The effect of the measurement posture on heart-to-brachium pulse wave velocity

Heart-brachium pulse wave velocity (hbPWV), an emerging measure of arterial stiffness including the proximal aorta, can be obtained by a phonocardiogram and brachial arterial pressure wave. hbPWV undergoes a linear elevation with age, starting from an early adult life stage onward, rendering it a potential marker for discerning cardiovascular disease risk. If it can be measured in a seated posture, it has a potential to become as widespread as blood pressure measurement. However, the effect of measurement posture on hbPWV remains to be elucidated. The aim of this pilot study was to test the hypothesis that there is no difference in hbPWV between sitting and supine measurements. Nineteen healthy adults participated in this study (40 ± 13 years, mean ± standard deviation). Both hbPWV and heart-to-ankle PWV (haPWV) were measured on the right side in the supine and sitting positions. haPWV was used as a comparative measure. The measurements were taken in random order, separated by more than 3 minutes of rest. In the sitting measurement, all participants were seated in a chair with a backrest and placed their right arm down. PWV was calculated as the estimated arterial path length divided by the pulse transit time. There were the positive relationships of both PWV between sitting and supine postures (r = 0.66 and r = 0.72 in hbPWV and haPWV, respectively, P < 0.01 for both). hbPWV did not differ between postures (803 ± 121 cm/s and 761 ± 113 cm/s in sitting and supine positions, respectively; P = 0.08). In contrast, higher haPWV was observed in the sitting position (1196 ± 104 cm/s) compared with the supine position (938 ± 118 cm/s, P < 0.01). These results suggest that hbPWV may be a specific indicator of the proximal aortic stiffness independent of posture during measurement. In clinical practice, using hbPWV in both sitting and supine positions may allow a regular and simple assessment of proximal aortic stiffness. This abstract was presented at the American Physiology Summit 2025 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.