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High and low strength nonsynchronized shocks given during canine ventricular tachycardia.

Publication ,  Journal Article
McClelland, JH; Daubert, JP; Kavanagh, KM; Harrell, FE; Ideker, RE
Published in: Pacing Clin Electrophysiol
July 1992

UNLABELLED: Cardioversion shocks given during ventricular tachycardia may cause ventricular fibrillation or acceleration of ventricular tachycardia, or arrest the tachycardia. A recently proposed theory may explain why the former two phenomena may occur. Briefly, this theory states that potential gradient shock fields of a critical strength delivered to tissue with a critical degree of refractoriness will cause circulating wave fronts of ventricular activation ("rotors") manifest as ventricular arrhythmia. We tested this theory by delivering nonsynchronized shocks 50% higher than defibrillation threshold or 50% lower than defibrillation threshold during 275 episodes of ventricular tachycardia in eight dogs with 5- to 7-day-old myocardial infarcts. Shocks stronger than the defibrillation threshold are likely to create shock fields in the ventricles everywhere stronger than this critical value, and therefore would not generate rotors. Shocks less strong than the defibrillation threshold may create shock fields within the ventricles that include the critical value, and therefore cause rotors if given when critically refractory tissue is present. Nonsynchronized shocks were used to increase the likelihood of encountering tissue with a critical degree of refractoriness. Ventricular fibrillation or acceleration of ventricular tachycardia occurred following 83 of 138 (60%) low strength shocks and following 20 of 137 (14.6%) high strength shocks. The pooled odds ratio for induction of ventricular fibrillation or accelerated ventricular tachycardia after low strength shocks as compared to high strength shocks was 8.9. CONCLUSION: when given during ventricular tachycardia, low strength shocks are much more likely to cause ventricular fibrillation or accelerated ventricular tachycardia than are high strength shocks (P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Duke Scholars

Published In

Pacing Clin Electrophysiol

DOI

ISSN

0147-8389

Publication Date

July 1992

Volume

15

Issue

7

Start / End Page

986 / 992

Location

United States

Related Subject Headings

  • Ventricular Fibrillation
  • Tachycardia
  • Odds Ratio
  • Incidence
  • Electrocardiography
  • Electric Countershock
  • Dogs
  • Cardiovascular System & Hematology
  • Cardiac Pacing, Artificial
  • Animals
 

Citation

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McClelland, J. H., Daubert, J. P., Kavanagh, K. M., Harrell, F. E., & Ideker, R. E. (1992). High and low strength nonsynchronized shocks given during canine ventricular tachycardia. Pacing Clin Electrophysiol, 15(7), 986–992. https://doi.org/10.1111/j.1540-8159.1992.tb03091.x
McClelland, J. H., J. P. Daubert, K. M. Kavanagh, F. E. Harrell, and R. E. Ideker. “High and low strength nonsynchronized shocks given during canine ventricular tachycardia.Pacing Clin Electrophysiol 15, no. 7 (July 1992): 986–92. https://doi.org/10.1111/j.1540-8159.1992.tb03091.x.
McClelland JH, Daubert JP, Kavanagh KM, Harrell FE, Ideker RE. High and low strength nonsynchronized shocks given during canine ventricular tachycardia. Pacing Clin Electrophysiol. 1992 Jul;15(7):986–92.
McClelland, J. H., et al. “High and low strength nonsynchronized shocks given during canine ventricular tachycardia.Pacing Clin Electrophysiol, vol. 15, no. 7, July 1992, pp. 986–92. Pubmed, doi:10.1111/j.1540-8159.1992.tb03091.x.
McClelland JH, Daubert JP, Kavanagh KM, Harrell FE, Ideker RE. High and low strength nonsynchronized shocks given during canine ventricular tachycardia. Pacing Clin Electrophysiol. 1992 Jul;15(7):986–992.
Journal cover image

Published In

Pacing Clin Electrophysiol

DOI

ISSN

0147-8389

Publication Date

July 1992

Volume

15

Issue

7

Start / End Page

986 / 992

Location

United States

Related Subject Headings

  • Ventricular Fibrillation
  • Tachycardia
  • Odds Ratio
  • Incidence
  • Electrocardiography
  • Electric Countershock
  • Dogs
  • Cardiovascular System & Hematology
  • Cardiac Pacing, Artificial
  • Animals