Physiological basis of fractal complexity properties of heart rate variability in man
Physiological basis of fractal complexity properties of heart rate variability in man
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DOI：
10.1113/jphysiol.2001.013389
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发表时间：
2002-07-15
影响因子：
5.5
通讯作者：
Piepoli, M
中科院分区：
文献类型：
--
作者：
Francis, DP;Willson, K;Piepoli, M
去趋势波动分析（DFA）的分形复杂性度量“α”的诊断和预测能力仍然是神秘的，因为没有解释它的含义，特别是与谱分析有关。首先，我们提出了一个数学分析的意义阿尔法，加权功率谱方面。其次，我们检验了这一假设，并观察到基于DFA和加权谱方法之间的相关性，α（1）为0.97（P < 0.0001），α（2）为0.98（P < 0.0001）。第三，我们在数学上预测，即使在传统的（未加权的）频谱分析中，也应该有近似的DFA对应物，即α（1）和α（2）分别与传统的（未加权的）比率LF/（HF + LF）和VLF/（LF + VLF）成比例，其中HF是高频，LF是低频，VLF是非常低频。第四，我们测试这一假设的生理操纵光谱比在健康志愿者在两种方式。0.1Hz控制呼吸对LF/（HF + LF）和α（1）的影响显著相关（r = 0.73，P = 0.01），对VLF/（LF + VLF）和α（2）的影响显著相关（r = 0.76，P < 0.01）。同样，在自主周期性呼吸中，α 1的降低与VLF/（LF + VLF）密切相关（r = 0.88，P < 0.001）;对α 1的影响与LF/（HF + LF）也明显相关（r = 0.73，P = 0.01）。最后，我们研究了已发表的文献，以确定以前未讨论的证据之间的关系α（1）和LF/（HF + LF）。我们得出结论，α和α（2）指数分别是频谱比LF/（HF + LF）和VLF/（LF + VLF）的简单频率加权版本，乘以2（给出0-2的范围）。我们现在可以理解生理异常的分形表现：压力反射敏感性降低-->低LF/HF -->低LF/（HF + LF）-->低α（1），而周期性呼吸-->高VLF/LF -->高VLF/（LF + VLF）-->高α（2）。a的预后关联不再神秘。
The diagnostic and prognostic power of the fractal complexity measure 'alpha' of detrended fluctuation analysis (DFA) has remained mysterious because there has been no explanation of its meaning, particularly in relation to spectral analysis. First, we present a mathematical analysis of the meaning of alpha, in weighted power-spectral terms. Second, we test this hypothesis and observe correlations between DFA-based and weighted spectral methods of 0.97 (P < 0.0001) for alpha(1) and 0.98 (P < 0.0001) for alpha(2). Third, we predict mathematically that even in conventional (unweighted) spectral analysis there should be approximate counterparts to DFA, namely that alpha(1) and alpha(2) behave broadly in proportion to the conventional (unweighted) ratios LF/(HF + LF) and VLF/(LF + VLF), respectively, where HF is high frequency, LF is low frequency and VLF is very low frequency. Fourth, we test this hypothesis by physiologically manipulating spectral ratios in healthy volunteers in two ways. The effect of 0.1 Hz controlled breathing on LF/(HF + LF) correlates markedly with the effect on alpha(1) (r = 0.73, P = 0.01); the effect on VLF/(LF + VLF) correlates markedly with that on alpha(2) (r = 0.76, P < 0.01). Likewise, with voluntary periodic breathing the reduction in a, correlates strongly with that in VLF/(LF + VLF) (r = 0.88, P < 0.001); effects on alpha(1) and LF/(HF + LF) again clearly correlate (r = 0.73, P = 0.01). Finally, we examine published literature to identify previously undiscussed evidence of the relationship between alpha(1) and LF/(HF + LF). We conclude that the a, and alpha(2) indices are simply frequency-weighted versions of the spectral ratios LF/(HF + LF) and VLF/(LF + VLF), respectively, multiplied by two (giving a range of 0-2). We can now understand fractal manifestations of physiological abnormalities: depressed baroreflex sensitivity --> low LF/HF --> low LF/(HF + LF) --> low alpha(1) while periodic breathing --> high VLF/LF --> high VLF/(LF + VLF) --> high alpha(2). Prognostic associations of a are no longer mysterious.