Device-guided slow breathing with direct biofeedback of pulse wave velocity – acute effects on pulse arrival time and self-measured blood pressure

Abstract

Background There isevidence that device-guided slow breathing using biofeedback acutely reduces blood pressure (BP) and pulse wave velocity [i.e. increased pulse arrival time (PAT)]. Objectives The objectives of the study presented here were to test whether the results of changes observed in PAT in earlier studies are reproducible over 1 week and how changes in pulse wave velocity/PAT translate into absolute self-measured BP changes. Methods Patients with a systolic BP 130–160 mmHg or treated essential hypertension (21 females/23 males) were trained to perform unattended device-guided slow breathing exercises for 10 min daily over 5 days. Furthermore, they were skilled to perform self-measurement of BP before and after the breathing exercise using a validated upper-arm device. Results Office BP at screening [median (1, 3. Q)] was 137 (132, 142)/83 (79, 87) mmHg. We observed a significant ( P < 0.05) increase in PAT of 5 ms (SD 12.5 ms) on average after 10 min of guided breathing and an additional 1 ms ( P < 0.05, SD 8 ms) during the following 5 min of spontaneous breathing compared to baseline. PAT before the exercise remained constant over 5 days paralleled by constant self-measured BP before the exercise. Device-guided breathing was associated with a significant reduction of self-measured SBP of 5 mmHg ( P < 0.01, SD 8 mmHg). Data furthermore demonstrated that these changes were highly reproducible over 1 week. Conclusions Device-guided slow breathing and biofeedback lead to reproducible and favorable changes (increase) in PAT and SBP (decrease).

Non-invasive pulse arrival time as a surrogate for oscillometric systolic blood pressure changes during non-pharmacological intervention

“…Being limited to a low number (especially in the control group) of young and healthy participants, generalization of the results to older and unhealthy subjects should be done with caution. Especially, the latter might complicate the analysis and validity of the PWA technique due to arrhythmia and other pathologies influencing the biosignals, although previous studies did not raise any problems (Bachler et al 2020, Mengden et al 2023. Furthermore, the participants had on average normotensive BPs, thus an extrapolation of results to hypertensive patients needs to be done with caution and warrants further investigations.…”

“…Physiological changes and changes of pulse wave features were recorded using the digital, handheld smartPWA device (AIT Austrian Institute of Technology) using a single lead ECG and finger PPG (Bachler et al 2020, Mengden et al 2023, for details see supplemental figure 1. The medical-grade bio-signal acquisition sensor device uses conductive surface areas to derive a standard Einthoven I lead ECG and combines these with an optical sensor for PPG to measure blood volume changes in the finger's microvascular bed (Mengden et al 2023), but not absolute BP. Data are streamed to a tablet via Bluetooth low energy (Mengden et al 2023).…”

“…The medical-grade bio-signal acquisition sensor device uses conductive surface areas to derive a standard Einthoven I lead ECG and combines these with an optical sensor for PPG to measure blood volume changes in the finger's microvascular bed (Mengden et al 2023), but not absolute BP. Data are streamed to a tablet via Bluetooth low energy (Mengden et al 2023). Algorithms are utilized to compute various measures, including the PAT, which represents the time difference between the R-peak of the ECG and the pulse wave's arrival in the finger.…”

“…It has recently been shown that device guided breathing using PAT as a surrogate for continuous systolic BP changes as biofeedback is feasible and reduces systolic BP by about 5 mmHg (Bachler et al 2020). Furthermore, it has been shown that PAT pursues self-assessed cuff-based oscillometric systolic BP correctly and repeatably over 5 consecutive days (Mengden et al 2023). Nevertheless, the accordance of PAT to oscillometric systolic BP in the context of moderate physical or mental workload is not clear yet.…”

Fit for Duty Assessment of Driver Fatigue based on Statistical Modelling of Cardiovascular Parameters

“…Measurements while driving are not possible, since the device must be held with both hands for recording signals. A detailed description of the device can be found in Mengden et al [13]. In accordance with the standards of measurement for heart rate variability [14], at least two minutes of ECG and PPG data were recorded for each measurement in this trial.…”