Initial experience with a novel remote-guided magnetic catheter navigation system for left ventricular scar mapping and ablation in a porcine model of healed myocardial infarction

Abstract

Objective: This study examined the feasibility of using a remote magnetic catheter navigation system (MNS) in concert with an EAM system to perform detailed left ventricular scar mapping and ablation in a porcine model of healed myocardial infarction.

Background: Substrate-based catheter ablation of ventricular tachycardia (VT) involves detailed electroanatomical mapping (EAM) of the ventricles. While a safe and effective procedure, VT ablation is nonetheless uncommonly performed, due in part to the technical challenges related to ventricular mapping.

Methods: Using a prototype EAM system (CARTO-RMT), seven chronically infarcted swine were mapped using either: (i) a standard manually manipulated catheter or (ii) a magnetic remotely manipulated (Niobe) catheter. A total of 191 +/- 54 and 221 +/- 64 points were acquired to map the chamber either manually or remotely, respectively.

Results: Procedure times were longer remotely (94 +/- 22 vs. 59 +/- 19 minute, P = 0.004; and 27 +/- 8 vs. 18 +/- 3 sec/point, P = 0.04), but this became less apparent with increased operator experience. However, the fluoroscopy time was significantly shorter with remote mapping (56 +/- 56 vs. 244 +/- 67 sec/map, P = 0.03). The calculated scar size was comparable between the two methods (16.3 +/- 4.9 vs. 16.4 +/- 4.8 cm2, P = 0.37). Pathologic examination confirmed that the MNS was able to precisely deliver radiofrequency lesions to the scar borders. Using the MNS, the error to reach an evenly distributed set of endocardial targets was 6.6 +/- 3.6 mm and 4.6 +/- 2.0 mm, using transseptal and retrograde approaches, respectively.

Conclusions: Ventricular mapping using this remote navigation paradigm is technically possible and requires minimal fluoroscopy exposure, potentially facilitating ventricular substrate mapping and ablation.