Catheter Ablation -> Atrial Fibrillation & Atrial Flutter: -> Ablation Techniques D-AB07 - Alternate Techniques in Energy Sources (ID 6) Abstract Plus

D-AB07-03 - Resistive Heating During Irreversible Electroporation Pulses (ID 1421)

Disclosure
 R. Van Es: Nothing relevant to disclose.

Abstract

Background: Multiple studies have shown the non-thermal nature of lesions caused by irreversible electroporation (IRE). However, even an extremely short current application inevitably will lead to some resistive heating. Absolute temperature measurements during IRE pulses are technically challenging due to the extremely short pulse duration and the strong electrical field. Optical temperature methods like Schlieren imaging may allow for fast temperature recording in a qualitative way, caused by local temperature differences.
Objective: Visualize resistive heating near the catheter electrodes during IRE pulses.
Methods: A 14-electrode circular catheter was positioned in saline. The catheter was backlit with a parallel light source and focused on a color Schlieren filter. Imaging was performed at 5000 frames/s during cathodal 200J IRE pulses while simultaneously registering voltage and current waveforms.
Results: Peak voltage and current were 2067±76 V and 35.5±1.8 A pulses, respectively. Resistive heating occurred mostly at the electrode edges. Maximum heat penetration depth measured at the end of the IRE pulse was 1.08 ± 0.02 mm. All temperatures returned to baseline within 200ms after 200J IRE pulses.
Conclusion: Resistive heating is largest near the electrode edges, where the current density highest. Although no absolute temperature was measured, the rapid dissipation of heat and the low penetration depth suggests that the generated heat at the catheter electrodes is unlikely to result in thermal damage when applied in the heart.
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