Baroreflex dynamics during the rest to exercise transient in acute normobaric hypoxia in humans.

ABSTRACT:

Purpose

We hypothesised that during a rest-to-exercise transient in hypoxia (H), compared to normoxia (N), (i) the initial baroreflex sensitivity (BRS) decrease would be slower and (ii) the fast heart rate (HR) and cardiac output (CO) response would have smaller amplitude (A₁) due to lower vagal activity in H than N.

Methods

Ten participants performed three rest-to-50 W exercise transients on a cycle-ergometer in N (ambient air) and three in H (inspired fraction of O₂ = 0.11). R-to-R interval (RRi, by electrocardiography) and blood pressure profile (by photo-plethysmography) were recorded non-invasively. Analysis of the latter provided mean arterial pressure (MAP) and stroke volume (SV). CO = HR·SV. BRS was calculated by modified sequence method.

Res

SUBMITTER: Taboni A 

PROVIDER: S-EPMC11365845 | biostudies-literature | 2024 Sep

REPOSITORIES: biostudies-literature