Document Detail


Global versus regional myocardial ischaemia: differences in cardiovascular and sympathetic responses in cats.
MedLine Citation:
PMID:  6692445     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The cardiovascular and sympathetic responses to occlusions of the left main ("global" ischaemia) or distal left anterior descending ("regional" ischaemia) coronary artery were studied in 19 anaesthetised cats with chronic sinoaortic baroreceptor denervation. "Global" ischaemia, before vagotomy, resulted in a significant reduction of mean arterial pressure (MAP), left ventricular pressure (LVP), and LVdP/dtmax while sympathetic efferent impulse activity was significantly augmented during the initial 15 +/- 2 s of occlusion (early phase) and, vice versa inhibited during the subsequent 20 +/- 2 s of occlusion (late phase). Vagotomy did not modify the haemodynamic responses, however, a significant increase in sympathetic discharge was detectable during the whole occlusion period (early and late phases). "Regional" ischaemia, before vagotomy, resulted in a significant increase in sympathetic neural discharge and MAP, with no changes in left ventricular function. After vagotomy the occlusion elicited a significant increase in MAP, LVP, LVdP/dtmax and efferent sympathetic neural activity. These excitatory responses were abolished after the interruption of a large part of the cardiac sympathetic afferents. Thus coronary artery occlusion induced haemodynamic and sympathetic reflex responses that were dependent upon the interaction of opposite influences mediated by the simultaneous activation of cardiac vagal and sympathetic afferents. The extent of "ischaemic myocardium" represented a determinant factor for the prevailing type of neural response.
Authors:
F Lombardi; C Casalone; P Della Bella; G Malfatto; M Pagani; A Malliani
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Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Cardiovascular research     Volume:  18     ISSN:  0008-6363     ISO Abbreviation:  Cardiovasc. Res.     Publication Date:  1984 Jan 
Date Detail:
Created Date:  1984-03-14     Completed Date:  1984-03-14     Revised Date:  2007-11-15    
Medline Journal Info:
Nlm Unique ID:  0077427     Medline TA:  Cardiovasc Res     Country:  ENGLAND    
Other Details:
Languages:  eng     Pagination:  14-23     Citation Subset:  IM    
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MeSH Terms
Descriptor/Qualifier:
Action Potentials
Animals
Cats
Coronary Disease / physiopathology*
Denervation
Heart / innervation,  physiopathology*
Hemodynamics
Nerve Fibers / physiology
Neurons, Afferent / physiology
Pressoreceptors / physiology
Reflex / physiology
Sympathetic Nervous System / physiopathology*
Vagotomy
Vagus Nerve / physiopathology*

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


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