Evidence for a vestibulo-cardiac reflex in man.
Changes in posture demand rapid cardiovascular adjustments to maintain blood pressure and volume distribution. We demonstrated a vestibulo-cardiac reflex in supine individuals by measuring electrocardiogram and arterial blood pressure after small backwards drops of the head triggered at varying intervals after the R-spike. In normal volunteers heart rate was accelerated by drops occurring within 500-600 ms of a beat, but no rapid effect was noted in patients with a vestibular defect. The speed at which the vestibular signal of head drop accelerated heart rate implies a direct reflex. Impairment of the vestibulo-cardiac reflex would help to explain the vaso-vagal consequences of labyrinthitis.
Radtke
A
A
Popov
K
K
Bronstein
A M
AM
Gresty
M A
MA
D000328:Adult; D000368:Aged; D001794:Blood Pressure; D016022:Case-Control Studies; D004558:Electric Stimulation; D004562:Electrocardiography; D004594:Electrophysiology; D005260:Female; D006339:Heart Rate; D006801:Humans; D007024:Hypotension, Orthostatic / Q000209:etiology; D007759:Labyrinth Diseases / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D012018:Reflex; D016683:Supine Position; D014722:Vestibule, Labyrinth / Q000502:physiology*