Power spectral analysis of heart rate variability: normal values of subjects over 60 years old.

Power spectral analysis of heart rate variability (HRV) provides a non-invasive method of estimating cardiac autonomic nerve activity. It has been reported that HRV decreases with age. The purpose of this study was to assess the values of and determine the reliability of HRV in healthy older people. The study found lower and highly variable values of HRV. It was concluded that the reliability of HRV in older subjects might need to be reinvestigated and only normalized values of HF and LF might be useful. Larger study groups and different recording periods of HRV are needed.