Effect of Downstream Cross-sectional Area of an Arterial Bed on the Resistive Index and the Early Systolic Acceleration

Publisher Website
Google Scholar
Abstract
PURPOSE: To evaluate the effect of the increase in total cross-sectional area of arteries as they branch beyond the main trunks on the resistive index (RI) and early systolic acceleration (ESA). MATERIALS AND METHODS: An essentially noncompliant in vitro model that used a pulsatile pump, blood-mimicking fluid, and a branching tubing network that could be configured to produce a downstream cross-sectional area one, two, four, or eight times that of the feeding vessel was used to investigate the relationship, if any, between arterial bed cross-sectional area and the RI and ESA. RESULTS: The mean ESA in the branching network was inversely proportional to cross-sectional area, decreasing by approximately a factor of two for every doubling of the cross-sectional area. The mean RI in the branching network decreased with increasing cross-sectional area, but not as greatly as the ESA did; the mean RI in the bed with eight times the upstream cross-sectional area had an RI that was approximately three-fourths the u...