Impact of Using Different Levels of Threshold-Based Artefact Correction on the Quantification of Heart Rate Variability in Three Independent Human Cohorts

Figure 1. Study design. HRV: heart rate variability. None (A), Very Low (B), Low (C), Medium (D), Strong (E) and Very Strong (F) filters refers to the level of threshold-based artefact correction (i.e., Kubios filter). Graphs are examples of the same best 5 min period (of the whole heart rhythm recoding) that met the selection criteria after using different Kubios filters. RR: R-R intervals; S: seconds; min: minutes.

Figure 2. Differences on the Heart Rate Variability (HRV) time-domain parameters using different Kubios filters in three different cohorts. Data are represented as mean and standard deviation. SDNN: standard deviation of all normal R–R intervals (Panels A, D and G); RMSSD: squared root of the mean of the sum of the squares of successive normal R–R interval differences (Panels B, E and H); pNN50: number of pairs of adjacent normal R–R intervals differing by more than 50ms in the entire recording (Panels C, F and I); p value from the ANOVA comparisons; similar letters means Bonferroni post-hoc differences.

Figure 3. Differences on the Heart Rate Variability (HRV) frequency-domain parameters using different Kubios filter in three different cohorts. Data are represented as mean and standard deviation. HF: power in the high frequency (in absolute units, ms2; Panels A, E and I); LF: power in the low frequency (in absolute units, ms2; Panels B, F and J); LF/HF: ratio of the power in the low frequency divided by the power in the high frequency (Panels C, G and K); VLF: power in the very low frequency (in absolute units, ms2; Panels D, H and L). p value from the ANOVA comparisons; similar letters means Bonferroni post-hoc differences.