Pulse Wave Propagation Velocity Research Articles

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.

Analysis of pulse-wave propagation characteristics in abdominal aortic sclerosis disease

In this work, a bidirectional fluid‒structure coupling finite element analysis model of the abdominal aorta was established with the various vascular elastic modulus as the main parameter of atherosclerosis, in consideration of blood dynamic viscosity and compressibility. Pressure and velocity pulse-wave propagation were investigated by the application of full-coupling analysis algorithm. The effect of atherosclerosis degree on the propagation characteristics of pulse waves in the bifurcated abdominal aorta was quantitatively analyzed. Arterial bifurcation can cause a substantial attenuation on the peak of pressure pulse waveform and an increase in wave velocity during the cardiac cycle. The elastic modulus and bifurcation properties of the arterial wall directly affected the peak value and wave propagation velocity of the pressure pulse wave. The preliminary results of this work will be crucial in guiding the evolution of the pressure pulse wave and the initial diagnosis of atherosclerotic disease through the waveform.

Investigation of hydraulic resistance of pulsating flows of viscous fluid in elastic pipe

In recent years, flexible pipes made of synthetic polymer materials are being rapidly introduced into practice. Pulsating currents are important in driving water and other liquids in main pipes. This paper examines the pulsating currents of a viscous incompressible fluid in an elastic pipe. The necessary hydrodynamic parameters will be determined by solving the problem, such as distributions of pressure, velocity, flow rate, propagation velocity of the pressure pulse wave, and their attenuation. For the first time in this article, the decrease in hydraulic resistance in a pulsating flow through pipes due to the elasticity of the wall will be determined. The dependence of the dimensionless value of the pressure pulse wave on the vibrational numberαis studied. The pulse wave speed is compared with the speed of Moens-Korteweg, c∞and significant differences between them are found. The dependence of the reciprocal value of attenuation, related to the wavelength, on the vibrational numberαis also studied; it is shown that the attenuation is free at lower values of the Womersley vibrational parameter, practically equals zero, and at large values of which it asymptotically approaches unity [1-9].

Antihypertensive therapy in patients with concomitant chronic obstructive pulmonary disease

Objective. Evaluation of the effectiveness and safety of antihypertensive therapy with a fixed dose combination of amlodipine/indapamide in patients with hypertension (HTN) and chronic obstructive pulmonary disease (COPD).Design and methods. We conducted a non-randomized, open, single-center study, which included 74 comorbid patients (62 men, 12 women) with stage I–II HTN, grade 1–2 HTN, moderate cardiovascular risk and COPD (GOLD I–III). We also assessed respiratory function, the parameters of the microcirculatory bed, vascular stiffness, level of tumor necrosis factor α (TNF-α). For HTN, after the examination all patients were prescribed a fixed combination of amlodipine and indapamide (Arifam, Les Laboratoires Servier, France). The observation period was 6 months.Results. The study was completed by 58 patients who achieved blood pressure (BP values of 132,7 + 4,8 mm Hg), 54% patients took the initial dose of amlodipine/indapamide was 5/1,5 mg and in 46% patients, the dose of the drug was increased to 10/1,5 mg. After 6 months of treatment, a statistically significant increase in forced expiratory volume in 1st second (FEV1) was detected (p < 0,05), decrease in the average linear velocity along the maximum velocity curve (p < 0,05), Purcelo peripheral resistance index (p < 0,05), pulse wave propagation velocity in the elastic arteries, which was increased at the beginning of the study (p < 0,05), TNF-α (p < 0,05).Conclusions. The administration of a fixed combination of amlodipine/indapamide in patients with COPD and HTN leads to the achievement of target BP levels, reduction of vascular stiffness, reduction in TNF-α level, improvement of microcirculatory blood flow. The combination is safe and well-tolerated.

TU84. A ROLE OF DNA METHYLATION IN THE ASSOCIATION BETWEEN THE IGSF9B LOCUS AND CLINICAL FEATURES OF SCHIZOPHRENIA

The article discusses a new method for the pulse wave velocity estimation using a pneumatic blood pressure sensor previously developed by the authors and the capability of that method for the early atherosclerosis diagnosis. The method proposed is based on measuring by the pneumatic sensor of the so-called pulse transit time - the time delay between the pulse wave signal and the synchronous ECG record. The article substantiates the way of determining, according to the waveform of the pulse signal, of that front characteristic time moment, which is more reliable for the measuring the delay to the R-peak of an ECG. The issues of accounting the variability of the pulse wave front delay at different points of the artery in the calculating the mean value and standard deviation of the pulse wave propagation velocity are discussed in detail. Almost all discussed features of the proposed methodology are illustrated by experimental data.

