Document Detail

External mechanical work from relaxing ventricle.
MedLine Citation:
PMID:  426085     Owner:  NLM     Status:  MEDLINE    
The possibility has been proposed earlier that the specific pressure-volume (P-V) area bounded by the left ventricular end-systolic and end-diastolic P-V curves and the isovolumic relaxation part of the P-V loop represents mechanical potential energy that has been built during systole and is stored at end systole in the wall of the ventricle. In the present study on canine left ventricles, as much as 70% of the P-V area was actually converted into external mechanical work when ventricular volume was allowed to decrease at an appropriate speed (about 55 ml/s in 70 g left ventricle) during relaxation. Less external work was extracted from the same P-V area when the speed of volume reduction was either higher or lower than that speed. These results indicate that the P-V area is equivalent to a form of potential energy, which is wasted with isovolumic relaxation but most of which is convertible to external mechanical work if the ventricle is allowed to eject against an appropriately decreasing afterload during relaxation.
H Suga
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Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  The American journal of physiology     Volume:  236     ISSN:  0002-9513     ISO Abbreviation:  Am. J. Physiol.     Publication Date:  1979 Mar 
Date Detail:
Created Date:  1979-05-24     Completed Date:  1979-05-24     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0370511     Medline TA:  Am J Physiol     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  H494-7     Citation Subset:  IM    
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MeSH Terms
Cardiac Volume
Energy Metabolism
Models, Biological
Myocardial Contraction*

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

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