复杂度在立位期间心率变异分析中的应用

目的 介绍非线性指标复杂度，并将之应用于心率变异分析。分析立位测试过程中心血管系统复杂性的变化。方法 对8名被试者进行立位耐力测试。记录心电信号并用复杂度进行心率变异分析。结果 与立位前平卧位相比，立位0-5min,5-10min,10-15min和15-20min心脏R-R间期，R-R间期标准差和相临R-R间期差值的标准差（RMSSD）显著降低。立位0-5min,15-20min复杂度和近似熵显著低于平卧位。结论 立位期间心率变异降低。心血管系统复杂性降低。复杂度应用于心率变异的分析是可行的。

Application of Degree of Complexity in Heart Rate Variability Analysis during Orthosatic Standing.

Objective. To introduce the degree of complexity in characterizing heart rate variability (HRV), and to discuss the changes in complexity of the cardiovascular system during orthostatic standing posture. Method. ECG of 8 subjects were recorded during supine and orthostatic standing postures. Degree of complexity was used to analyze the HRV. Result. Compared to supine before orthostatic standing posture, R-R intervals and its standard deviation at 0-5 min, 5-10 min, 10-15 min and 15-20 min during orthostatic standing posture were decreased significantly; the degree of complexity of HRV at 0-5 min and 15-20 min during orthostatic standing posture were decreased significantly; the approximate entropy of 0-5 min and 15-20 min were decreased significantly. Conclusion. The results showed that HRV and complexity of cardiovascular system was decreased during orthostatic standing. It was feasible that the degree of complexity can be used to analyze HRV.