Analysis of arterial waves by the single-pulse-response in time domain

We induced transient but abrupt cardiac arrests in 9 rabbits by applying electrical stimulation to the vagus nerve. “Single-pulse-response” of both blood pressure (BP) and blood flow (BF) in the carotid artery was then obtained by subtracting the wave from itself after being shifted forward by one R-R interval. The time domain characteristic impedance was used to calculate forward and backward pressure and flow waves. Results showed that the carotid blood pressure and blood flow could be decomposed into forward and backward waves. The backward pressure wave, essentially, has the same characteristics as that of the forward pressure wave but was lower in amplitude and delayed in time. This analytic method will be useful in understanding the characteristics of the arterial system in different states and also in the understanding ventricular/arterial Interaction.