Pressure Pulse Wave Research Articles

Relationship between coronary atherosclerotic lesion and arterial stiffness in patients with coronary artery disease

Abstract Introduction Some of the previous studies demonstrated that arterial stiffness independently predicts mortality and morbidity associated with CAD. Purpose to evaluate the relationship between coronary atherosclerosis severity and arterial stiffness. Material and methods The study included 158 people aged 40 to 70 years: control group – 25 people (mean age 61,7±6,6 years; 21 men and 4 women) without cardiovascular diseases (CVD) and 133 patients (mean age 62,5±6,9 years; 80 men and 53 women) with CAD, confirmed by coronary angiography (CAG). Arterial stiffness was assessed using applanation tonometry (AT). Аssessment of the coronary calcium (CC) was performed with computer tomography (CT). Results In 133 patients with CAD, the results of AT were compared with the degree of atherosclerotic lesion according to CT and CAG data. All patients were divided into groups depending on the CC value. Group I included 19 people with a CC value of 0, group II - 55 people with a CC of up to 400, and group III - 59 patients with a CC of more than 400. With an increase in the degree of the atherosclerotic lesion, the values of peripheral and central pulse pressure (PP), augmentation index (AIx), additional augmentation index normalised for heart rate of 75 bpm (AIx@HR75) and pulse wave velocity (PWV) statistically significantly increased (Table 1). Indicators characterising augmentation of сentral PP and arterial stiffness also increased. Conclusion Increases in Pulse Pressure, Augmentation Index, and Pulse Wave Velocity reflect the worsening of atherosclerosis in coronary arteries, thereby indicating a higher risk of cardiovascular complications. Monitoring of these parameters can be crucial for early diagnosis and prevention of major adverse cardiovascular events.

Effects of multicomponent exercise intervention on cardiometabolic risk factors in children and young adults with cerebral palsy: a multiple-baseline trial.

Adults with cerebral palsy (CP) have a high risk of cardiometabolic diseases. It is unknown whether this risk is elevated in young people with CP and whether exercise can reduce this risk. Therefore, we investigated the effects of the EXErcise for Cerebral Palsy (EXECP) intervention on cardiometabolic risk in children and young adults with CP and compared this risk to typically developing children and young adults (TDs). Ambulatory male and female participants with spastic CP, aged 9-24 years, and age- and sex-matched TDs without musculoskeletal disorders were recruited. Participants with CP were measured at baseline, after a three-month control period manifesting normal development, and after the three-month strength, gait, and flexibility training intervention. TDs were measured at baseline and after the control period. They did not attend the intervention. Cardiometabolic risk factors included body weight, body fat percentage, and skeletal muscle mass index assessed with bioimpedance; resting systolic and diastolic blood pressure and aortic pulse wave velocity assessed with a non-invasive oscillometric device; fasting plasma high-density and low-density lipoprotein cholesterol, triglyceride, and glucose levels. Data were analyzed with independent samples t-tests and linear mixed-effects models adjusted for sex and age. The study involved 18 participants with CP (13 males, 9-22year, mean 14.2 ± 4.4) and 17 TDs (12 males, 9-22year, mean 14.6 ± 4.3). At baseline, participants with CP had a 1.0 (95% confidence interval (CI) [-2.0, -0.0]) kg/m2 lower skeletal muscle mass index than TDs. During the control period, no statistically significant between-group differences were observed in the change of any outcome. In the CP group, body weight (β = 1.87, 95% CI [1.04, 2.70]), fat percentage (β = 1.22 [0.07, 2.37], and blood glucose (β = 0.19, 95% CI [0.01, 0.37]) increased, while diastolic blood pressure (β=-2.31, 95% CI [-4.55, -0.06]) and pulse wave velocity (β=-0.44, 95% CI [-0.73, -0.16]) decreased. In the TD group, only body weight increased (β = 0.85, 95% CI [0.01, 1.68]) statistically significantly. In the CP group, no changes were observed during the intervention. Young people with and without CP do not exhibit significant differences in most cardiometabolic risk factors. EXECP intervention may attenuate some adverse development trajectories occurring without the intervention but greater volume and intensity of aerobic exercise may be needed to reduce cardiometabolic risk. ISRCTN69044459; Registration date 21/04/2017.

