Document Detail


Effect of autonomic neurotransmitters on excitable gap composition in canine atrial flutter.
MedLine Citation:
PMID:  11201496     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Atrial arrhythmias are believed to be influenced by autonomic nervous system tone. We evaluated the effects of sympathetic and parasympathetic activation on atrial flutter (AF1) by determining the effects of norepinephrine (NE) and acetylcholine (ACh) on the composition of the excitable gap. A model of reentry around the tricuspid valve was produced in 17 chloralose anesthetized dogs using a Y-shaped lesion in the intercaval area that extended to the right atrial appendage. Excitable gap characteristics were determined during AF1 by scanning diastole with a single premature extrastimulus at progressively shorter coupling intervals to define the reset-response curve. Measurements were made during a constant infusion of NE (15 microg/min) into the right coronary artery and repeated during ACh infusion (2 microg/min) following a 15 min recovery period. The excitable gap (27 +/- 1 ms) was significantly (P < 0.001) increased by NE (34 +/- 1 ms) and ACh (50 +/- 2 ms). The fully excitable portion (7 +/- 1 ms) was also significantly (P < 0.001) increased by NE (17 +/- 1 ms) and ACh (43 +/- 2 ms). We conclude that both neurotransmitters increase the safety margin of full excitability ahead of the wavefront, demonstrating that parasympathetic and sympathetic activation can facilitate the persistence of this refractory atrial arrhythmia.
Authors:
M M Rahme; E Jalil; M Laflamme; T Kus
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Canadian journal of physiology and pharmacology     Volume:  79     ISSN:  0008-4212     ISO Abbreviation:  Can. J. Physiol. Pharmacol.     Publication Date:  2001 Jan 
Date Detail:
Created Date:  2001-01-26     Completed Date:  2001-04-05     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0372712     Medline TA:  Can J Physiol Pharmacol     Country:  Canada    
Other Details:
Languages:  eng     Pagination:  13-7     Citation Subset:  IM    
Affiliation:
Department of Pharmacology, Université de Montréal, Québec, Canada.
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MeSH Terms
Descriptor/Qualifier:
Acetylcholine / pharmacology
Animals
Arteries / innervation,  physiopathology
Atrial Appendage / physiology
Atrial Flutter / physiopathology*
Autonomic Nervous System / physiopathology*
Dogs
Electric Stimulation
Electrophysiology
Female
Male
Neurotransmitter Agents / pharmacology*
Norepinephrine / pharmacology
Sympathomimetics / pharmacology
Chemical
Reg. No./Substance:
0/Neurotransmitter Agents; 0/Sympathomimetics; 51-41-2/Norepinephrine; 51-84-3/Acetylcholine

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


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