Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Experiment Videos

Atrial ectopic pacemaker escape mediated by phasic vagal nerve activity.

G J Rozanski1

  • 1Department of Physiology, University of Nebraska College of Medicine, Omaha 68198-4575.

The American Journal of Physiology
|May 1, 1991
PubMed
Summary

Phasic vagal nerve stimulation can protect atrial ectopic pacemaker foci from sinus impulses by causing temporary inexcitability. This mechanism, particularly with longer sinus cycle lengths, may lead to spontaneous discharges, manifesting as late atrial premature beats.

Related Concept Videos

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Redox control of K+ channel remodeling in rat ventricle.

Journal of molecular and cellular cardiology·2005
Same author

Inhibition of K+ currents by homocysteine in rat ventricular myocytes.

Journal of cardiovascular electrophysiology·2001
Same author

K+ current inhibition by amphiphilic fatty acid metabolites in rat ventricular myocytes.

The American journal of physiology·1998
Same author

Altered K+ current of ventricular myocytes in rats with chronic myocardial infarction.

The American journal of physiology·1998
Same author

Proton inhibition of transient outward potassium current in rat ventricular myocytes.

Journal of molecular and cellular cardiology·1997
Same author

Electrophysiology of rabbit ventricular myocytes following sustained rapid ventricular pacing.

Journal of molecular and cellular cardiology·1997

Area of Science:

  • Cardiovascular Physiology
  • Autonomic Nervous System Function

Background:

  • Atrial ectopic pacemaker foci can initiate abnormal heart rhythms.
  • Vagal nerve activity influences cardiac electrophysiology.

Purpose of the Study:

  • To investigate the effects of vagal nerve stimulation on atrial ectopic pacemaker foci in vitro.
  • To determine the mechanisms by which vagal activity modulates pacemaker activity.

Main Methods:

  • In vitro study using rabbit tricuspid valve strips.
  • Recording transmembrane potentials from pacemaker and atrial fibers.
  • Stimulating postganglionic vagal nerve endings during diastole.

Main Results:

  • Vagal stimulation induced hyperpolarization and a period of inexcitability in pacemaker fibers.

Related Experiment Videos

  • This inexcitability prevented conducted impulses from activating the pacemaker.
  • Escape beats occurred late in diastole, influenced by pacing cycle length and vagal input.

    • Conclusions:

    • Phasic vagal stimuli can transiently protect atrial ectopic pacemaker foci from sinus impulses.
    • Vagal-induced inexcitability may lead to spontaneous pacemaker discharges.
    • This mechanism could explain late atrial premature beats observed in certain conditions.