Clinical Study of Ultrasonic Extreme Velocity Imaging Pulse Wave Technique in Carotid Elasticity in Patients with Type II Diabetes Mellitus

In this study, extreme velocity ultrasonic imaging pulse wave technology was used to detect the main indices of atherosclerosis such as carotid intima-media thickness (IMT) and carotid elasticity, and biochemical indices such as glycated hemoglobin, blood glucose and blood lipids in one hundred twenty 18–60-year-old patients with type II diabetes mellitus (T2DM) and 120 healthy controls. We analyzed the correlations between carotid elasticity, carotid IMT, and a range of biochemical indices. The results indicated that when the carotid IMT in young and middle-aged patients with T2DM was within the normal range (0.56±0.03 mm), the carotid artery elasticity was abnormal [Pulse wave propagation velocity (PWV)-BS = 7.69± 1.26 m/s; PWV-ES = 8.34±1.51 m/s; P < 0.05]. Additionally, PWV-BS was positively correlated with age, course of the disease, glycated hemoglobin (HbA1c), and fasting blood glucose (FBG) (r = 0.297, 0.377, 0.369, 0.382), and PWV-ES was positively correlated with age, course of the disease, HbA1c, and FBG (r = 0.318, 0.386, 0.392, 0.339). This finding provides a basis for extreme velocity ultrasonic imaging pulse wave technology to become a new method for the early screening of atherosclerosis in patients with T2DM; this is important for timely clinical intervention in patients with T2DM.

Arterial Stiffness and Vascular Aging: Effects of Hypertension

This review highlights the relationship of age and arterial hypertension observed in the aging process. The main structural and functional changes underlying the increase in vascular stiffness are analyzed. The similarity of vascular changes in aging and arterial hypertension was noted. The negative effect of increased central blood pressure on target organs is considered. Attention is paid to the analysis of arterial stiffness as a marker of vascular aging. The parameters of the carotid-femoral pulse wave propagation velocity, the cardio-ankle vascular index (CAVI), the ankle-brachial index, the finger-brachial index, and the augmentation index were examined separately. The prognostic and clinical value of the parameters of vascular stiffness is considered. In particular, the clinical guidelines for arterial hypertension report the need to use arterial stiffness indicators to improve the accuracy of cardiovascular risk stratification, especially in medium-risk patients. Measurement of vascular stiffness and central aortic pressure should be recommended as one of the methods for stratifying cardiovascular risk in patients with intermediate SCORE risk, as well as in those whose target organ damage was not detected by routine methods. The article also notes the independent diagnostic and prognostic value of the CAVI.

Method for estimation of the pulse wave propagation velocity by a manual pneumatic arterial pressure sensor

The paper discusses a new method for diagnosing atherosclerosis using a pneumatic arterial blood pressure sensor previously developed by the authors hereof. The possibility of applying a pneumatic sensor to measure the pulse wave transit time referring to a synchronous ECG is treated herein. The specification of the method consisting in the selection of the characteristic moment of the pulse wave as the timestamp, when measuring the signal transit time in relation to the R-peak of the synchronous ECG, is justified hereby. The averaged values of the wave transit time at different points of the artery, taking into account the variability of the front delay values, are used to directly determine the pulse wave propagation velocity in the area between the measurement points.

Structural change detection applying long-term seismic interferometry by deconvolution method to a modern civil engineering structure (New Zealand)

Pulse-wave propagation velocity and resonance frequency measured in civil engineering structures are both related to structural design. Monitoring their variation following seismic strong shaking provides information about the immediate building capacity. Joint-interpretation of frequency and velocity variation requires a better understanding of the processes controlling seismic structural health. In this study, we analysed 8 years of earthquake data recorded by the vertical array installed in the Te Puni building in Wellington, New Zealand, as part of the GeoNet building instrumentation programme. Co-seismic variations of pulse wave velocity and fundamental frequency are analysed and interpreted through a Timoshenko beam-like building model. This study shows that even though no structural damage was visually reported over the considered time of monitoring, co- and post-seismic variation of both parameters’ values are observed for almost all earthquakes, including a permanent shift following strong ground shaking. Variations of pulse-wave velocity and resonance frequency are cross-interpreted in terms of the building model. They reflect a time variant building response, correlated with the seismic loading. In addition, time delay of the pulse-wave velocity as a function of the building height provides relevant information on the location of the changes and confirms the efficient cross-interpretation of both methods for seismic Structural Health monitoring.