Electret mechano-sensor array integrated with tribopotential-modulated thin film transistors for precise spatiotemporal pressure perception

Spatiotemporal pressure perception is a key function of electronic skins. Electret mechano-sensors, as active sensors for E-skins, have garnered significant interest, with outstanding sensing performance in dynamic pressure measurement. However, their high output impedance poses a challenge in accurately and simply measuring low-frequency or static pressure distribution. Herein, we proposed an electret mechano-sensor array, in which each sensing cell is based on an electret sensor integrated with an IGZO TFT. The high input impedance of the TFT facilitates the sensor signal readout and enables the measurement of static pressure. The super-linear amplification feature of the TFTs improves the sensitivity and linearity of the sensors. An IGZO TFT layer with the lower electrodes of the electret sensor was fabricated through microfabrication process and assembled with a pre-charged electret film to achieve a mechano-sensor array with a high density. The fabricated TFT-integrated electret mechano-sensor array has achieved pattern detection and spatial tactile perception. Moreover, the sensor array can record spatiotemporal static pressure and arterial pulse waves simultaneously, exhibiting high resolution in detecting subtle changes and potentially offering various physiological information regarding the cardiovascular system. This work demonstrated that the proposed mechano-sensor array has capabilities for broad-scale pressure distribution detection in healthcare monitoring and human-computer interaction.

The role of a medium-term physical exercise program in improving cardiovascular parameters in hypertensive patients

The objective of our study was to evaluate the changes in cardiovascular parameters in patients with hypertension who completed a 3-month physical exercise program. 229 sub-jects with high normal values of blood pressure and stage 1 hypertension (group 1) and 120 patients with stage 2 hypertension (group 2) followed a 3-month physical exercise program. The following parameters were measured: systolic blood pressure, diastolic blood pressure, pulse pressure, heart rate, pulse wave velocity. For group 1 there were sta-tistically significant differences for all the tested parameters after the 3-month program (decreased systolic blood pressure, heart rate, pulse pressure and pulse wave velocity, p< 0.0001; lower diastolic blood pressure, p=0.018)). In group 2 all the tested parameters had decreased values after the 3-month rehabilitation program. However, only for the pulse wave velocity there was recorded a statistically significant reduction after the exercise program (p< 0.001). There were significant direct correlations between total cholesterol and pulse wave velocity for group 1 at both initial (p=0.024) and final assessments (p=0.03), and for group 2 patients at the 3-month assessment (p=0.001). A medium-term physical exercise program improved the cardiovascular parameters (blood pressure, arte-rial stiffness) in hypertensive patients.

P005 CHILDREN WITH REPAIRED COARCTATION OF THE AORTA: FOLLOW-UP AND HYPERTENSIO5

Background and objective: Coarctation of the aorta (CoA) is a congenital heart disease with high morbidity and mortality due to cardiovascular disease even after adequate therapeutic management. A fundamental factor is the development of high blood pressure over the years. The objective of this work is to analyze the blood pressure phenotype of the population under follow-up in a high blood pressure clinic. Methods: Retrospective review of medical records of patients aged 0 to 22 years with CoA corrected by surgery or interventional catheterizations, which were followed up between January 2017 and February 2023 in the high blood pressure clinic of a pediatric center. Variables to analyze: age at the time of correction, technique, time since correction, associated cardiac or extracardiac pathologies, office blood pressure, left ventricular hypertrophy. In patients with adequate height and tolerance to the procedure: Ambulatory Blood Pressure Monitoring (ABPM) and pulse wave velocity study were performed. Results: 142 medical records were reviewed (see table 1). Two groups were formed according to the age of the patients due to the possibility of performing ABPM. There were no significant differences between the age of surgical approach and the association with complex heart diseases between the groups. The younger population presented a greater number of extended terminal anastomosis technique and increased concentric remodeling. The prevalence of hypertension and overweight obesity increased over the years. The older group had 25% masked hypertension and 25% increased pulse wave velocity Conclusion: Our population has 28% of hypertension among those under 8 years of age and it increases to 46% among the eldest, coinciding with international reports that indicate that the evolution towards arterial hypertension in this population is progressive. Lifelong follow-up of these patients with corrected CoA is important to detect recoarctation or the development of hypertension and act accordingly to improve morbidity and mortality.

Pulse signal may be a key bridge connecting cardiology and pulse diagnosis of TCM

