Analysis of Heart Rate Variability in Preoperative Diabetic Patients by Linear and Nonlinear Dynamics

Min, Seong Won

Abstract

BACKGROUND
The aim of this study was to investigate the underlying changes in heart rate variability (HRV) of preoperative diabetic patients using five analytical methods; SDNN (standard deviation of normal to normal intervals), SDANN (standard deviation of the mean of normal RR intervals for each 5 min period of the entire electrocardiographic recording), RMSSD (root mean square successive difference, the squre root of the mean of the sum of the squares of differences between adjacent normal RR intervals over the entire electrocardiographic recording), PNN50 (percent of difference between adjacent normal RR intervals that are greater than 50 ms computed over the entire electrocardiographic recording) for linear time domain analysis and approximate entropy for nonlinear complexity analysis.
METHODS
HRV values analyzed by five different measures were compared between a control group of ten nondiabetics without any significant systemic disease and a diabetic group of ten patients from the preoperative ambulatory electrocardiographic recordings.
RESULTS
Approximate entropy, SDNN and SDANN values were significantly lower in the diabetic group than those of the control group (P< 0.01).
CONCLUSIONS
Significantly decreased approximate entropy, SDNN and SDANN could provide information about decreased cardiovascular complexity and sympathetic output, suggesting the nature of dysfunction of the diabetic cardiovascular system.