Peripheral arterial elasticity changes derived by volume-oscillometry in reaction to hyperemia as a possible assessment of flow-mediated vasodilatation

Figures

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  Figure 1. Examples of Ev(Ptr)− Ptr and ηv(Ptr) − Ptr curves before (pre-mFMD) and after cuff occlusion (post-mFMD) on the finger and the radial arteries. Two examples of Ev(Ptr) − Ptr curves (upper left panel; (a-1) and lower left; (b-1)) and ηv(Ptr) − Ptr curves (upper right panel; (a-2) and lower right; (b-2)) before (data points of solid circles; pre-mFMD) and after cuff occlusion (data points of solid squares; post-mFMD) obtained in the finger (a, upper part: Sub. No. 11) and the radial artery (b, lower part: Sub. No. 05). Schematic illustrations of the measurement scene in the finger (left upper side) and in the wrist (left lower) are included in this Figure. Solid and grey curves indicate approximately exponential curves for Ev(Ptr) and ηv(Ptr) with coefficients of determination R2 before and after cuff occlusion, respectively. Each exponential equation is also inserted in this graph. Ev indicates volume elastic modulus; Ptr, transmural pressure; ηv, volume change ratio; mFMD, modified flow-mediated vasodilatation.

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  Figure 2. Summarized bar graphs of mean % changes in five parameters in both finger and radial arteries. Bar graphs indicating the mean % changes in five parameters of ηv0, Ev0, α, Kstif and kdist (%_ηv0, %_Ev0, %_α, %_Kstif and %_kdist) obtained in the finger (a) and the radial artery (b) of all volunteer subjects. Vertical lines in each parameter indicate ± SEM, and the p-values of their changes from the baseline are also shown. ηv0 indicates the volume change ratio at Ptr (transmural pressure) = 0; Ev0, volume elastic modulus at Ptr = 0; α, exponential coefficient related to a stiffness index; Kstif, effective stiffness index of arterial wall; kdist, distensibility (or vasodilatation) index of arterial wall.

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  Figure 3. Diameter ratio (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\overline{D}_{{\text{a}}}$$\end{document}D¯a(Ptr)/D0) − Ptr and %_\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\overline{D}_{{\text{a}}}$$\end{document}D¯a(Ptr)/D0 − Ptr relationships. (a) Diameter ratio (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\overline{D}_{{\text{a}}}$$\end{document}D¯a(Ptr)/D0) − Ptr curves calculated by Eq. (1) using the measured parameters kdist and α of mean values obtained from all subjects before (pre-mFMD: kd_pre = 1.59 (SEM = 0.0546), αpre = 0.0487) and after cuff occlusion (post-mFMD: kd_post = 2.14 (SEM = 0.115), αpost = 0.0443). In this…