Contact force with magnetic-guided catheter ablation

Area of Science:

• Cardiovascular Interventions
• Medical Device Technology
• Electrophysiology

Background:

• Adequate catheter tip-tissue contact is crucial for effective radiofrequency (RF) ablation lesion creation.
• Remote magnetic navigation systems offer a potential method for precise catheter control during electrophysiological procedures.

Purpose of the Study:

• To measure and evaluate the contact force generated by a remote magnetic-guided catheter navigation system.
• To assess the influence of magnetic field strength and sheath usage on catheter contact force.

Main Methods:

• A plexiglass model simulating cardiac anatomy was used to test an 8 Fr RF ablation catheter guided by magnetic fields (0.08 and 0.10 T).
• Contact force was measured with and without a long sheath, with the scale recalibrated for each measurement.
• Generalized estimating equations were employed to analyze 240 contact force measurements.

Main Results:

• Contact forces were similar between 0.08 T and 0.10 T magnetic fields without a sheath (approx. 6 g).
• Contact forces were not significantly different between transvenous and retrograde approaches without a sheath.
• A significant increase in contact force was observed with a long sheath (approx. 20 g), particularly at 0.10 T.

Conclusions:

• Remote magnetic navigation at 0.08 T and 0.10 T yields stable catheter contact forces.
• The use of a long sheath substantially increases catheter contact force, which is critical for robust lesion formation.
• These findings support the utility of magnetic guidance for achieving reliable catheter-tissue contact in RF ablation.