ARTERIAL PULSE WAVE REFLECTION

It seems that recently the interest in the role of pulse wave reflection in the arterial system has been amplified. In recognition of the effect of wave reflection a new pulse-related „amplification index“ was introduced for diagnostic purpose.
During the early 20th century Otto Frank and his pupils Ph. Broemser and O.F. Ranke became well known through their application of the windkessel model. In the middle of the century E. Wetterer designed the first catheter tip manometer and invented an electromagnetic flow meter. He also contributed to the theory of pulse waves. In the Anglo-American literature D.A. McDonald and J.R. Womersley have to be mentioned. The increasing application of computers in the later part of the 20th century gave rise to the recent period of rediscovery of knowledge, which was already well known in preceding times. It seems interesting to discuss some special aspects of wave reflection in arteries. Any location in elastic tubes where the mechanical properties or the dimension changes gives rise to reflection of pressure and flow waves. In the periphery of the arteries the reflection usually is positive. The increase of the pressure amplitude towards the periphery is due to reflection and to the effect of tapering of the arteries. Since the pressure-flow-relation in the peripheral resistance vessels is nonlinear, the magnitude of the reflection factor depends on the pressure level. Reflected waves returning from a peripheral artery, e.g. from the upper extremity, are reflected negatively when arriving at the branching point from the aorta.
E. Wetterer and T. Kenner: Dynamik des Arterienpulses. Springer 1968
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