Radial artery pulse wave velocity: a new characterization technique and the instabilities associated with the respiratory phase and breath-holding

Abstract

Objective. Pulse wave velocity (PWV) is a key diagnostic parameter of the cardiovascular system state. However, the approaches aimed at the PWV characterization often suffer from inevitable drawbacks. The statistical results demonstrating how closely the PWV in the radial artery (RA) and the respiration phase correlate, as well as the RA PWV evolution during breath-holding (BH), have not been presented in the literature yet. The aims of this study are: a) to propose a simple robust technique for measuring RA PWV, b) to reveal the phase relation between the RA PWV and spontaneous breathing, c) to disclose the BH influence on the RA PWV. Approach. The high-resolution remote breathing monitoring method, Sorption-Enhanced Infrared Thermography (SEIRT), and the described new technique aimed at measuring RA PWV, were used synchronously, and their measurement data were processed simultaneously. Main Results. Spontaneous breathing leaves a synchronous "trace" on the RA PWV. The close linear correlation of the respiration phase and the phase of concomitant RA PWV changes is statistically confirmed in 5 tested persons (Pearson's r is of the order of 0.5-0.8, P<0.05). The BH appreciably affects the RA PWV. A phenomenon showing that the RA PWV is not indifferent to hypoxia is observed for the first time. Significance. The proposed technique for the RA PWV characterization has high prospects in biomedical diagnostics. The presented pilot study deserves attention in the context of mutual respiratory and cardiovascular systems interplay. It may also be useful in cases where the peripheral pulse wave propagation helps assess the respiratory function.