The timing statistics of spontaneous calcium release in cardiac myocytes.
A variety of cardiac arrhythmias are initiated by a focal excitation that disrupts the regular beating of the heart. In some cases it is known that these excitations are due to calcium (Ca) release from the sarcoplasmic reticulum (SR) via propagating subcellular Ca waves. However, it is not understo...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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Public Library of Science (PLoS)
2013-01-01
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| Series: | PLoS ONE |
| Online Access: | http://europepmc.org/articles/PMC3656860?pdf=render |
| _version_ | 1828471892338540544 |
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| author | Mesfin Asfaw Enric Alvarez-Lacalle Yohannes Shiferaw |
| author_facet | Mesfin Asfaw Enric Alvarez-Lacalle Yohannes Shiferaw |
| author_sort | Mesfin Asfaw |
| collection | DOAJ |
| description | A variety of cardiac arrhythmias are initiated by a focal excitation that disrupts the regular beating of the heart. In some cases it is known that these excitations are due to calcium (Ca) release from the sarcoplasmic reticulum (SR) via propagating subcellular Ca waves. However, it is not understood what are the physiological factors that determine the timing of these excitations at both the subcellular and tissue level. In this paper we apply analytic and numerical approaches to determine the timing statistics of spontaneous Ca release (SCR) in a simplified model of a cardiac myocyte. In particular, we compute the mean first passage time (MFPT) to SCR, in the case where SCR is initiated by spontaneous Ca sparks, and demonstrate that this quantity exhibits either an algebraic or exponential dependence on system parameters. Based on this analysis we identify the necessary requirements so that SCR occurs on a time scale comparable to the cardiac cycle. Finally, we study how SCR is synchronized across many cells in cardiac tissue, and identify a quantitative measure that determines the relative timing of SCR in an ensemble of cells. Using this approach we identify the physiological conditions so that cell-to-cell variations in the timing of SCR is small compared to the typical duration of an SCR event. We argue further that under these conditions inward currents due to SCR can summate and generate arrhythmogenic triggered excitations in cardiac tissue. |
| first_indexed | 2024-12-11T05:19:27Z |
| format | Article |
| id | doaj.art-b207546d6f094f6da801bc15e8286e6a |
| institution | Directory Open Access Journal |
| issn | 1932-6203 |
| language | English |
| last_indexed | 2024-12-11T05:19:27Z |
| publishDate | 2013-01-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLoS ONE |
| spelling | doaj.art-b207546d6f094f6da801bc15e8286e6a2022-12-22T01:19:44ZengPublic Library of Science (PLoS)PLoS ONE1932-62032013-01-0185e6296710.1371/journal.pone.0062967The timing statistics of spontaneous calcium release in cardiac myocytes.Mesfin AsfawEnric Alvarez-LacalleYohannes ShiferawA variety of cardiac arrhythmias are initiated by a focal excitation that disrupts the regular beating of the heart. In some cases it is known that these excitations are due to calcium (Ca) release from the sarcoplasmic reticulum (SR) via propagating subcellular Ca waves. However, it is not understood what are the physiological factors that determine the timing of these excitations at both the subcellular and tissue level. In this paper we apply analytic and numerical approaches to determine the timing statistics of spontaneous Ca release (SCR) in a simplified model of a cardiac myocyte. In particular, we compute the mean first passage time (MFPT) to SCR, in the case where SCR is initiated by spontaneous Ca sparks, and demonstrate that this quantity exhibits either an algebraic or exponential dependence on system parameters. Based on this analysis we identify the necessary requirements so that SCR occurs on a time scale comparable to the cardiac cycle. Finally, we study how SCR is synchronized across many cells in cardiac tissue, and identify a quantitative measure that determines the relative timing of SCR in an ensemble of cells. Using this approach we identify the physiological conditions so that cell-to-cell variations in the timing of SCR is small compared to the typical duration of an SCR event. We argue further that under these conditions inward currents due to SCR can summate and generate arrhythmogenic triggered excitations in cardiac tissue.http://europepmc.org/articles/PMC3656860?pdf=render |
| spellingShingle | Mesfin Asfaw Enric Alvarez-Lacalle Yohannes Shiferaw The timing statistics of spontaneous calcium release in cardiac myocytes. PLoS ONE |
| title | The timing statistics of spontaneous calcium release in cardiac myocytes. |
| title_full | The timing statistics of spontaneous calcium release in cardiac myocytes. |
| title_fullStr | The timing statistics of spontaneous calcium release in cardiac myocytes. |
| title_full_unstemmed | The timing statistics of spontaneous calcium release in cardiac myocytes. |
| title_short | The timing statistics of spontaneous calcium release in cardiac myocytes. |
| title_sort | timing statistics of spontaneous calcium release in cardiac myocytes |
| url | http://europepmc.org/articles/PMC3656860?pdf=render |
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