Cargando…

Integrative model of coronary flow in anatomically based vasculature under myogenic, shear, and metabolic regulation

Coronary blood flow is regulated to match the oxygen demand of myocytes in the heart wall. Flow regulation is essential to meet the wide range of cardiac workload. The blood flows through a complex coronary vasculature of elastic vessels having nonlinear wall properties, under transmural heterogeneo...

Descripción completa

Detalles Bibliográficos
Autores principales: Namani, Ravi, Kassab, Ghassan S., Lanir, Yoram
Formato: Online Artículo Texto
Lenguaje:English
Publicado: The Rockefeller University Press 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5749109/
https://www.ncbi.nlm.nih.gov/pubmed/29196421
http://dx.doi.org/10.1085/jgp.201711795
_version_ 1783289533542957056
author Namani, Ravi
Kassab, Ghassan S.
Lanir, Yoram
author_facet Namani, Ravi
Kassab, Ghassan S.
Lanir, Yoram
author_sort Namani, Ravi
collection PubMed
description Coronary blood flow is regulated to match the oxygen demand of myocytes in the heart wall. Flow regulation is essential to meet the wide range of cardiac workload. The blood flows through a complex coronary vasculature of elastic vessels having nonlinear wall properties, under transmural heterogeneous myocardial extravascular loading. To date, there is no fully integrative flow analysis that incorporates global and local passive and flow control determinants. Here, we provide an integrative model of coronary flow regulation that considers the realistic asymmetric morphology of the coronary network, the dynamic myocardial loading on the vessels embedded in it, and the combined effects of local myogenic effect, local shear regulation, and conducted metabolic control driven by venous O(2) saturation level. The model predicts autoregulation (approximately constant flow over a wide range of coronary perfusion pressures), reduced heterogeneity of regulated flow, and presence of flow reserve, in agreement with experimental observations. Furthermore, the model shows that the metabolic and myogenic regulations play a primary role, whereas shear has a secondary one. Regulation was found to have a significant effect on the flow except under extreme (high and low) inlet pressures and metabolic demand. Novel outcomes of the model are that cyclic myocardial loading on coronary vessels enhances the coronary flow reserve except under low inlet perfusion pressure, increases the pressure range of effective autoregulation, and reduces the network flow in the absence of metabolic regulation. Collectively, these findings demonstrate the utility of the present biophysical model, which can be used to unravel the underlying mechanisms of coronary physiopathology.
format Online
Article
Text
id pubmed-5749109
institution National Center for Biotechnology Information
language English
publishDate 2018
publisher The Rockefeller University Press
record_format MEDLINE/PubMed
spelling pubmed-57491092018-07-02 Integrative model of coronary flow in anatomically based vasculature under myogenic, shear, and metabolic regulation Namani, Ravi Kassab, Ghassan S. Lanir, Yoram J Gen Physiol Research Articles Coronary blood flow is regulated to match the oxygen demand of myocytes in the heart wall. Flow regulation is essential to meet the wide range of cardiac workload. The blood flows through a complex coronary vasculature of elastic vessels having nonlinear wall properties, under transmural heterogeneous myocardial extravascular loading. To date, there is no fully integrative flow analysis that incorporates global and local passive and flow control determinants. Here, we provide an integrative model of coronary flow regulation that considers the realistic asymmetric morphology of the coronary network, the dynamic myocardial loading on the vessels embedded in it, and the combined effects of local myogenic effect, local shear regulation, and conducted metabolic control driven by venous O(2) saturation level. The model predicts autoregulation (approximately constant flow over a wide range of coronary perfusion pressures), reduced heterogeneity of regulated flow, and presence of flow reserve, in agreement with experimental observations. Furthermore, the model shows that the metabolic and myogenic regulations play a primary role, whereas shear has a secondary one. Regulation was found to have a significant effect on the flow except under extreme (high and low) inlet pressures and metabolic demand. Novel outcomes of the model are that cyclic myocardial loading on coronary vessels enhances the coronary flow reserve except under low inlet perfusion pressure, increases the pressure range of effective autoregulation, and reduces the network flow in the absence of metabolic regulation. Collectively, these findings demonstrate the utility of the present biophysical model, which can be used to unravel the underlying mechanisms of coronary physiopathology. The Rockefeller University Press 2018-01-02 /pmc/articles/PMC5749109/ /pubmed/29196421 http://dx.doi.org/10.1085/jgp.201711795 Text en © 2018 Namani et al. http://www.rupress.org/terms/https://creativecommons.org/licenses/by-nc-sa/4.0/This article is distributed under the terms of an Attribution–Noncommercial–Share Alike–No Mirror Sites license for the first six months after the publication date (see http://www.rupress.org/terms/). After six months it is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 4.0 International license, as described at https://creativecommons.org/licenses/by-nc-sa/4.0/).
spellingShingle Research Articles
Namani, Ravi
Kassab, Ghassan S.
Lanir, Yoram
Integrative model of coronary flow in anatomically based vasculature under myogenic, shear, and metabolic regulation
title Integrative model of coronary flow in anatomically based vasculature under myogenic, shear, and metabolic regulation
title_full Integrative model of coronary flow in anatomically based vasculature under myogenic, shear, and metabolic regulation
title_fullStr Integrative model of coronary flow in anatomically based vasculature under myogenic, shear, and metabolic regulation
title_full_unstemmed Integrative model of coronary flow in anatomically based vasculature under myogenic, shear, and metabolic regulation
title_short Integrative model of coronary flow in anatomically based vasculature under myogenic, shear, and metabolic regulation
title_sort integrative model of coronary flow in anatomically based vasculature under myogenic, shear, and metabolic regulation
topic Research Articles
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5749109/
https://www.ncbi.nlm.nih.gov/pubmed/29196421
http://dx.doi.org/10.1085/jgp.201711795
work_keys_str_mv AT namaniravi integrativemodelofcoronaryflowinanatomicallybasedvasculatureundermyogenicshearandmetabolicregulation
AT kassabghassans integrativemodelofcoronaryflowinanatomicallybasedvasculatureundermyogenicshearandmetabolicregulation
AT laniryoram integrativemodelofcoronaryflowinanatomicallybasedvasculatureundermyogenicshearandmetabolicregulation