Goldberger A L, West B J
Ann N Y Acad Sci. 1987;504:195-213. doi: 10.1111/j.1749-6632.1987.tb48733.x.
(1) Nonlinear mechanisms may apply both to the understanding of SA-AV node interactions and to bifurcations leading to certain types of AV block. (2) The fractal His-Purkinje system serves as the structural substrate for the generation of the broadband, inverse power-law spectrum of the stable ventricular depolarization (QRS) waveform. (3) Fractal anatomy is also seen in multiple other systems: pulmonary, hepatobiliary, renal, etc. Fractal morphogenesis may reflect a type of critical phenomenon that results in the generation of these irregular, but self-similar structures. (4) Self-similar (fractal) scaling may underlie the 1/f-like spectra seen in multiple systems (e.g., interbeat interval variability, daily neutrophil fluctuations). This fractal scaling may provide a mechanism for the "constrained randomness" that appears to underlie physiological variability and adaptability. (5) Behavior consistent with subharmonic bifurcations is seen in cardiac electrophysiology (e.g., sick sinus syndrome) and hemodynamic perturbations (e.g., swinging heart phenomenon in pericardial tamponade). (6) Ventricular tachyarrhythmias associated with sudden cardiac death (e.g., torsades de pointes, ventricular fibrillation) appear to reflect relatively periodic, not chaotic (turbulent) processes resulting from disruption of the physiologic fractal depolarization sequence. (7) Spectral analysis of Holter monitor data may help in the detection of patients at high risk for sudden death.
(1) 非线性机制可能既适用于理解窦房结与房室结的相互作用，也适用于导致某些类型房室传导阻滞的分叉现象。(2) 分形的希氏 - 浦肯野系统是稳定心室去极化（QRS）波形宽带、反幂律频谱产生的结构基础。(3) 在多个其他系统中也可见分形解剖结构：肺、肝胆、肾等。分形形态发生可能反映了一种临界现象，这种现象导致了这些不规则但自相似结构的产生。(4) 自相似（分形）标度可能是多个系统中所见的1/f类频谱（例如，心跳间期变异性、每日中性粒细胞波动）的基础。这种分形标度可能为似乎是生理变异性和适应性基础的“受限随机性”提供一种机制。(5) 在心脏电生理学（例如病态窦房结综合征）和血流动力学扰动（例如心包填塞时的摆动心现象）中可见与次谐波分叉一致的行为。(6) 与心脏性猝死相关的心室快速心律失常（例如尖端扭转型室速、心室颤动）似乎反映了由于生理分形去极化序列中断导致的相对周期性而非混沌（湍流）过程。(7) 动态心电图监测数据的频谱分析可能有助于检测猝死高危患者。
