Mechanisms of ventricular fibrillation induction by 60-Hz alternating current in isolated swine right ventricle

Olga Voroshilovsky, Zhilin Qu, Moon Hyoung Lee, Toshihiko Ohara, Gregory A. Fishbein, Hsun Lun A. Huang, Charles D. Swerdlow, Shien Fong Lin, Alan Garfinkel, James N. Weiss, Hrayr S. Karagueuzian, Peng Sheng Chen

Research output: Contribution to journalArticle

18 Scopus citations

Abstract

Background - The mechanisms by which 60-Hz alternating current (AC) can induce ventricular fibrillation (VF) are unknown. Methods and Results - We studied 7 isolated perfused swine right ventricles in vitro. The action potential duration restitution curve was determined. Optical mapping techniques were used to determine the patterns of activation on the epicardium during 5-second 60-Hz AC stimulation (10 to 999 μA). AC captured the right ventricles at 100±65 μA, which is significantly lower than the direct current pacing threshold (0.77±0.45 mA, P<0.05). AC induced ventricular tachycardia or VF at 477±266 μA, when the stimulated responses to AC had (1) short activation CLs (128±14 ms), (2) short diastolic intervals (16±9 ms), and (3) short diastolic intervals associated with a steep action potential duration restitution curve. Optical mapping studies showed that during rapid ventricular stimulation by AC, a wave front might encounter the refractory tail of an earlier wave front, resulting in the formation of a wave break and VF. Computer simulations reproduced these results. Conclusions - AC at strengths less than the regular pacing threshold can capture the ventricle at fast rates. Accidental AC leak to the ventricles could precipitate VF and sudden death if AC results in a fast ventricular rate coupled with a steep restitution curve and a nonuniform recovery of excitability of the myocardium.

Original languageEnglish (US)
Pages (from-to)1569-1574
Number of pages6
JournalCirculation
Volume102
Issue number13
DOIs
StatePublished - Sep 26 2000
Externally publishedYes

Keywords

  • Action potentials
  • Electrical stimulation
  • Electrophysiology
  • Mapping

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine
  • Physiology (medical)

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    Voroshilovsky, O., Qu, Z., Lee, M. H., Ohara, T., Fishbein, G. A., Huang, H. L. A., Swerdlow, C. D., Lin, S. F., Garfinkel, A., Weiss, J. N., Karagueuzian, H. S., & Chen, P. S. (2000). Mechanisms of ventricular fibrillation induction by 60-Hz alternating current in isolated swine right ventricle. Circulation, 102(13), 1569-1574. https://doi.org/10.1161/01.CIR.102.13.1569