ATRIAL FIBRILLATION, HEART
In the patients, five short‐term HRV recordings that did not make it through the pre‐processing procedure were excluded from further analysis. Additionally, one patient suffered from atrial fibrillation, rendering HRV analysis impossible. In healthy volunteers, two recordings (one supine and one during head‐up tilt) did not make it through the pre‐processing procedure and were excluded from further analysis. Thus, data from 30 patients and 15 volunteers were included in the analysis.The HRV measures in the supine position differed between the patient group and the healthy volunteers for all variables except for sample entropy; thus LF, LFHF, and DFA1 were lower, while HF, total power, SDNN, and RMSSD were higher in healthy volunteers compared to patients (Figures Heart rate variability (HRV) analysis of short‐term ECG between supine and head‐up tilt in healthy volunteers. HRV analysis of short‐term recordings from head‐up tilt presented as the median with interquartile range with total power, SDNN, and RMSSD on a log‐scale for better visual presentation. There was a significant difference in LF (During head‐up tilt compared to the supine position in patients, three out of eight HRV measures (SDNN, RMSSD, and total power of the frequency domain) decreased (Figure During head‐up tilt compared to the supine position in the healthy volunteers, three out of eight measures (LF, LF/HF, and DFA1) increased, while HF, RMSSD, and sample entropy decreased tilt (Figure An exploratory correlation analysis on short‐term HRV measures in the patients suggested an association between age and sample entropy during tilt (