Catheter Ablation -> Atrial Fibrillation & Atrial Flutter: -> Experimental methods D-PO04 - Poster Session IV (ID 15) Poster

D-PO04-153 - Is There Any Significant Thermal Effect During Focal Biphasic Pulse Field Ablation Of Atrial Tissue? - Insights From A Lattice-tip Catheter (ID 471)


Background: Because the energy is delivered over a very short time period, pulse field ablation (PFA) is widely considered to be non- thermal. However, the current densities at the upper doses can in theory be high enough to elicit a thermal response. The extent of this phenomenon has not been described.
Objective: To assess the thermal response using a 9mm surface thermocouple-enabled lattice-tip catheter.
Methods: Under general anesthesia, 12 swine underwent focal PFA using the lattice catheter and the compatible electroanatomical mapping system (Sphere-9 and Prism-1, respectively; Affera Inc). PFA was employed for: i) isolating 12 right superior pulmonary veins (RSPV) and 12 superior vena cava (SVC), and ii) linear ablation in 5 right atria (RA) and 6 mitral isthmuses (MI). During PFA (saline irrigation at 4 cc/min), local surface temperatures were recorded from the 9 thermocouples embedded on the surface of the spherical electrode. The highest temperature from each lesion was used for analysis (Figure).
Results: The mean number of PFA applications to the RSPV, SVC, RA and MI ranged between 10.5 and 13.4. Total ablation times ranged between 44.3 and 81.0 secs. All applications were successfully delivered without complications. The maximum temperature recorded at RSPV, SVC, RA and MI sites were 46.1±2.7, 44.0±2.8, 42.4±1.7, and 43.5±2.7°C, with mean temperatures of 43.7±2.3, 41.9±2.2, 40.6±1.4, and 41.7±2.0°C respectively.
Conclusion: Biphasic focal PFA at ablative/electroporative doses using the lattice-tip catheter recorded only minimal rises in temperature during ablation, confirming the non-thermal nature of PFA.