THE EFFECT OF VISCERAL OBESITY ON THE CONDITION OF THE MAIN ARTERIES IN PATIENTS WITH CHRONIC HEART FAILURE

Aim: to study the relationship between the severity of visceral obesity and the condition of the main arteries in patients with chronic heart failure (CHF) with obesity. Materials and methods. 116 patients with CHF of stage I -IIA of functional class I -III (FC) aged 40 to 65 years were included. All patients were divided into 3 comparable groups: group 1 included patients with CHF with normal body weight (n = 34), group 2 - overweight CHF (n = 40), group 3 - CHF and 1 - 2 degree obesity (n = 42). There were no differences in severity, CHF FC and NT-proBNP levels between the study groups. A clinical examination was performed, indicators of visceral obesity and adipokine status were evaluated. Arterial stiffness was assessed by measuring the pulse wave propagation velocity (CWPV) through the vessels of muscular (CWPVm) and elastic (CWPVe) types. Results. A high percentage of visceral obesity was found: 17.6 % among people with normal BMI, 70 % among overweight people and 100 % among obese people. A statistically significant increase in CWPVe was found in patients with CHF and obesity in comparison with patients with CHF and normal body weight (10,5 [8,9; 11,6] vs 8,5 [7,5; 8,4] m/s). CWPVe > 10 m/s was significantly more common among overweight or obese patients compared to patients with normal body weight (62,4 and 83,2 % vs 37,5 %, respectively). There was a significant decrease in the concentration of adiponectin and an increase in the level of leptin from group 1 to group 3. The correlation analysis showed the presence of reliable relationships between the parameters characterizing the elasticity of the vascular wall and the severity of visceral obesity, as well as laboratory markers of obesity. Conclusion. The data obtained indicate a negative effect of visceral obesity, hyperleptinemia and hypoadiponectinemia on the condition of the main arteries in patients with CHF.

Assessment of arterial wall stiffness based on the results of pulse wave propagation velocity measurement

Assessment of arterial wall stiffness based on the results of pulse wave propagation velocity measurement

Artery wall stiffness evaluation by new pneumatic sensor using improved method for measuring the pulse wave velocity

The article discusses a new method for the pulse wave velocity estimation using a pneumatic blood pressure sensor previously developed by the authors and the capability of that method for the early atherosclerosis diagnosis. The method proposed is based on measuring by the pneumatic sensor of the so-called pulse transit time - the time delay between the pulse wave signal and the synchronous ECG record. The article substantiates the way of determining, according to the waveform of the pulse signal, of that front characteristic time moment, which is more reliable for the measuring the delay to the R-peak of an ECG. The issues of accounting the variability of the pulse wave front delay at different points of the artery in the calculating the mean value and standard deviation of the pulse wave propagation velocity are discussed in detail. Almost all discussed features of the proposed methodology are illustrated by experimental data.

Ventilation disorders and arterial stiffness indicators in patients with chronic obstructive pulmonary disease

The aim of the study was to identify the correlation between ventilation disorders of the lungs and the development of arterial stiffness in patients with chronic obstructive pulmonary disease (COPD).Methods. The following parameters were evaluated in the patients (n = 61) enrolled in the study: spirometry, bodyplethysmography, cardiac-ankle vascular index (CAVI) and an ancho-brachial vascular index. Additionally, the pulse wave propagation velocity was calculated in the area from the ostium of the aorta to the infragenicular arteries.Results. According to the study results, a direct correlation, characterized by moderate to noticeable strength, was found between the parameters of pulmonary ventilation (bronchial resistance, intrathoracic gas volume, residual lung volume (RLV), total lung capacity (TLC), RLV/TLC) and the CAVI parameter, characterizing vascular stiffness on the section from the aorta ostium to the infragenicular arteries. It was shown that the best method for assessing changes in blood vessels is CAVI, which is independent of the level of blood pressure at the moment of the study.Conclusion. It has been established that if there is a correlation between impaired ventilation and arterial stiffness, the systemic nature of the lesion in COPD is confirmed, which explains the high incidence of cardiovascular diseases in patients with COPD.

