Ambulatory pulse wave monitoring: current and future. Opinion paper of Russian Experts

Frequency-Dependent Variability of Pulse Wave Transit Time: Pilot Study

The dynamics of the pulse wave (PW) associated with the PW transit time variability (PWTTV) determines the peripheral pulse rate variability, which is used as a surrogate for heart rate variability (HRV). The aim of the work is to analyze the frequency-dependent dynamics of PWTTV and to identify the possible frequency-phase modulation of PW velocity oscillations on the transit from the heart to the soft tissues of the distal parts of the upper extremities. RR-interval recordings and synchronous records of photoplethysmograms of 12 conditionally healthy subjects from the PhysioNet open database were used in this work. Using the Hilbert-Huang transform 3 spectral components of PWTTV and HRV were identified. It was shown that the amplitudes of PWTTV oscillations were many times (up to 8.4 times) smaller than the amplitudes of HRV, and the peaks of PWTTV spectral components were shifted towards higher frequencies than those of HRV. Functional relations between PWTTV and HRV, which can determine the phase modulation of periodic changes in the PW propagation velocity, were revealed.

[Clinical and diagnostical value of 24-hour arterial stiffness monitoring in patients with bronchial asthma]

AIM

To evaluate 24-hour dynamics of the arterial stiffness main indicators in patients with bronchial asthma of various severity and control.

MATERIALS AND METHODS

The study included 119 patients with bronchial asthma, who formed main groups: the first group 48 patients with mild and moderate asthma, the second 71 patients with severe asthma. All patients underwent the vascular stiffness parameters study using a multifunctional complex for the 24-hour monitoring and office measurements of blood pressure and vessels condition. At the same time vascular stiffness indicators were examined: PWVao pulse wave velocity in the aorta (m/s); Aix augmentation index (%); ASI the arterial stiffness index (mmHg).

RESULTS

When comparing the 24-hour arterial stiffness dynamics indicators, changes were found in patients with severe asthma and non-control. Thus, a statistically significant increase in the pulse wave velocity in the aorta and augmentation index in second group compared to patients of the 1st group and control subjects. In patients with severe asthma Aix at night is significantly higher than daytime, which indicates an increase in arterial stiffness at night.

CONCLUSIONS

Patients with severe bronchial asthma have increased arterial stiffness in comparison with controls and mild and moderate asthma. Also, in patients with severe asthma arterial stiffness parameters were higher at night-time in comparison with daytime.