Assessment of contact force variability in the MAGiC catheter under different magnetic field strengths, vector orientations, and catheter extensions in robotic magnetic navigation.

Background: Contact force (CF) in manually controlled catheters is crucial for forming an optimal lesion. There is lack of published data on CF values of MAGiC catheter (Stereotaxis, St. Louis, MO, USA) in magnetic field.

Methods: We conducted a total of 2500 CF measurements using the Robotic Magnetic Navigation (RMN) system (Stereotaxis, St. Louis, MO, USA), a magnetic-guided 8,5 Fr RF ablation catheter MAGiC (Stereotaxis, St. Louis, MO, USA) inserted through a long sheath, and a precision jewelry scale (IKEME, Guangdong, CN). We analyzed the impact on the obtained CF values of five different magnetic field vectors (transverse, caudal, cranial, sagittal, and anterior), two field strengths (0.1 T and 0.08 T), and five catheter extension configurations from the long sheath. Additionally, we compared the CF values of the MAGiC catheter and the THERMOCOOL® RMT Catheter (Biosense Webster, Irvine, CA, USA) using two models.

Results: The measured CF values of MAGiC catheter ranged from 5.62 to 21.61 g (0.1 T) and 3.63 to 20.74 g (0.08 T) and varied depending on the vectors. CF was higher at 0.1 T than 0.08 T, with values ranging from 9.32 to 21.61 g (0.1 T) and 8.71 to 20.74 g (0.08 T). In Model I comparison of MAGiC and THERMOCOOL® RMT, the MAGiC catheter had significantly higher CF (p < 0.001) in 28/30 measurements scenarios. In Model II, CF was higher in 24/30 scenarios (p < 0.001).

Conclusion: The MAGiC catheter provides consistently optimal CF values across multiple orientations and catheter extension models, outperforming the THERMOCOOL® RMT Catheter in most scenarios.