Document Detail


Contractile Strength during Variable Heart Duration Is Species and Preload Dependent.
MedLine Citation:
PMID:  22131801     Owner:  NLM     Status:  In-Data-Review    
Abstract/OtherAbstract:
We investigate the effect of beat-to-beat variability on cardiac contractility. Cardiac trabeculae were isolated from the right ventricle of rabbits and beagle dogs and stimulated to isometrically contract, alternating between fixed steady state versus variable interbeat intervals. Trabeculae were stimulated at physiologically relevant frequencies for each species (dog 1 and 4 Hz; rabbit 2 and 4 Hz) intercalating fixed periods with 40% variability. A subset of the trabeculae (at 90% of optimal length) was stretched prior to stimulation between 5 and 13% and stimulated at the same frequencies with a fixed versus 40% variation. Fixed rate response at the same base frequency was measured before and after each variable period and the average force reported. In canine preparations no change in force was observed as a result of the imposed variability in beat-to-beat duration. In the rabbit, we observed a nonsignificant decrease in force between fixed and variable pacing at both 2 and 4 Hz (n = 8) when 40% variability was introduced. When a 5% and 13% stretch was applied, the correlation coefficient sharply increased, indicating a more prominent impact of the prebeat duration on the following cycle with higher preload.
Authors:
Carlos A A Torres; Paul M L Janssen
Publication Detail:
Type:  Journal Article     Date:  2011-10-26
Journal Detail:
Title:  Journal of biomedicine & biotechnology     Volume:  2011     ISSN:  1110-7251     ISO Abbreviation:  J. Biomed. Biotechnol.     Publication Date:  2011  
Date Detail:
Created Date:  2011-12-01     Completed Date:  -     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  101135740     Medline TA:  J Biomed Biotechnol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  294204     Citation Subset:  IM    
Affiliation:
Department of Physiology and Cell Biology, The Ohio State University, Columbus, OH 43210, USA.
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