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Oscillation in Cycle Length Induces Transient Discordant and Steady-State Concordant Alternans in the Heart
Alternans is a beat-to-beat alternation of the cardiac action potential duration (APD) or intracellular calcium (Ca(i)) transient. In cardiac tissue, alternans can be spatially concordant or discordant, of which the latter has been shown to increase dispersion of repolarization and promote a substra...
Autores principales: | , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Public Library of Science
2012
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3390356/ https://www.ncbi.nlm.nih.gov/pubmed/22792346 http://dx.doi.org/10.1371/journal.pone.0040477 |
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author | Weinberg, Seth H. Tung, Leslie |
author_facet | Weinberg, Seth H. Tung, Leslie |
author_sort | Weinberg, Seth H. |
collection | PubMed |
description | Alternans is a beat-to-beat alternation of the cardiac action potential duration (APD) or intracellular calcium (Ca(i)) transient. In cardiac tissue, alternans can be spatially concordant or discordant, of which the latter has been shown to increase dispersion of repolarization and promote a substrate for initiation of ventricular fibrillation. Alternans has been studied almost exclusively under constant cycle length pacing conditions. However, heart rate varies greatly on a beat-by-beat basis in normal and pathological conditions. The purpose of this study was to determine if applying a repetitive but non-constant pacing pattern, specifically cycle length oscillation (CLO), promotes or suppresses a proarrhythmic substrate. We performed computational simulations and optical mapping experiments to investigate the potential consequences of CLO. In a single cell computational model, CLO induced APD and Ca(i) alternans, which became “phase-matched” with the applied oscillation. As a consequence of the phase-matching, in one-dimensional cable simulations, neonatal rat ventricular myocyte monolayers, and isolated adult guinea pig hearts CLO could transiently induce spatial and electromechanical discordant alternans followed by a steady-state of concordance. Our results demonstrated that under certain conditions, CLO can initiate ventricular fibrillation in the isolated hearts. On the other hand, CLO can also exert an antiarrhythmic effect by converting an existing state of discordant alternans to concordant alternans. |
format | Online Article Text |
id | pubmed-3390356 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2012 |
publisher | Public Library of Science |
record_format | MEDLINE/PubMed |
spelling | pubmed-33903562012-07-12 Oscillation in Cycle Length Induces Transient Discordant and Steady-State Concordant Alternans in the Heart Weinberg, Seth H. Tung, Leslie PLoS One Research Article Alternans is a beat-to-beat alternation of the cardiac action potential duration (APD) or intracellular calcium (Ca(i)) transient. In cardiac tissue, alternans can be spatially concordant or discordant, of which the latter has been shown to increase dispersion of repolarization and promote a substrate for initiation of ventricular fibrillation. Alternans has been studied almost exclusively under constant cycle length pacing conditions. However, heart rate varies greatly on a beat-by-beat basis in normal and pathological conditions. The purpose of this study was to determine if applying a repetitive but non-constant pacing pattern, specifically cycle length oscillation (CLO), promotes or suppresses a proarrhythmic substrate. We performed computational simulations and optical mapping experiments to investigate the potential consequences of CLO. In a single cell computational model, CLO induced APD and Ca(i) alternans, which became “phase-matched” with the applied oscillation. As a consequence of the phase-matching, in one-dimensional cable simulations, neonatal rat ventricular myocyte monolayers, and isolated adult guinea pig hearts CLO could transiently induce spatial and electromechanical discordant alternans followed by a steady-state of concordance. Our results demonstrated that under certain conditions, CLO can initiate ventricular fibrillation in the isolated hearts. On the other hand, CLO can also exert an antiarrhythmic effect by converting an existing state of discordant alternans to concordant alternans. Public Library of Science 2012-07-05 /pmc/articles/PMC3390356/ /pubmed/22792346 http://dx.doi.org/10.1371/journal.pone.0040477 Text en Weinberg, Tung. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly credited. |
spellingShingle | Research Article Weinberg, Seth H. Tung, Leslie Oscillation in Cycle Length Induces Transient Discordant and Steady-State Concordant Alternans in the Heart |
title | Oscillation in Cycle Length Induces Transient Discordant and Steady-State Concordant Alternans in the Heart |
title_full | Oscillation in Cycle Length Induces Transient Discordant and Steady-State Concordant Alternans in the Heart |
title_fullStr | Oscillation in Cycle Length Induces Transient Discordant and Steady-State Concordant Alternans in the Heart |
title_full_unstemmed | Oscillation in Cycle Length Induces Transient Discordant and Steady-State Concordant Alternans in the Heart |
title_short | Oscillation in Cycle Length Induces Transient Discordant and Steady-State Concordant Alternans in the Heart |
title_sort | oscillation in cycle length induces transient discordant and steady-state concordant alternans in the heart |
topic | Research Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3390356/ https://www.ncbi.nlm.nih.gov/pubmed/22792346 http://dx.doi.org/10.1371/journal.pone.0040477 |
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