Harmonic Analysis of Aortic Pressure Pulses in the Dog

Aortic pulse waves were recorded in dogs at the junctions of the left renal artery and the inferior mescntcric artery with the aorta, under normal conditions, after administration of norepincphriue and acetylcholine, and after manual blocking of the femoral arteries. These pulses (343) were subjected to Fourier analysis, and apparent phase velocities and foot-of-the-wave velocities were calculated. The results strongly indicate the presence of reflected waves, and it is shown that foot-of-the- wave velocities provide erroneous information. The arterial system is such that in the arteries per se, the reflected wave is a discrete and definable quantity; its origin can be shown to be an apparent site of reflection located in the peripheral one-third of the thighs of the dog.