Sampling Rate Impact on Heart Rate Variability

We set a research question to find the impact of the sampling rate in the electrocardiograms on the calculation of the heart rate variability. Our evaluation method analyzes the heart rate variability on the MITDB electrocardiogram benchmark database originally sampled to 360 Hz. Then the electrocardiogram records are resampled to 125 Hz, and a new set of heart rate variability parameters are calculated and compared to those calculated on 360 Hz. The analysis performed on time-domain heart rate variability parameters showed that the impact of sampling frequency was large for NN50 and pNN50 parameters (up to a max value of 50%, and mean of 10%), and smaller for SDNN and RMSSD (up to a max value of 10%, and an average of 2%). In conclusion, heart rate variability needs a higher sampling frequency to reveal more precise results.