Defibrillation causes immediate cardiac dilation in humans.

Published

Journal Article

UNLABELLED:Defibrillation Causes Dilation. INTRODUCTION:Prior studies in isolated heart tissue have shown both excitation and deexcitation to be the primary mechanism of defibrillation. This article presents the first evidence in man of deexcitation immediately following defibrillation by tracking the heart's mechanical response. METHODS AND RESULTS:The geometric changes of the ventricular chambers were measured before and after defibrillation in seven human subjects receiving an implantable cardioverter defibrillator (ICD). The ICD was used to produce approximately three episodes of ventricular fibrillation and defibrillation in each subject. Twenty-two two-dimensional echocardiographic images of the right ventricle (RV) and 11 images of the left ventricle (LV) were recorded and analyzed at 30 frames per second. Just over 2 seconds of each episode were digitized, beginning half a second before the defibrillation shock. Individual frames were analyzed to yield cross-sectional, ventricular chamber area as a function of time. Immediately following defibrillation, ventricular chambers dilated with significant fractional area increase (RV: 1.58 +/- 0.25, LV: 1.10 +/- 0.06), with peak dilation at 194 +/- 114 msec. CONCLUSION:Defibrillation causes a rapid increase in ventricular chamber area due to relaxation of the myocardium, suggesting that defibrillation synchronizes the cardiac cells to the deexcited state in man.

Full Text

Duke Authors

Cited Authors

  • Sylvester, E; Johnson, E; Hess, P; Malkin, R

Published Date

  • August 2003

Published In

Volume / Issue

  • 14 / 8

Start / End Page

  • 832 - 836

PubMed ID

  • 12890045

Pubmed Central ID

  • 12890045

Electronic International Standard Serial Number (EISSN)

  • 1540-8167

International Standard Serial Number (ISSN)

  • 1045-3873

Digital Object Identifier (DOI)

  • 10.1046/j.1540-8167.2003.02592.x

Language

  • eng