Physiological background of the loss of fractal heart rate dynamics
Physiological background of the loss of fractal heart rate dynamics
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DOI：
10.1161/circulationaha.104.523712
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发表时间：
2005-07-19
期刊：
影响因子：
37.8
通讯作者：
Huikuri, HV
中科院分区：
文献类型：
--
作者：
Tulppo, MP;Kiviniemi, AM;Huikuri, HV
背景-分形性心率(HR)动力学改变发生在各种疾病状态中，但异常分形性心率行为的生理背景尚不清楚。方法与结果：用去趋势波动分析(DFA)方法分析了心率动力学的短期分形标度指数(α(1))、R-R间期(0.15~0.4 Hz；n=13)的高频(HF)和低频(LF)频谱成分，以及来自腓肠神经(n=11)的肌交感神经活动(MSNA)。在冷表面浸泡时，高频功率增加(从6.9+/-1.3lnms(2)增加到7.6lnms(2)，P<；0.01)，MSNA也增加(从32+/-17次/百次心跳增加到44+/-14次/百次，P<；0.001)，低频/高频比值降低(P<；0.01)。冷手浸泡导致MSNA增加(从34+/-17次增加到52+/-19次/百次心跳，P<；0.001)，但HF频谱功率下降(从7.0lnms(2)下降到6.5+/-1.1lnms(2)，P<；0.05)和增加低频/HF比率(P<；0.05)。在冷面浸泡时，所有受试者的分数尺度指数α(1)均降低(从0.85+/-0.27降至0.67+/-0.30，P&0.0001)，而在冷手浸泡时，则升高(从0.77+/-0.22升至0.97+/-0.20，P<；0.01)。结论：人类HR动力学的分形组织是由交感神经流出与迷走神经流出之间的微妙相互作用决定的，在交感神经与迷走神经流出共同激活时，心率向更随机动力学方向的分维行为崩溃。
Background - Altered fractal heart rate (HR) dynamics occur during various disease states, but the physiological background of abnormal fractal HR behavior is not well known. We tested the hypothesis that the fractal organization of human HR dynamics is determined by the balance between sympathetic and vagal outflow.Methods and Results - A short-term fractal scaling exponent (alpha(1)) of HR dynamics, analyzed by the detrended fluctuation analysis (DFA) method, and the high-frequency (HF) and low-frequency (LF) spectral components of R-R intervals (0.15 to 0.4 Hz; n = 13), along with muscle sympathetic nervous activity (MSNA) from the peroneus nerve ( n = 11), were assessed at rest and during cold face and cold hand immersion in healthy subjects. During cold face immersion, HF power increased ( from 6.9 +/- 1.3 to 7.6 +/- 1.2 ln ms(2), P < 0.01), as did MSNA ( from 32 +/- 17 to 44 +/- 14 bursts/ 100 heartbeats, P < 0.001), and LF/HF ratio decreased ( P < 0.01). Cold hand immersion resulted in a similar increase in MSNA ( from 34 +/- 17 to 52 +/- 19 bursts/ 100 heartbeats, P < 0.001) but a decrease in HF spectral power ( from 7.0 +/- 1.3 to 6.5 +/- 1.1 ln ms(2), P < 0.05) and an increase in the LF/HF ratio ( P < 0.05). The fractal scaling index alpha(1) decreased in all subjects ( from 0.85 +/- 0.27 to 0.67 +/- 0.30, P < 0.0001) during cold face immersion but increased during cold hand immersion ( from 0.77 +/- 0.22 to 0.97 +/- 0.20, P < 0.01).Conclusions - The fractal organization of human HR dynamics is determined by a delicate interplay between sympathetic and vagal outflow, with the breakdown of fractal HR behavior toward more random dynamics occurring during coactivation of sympathetic and vagal outflow.