Progressive withdrawal of muscle nerve sympathetic activity preceding vaso-vagal syncope during lower-body negative pressure.
We report the observation of a vaso-vagal syncope (VVS) occurring during lower body negative pressure in a young male volunteer. Recording of the peripheral blood flow, blood pressure and muscular sympathetic nerve activity revealed first a progressive withdrawal of muscle nerve sympathetic activity with redistribution of blood flow before the onset of the VVS.
Hayoz
D
D
Division of Hypertension, CHUV, Lausanne, Switzerland.
Noll
G
G
Passino
C
C
Weber
R
R
Wenzel
R
R
Bernardi
L
L
D000328:Adult; D001794:Blood Pressure / Q000502:physiology; D004562:Electrocardiography; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D017078:Laser-Doppler Flowmetry; D008150:Lower Body Negative Pressure; D008297:Male; D009132:Muscles / Q000294:innervation*; D010991:Plethysmography; D012039:Regional Blood Flow / Q000502:physiology; D012815:Signal Processing, Computer-Assisted; D013564:Sympathetic Nervous System / Q000503:physiopathology*; D013575:Syncope / Q000503:physiopathology*; D014630:Vagus Nerve / Q000503:physiopathology*