The beat-to-beat decay of cardiac contractility from highly potentiated levels is bi-exponential
(2006) In Journal of Biomechanics 39(14). p.2657-2664- Abstract
- In order to determine the mode of beat-to-beat decay of contractility from very high levels, we studied the beat-by-beat decay of cardiac contractility following potentiation. Such decay curves are normally analysed using a mono-exponential decay function, which assumes that a fixed fraction of activator calcium ions is recirculated from one beat to the next. We postulated that there might be deviations from such a mono-exponential expression at high levels of contractility. In single sucrose-gap voltage clamp experiments of isolated ferret papillary muscle, we obtained very high contractility by potentiation due to prolonged depolarisations. We found a bi-exponential decay in 9 of 11 muscles studied, in which the initial decay is much... (More)
- In order to determine the mode of beat-to-beat decay of contractility from very high levels, we studied the beat-by-beat decay of cardiac contractility following potentiation. Such decay curves are normally analysed using a mono-exponential decay function, which assumes that a fixed fraction of activator calcium ions is recirculated from one beat to the next. We postulated that there might be deviations from such a mono-exponential expression at high levels of contractility. In single sucrose-gap voltage clamp experiments of isolated ferret papillary muscle, we obtained very high contractility by potentiation due to prolonged depolarisations. We found a bi-exponential decay in 9 of 11 muscles studied, in which the initial decay is much faster than the subsequent slower decay, as judged by residual variance of least-squares exponential fitting and by analysis of covariance using a linear equation (force of beat versus force of previous beat), p = 0.0089. In the slower decay period (physiological range), the decay was identical to that following post-extrasystolic potentiation in the same muscles studied with conventional stimulation. (c) 2005 Elsevier Ltd. All rights reserved. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/377016
- author
- Noble, Mark I. M. ; Arlock, Per LU ; Wohlfart, Björn LU and Drake-Holland, Angela J.
- organization
- publishing date
- 2006
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- force-interval, myocardium, sarcoplasmic reticulum, handling, cardiac calcium, post-extrasystolic potentiation, voltage clamp, relationship, sodium-calcium exchange, excitation-contraction coupling
- in
- Journal of Biomechanics
- volume
- 39
- issue
- 14
- pages
- 2657 - 2664
- publisher
- Elsevier
- external identifiers
-
- wos:000241850100013
- scopus:33749252754
- ISSN
- 1873-2380
- DOI
- 10.1016/j.jbiomech.2005.08.011
- language
- English
- LU publication?
- yes
- id
- dcf159cc-214c-4d69-a56c-05e1cdd868b6 (old id 377016)
- date added to LUP
- 2016-04-01 11:41:38
- date last changed
- 2022-01-26 08:50:30
@article{dcf159cc-214c-4d69-a56c-05e1cdd868b6,
abstract = {{In order to determine the mode of beat-to-beat decay of contractility from very high levels, we studied the beat-by-beat decay of cardiac contractility following potentiation. Such decay curves are normally analysed using a mono-exponential decay function, which assumes that a fixed fraction of activator calcium ions is recirculated from one beat to the next. We postulated that there might be deviations from such a mono-exponential expression at high levels of contractility. In single sucrose-gap voltage clamp experiments of isolated ferret papillary muscle, we obtained very high contractility by potentiation due to prolonged depolarisations. We found a bi-exponential decay in 9 of 11 muscles studied, in which the initial decay is much faster than the subsequent slower decay, as judged by residual variance of least-squares exponential fitting and by analysis of covariance using a linear equation (force of beat versus force of previous beat), p = 0.0089. In the slower decay period (physiological range), the decay was identical to that following post-extrasystolic potentiation in the same muscles studied with conventional stimulation. (c) 2005 Elsevier Ltd. All rights reserved.}},
author = {{Noble, Mark I. M. and Arlock, Per and Wohlfart, Björn and Drake-Holland, Angela J.}},
issn = {{1873-2380}},
keywords = {{force-interval; myocardium; sarcoplasmic reticulum; handling; cardiac calcium; post-extrasystolic potentiation; voltage clamp; relationship; sodium-calcium exchange; excitation-contraction coupling}},
language = {{eng}},
number = {{14}},
pages = {{2657--2664}},
publisher = {{Elsevier}},
series = {{Journal of Biomechanics}},
title = {{The beat-to-beat decay of cardiac contractility from highly potentiated levels is bi-exponential}},
url = {{http://dx.doi.org/10.1016/j.jbiomech.2005.08.011}},
doi = {{10.1016/j.jbiomech.2005.08.011}},
volume = {{39}},
year = {{2006}},
}