Neurohormonal response to head-up tilt and its role in vasovagal syncope.
In a controlled study, 26 patients with a history of recurrent syncope were found to have increased arginine vasopressin, corticotrophin, and atrial natriuretic factor levels after 5 minutes of 60 degrees head-up tilt, long before they became hypotensive. The exaggerated neurohormonal response in these patients may indicate a greater sensitivity to central hypovolemia which may predispose to vasovagal syncope, mediated by the vasodilatory effects of atrial natriuretic factor or the sensitization of mechanoreceptors by arginine vasopressin.
Jardine
D L
DL
Cardiology Department, Christchurch Hospital, New Zealand.
Melton
I C
IC
Crozier
I G
IG
Bennett
S I
SI
Donald
R A
RA
Ikram
H
H
D000324:Adrenocorticotropic Hormone / Q000097:blood; D000704:Analysis of Variance; D001127:Arginine Vasopressin / Q000097:blood; D001830:Body Surface Area; D005542:Forearm / Q000098:blood supply; D006439:Hemodynamics / Q000502:physiology; D006728:Hormones / Q000097:blood*; D006801:Humans; D008875:Middle Aged; D011187:Posture / Q000502:physiology*; D012039:Regional Blood Flow / Q000502:physiology; D019462:Syncope, Vasovagal / Q000503:physiopathology*; D018667:Tilt-Table Test
D006728:Hormones; D001127:Arginine Vasopressin; D000324:Adrenocorticotropic Hormone