Assessment of Local Venous Pulse Wave Velocity: A Pilot Feasibility Study

Local pulse wave velocity (PWV) is a well-established marker for determining cardiac health. Despite numerous studies in the arterial domain indicating PWV as a metric for stiffness assessment, only a few studies are predicated on veins. In this work, we have investigated the feasibility of measuring local venous PWV (vPWV) using a dual-element A-mode ultrasound system. The device could acquire simultaneous jugular venous pulses (JVP) from two proximal sites along the internal jugular vein (JV) at a framerate of 500 Hz. The time delay between the measured JVP cycles was computed as the venous pulse transit time (vPTT). An in-vivo study was conducted on a cohort of 20 participants (10 male, 10 female) where the feasibility of local vPWV measurement was validated. The local vPWV was computed using the thresholding technique (vPWV|th), where the cursor was preset at a known pulse amplitude. This study is the first to our knowledge to measure local PWV from the JV, the vein closest to the heart. The measurement system could acquire JV echoes (SNR > 20dB) at a temporal resolution of 2 ms and an amplitude resolution of 10 μm. To evaluate the variability in vPWV|th, passive leg raise (PLR) intervention was conducted on a subset of the cohort. The study findings suggested that the PLR slightly increases vPWV|th. The vPWV|th during baseline and PLR were found to be 1.13 ± 0.30 m/s and 1.48 ± 0.42 m/s, respectively. The results demonstrated the feasibility of the proposed image-free ultrasound system in measuring reliable and repeatable local vPWV from the JV and investigating the variations in local vPWV resulting from physiological perturbations during PLR. Multicentric large-scale clinical studies are necessary for its clinical and field usability assessment and are in progress.