New indices of arterial stiffness measured from longitudinal motion of common carotid artery in relation to reference methods, a pilot study

BackgroundLongitudinal wall motion of carotid artery is a useful but challenging parameter to measure. In this study, we tested our previously published motion tracking algorithm and validated our method against applanation tonometry measurements. Methods and ResultsWe measured the two-dimensional carotid artery wall motion from 19 healthy subjects and, as a reference, performed applanation tonometry measurements in parallel with the ultrasound study. The results show that peak velocities (R=-0484; P<005) and accelerations (R=-0524; P<005) of the longitudinal motion between intima and adventitia layers exhibit a greater correlation with the arterial stiffness parameters, for example the augmentation index than the corresponding amplitude of the longitudinal motion (R=-0132; P>005). The amplitudes of the longitudinal motion, between intima and adventitia, are related more to the physical size of the subject, as they correlated significantly with the height (R=0597; P<001) and weight (R=0562; P<005) of the subject as well as the cross-sectional dimension of the measured artery (R=0611; P<001). Furthermore, two new indices have been introduced, Polydeg and RAlength, with which to study the shape of the longitudinal motion curve; both parameters displayed significant correlation with arterial stiffness, for example augmentation index (R=0468; P<005 and R=0609; P<001, respectively). ConclusionsThe new longitudinal motion parameters presented here displayed clear potential to be used as novel stiffness indices.