: An in vitro and in vivo validation study

Introduction During mapping and ablation procedures, the movement of large ferromagnetic items (i.e., fluoroscopic equipment) introduce heterogeneities in the electromagnetic field, which may affect the accuracy of electromagnet-based navigation. We aimed to assess the impact of common periprocedural fluoroscopic equipment movement on the accuracy of an electromagnet-based navigation system. Methods and Results The impact of fluoroscopic equipment movement on the accuracy of the Carto® 3 System (Biosense Webster, Inc., Diamond Bar, CA, USA) was assessed both in vitro (n = 20 patients, phantom model) and in vivo (n = 18 patients). Location recordings were obtained with unchanged catheter position for fluoroscopic equipment rotational movements (RMs) and maximal to closest distance (MD to CD) to phantom/patient. The effects of both single- and biplane fluoroscopy were assessed. In vitro, the movement of fluoroscopic equipment resulted in an average catheter location estimation error of 0.8 mm (interquartile range 0.3-1.3). The maximal location estimation errors with MD to CD movement and RM were 2.3 mm and 1.3 mm, respectively. Changing from single-plane to biplane setup resulted in an average location estimation change of 1.5 mm (maximum 2.1). Larger location changes were observed in vivo (2.9 mm vs 0.8 mm, P < 0.0001) with 28.7% of these exceeded 4 mm versus none of the in vitro measurements (P < 0.0001). Conclusion Although fluoroscopy manipulation affected the accuracy of the Carto® 3 System, the in vitro data suggest that these inaccuracies are likely of limited clinical consequences. The larger in vivo inaccuracies are most likely due to nonferromagnetic interferences, such as respiratory or cardiac movements.