Schmidt G, Morfill G E, Barthel P, Hadamitzky M, Kreuzberg H, Demmel V, Schneider R, Ulm K, Schömig A
I. Medizinische Klinik, Technischen Universität München, Germany.
Pacing Clin Electrophysiol. 1996 Jun;19(6):976-80. doi: 10.1111/j.1540-8159.1996.tb03395.x.
A method using a parameter from the field of nonlinear dynamics to quantify the variability of ventricular premature complexes (VPCs) is presented. One hundred patients with coronary artery disease and > or = 10 VPCs/hour were included in the study. The RR intervals were plotted in a three-dimensional artificial phase space, and the structures in phase space were quantified by the local scaling indices, alpha. In the frequency distribution histogram, n(alpha), for each patient, the maximum of the ventricular ectopies alpha VPC, adjusted to the VPC frequency, was assessed; alpha VPC was used as the risk indicator. Endpoints were total mortality and sudden cardiac death. During follow-up (mean 3.1 years), 28 out of 100 patients died, 16 suddenly; alpha VPC had a significant prognostic impact and was independent from other risk indicators, such as left ventricular ejection fraction (LVEF). Patients who died during follow-up were characterized by a high alpha VPC. The optimal discrimination of high risk patients and low risk patients occurred at alpha VPC = 3.0. After 4 years, the survival rate of patients with a alpha VPC > 3.0 was 59%, in contrast to 97% in patients with alpha VPC < or = 0.3. As to the sudden death mortality, the survival rates were 74% and 97%, respectively. The difference between the groups were significant for both endpoints. Patients with an increased VPC variability (i.e., alpha VPC > 3.0) were at enhanced risk of sudden death and total mortality risk; alpha VPC was independent from other risk indicators such as the LVEF or heart rate variability parameters.
本文提出了一种利用非线性动力学领域的参数来量化室性早搏（VPC）变异性的方法。该研究纳入了100例冠心病患者，每小时室性早搏≥10次。将RR间期绘制在三维人工相空间中，并通过局部标度指数α对相空间结构进行量化。在每位患者的频率分布直方图n(α)中，评估经室性早搏频率调整后的室性异位搏动αVPC的最大值；αVPC用作风险指标。终点为全因死亡率和心源性猝死。在随访期间（平均3.1年），100例患者中有28例死亡，其中16例为心源性猝死；αVPC具有显著的预后影响，且独立于其他风险指标，如左心室射血分数（LVEF）。随访期间死亡的患者具有较高的αVPC。αVPC = 3.0时，高风险患者和低风险患者的最佳区分度出现。4年后，αVPC＞3.0的患者生存率为59%，而αVPC≤0.3的患者生存率为97%。在心源性猝死死亡率方面，生存率分别为74%和97%。两组在两个终点方面的差异均具有显著性。室性早搏变异性增加（即αVPC＞3.0）的患者心源性猝死风险和全因死亡风险增加；αVPC独立于其他风险指标，如LVEF或心率变异性参数。
