Radio-frequency ablation: effect of voltage and pulse duration on canine myocardium

Abstract

The purpose of this investigation was to examine in vivo the relationship of radio-frequency (RF) pulse voltage and duration on the volume of tissue injury. RF 500-kHz pulses of 20-, 40-, and 60-V amplitude (RMS) were applied to the epicardium of 18 dogs for pulsing periods of 5-20 s. Systematic and quantitative tissue analysis was then performed after 30 days. No chronic lesions were evident on microscopic examination for 20-V RF pulse applications up to 15 s. Application of 20-V pulses for 20 s produced small lesions having a volume of 2.4 +/- 0.7 mm3. At 40 V, the volume of tissue injury ranged from 39.1 +/- 10.3 mm3 for 5 s of pulse application to 128.8 +/- 24.8 mm3 for 20 s of pulse application. Over the first 15 s of 40-V pulse application, the volume of tissue injury increased as pulse application time increased. There was no further increase in tissue injury for 40-V pulsing durations greater than 15 s. At 60 V, volumes of tissue injury ranged from 122.7 +/- 33.5 mm3 at 5 s to 313.6 +/- 73.7 mm3 at 20 s. Lesion size increased significantly for pulse durations of up to 10 s. Thereafter, 60-V pulses yielded little increase in tissue injury. In addition, persistent 60-V pulsing for periods greater than 9 s duration resulted in arcing and tissue vaporization in 28% of the applications. Thus RF energy is limited in its ability to create safe and effective tissue injury.(ABSTRACT TRUNCATED AT 250 WORDS)

Integrated, Transparent Silicon Carbide Electronics and Sensors for Radio Frequency Biomedical Therapy

“…To deliver the tissue ablation in the radio frequency range (e.g., 400–600 kHz), the required voltage and current can reach up to 60 V and 1 A (peak-to-peak values), respectively. This voltage/current range has been proven in maintaining safe operations in animal and human studies. , The high frequency range and generated RF power aim to increase the tissue temperature while minimizing muscle contraction and pain to patients . For electroporation, the common applied peak-to-peak voltage is up to 200 V at a relatively low frequency of below 100 Hz.…”

“…This voltage/current range has been proven in maintaining safe operations in animal and human studies. 3 , 4 The high frequency range and generated RF power aim to increase the tissue temperature while minimizing muscle contraction and pain to patients. 5 For electroporation, the common applied peak-to-peak voltage is up to 200 V at a relatively low frequency of below 100 Hz.…”