Objective:
Pulse wave velocity (PWV) is used to evaluate arterial stiffness of large and medium-sized arteries. Here, we examine the feasibility and reliability of radial-digital PWV (RD-PWV) as a measure of stiffness of smaller arteries, and its response to changes in hydrostatic pressure.
Design and method:
In 29 healthy subjects, we used Complior Analyse piezoelectric probes to record arterial pulse wave at radial artery and tip of the index. We determined transit time by second-derivative and intersecting-tangents using the device-embedded algorithms, in house Matlab-based analyses of only reliable waves, and by numerical simulation using a one dimensional (1-D) arterial tree model coupled with heart model.
Results:
Second-derivative RD-PWV were 4.68 ± 1.18, 4.69 ± 1.21, 4.32 ± 1.19 m/s for device-embedded, Matlab-based and numerical simulation analyses, respectively. Intersecting-tangents RD-PWV were 4.73 ± 1.20, 4.45 ± 1.08, 4.50 ± 0.84 m/s for device-embedded, Matlab-based and numerical simulation analyses, respectively. Intersession coefficients of variation were 7.0 ± 4.9% and 3.2 ± 1.9% (P = 0.04) for device-embedded and Matlab-based second derivative algorithms. In 15 subjects, we examine the response of RD-PWV to changes in local hydrostatic pressure by vertical displacement of the hand. For an increase of 10 mm Hg in local hydrostatic pressure RD-PWV increased by 0.28 m/s (95% CI: 0.16 to 0.40; P < 0.001).
Conclusions:
This study shows that RD-PWV can be used for the non-invasive assessment of stiffness of small-sized arteries. This finding allows for an integrated approach for assessing arterial stiffness gradient from aorta, to medium-sized arteries, and now to small-sized arteries.
