[Study of exercise heart rate variability based on correlation dimension].

This paper is mainly devoted to the relationship between the correlation dimension (CD) of exercise heart rate variability (EHRV) and the status of cardiovascular function. Hypertensive patients and healthy people were enrolled in two contrast groups. Dynamic electrocardiograph (ECG) in step exercise was recorded. EHRV was extracted by wavelet transform. The CDs in the whole course of exercise and in three stages of exercise were calculated, the three stages being named rest-before-exercise, during-exercise, and after-exercise. SPSS software was used for statistical analysis. The results revealed all the CDs showed significant difference between two groups except that in the stage of during exercise. By discrimination analysis, the average correct rate was 92.2%. It indicated that the CD in stress status probably could be an effective non-linear parameter for assessing cardiovascular function status.