A Closed-Loop Modeling Framework for Cardiac-to-Coronary Coupling

Abstract

The mechanisms by which cardiac mechanics effect coronary perfusion (cardiac-to-coronary coupling) remain incompletely understood. Several coronary models have been proposed to deepen our understanding of coronary hemodynamics, but possibilities for in-depth studies on cardiac-to-coronary coupling are limited as mechanical properties like myocardial stress and strain are most often neglected. To overcome this limitation, a mathematical model of coronary mechanics and hemodynamics was implemented in the previously published multi-scale CircAdapt model of the closed-loop cardiovascular system. The coronary model consisted of a relatively simple one-dimensional network of the major conduit arteries and veins as well as a lumped parameter model with three transmural layers for the microcirculation. Intramyocardial pressure was assumed to arise from transmission of ventricular cavity pressure into the myocardial wall as well as myocardial stiffness, based on global pump mechanics and local myofiber mechanics. Model-predicted waveforms of global epicardial flow velocity, as well as of intramyocardial flow and diameter were qualitatively and quantitatively compared with reported data. Versatility of the model was demonstrated in a case study of aortic valve stenosis. The reference simulation correctly described the phasic pattern of coronary flow velocity, arterial flow impediment, and intramyocardial differences in coronary flow and diameter. Predicted retrograde flow during early systole in aortic valve stenosis was in agreement with measurements obtained in patients. In conclusion, we presented a powerful multi-scale modeling framework that enables realistic simulation of coronary mechanics and hemodynamics. This modeling framework can be used as a research platform for in-depth studies of cardiac-to-coronary coupling, enabling study of the effect of abnormal myocardial tissue properties on coronary hemodynamics.

Role of Electromechanical Dyssynchrony Assessment During Acute Circulatory Failure and Its Relation to Ventriculo-Arterial Coupling

“…This discrepancy could be explained by the fact that we studied patients during acute hemodynamic resuscitation phase, where the patients are mostly hemodynamically instable with arterial hypotension and myocardial perfusion mismatch. Several studies have highlighted the complex relationship between ventricular dyssynchrony, aortic blood pressure, coronary flow, and myocardial contractility (32)(33)(34). Tavazzi et al (24) already demonstrated that the underlying disease (i.e., cardiovascular or respiratory) was not associated to ventricular dyssynchrony.…”

Myocardial perfusion and flow reserve in the asynchronous heart: mechanistic insight from a computational model

“…The modeling framework presented in this article builds upon the previously validated CircAdapt modeling framework for cardiac-to-coronary coupling ( 18 ) by taking into account demand-driven coronary flow autoregulation. In brief, the CircAdapt modeling framework ( 18 – 22 ) consists of a network of different modules describing myocardial walls, cardiac valves, large blood vessels, as well as the pulmonary, systemic, and coronary circulations ( www.circadapt.org ). The LV lateral wall, interventricular septum, and RV lateral wall are mechanically coupled in a junction, and ventricular mechanical interaction is established by equilibrium of tensile forces in the junction ( 20 ).…”

“…The aim of the present study was to investigate whether coronary autoregulation can explain the distribution of myocardial perfusion and flow reserve as observed in patients with LBBB and to what extent asymmetric hypertrophy influences this distribution. To this purpose, the multiscale CircAdapt modeling framework for cardiac-to-coronary coupling ( 18 ) was built upon by introducing coronary flow regulation to myocardial oxygen demand, enabling investigation of the isolated effect of acute LBBB (dyssynchrony-induced alterations) and chronic LBBB (demand-driven growth-induced alterations) on cardiac mechanics and myocardial oxygen demand, perfusion, and flow reserve. In this modeling framework, regional coronary perfusion is dependent on myocardial contraction through the intramyocardial pressure, which is, in turn, determined by global pump mechanics and regional myofiber mechanics.…”

Review of cardiac–coronary interaction and insights from mathematical modeling

“…The 0D‐lumped parameter models are the most simplified and computationally inexpensive approach for describing blood flow and pressure dynamics in the cardiovascular system, especially when modeling the entire coronary system or large‐scale circulatory networks. These models are formulated based on a set of ordinary differential equations (ODEs) to represent the overall behavior of blood flow and pressure in discrete compartments such as individual vessels or segments (Fan, Choy, et al, 2021; Fan, Namani, Choy, Awakeem, et al, 2021; Fan, Namani, Choy, Kassab, et al, 2021; Fan et al, 2022; Pagoulatou et al, 2021; Munneke et al, 2022; Namani et al, 2020; Wang et al, 2024). For example, mass conservation in each vessel within a circulation network requires where and are the inlet and outlet pressures of the vessel , denotes the vessel pressure and is the intramyocardial pressure.…”

“…Existing cardiac–coronary mathematical models are either geometrically simplified (Fan, Namani, Choy, Kassab, et al, 2021; Fan et al, 2022; Munneke et al, 2022) in terms of myocardium and coronary vasculature or homogenized based on the poroelastic modeling framework (Chapelle et al, 2010; Lee, Nordsletten, et al, 2016; Richardson et al, 2021). These models do not capture complete anatomical, morphological, and structural details of the coronary vasculature, especially the microcirculation where blood transport and flow regulation are significant.…”