Document Detail


Differing effects of spontaneous and atropine-induced variations of vagal tone on atrial refractoriness in the conscious dog.
MedLine Citation:
PMID:  3762264     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The effects of spontaneous and atropine-induced variations of vagal tone on atrial refractoriness were studied in the conscious dog with complete atrioventricular block. Atrial rate and vagal tone, assessed with atropine, along with maximal paced atrial frequency were monitored for 90 days after the creation of atrioventricular block. The effects of atropine on maximal paced atrial frequency were also studied over the same period. Atrial rate was initially high and then fell back to values close to preoperative sinus levels. Vagal tone was first low and then rose back to values close to preoperative ones. The time-courses of atrial rate and vagal tone were correlated. The rise in vagal tone was accompanied by a correlated increase in maximal paced atrial frequency and thus a shortening of the atrial effective refractory period. However, atropine never significantly lengthened the atrial effective refractory period. This work clearly demonstrates the consistent shortening effect of vagal tone on the atrial effective refractory period in the conscious dog as well as the still unexplained inability of atropine to offset this effect, which may arise from a two-fold action of atropine on the heart.
Authors:
M Boucher; C Dubray; P Duchene-Marullaz
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Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Methods and findings in experimental and clinical pharmacology     Volume:  8     ISSN:  0379-0355     ISO Abbreviation:  Methods Find Exp Clin Pharmacol     Publication Date:  1986 Jul 
Date Detail:
Created Date:  1986-11-07     Completed Date:  1986-11-07     Revised Date:  2003-11-14    
Medline Journal Info:
Nlm Unique ID:  7909595     Medline TA:  Methods Find Exp Clin Pharmacol     Country:  SPAIN    
Other Details:
Languages:  eng     Pagination:  397-401     Citation Subset:  IM    
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MeSH Terms
Descriptor/Qualifier:
Animals
Atrial Function
Atrioventricular Node / drug effects*
Atropine / pharmacology*
Cardiac Pacing, Artificial
Dogs
Electrocardiography
Female
Heart Atria / drug effects
Heart Conduction System / drug effects*
Heart Rate / drug effects
Male
Vagus Nerve / drug effects*,  physiology
Chemical
Reg. No./Substance:
51-55-8/Atropine

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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