Assessing the Impact of Blood Pressure Variability on Cerebral and Peripheral Blood Flow under Postural Stress: A Bivariate Predictability Approach

Abstract

Study objectives: To preserve cerebral and peripheral homeostasis and prevent the occurrence of vascular pathologies, i.e., stroke and ischemia, it is necessary that the different organs communicate with each other through fine interaction mechanisms. The present work proposes an innovative approach for the combined assessment of causal and autonomous dynamics in vascular interactions along the pressure-tocerebral and pressure-to-peripheral blood flow links. The aim is to assess simultaneously the dynamic effect of mean arterial pressure (MAP) on both cerebral and peripheral blood flow (i.e., MCBv and MSBv, respectively) and to give a complete characterization of intrinsic physiological mechanisms acting in the two vascular districts, by evaluating bivariate parametric causality and autonomous measures in time and within the frequency bands of physiological interest. The analyses have been conducted on 30 healthy subjects in resting (REST) and standing (STAND) positions to also elucidate the effects of postural stress on cerebral and peripheral vascular control and interactions.