Relationship between the blood-vessel coupling characteristics and the propagation of pulse waves

Pulse waves cannot be understood simply as pressure waves (longitudinal waves) propagating in compressible blood fluid, nor as radially expanding-contracting displacement waves (transverse waves) propagating along solid blood vessels, but rather as complex waves with fluid-solid coupling and longitudinal wave-transverse wave coupling beyond ordinary imagination. Starting from a new approach to analyze the coupling constitutive relation, a series model is proposed, providing more information for traditional Chinese medicine (TCM) pulse diagnosis in terms of the “position, rate, shape and potential”. It is shown that the equivalent volumetric compression modulus Ks and the corresponding pulse wave propagation velocity cs of the coupling pulse wave system, mainly depend on two dimensionless parameters: the ratio of the blood modulus to the vessel modulus, Kb(p)/E(p) and the ratio of the diameter to the thickness, D(p)/h0, of thin-walled blood vessels, which may vary from person to person and from different pulse locations for the same person. The influences of them on the cs are quantitatively analyzed, showing that for human body the magnitude of Kb/E is in the order of 103 so that the magnitude of cs is in the order of 100–101 m/s to adapt to the human physio-biochemical reactions. By clinical invasive measurements, it is confirmed that the pulse volume transverse wave and the pulse pressure longitudinal wave are coupled and propagate at the same speed, and it is shown that the pulse wave is actually a “biological wave” with oxygenation and biochemical reactions on the wave front. Furthermore, the relations of the “pulse pressure amplification” with the nonlinear constitutive relation and with the load enhanced reflection at the bifurcation of blood vessels, as well as the Lewis’s hypothesis about the formation of dicrotic wave are discussed.

РАСПРОСТРАНЕНИЕ ПУЛЬСОВОЙ ВОЛНЫ ПО МАЛЫМ СОСУДАМ: РЕЗУЛЬТАТЫ ИЗМЕРЕНИЙ И ПОДХОДЫ К МОДЕЛИРОВАНИЮ

The objective of the research work was to develop devices and algorithm for synchronous recording of pulse waves and ECG for measuring the delay time of pulse waves in the branches of various arteries relative to the R wave on an ECG, and to carry out computer simulation of the pulse wave propagation process to determine the dependence of the pulse wave propagation velocity on branching and other hemodynamic and morphological parameters of blood vessels. Material and methods. The study was conducted in 74 healthy subjects aged 18-23 years. The propagation time of the pulse wave by the arterial branches of the vessels of the common carotid, internal, external carotid and radial arteries was measured. The time was calculated by the delay of the beginning of the pulse wave relative to the tip of the R wave on the ECG. Vascular pulsations were recorded using mechanical sensitive and photosensitive sensors, which signals were amplified, digitized, recorded and analyzed using original computer soft wares. Computer simulation of the propagation of pulse waves along the wall of an “equivalent” vessel corresponding to the branching of several arterial vessels was carried out. Results. The velocity of propagation of a pulse wave along the branches of small arterial vessels was lower than its value for larger main arteries. The simulation results confirmed that the propagation velocity of a pulse wave can significantly slow down its movement along branched arterial vessels, which differ in the mechanical properties of the main arteries. Conclusion. The data obtained indicate that the developed devices and measurement algorithms make it possible to register pulse waves of various small arteries and obtain reproducible indices of the delay time of the pulse wave relative to the R wave on the ECG. The time and velocity of the pulse wave propagation depends on the length of the studied vessels, the mechanical properties of the walls of the vessels, which follows from the comparison of the obtained data with the morphological features of the structure of vascular networks. Simulation results for an “equivalent” vessel show that one of the possible causes of a lower pulse wave propagation velocity in small vessels is lower mechanical properties of the branches of small vessels compared with those of larger arteries. However, the identification of the nature of these dependencies and their connection with stiffness of the walls of small vessels requires further study.

Оценка скорости распространения пульсовой волны артериального давления на основе данных измерения пневматическим датчиком со встроенным каналом ЭКГ

Оценка скорости распространения пульсовой волны артериального давления на основе данных измерения пневматическим датчиком со встроенным каналом ЭКГ

Abstract P168: Vascular Stiffness in Young Men Subject to Presence of Chronic Decompensated Tonsillitis

