Influence of ECG sampling frequency on spectral analysis of RR intervals and baroreflex sensitivity using the EUROBAVAR data set.

To evaluate the impact of different ECG sampling frequencies on parameters of spectral and baroreflex analysis. Spectral and baroreflex analyses were performed in the EUROBAVAR data set (46 recordings of 23 persons) using the original ECG sampling frequency of 500 Hz and - simulated - sampling frequencies of 200 and 100 Hz. For this analysis, the technique of trigonometric regressive spectral (TRS) analysis was used. In the standing position, there were no statistically significant differences in baroreflex sensitivity and frequency bands ranging from VLF to HF using 100 Hz instead of the original 500 Hz. Only the UHF band (>0.40 Hz) was significantly different. In the supine position, similar results could be described for 100 Hz, although there were slight, but significant (P < 0.05) changes in baroreflex sensitivity of around 1 ms/mmHg at the simulated 100 Hz. Using a simulated 200 Hz instead of a 500 Hz sampling frequency had no significant impact on the spectral and baroreflex parameters. The probability to demonstrate an impact of different ECG sampling frequencies was higher in people with pathologically decreased variability of RR intervals. In most of the cases, it is sufficient for spectral and baroreflex analysis by TRS to use data with an ECG sampling frequency of 100 Hz in comparison to 500 Hz. Only if there is a pathologically decreased variability of RR intervals in patients, spectral and baroreflex parameters could be significantly influenced by lower ECG sampling frequencies of up to 100 Hz, but only to a minor degree.