Association Between Contact Force and Acute Lesion Effectiveness in Focal Pulsed Field Ablation.

Area of Science:

• Electrophysiology
• Cardiovascular Ablation Technologies
• Medical Device Engineering

Background:

• Pulsed field ablation (PFA) utilizes irreversible electroporation for non-thermal myocardial lesion creation.
• Minimizing collateral injury is a key advantage of PFA.
• Understanding acute lesion effectiveness determinants in human PFA is critical.

Purpose of the Study:

• To evaluate the association between contact force (CF) and impedance drop (ID) with acute lesion effectiveness.
• To assess these factors during focal PFA index-guided pulmonary vein isolation (PVI).

Main Methods:

• Analysis of 1460 ablation points in 24 patients undergoing PFA-guided PVI for atrial fibrillation (AF).
• High-density electroanatomical mapping in sinus rhythm.
• Ablation delivered using a CF catheter guided by a PFA index.

Main Results:

• Higher median CF was observed in successful lesions (15g) versus unsuccessful ones (11.3g) (p < 0.001).
• A CF threshold of 8g showed high sensitivity but low specificity for lesion effectiveness.
• Impedance drop (ID) did not significantly differ between successful and unsuccessful lesions (p = 0.58).
• Target PFA index achievement was significantly higher in successful lesions (67% vs. 9.4%, p < 0.01).

Conclusions:

• Contact force (CF) is a significant predictor of acute lesion effectiveness in PFA.
• Average CF values may not fully capture instantaneous catheter-tissue interaction during pulse delivery.
• Maintaining sufficient real-time CF is critical for effective lesion formation in PFA procedures.