Normative Values of Short-Term Heart Rate Variability Parameters in Koreans and Their Clinical Value for the Prediction of Mortality

Background: Heart rate variability (HRV) analysis is an important clinical tool for characterising cardiac autonomic status. We sought to determine the normative values and characteristics of the HRV parameters derived from a short-term study in Koreans and to determine their clinical role in predicting mortality. Methods: A total of 1828 consecutive patients (range 20–84 years, men 64.8%) with no serious comorbid conditions were recruited. The RR intervals from 10-minute electrocardiograms were used for computation of the following HRV parameters: conventional time- and frequency-domain measures and nonlinear measures. Results: A greater age-dependence of most conventional parameters, including the low frequency (LF) and high frequency (HF) powers, was observed than that of the Shannon entropy (ShanEn), approximate entropy (ApEn), and sample entropy. Fifty-four patients (14 cardiac deaths) died during a 10-year follow-up period. The LF/HF ratio (odds ratio [OR], 0.876; p = 0.025), ShanEn (OR, 0.372; p = 0.028), and ApEn (OR, 0.093; p = 0.030) were found to be predictors of all-cause mortality in the multivariate regression analysis. Age was also a powerful risk factor for all-cause mortality (OR, 1.141; p < 0.001). Conclusions: We presented the normative values and characterised the short-term HRV parameters in Koreans. Among the short-term nonlinear parameters, the ShanEn and ApEn were adjunctive parameters for predicting the all-cause mortality in the general population.