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Contractile Strength during Variable Heart Duration Is Species and Preload Dependent
Joint Authors
Janssen, Paul M. L.
Torres, Carlos A. A.
Source
Journal of Biomedicine and Biotechnology
Issue
Vol. 2011, Issue 2011 (31 Dec. 2011), pp.1-6, 6 p.
Publisher
Hindawi Publishing Corporation
Publication Date
2011-10-26
Country of Publication
Egypt
No. of Pages
6
Main Subjects
Abstract EN
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.
American Psychological Association (APA)
Torres, Carlos A. A.& Janssen, Paul M. L.. 2011. Contractile Strength during Variable Heart Duration Is Species and Preload Dependent. Journal of Biomedicine and Biotechnology،Vol. 2011, no. 2011, pp.1-6.
https://search.emarefa.net/detail/BIM-461117
Modern Language Association (MLA)
Torres, Carlos A. A.& Janssen, Paul M. L.. Contractile Strength during Variable Heart Duration Is Species and Preload Dependent. Journal of Biomedicine and Biotechnology No. 2011 (2011), pp.1-6.
https://search.emarefa.net/detail/BIM-461117
American Medical Association (AMA)
Torres, Carlos A. A.& Janssen, Paul M. L.. Contractile Strength during Variable Heart Duration Is Species and Preload Dependent. Journal of Biomedicine and Biotechnology. 2011. Vol. 2011, no. 2011, pp.1-6.
https://search.emarefa.net/detail/BIM-461117
Data Type
Journal Articles
Language
English
Notes
Includes bibliographical references
Record ID
BIM-461117