Document Detail


Isolated cat trabeculae in a simulated feline heart and arterial system. Contractile basis of cardiac pump function.
MedLine Citation:
PMID:  7127679     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Isolated cat trabeculae were studied under conditions resembling those present for the muscle fibers in the wall of the left ventricle. To obtain such a situation experimental animals, perfusion fluid, temperature, stimulation frequency, peak stress values, contraction sequence, length, and force control were chosen with respect to that criterion. Results were compared with those described for the intact feline heart in previous studies. Special emphasis was placed on determinants of the pump function graph, i.e., the relationship between mean ventricular pressure and output. It was found that peak isometric stress values measured in the trabeculae were about twice as high as those existing on average at the base of the intact left ventricle in the circumferential direction. However, the duration of the mechanical activity, as measured in iso(volu)metric contractions, was in the isolated trabeculae (206 msec) significantly less (P less than 0.01) than found in intact right (292 msec) or intact left ventricle (344 msec). Furthermore the (maximum) output of the intact left ventricle at end-diastolic pressure could not be accounted for in a simple manner by the maximum amount of shortening found in isolated trabeculae. The points of the pump function graph obtained by varying the input impedance of the loading arterial system over a wide range of compliance and resistance values in the steady state deviated only little from the graph obtained from a series of constant pressure levels applied in a beat-to-beat fashion. Therefore, the insensitivity of the pump function graph to the nature of the arterial load is found in the intact heart as well as in isolated cardiac muscle.
Authors:
G Elzinga; N Westerhof
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Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Circulation research     Volume:  51     ISSN:  0009-7330     ISO Abbreviation:  Circ. Res.     Publication Date:  1982 Oct 
Date Detail:
Created Date:  1982-12-16     Completed Date:  1982-12-16     Revised Date:  2003-11-14    
Medline Journal Info:
Nlm Unique ID:  0047103     Medline TA:  Circ Res     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  430-8     Citation Subset:  IM; S    
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MeSH Terms
Descriptor/Qualifier:
Animals
Aorta / physiology
Blood Pressure
Cats
Coronary Circulation
Coronary Vessels / physiology*
Heart / physiology*
Male
Models, Biological*
Myocardial Contraction*
Pulmonary Artery / physiology

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


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