Luo Daiyi, Pan Weifeng, Li Yifan, Feng Kaicheng, Liu Guanzheng
School of Biomedical Engineering, Sun Yat-sen University, Guangzhou 510275, China.
Key Laboratory of Sensing Technology and Biomedical Instrument of Guangdong Province, School of Engineering, Sun Yat-sen University, Guangzhou 510275, China.
Entropy (Basel). 2018 Oct 16;20(10):795. doi: 10.3390/e20100795.
Congestive heart failure (CHF) is a cardiovascular disease associated with autonomic dysfunction, where sympathovagal imbalance was reported in many studies using heart rate variability (HRV). To learn more about the dynamic interaction in the autonomic nervous system (ANS), we explored the directed interaction between the sympathetic nervous system (SNS) and the parasympathetic nervous system (PNS) with the help of transfer entropy (TE). This article included 24-h RR interval signals of 54 healthy subjects (31 males and 23 females, 61.38 ± 11.63 years old) and 44 CHF subjects (8 males and 2 females, 19 subjects' gender were unknown, 55.51 ± 11.44 years old, 4 in class I, 8 in class II and 32 in class III~IV, according to the New York Heart Association Function Classification), obtained from the PhysioNet database and then segmented into 5-min non-overlapping epochs using cubic spline interpolation. For each segment in the normal group and CHF group, frequency-domain features included low-frequency (LF) power, high-frequency (HF) power and LF/HF ratio were extracted as classical estimators of autonomic activity. In the nonlinear domain, TE between LF and HF were calculated to quantify the information exchanging between SNS and PNS. Compared with the normal group, an extreme decrease in LF/HF ratio ( = 0.000) and extreme increases in both TE(LF→HF) ( = 0.000) and TE(HF→LF) ( = 0.000) in the CHF group were observed. Moreover, both in normal and CHF groups, TE(LF→HF) was a lot greater than TE(HF→LF) ( = 0.000), revealing that TE was able to distinguish the difference in the amount of directed information transfer among ANS. Extracted features were further applied in discriminating CHF using IBM SPSS Statistics discriminant analysis. The combination of the LF/HF ratio, TE(LF→HF) and TE(HF→LF) reached the highest screening accuracy (83.7%). Our results suggested that TE could serve as a complement to traditional index LF/HF in CHF screening.
充血性心力衰竭（CHF）是一种与自主神经功能障碍相关的心血管疾病，许多使用心率变异性（HRV）的研究报道了其交感迷走神经失衡。为了更深入了解自主神经系统（ANS）中的动态相互作用，我们借助转移熵（TE）探索了交感神经系统（SNS）与副交感神经系统（PNS）之间的定向相互作用。本文纳入了54名健康受试者（31名男性和23名女性，年龄61.38±11.63岁）和44名CHF受试者（8名男性和2名女性，19名受试者性别未知，年龄55.51±11.44岁，根据纽约心脏协会功能分级，I级4例，II级8例，III~IV级32例）的24小时RR间期信号，这些信号来自PhysioNet数据库，然后使用三次样条插值法将其分割为5分钟不重叠的时段。对于正常组和CHF组中的每个时段，提取频域特征，包括低频（LF）功率、高频（HF）功率和LF/HF比值，作为自主神经活动的经典估计指标。在非线性领域，计算LF与HF之间的TE，以量化SNS与PNS之间的信息交换。与正常组相比，CHF组中LF/HF比值极度降低（ = 0.000），TE（LF→HF）（ = 0.000）和TE（HF→LF）（ = 0.000）均极度升高。此外，在正常组和CHF组中，TE（LF→HF）均远大于TE（HF→LF）（ = 0.000），这表明TE能够区分ANS中定向信息传递量的差异。提取的特征进一步应用于使用IBM SPSS Statistics判别分析来鉴别CHF。LF/HF比值、TE（LF→HF）和TE（HF→LF）的组合达到了最高的筛查准确率（83.7%）。我们的结果表明，TE可作为CHF筛查中传统指标LF/HF的补充。
