title: Time-frequency analysis of heart rate variability during the cold pressor test using a time-varying autoregressive model.
abstract: Heart rate variability is a useful clinical tool for autonomic function assessment and cardiovascular disease diagnosis. To investigate the dynamic changes of sympathetic and parasympathetic activities during the cold pressor test, we used a time-varying autoregressive model for the time-frequency analysis of heart rate variability in 101 healthy subjects. We found that there were two sympathetic peaks (or two parasympathetic valleys) when the abrupt changes of temperature (ACT) occurred at the beginning and the end of the cold stimulus and that the sympathetic and parasympathetic activities returned to normal in about the last 2 min of the cold stimulus. These findings suggested that the ACT rather than the low temperature was the major cause of the sympathetic excitation and parasympathetic withdrawal. We also found that the onsets of the sympathetic peaks were 4-26 s prior to the ACT and the returns to normal were 54-57 s after the ACT, which could be interpreted as the feedforward and adaptation of the autonomic regulation process in the human body, respectively. These results might be helpful for understanding the regulatory mechanisms of the autonomic system and its effects on the cardiovascular system.
authors: Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, People's Republic of China. Shenzhen College of Advanced Technology, University of Chinese Academy of Sciences, Shenzhen, People's Republic of China. Key Lab for Health Informatics of Chinese Academy of Sciences (HICAS), Shenzhen, People's Republic of China.
authors: Rong-Chao
authors: RC
authors: Peng
authors: Wen-Rong
authors: WR
authors: Yan
authors: Xiao-Lin
authors: XL
authors: Zhou
authors: Ning-Ling
authors: NL
authors: Zhang
authors: Wan-Hua
authors: WH
authors: Lin
authors: Yuan-Ting
authors: YT
authors: Zhang
mesh_terms: D000328:Adult; D001794:Blood Pressure / Q000502:physiology*; D003080:Cold Temperature; D004562:Electrocardiography / Q000379:methods*; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008955:Models, Cardiovascular; D010275:Parasympathetic Nervous System / Q000502:physiology; D012815:Signal Processing, Computer-Assisted; D013564:Sympathetic Nervous System / Q000502:physiology; D055815:Young Adult