Beat-to-beat blood pressure variability demonstrated good-moderate reliability at a 10-minute duration (SBPv ICC=0.664; p≤0.001), but was less reliable than time-domain heart rate variability.
Observational (n=79)
Does recording duration affect the reliability of beat-to-beat blood pressure variability and heart rate variability in healthy adults?
Time-domain heart rate variability demonstrates excellent reliability over 10-minute recordings, outperforming beat-to-beat blood pressure variability for potential use in cardiovascular risk stratification.
p-value: p=≤0.001
Introduction: Heart rate variability (HRV) is an established predictor of cardiovascular risk. Likewise, beat-to-beat blood pressure variability (BPV) has gained recent attention as a prognostic cardiovascular health indicator. The efficacy of BPV as a risk stratification tool is conditional upon its reliability across time. However, few studies have investigated beat-to-beat BPV reliability across time in healthy adults. The purpose of the current study was to evaluate the reliability of BPV across 2-, 5-, and 10-min recording durations alongside commonly used HRV metrics. We hypothesized that reliability of both variability measures would increase with recording duration. Methods: 10-minutes of resting heart rate (HR, electrocardiogram) and beat-to-beat blood pressure (BP, finger plethysmography) were recorded in 79 participants (40 females; age: 23±5 yr; BMI: 25±4 kg/m 2 ) on two separate occasions separated by ~1 month. Systolic and diastolic BP variabilities were obtained using the standard deviation (SBPv and DBPv) and coefficient of variation (SBPcv and DBPcv) calculations. HRV was assessed using time (RMSSD) and frequency-domain (HF, LF, SBPcv: ICC= 0.633; DBPv: ICC= 0.674; DBPcv: ICC= 0.597, all p £0.001). In contrast, frequency domain HRV measures exhibited good-to-excellent reliability (HF: ICC= 0.903; LF: ICC = 0.765, all p< 0.001), with the exception of LF/HF, which demonstrated good-moderate reliability (ICC= 0.629, p< 0.001). Time-domain HRV measures displayed excellent reliability (RMSSD: ICC= 0.904, p< 0.001). Conclusion: Beat-to-beat BPV tended to have poor-to-moderate relative reliability with shorter recording duration, though relative reliability increased to good-moderate with 10-min recording duration. Similar recording-duration-dependent increases in reliability were observed across HRV metrics. Time-domain HRV tended to have the best relative reliability compared to both frequency HRV and BPV metrics. In comparison with time-domain HRV, frequency-domain HRV metrics were less reliable, with HF as an exception. When compared to RMSSD, the complete set of BPV metrics tended to be less reliable than time-domain HRV. The present findings demonstrate reliability of time-domain HRV, supporting its use as a risk stratification tool for an extended recording duration. In contrast, these findings highlight reduced reliability of BPV metrics relative to time-domain HRV, hindering their effectiveness as a risk stratification tool. Lastly, our findings demonstrate the importance of recording duration when assessing reliability of autonomic and cardiovascular variables. This abstract was presented at the American Physiology Summit 2026 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.
Rendon et al. (Fri,) conducted a observational in Healthy adults (n=79). Beat-to-beat blood pressure variability (BPV) assessment vs. Heart rate variability (HRV) assessment was evaluated on Relative reliability (Intraclass correlation coefficient) across recording durations (p=≤0.001). Beat-to-beat blood pressure variability demonstrated good-moderate reliability at a 10-minute duration (SBPv ICC=0.664; p≤0.001), but was less reliable than time-domain heart rate variability.