Publication Date
2011
Journal
The Texas Heart Journal
PMID
22199421
Publication Date(s)
2011
Language
English
PMCID
PMC3233327
PubMedCentral® Posted Date
2011
PubMedCentral® Full Text Version
Post-Print
Published Open-Access
yes
Keywords
Animals, arrhythmias, cardiac/etiology, dogs, electrophysiology, Fourier analysis, heart ventricles/physiopathology, signal processing, computer-assisted, pilot projects, vagus nerve/physiology, ventricular fibrillation/physiopathology
Copyright
This work is licensed under a Creative Commons Attribution-NonCommercial-No Derivative Works 4.0 International License.
Abstract
Studies have shown that long-term vagal stimulation is protective against ventricular fibrillation; however, the effects of acute vagal stimulation during ventricular fibrillation in the normal heart have not been investigated. We examined the effects of acute vagal stimulation on ventricular fibrillation in a canine model. In 4 dogs, we induced 30-second periods of ventricular fibrillation by means of intraventricular pacing. During 2 of the 4 periods of fibrillation that we analyzed, vagal stimulation was delivered through electrodes in the caudal ends of the vagus nerves. Noncontact unipolar electrograms were recorded from 3 ventricular regions: the basal septum, apical septum, and lateral free wall. We then computed the most frequent cycle length, mean organization index, and mean electrogram amplitude for each region. During fibrillation, vagal stimulation shortened the most frequent cycle lengths in the basal septum (P=0.02) and apical septum (P=0.0001), but not in the lateral wall (P=0.46). In addition, vagal stimulation significantly reduced the mean organization indices in the apical septum (P