Complex character analysis of heart rate variability following brain asphyxia

Cai, Yuanyuan; Qiu, Yihong; Wei, Lan; Zhang, Wei; Hu, Sijun; Smith, Peter R.; Crabtree, Vincent P.; Tong, Shanbao; Thakor, Nitish V.; Zhu, Yisheng

doi:10.1016/j.medengphy.2005.05.002

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Volume 28, Issue 4 , Pages 297-303, May 2006

Complex character analysis of heart rate variability following brain asphyxia

Yuanyuan Cai
- Department of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200030, China
Yihong Qiu
- Department of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200030, China
Lan Wei
- Department of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200030, China
Wei Zhang
- Department of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200030, China
Sijun Hu
- Department of Electronic & Electrical Engineering, Loughborough University, UK
Peter R. Smith
- Department of Electronic & Electrical Engineering, Loughborough University, UK
Vincent P. Crabtree
- Department of Electronic & Electrical Engineering, Loughborough University, UK
Shanbao Tong
- Department of Biomedical Engineering, Johns Hopkins School of Medicine, USA
Nitish V. Thakor
- Department of Biomedical Engineering, Johns Hopkins School of Medicine, USA
Yisheng Zhu
- Department of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200030, China
- Corresponding author. Tel.: +86 21 62933451.

Received 4 December 2004; received in revised form 11 April 2005; accepted 25 May 2005. published online 30 August 2005.

Abstract

In the present study Renyi entropy and L–Z complexity were used to characterize heart rate variability (HRV) of rats that were suffered from brain asphyxia and ischemia. Two groups of rats were studied: (a) rats (n=5) injected with NAALADase inhibitor, 2-PMPA, which has been proven neuroprotective in asphyxia injury and (b) control subjects (n=5) without medication. Renyi entropy and L–Z complexity of the R–R intervals (RRI) at different experiment stages were investigated in the two groups. The results show that both measures indicate less injury and better recovery in the drug injection group. The dynamic change of 90min RRI signal after the asphyxia was investigated. The sudden reduction of the two parameters shows their sensitivity to the asphyxia insult.