The defibrillation efficacy of high frequency alternating current sinusoidal waveforms in guinea pigs.

Published

Journal Article

There have been few basic studies of alternating current (AC) defibrillation, despite growing interest in the ability of AC to terminate or alter ongoing fibrillation. Based on fibrillation threshold testing, it has been suggested that cardiac tissue is most sensitive to long duration, low strength AC stimulation at around 50 Hz. This has not been directly tested for defibrillation. Two subcutaneous electrodes were placed 40 mm apart on opposing aspects of the guinea pig thorax. Seven seconds were allowed to elapse between fibrillation initiation and defibrillation. The tested waveforms were at 50, 100, 200, 500, and 1000 Hz with 2, 4, 8, 16, and 32-cycles. The efficacy of every waveform was measured using a single stimulus in a large population of animals. Forty-one guinea pigs were used in the fixed energy group. Thirty-three guinea pigs were used in the fixed amplitude group with additional 1-cycle waveforms tested. The 200-Hz and the 2-cycle waveforms were significantly more efficacious than those at other frequencies (P < 0.02) and other durations (P < 0.001). The 50-Hz waveforms were the least successful. Amplitude, not duration or energy, was the determinate of efficacy for 2-cycle (the most efficacious) waveforms. Unlike low strength stimulation, defibrillation strength stimuli are most effective with high frequency (200 Hz) pulses (2 cycles).

Full Text

Duke Authors

Cited Authors

  • Roberts, SJ; Guan, D; Malkin, R

Published Date

  • February 2003

Published In

Volume / Issue

  • 26 / 2 Pt 1

Start / End Page

  • 599 - 604

PubMed ID

  • 12710320

Pubmed Central ID

  • 12710320

Electronic International Standard Serial Number (EISSN)

  • 1540-8159

International Standard Serial Number (ISSN)

  • 0147-8389

Digital Object Identifier (DOI)

  • 10.1046/j.1460-9592.2003.00100.x

Language

  • eng