A computational analysis of atrial fibrillation effects on coronary perfusion across the different myocardial layers

Figures

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  Figure 1. Multiscale illustration of the overall closed-loop model, with emphasis onto the coronary circulation (in the left side panel). For symmetry reasons, lower body 1D arteries were modeled for one leg only, but their contribution was doubled to account also for the other leg. Parameter setting can be found in our previous works20,21.

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  Figure 2. The 0D lumped parameter circuital scheme of a kth generic coronary distal circulation and microvasculature. The scheme allows for the subdivision among myocardial layers (index j) and compartments (index i). Acronyms EPI, MID and ENDO stand for subepicardium, midwall and subendocardium, respectively, whereas an arterial, an intermediate and a venous compartment may be identified. Zca and Zcv represent input and output impedances of each district, Ri,j and Ci,j are the resistance and compliance parameter assigned to each i-th compartment belonging to the j-th layer, and pjim is the external forcing intra-myocardial pressure. Qter_art,k, Qout, Qa, Qv, Qca, Qcv, Qja, Qjm, Qjv, Qij, pter_art,k, pout, pa, pv and pij are the hemodynamic variables associated with each single branch or node of the considered coronary district.

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  Figure 3. Examples of flow rate time-series Q(t) for the three myocardial layers (EPI: subepicardium; MID: midwall; ENDO: subendocardium) of the LAD coronary microvascular district (vessel #57). (a) SR at 75 bpm; (b) AF at 75 bpm; (c) SR at 125 bpm; (d) AF at 125 bpm.

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  Figure 4. Graphical representation of the two analysis perspectives: (1) inter-layer analysis aims at comparing the \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\overline{Q} }_{AF}$$\end{document}Q¯AF/\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\overline{Q} }_{SR}$$\end{document}Q¯SR ratio, given a specific ventricular rate, across the different myocardial layers (subepicardium, midwall or subendocardium), to assess the differential impact of atrial fibrillation on the perfusion of the different myocardial strata; (2) inter-frequency analysis compares the \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\overline{Q}…

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  Figure 5. Dot plot reporting \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\overline{Q} }_{AF}$$\end{document}Q¯AF/\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\overline{Q} }_{SR}$$\end{document}Q¯SR at each simulated frequency across the myocardial layers, in three exemplificative coronary microvascular districts. Rate-specific regression lines (dashed lines) are also reported. LAD left anterior descending artery, EPI subepicardium, MID midwall, ENDO subendocardium, LCx left circumflex artery, RCA right coronary artery.