ABSTRACT
At any given point the pressure and velocity will change periodically, and hence, the flow is pulsatile associated with a propagation of pressure wave. The pressure wave changes both its shape and peak value as it travels down the arterial system. Whenever a pressure wave reaches a branch or discontinuity part of the wave is transmitted and part of the wave is reflacted. The mechanism of annihilation or amplification of the pressure wave is different for different components of the pulse, as the various components of the pressure wave might travel at different speeds. There is also an external effect of secondary pulsation due to respiration and changes in the intrathoracic pressure, and external pressure that results in changes in interstitial tissue pressure. With the new measurement techniques it was realized that flow distribution and flow rates contain more clinical information, and can serve as a better diagnostic tool for the source of pathological changes, than the blood pressure.
