Balance between sympathetic response to head-up tilt and cardiac vagal factors in healthy humans.
We evaluated the association between cardio-vagal baroreflex sensitivity (BRS; assessed with modified Oxford technique) and catecholamine response to 5 min 60 degrees head-up tilt (HUT) in 46 young healthy adults. HUT increased HR, mean arterial pressure, and NE (P < 0.05 for all). BRS was negatively correlated with NE response to HUT (r = -0.36, P < 0.05), suggesting that subjects with high vagal modulation (high BRS) require less sympathetic response (NE) to maintain normotension during orthostatic stress.
Ramírez-Marrero
Farah A
FA
Dept. of Anesthesiology, Mayo Clinic College of Medicine, 200 First St. SW, Rochester, MN 55905, USA. ramirezmarrero.farah@mayo.edu
Charkoudian
Nisha
N
Zhong
Liu
L
Hesse
Christiane
C
Eisenach
John H
JH
D000328:Adult; D017704:Baroreflex / Q000502:physiology; D001794:Blood Pressure / Q000502:physiology; D005260:Female; D006321:Heart / Q000502:physiology*; D006801:Humans; D008297:Male; D009638:Norepinephrine / Q000097:blood; D012016:Reference Values; D013564:Sympathetic Nervous System / Q000502:physiology*; D018667:Tilt-Table Test; D014630:Vagus Nerve / Q000502:physiology*
D009638:Norepinephrine
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