Altering peripheral resistance in dogs demonstrated that arteriolar reflections contribute a highly variable amount to the returning wave, while large vessel bifurcations contribute a constant amount.
The study demonstrates that aortic pressure and flow can be separated into forward and backward waves, highlighting the variable contribution of arteriolar reflections to arterial hemodynamics.
The total amount of reflection in the arterial system of the dog is evaluated during control, high, and low peripheral resistance, and an occluded descending aorta. Pressure, as measured in the ascending aorta, may be separated into a (composite) wave travelling from the heart towards the periphery, the forward wave, and a (composite) wave that travels in the opposite direction, the backward wave. This is also true for aortic flow. One may distinguish between reflections at bifurcations of the large vessels and reflections at the arteriolar part of the arterial tree. The former contribute a small, rather constant amount to the returning wave, while the latter reflects a strongly variable amount.
Westerhof et al. (1972) studied this question. Altered peripheral resistance and aortic occlusion vs. Control was evaluated on Total amount of reflection in the arterial system. Altering peripheral resistance in dogs demonstrated that arteriolar reflections contribute a highly variable amount to the returning wave, while large vessel bifurcations contribute a constant amount.
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