Fu Chin-Hua, Yang Cheryl C H, Kuo Terry B J
Department of Neurology, Buddhist Dalin Tzu Chi General Hospital, Chiayi 622, Taiwan.
Neurol Res. 2006 Dec;28(8):871-6. doi: 10.1179/016164106X110463.
This study was designed to evaluate the correlations between cerebral hemodynamics and cardiac autonomic functions in aging process using transfer function techniques.
Arterial blood pressure (ABP), middle cerebral artery flow velocity (MCAFV) detected by transcranial Doppler sonography and electrocardiogram were recorded simultaneously in 20 young (27.5 +/- 0.9 years) and 20 middle-old-aged (54.3 +/- 1.5 years) healthy volunteers. Variability of ABP, MCAFV and heart rate (HR) were diffracted into very low (VLF, 0.016-0.04 Hz), low (LF, 0.04-0.15 Hz) and high frequency (HF, 0.15-0.4 Hz) components. Cerebral vasomotor reserve was quantified by specific ABP-MCAFV transfer function measurements.
The young group had significantly higher LF transfer phase and HF transfer magnitudes of ABP-MCAFV transfer function; higher HF powers of HR variability; and higher baroreflex sensitivity than those of the middle-old-aged group. LF phase and HF magnitude of ABP-MCAFV transfer function were positively correlated with HF powers of HR variability.
Although aging process is not obviously associated with changes in the static values of ABP, MCAFV and HR in this study, it is accompanied by significant declines in cerebral vasomotor reserve, cardiac vagal activity and baroreflex sensitivity. Besides, age-related changes in cerebral vasomotor reserve are positively related to those in cardiac vagal activity.
本研究旨在运用传递函数技术评估衰老过程中脑血流动力学与心脏自主神经功能之间的相关性。
对20名年轻（27.5±0.9岁）和20名中老年（54.3±1.5岁）健康志愿者同时记录经颅多普勒超声检测的动脉血压（ABP）、大脑中动脉血流速度（MCAFV）和心电图。将ABP、MCAFV和心率（HR）的变异性分解为极低频（VLF，0.016 - 0.04 Hz）、低频（LF，0.04 - 0.15 Hz）和高频（HF，0.15 - 0.4 Hz）成分。通过特定的ABP - MCAFV传递函数测量来量化脑血管运动储备。
年轻组ABP - MCAFV传递函数的LF传递相位和HF传递幅度显著更高；HR变异性的HF功率更高；压力反射敏感性高于中老年组。ABP - MCAFV传递函数的LF相位和HF幅度与HR变异性的HF功率呈正相关。
尽管在本研究中衰老过程与ABP、MCAFV和HR的静态值变化无明显关联，但它伴随着脑血管运动储备、心脏迷走神经活动和压力反射敏感性的显著下降。此外，脑血管运动储备的年龄相关变化与心脏迷走神经活动的变化呈正相关。
