Document Detail


The effect of adrenergic enhancement on overdrive excitation.
MedLine Citation:
PMID:  978084     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The effect of adrenergic enhancement (stimulation of a stellate ganglion or administration of norepinephrine) on arrhythmias induced by ventricular overdrive ("overdirve excitation") was studied in dogs with complete atrioventricular block. The following results were obtained. (1) Adrenergic enhancement may lead to abnormal ventricular rhythms. (2) A brief drive during adrenergic enhancement induced or enhanced fast ventricular rhythms. (3) The induced rhythms were characterized by an abrupt onset, a fast rate of discharge, and a moderate degree of slowing before an abrupt cessation. (4) The induced rhythms were accelerated by further drive. (5) Increasing the duration of overdrive during adrenergic enhancement resulted in overdrive suppression and not in overdrive excitation. (6) Prolonged drive could induce a few beats (instead of suppression) but at a rate below control ("inhibited excitation"). (7) The arrhythmogenic effects of overdrive and adrenergic enhancement were potentiated by the simultaneous administration of calcium. It is concluded that interventions which increase the inward calcium current (overdrive, adrenergic enhancement and higher [Ca]o) favor the onset and the maintenance of overdrive excitation.
Authors:
M Vassalle; R E Knob; G A Lara; J H Stuckey
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Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, Non-P.H.S.    
Journal Detail:
Title:  Journal of electrocardiology     Volume:  9     ISSN:  0022-0736     ISO Abbreviation:  J Electrocardiol     Publication Date:  1976  
Date Detail:
Created Date:  1976-12-23     Completed Date:  1976-12-23     Revised Date:  2009-11-11    
Medline Journal Info:
Nlm Unique ID:  0153605     Medline TA:  J Electrocardiol     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  335-43     Citation Subset:  IM    
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MeSH Terms
Descriptor/Qualifier:
Animals
Arrhythmias, Cardiac / physiopathology*
Calcium / pharmacology
Dogs
Electric Stimulation
Female
Heart Block / complications
Heart Conduction System / drug effects
Heart Rate / drug effects
Male
Norepinephrine / pharmacology*
Stellate Ganglion / physiology*
Stimulation, Chemical
Chemical
Reg. No./Substance:
51-41-2/Norepinephrine; 7440-70-2/Calcium

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


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