HRV is mediated primarily by the changing levels of parasympathetic and sympathetic
outflow from the central nervous system to the sinoatrial node of the heart. Studies using selective pharmacologic blockade of the cardiac sympathetic and parasympathetic
receptors have shown that fluctuations in heart rate (HR) above 0.15 Hz and centered at the respiratory frequency, are mediated exclusively by changes in parasympathetic
outflow, whereas lower-frequency changes are mediated by both changes in parasympathetic and sympathetic outflows. 9,10 In adult, growing evidence highlights that pain, fear, or anxiety result in decrease in the HRV, in particular
the high-frequency (HF) power (>0.15Hz), indicating a drop in vagal tone during unpleasant stimuli or emotion.11–13 During surgical procedure in adult patients, HRV is correlated with the balance between the nociceptive stimulus and the level of analgesia.14
In infants, a decreased spectral power in the high-frequency band has been observed during routine heel-lancing procedure, suggesting a decrease in
parasympathetic output during acute nociceptive stimuli.
No comments:
Post a Comment