Evaluation of forearm vascular resistance during orthostatic stress: Velocity is proportional to flow and size doesn't matter.

ABSTRACT:

Background

The upright posture imposes a significant challenge to blood pressure regulation that is compensated through baroreflex-mediated increases in heart rate and vascular resistance. Orthostatic cardiac responses are easily inferred from heart rate, but vascular resistance responses are harder to elucidate. One approach is to determine vascular resistance as arterial pressure/blood flow, where blood flow is inferred from ultrasound-based measurements of brachial blood velocity. This relies on the as yet unvalidated assumption that brachial artery diameter does not change during orthostatic stress, and so velocity is proportional to flow. It is also unknown whether the orthostatic vascular resistance response is related to initial blood vessel diameter.

Methods

We deter

SUBMITTER: Claydon VE 

PROVIDER: S-EPMC6857923 | biostudies-literature | 2019

REPOSITORIES: biostudies-literature