Computational modeling demonstrates that in a distributed arterial system, the central arrival time of reflected waves is largely independent of pulse wave velocity, challenging assumptions based on simple tube models.
We used two models of the systemic arterial system based on oscillatory flow theory 6: a single uniform tube model ("single tube"; with a Windkessel load) representing the aorta, and a distributed (1D) model of the entire arterial tree ("whole system").We derived forward and reflected waves in the aorta following the standard method 7, to evaluate the return time of the reflected wave with increasing PWV.Also, forward and reflected waves along the aorta of both models were calculated.Input impedance and reflection coefficient along the model-aorta were derived.Detailed model descriptions are given in Westerhof and Westerhof 8. RESULTSCentral pressures with forward and reflected waves in the uniform tube and in the whole system were calculated for increasing PWVs (Figure 1).In the uniform tube, the central arrival time of the reflected wave is inversely related to the PWV, while in the whole system there is very little effect of increasing PWV.Pressures along the uniform tube and the aorta of the whole system and the corresponding forward and reflected waves were calculated (Figure 2) at a PWV of 720 cm/s.The uniform tube model predicts a reflected wave that travels proximally from the tube end, a
Westerhof et al. (2020) studied this question.