Variability in Tissue Interface Temperature During Pulse Field Atrial Ablation: Implications for Real-Time Contact...

Area of Science:

• Electrophysiology
• Medical Devices
• Cardiac Ablation

Background:

• Pulsed field ablation (PFA) utilizes low-intensity heating at the catheter-tissue interface.
• A novel large-focal PFA catheter allows for direct measurement of tip-tissue interface temperature.
• Characterizing temperature dynamics is crucial for understanding PFA efficacy and safety.

Purpose of the Study:

• To characterize the electrode tip-tissue interface temperature dynamics during pulsed field ablation (PFA).
• To evaluate the association of anatomical location and procedural parameters with interface temperatures.
• To correlate lesion dimensions with interface temperatures in a preclinical model.

Main Methods:

• Retrospective analysis of 2779 PFA lesions in 41 atrial fibrillation patients using a lattice-tip catheter.
• Interface temperatures measured via catheter tip thermocouples and grouped by anatomic location.
• Mixed-effects modeling to assess predictors of temperature; swine study for lesion dimension correlation.

Main Results:

• Mean peak temperature was 41.7°C (range 37.2-52.8°C); average temperature was 39.5°C (range 36.4-46.9°C).
• Temperatures >50°C occurred in 0.4% of lesions, predominantly in the anterosuperior left superior pulmonary vein.
• Lower temperatures observed at right carina and specific right superior pulmonary vein locations; positive correlation between lesion depth and temperature in swine.

Conclusions:

• Electrode tip-tissue interface temperatures during PFA exhibit significant variability.
• Right superior pulmonary vein sites may show a blunted temperature response.
• Peak and average temperatures during PFA correlate with lesion depth, informing procedural optimization.