Application of heart rate variability analysis in monitoring anesthesia

Heart rate variability (HRV) is one of objective indexes to evaluate the function of automatic nerve system. HRV analysis includes time-domain analysis, frequency-domain analysis and nonlinear analysis. At present, time-domain analysis and frequency-domain analysis are more commonly used, while nonlinear analysis is seldom used. In this review, the principles and characteristics of using nonlinear analysis for HRV study are summarized and the application of HRV analysis in monitoring anesthesia is illustrated. Key words: heart rate variability;  anesthesia monitoring;  nonlinear analysis