Continuous 24-hour cuffless blood pressure monitoring reveals high prevalence of non-dipping and blunted nocturnal heart rate reduction in rate-controlled atrial fibrillation
K H Lee, C H Kim, Y H LeeAbstract
Background
Ambulatory blood pressure monitoring (ABPM) may be challenging in atrial fibrillation (AF) due to beat-to-beat variability, limiting characterization of circadian blood pressure (BP) patterns in this population.
Purpose
To evaluate the feasibility of continuous cuffless 24-hour BP monitoring and to characterize circadian BP–heart rate profiles in patients with rate-controlled paroxysmal atrial fibrillation.
Methods
In this prospective pilot study, 50 patients with rate-controlled AF (mean age 69±12 years) underwent 24-hour monitoring using a PPG based ring type wearable cuffless BP monitoring device. Mean 24-hour, daytime (awake), and nighttime (asleep) systolic/diastolic BP and HR were calculated from successful measurements only. Nocturnal systolic dipping was defined as a ≥10% reduction in nighttime versus daytime systolic BP. Day–night differences were assessed using paired t-tests. The association between nocturnal HR reduction and systolic dipping was evaluated using Pearson correlation and multivariable linear regression.
Results
Participants achieved a mean monitoring duration of 23.9±0.5 hours, with 18.6±3.2 hours of analyzable BP data. Mean 24-hour BP was 120.7±10.0/77.6±7.8 mmHg. Daytime and nighttime BP were 123.1±10.1/79.9±8.2 and 117.5±10.6/74.6±8.0 mmHg, respectively (mean day–night differences: SBP 5.7 mmHg; DBP 5.3 mmHg; both p<0.001). Mean systolic dipping was 4.5±5.0%. Non-dipping (SBP dipping <10%) was present in 42/50 (84%), and reverse dipping (<0%) in 7/50 (14%). HR decreased from 65.8±10.2 bpm to 60.3±9.8 bpm (nocturnal reduction 8.2±7.0%), which correlated with systolic dipping (r=0.32, p=0.025). In multivariable analysis, nocturnal HR reduction independently predicted systolic dipping (β=0.27, p=0.008), whereas mean BP levels were not associated.
Conclusion
Continuous cuffless monitoring enabled reliable 24-hour BP assessment in rate-controlled AF and revealed a high prevalence of non-dipping accompanied by blunted nocturnal heart rate reduction. These findings suggest altered circadian BP–HR regulation in AF and support wearable cuffless monitoring as a practical tool for nocturnal phenotype characterization.