The main role in atherosclerotic damage of the vascular wall is given now to the inflammatory process, the development of which is facilitated by a variety of risk factors (RF). Many of these factors begin to affect on the cardiovascular (CV) system in youth and even in childhood. Some authors refer to RF infectious-inflammatory diseases (IID), which were transferred earlier. The aim is to evaluate some parameters of vascular status in young people in the presence of such focal infection (FI) as chronic decompensated tonsillitis (CDT). Material and methods. Within the main group, 52 young patients aimed at performing surgery due to the presence of IID (age from 18 to 27 years) were examined. 76 persons of comparable sex, age and profile of the main RF without any IID were served as control. The control group was formed from the number of students according to the results of the annual preventive examination in the framework of the Federal Program "University of healthy lifestyle". Both groups were quite comparable in age, sex and profile of the main RF. In addition to the assessment RF-profile it was carried out the determination of indicators of the central pressure and vascular stiffness with the help of hardware-diagnostic complex BPLab ("Petr Telegin", Nizhny-Novgorod, Russia) with the use of programs set Vasotens Office. This program involves an in-depth contour analysis of the properties of pulse waves at the level of both the aorta and peripheral arteries. Statistical processing was carried out using the software "Statistica 10.0" (StatSoft Inc, USA). Results: It was found that in the main group compared with the control group, the pulse wave propagation velocity in the aorta PWVao equal to 10.61±0.25 versus 9.73±0.15 m/s (p=0.004), the augmentation index in the aorta AIxao was 3.88±0.31 versus -1.04±0.08%. In discussing two groups augmentation index in the brachial artery AIx made up of 32.15±2,70 against -48,89±1,52% (p=0.05), arterial augmentation index, AIx normalized to heart rate heart rate was equal to -35,23±vs -49,67 of 5.39±2.56%. In this case, the values of both peripheral and aortic SBP, DBP, Medium BP and Puls BP in patients with DHT were slightly lower than in persons of the control group. Conclusion: The data of the youth study of the dense-elastic vascular potential in different parts of the arterial bed showed a marked increase in vascular rigidity from both the peripheral arteries and the aorta in presence of CDT. In this case, aortic remodeling was more pronounced. It is useful to consider these findings in process of planning and implementing individualized prevention programmes among young people, taking into account the availability of FI.

Multimodal Cardiovascular Information Monitor Using Piezoelectric Transducers for Wearable Healthcare

This report describes a multimodal cardiovascular information measurement method using a wearable sensor device. With the progress of aging populations worldwide, cardiovascular diseases are increasing. Such diseases account for a large share of causes of death and constitute the main cause of long-term care. Along with the miniaturization and longer life of measuring instruments in recent years, constant monitoring of biological information using a wearable biosensor has attracted attention for the prevention and early detection of cardiovascular diseases. However, today's wearable devices can only measure limited cardiovascular information such as the heart rate. Therefore, we propose a method that can simultaneously measure heart rate variation, pulse wave propagation velocity, and blood flow velocity with a single device equipped with a piezoelectric transducer array.

PECULIAR FEATURES OF STRUCTURAL AND FUNCTIONAL INDICES OF CARDIOVASCULAR SYSTEM IN YOUNG MEN WITH ARTERIAL HYPERTENSION ASSOCIATED WITH METABOLIC SYNDROME

Aim. To carry out dynamic assessment of the structural and functional indices of cardiovascular system in young men with arterial hypertension (AH) associated with excess body mass (Ebm) against the background of therapy. Materials and methods. Examination of 86 young men aged 18-27 years, including the group of comparison with practically healthy persons ( n = 24) and the group of observation ( n = 62) was performed. The group of observation joined patients with AH without EBM and AH+EBM. The study was conducted initially and 6 months later. Patients with AH+EBM ( n = 25) were divided into 2 subgroups: group 1 (12 persons) without therapy and group 2 (13 persons) against the background of antihypertensive therapy. Results. Six months later, in group 1 there was observed a growth of “office” systolic arterial pressure (SAP) by 3,8 % (145,0 ± 2,88 and 150,54 ± 2,99 Hg mm), p = 0,001, but in the group with antihypertensive therapy, SAP decreased by 12,7 % (145,75 ± 2,80 and 129,33 ± 1,5 Hg mm), p = 0,01 and DAP - by 12,1 % (86,5 ± 1,95 and 77,16 ± 2,41 Hg mm), p = 0,02. Pulse wave propagation velocity (PWPV) along the vessels of muscular and elastic types among patients without therapy was found to grow in dynamics by 12,2 and 16,2 %, respectively. Against the background of therapy, there was a tendency to a reliable reduction in PWPV indices. Conclusions. Antihypertensive therapy in patients with AH+EBM, while decreasing AP, leads to reduction of LVMM, LVMMI, PWPV and IMCV. The early diagnosed lesion of target organs among young men with AH+EBM and timely antihypertensive therapy can improve structural and functional characteristics of cardiovascular complications.

Relationship between pulse wave propagation velocity and living environment of the elderly in Okinawa healthy longevity area

Relationship between pulse wave propagation velocity and living environment of the elderly in Okinawa healthy longevity area