ObjectiveThis study extracts atherosclerosis indices from six channels of Cunkou and discusses the data distribution, aims to explore the connection between cardiology of modern medicine (MM) and traditional Chinese medicine (TCM) pulse diagnosis. MethodsWe use a device capable of simultaneously collecting the pulse signals of the Cun, Guan and Chi to test the population participating in routine physical examinations. Firstly, we collected pressure pulse waves from six channels of Cunkou of 1045 healthy subjects (578 men and 467 women, average age=37.99±16.02 years). Secondly, we extracted the two most common arteriosclerosis indices pulse transit time (PTT) and Augmentation index (AIx) from six-channel pulse waves. Lastly, T-test and correlation test were taken to analyze the differences and relevance of the atherosclerosis indices extracted from six channels of Cunkou. ResultsWhen analyzing AIx and PTT at different wrist, it was found that AIx of left wrist is significantly higher than that of right wrist (P<0.001), while the PTT of left wrist is significantly lower than that of right wrist (P<0.001), a phenomenon that is common in both men and women. Furthermore, regardless of whether it is left or right wrist, the AIx at Chi channel is higher than that at Cun (P<0.05) and Guan (P<0.05). At the same time, the PTT at Guan is bigger than that at Cun in two wrists (P<0.05). However, when the specific channel is not considered, there is no significant difference in AIx and PTT between each channel and the corresponding wrist (P>0.05). In addition, regardless of gender, when the specific channel is not considered, AIx and PTT of each wrist are significantly correlated with age (P<0.001). ConclusionsThe differences of the atherosclerosis indices AIx and PTT in six channels support that the method of six-channel pulse diagnosis is indispensable in TCM. Additionally, the pulse waves obtained from each channel can be utilized as a dependable foundation for diagnosing atherosclerotic conditions. This study is beneficial for promoting the integration of TCM and MM in diagnosing disease.

Analytical and Computational Modeling of Relaxation Times for Non-Newtonian Fluids

With the availability of efficient and sophisticated finite element analysis (FEA) and computational fluid dynamics (CFD) tools, engineering designs are becoming more software-driven and simulation-based. However, the insights relevant to engineering designs tend to be hidden within massive temporal and spatial data produced with full-fledged three-dimensional simulations. In this paper, we present a preliminary study of the controlled intermittent dispensing of a typical non-Newtonian glue employed in the manufacturing of electric vehicles (EVs). The focus of the study is on the scaling issues derived from different computational and analytical models of interest and importance to the precision control of this non-Newtonian fluid, the lowest dynamic viscosity of which at extremely high shear rates is nearly four million times that of water. More specifically, the abrupt change of the inlet pressure with a constant outlet or ambient pressure and various modeling strategies for transient viscous internal flow with both Newtonian and non-Newtonian fluids are modeled and compared. The analytical and computational results of the developing Newtonian fluid, i.e., water, are derived and computed for validation and verification purposes before the actual applications to the developing non-Newtonian fluid. The concept of a well-established relaxation time before the onset of the steady solution for Newtonian fluids has been validated with both analytical and computational approaches before its expansion and adoption to non-Newtonian fluids with complex rheological behaviors. Other issues attributed to transient operations and precision controls of non-Newtonian fluid delivery involve the pressure pulse and pressure wave propagation within the flexible pipe with compressible or almost incompressible non-Newtonian fluids with a constant pressure at the outlet and a constant mass flow rate or average axial velocity at the inlet, which will be addressed in a separate paper.

No association between vascular aging and sarcopenia in healthy participants

Background & AimsSeveral reports inform an association between vascular aging and sarcopenia. However, both conditions appear along with aging. Therefore, their association may be circumstantial and not casually linked. Our aim was to determine if individuals with higher-than-expected vascular aging have a higher frequency of sarcopenia. MethodsIn 802 participants we calculated the association between pulse wave pressure and carotid intima media thickness and age and blood pressure, to derive predictive regression equations. In 161 of these participants we measured body composition by double beam X ray absorptiometry (DEXA), hand grip strength, rectus femoris thickness by ultrasound, activity energy expenditure by actigraphy and peak oxygen consumption and workload in an incremental exercise test. We calculated their expected values for pulse wave velocity and carotid intima media thickness and compared muscle mass and function between those with higher or lower than expected parameters. In 60 of these participants, we measured body composition sequentially to assess its change over time. ResultsAge and blood pressure predicted the variance of pulse wave velocity and carotid intima media thickness with R2 values of 0.94 to 0.97 and 0.54 to 0.66, respectively. No differences in the frequency of sarcopenia and in muscle mass and strength were observed between participants with higher or lower than expected pulse wave velocity and carotid intima media thickness. In the group with sequential assessments, no differences in the change of muscle mass over time were observed in participants with and without accelerated vascular aging. ConclusionsWe were not able to find an association between vascular aging and sarcopenia

Intracranial pressure following surgery of an unruptured intracranial aneurysm—a model for normal intracranial pressure in humans

ObjectiveOptimizing the treatment of several neurosurgical and neurological disorders relies on knowledge of the intracranial pressure (ICP). However, exploration of normal ICP and intracranial pressure pulse wave amplitude (PWA) values in healthy individuals poses ethical challenges, and thus the current documentation remains scarce. This study explores ICP and PWA values for healthy adults without intracranial pathology expected to influence ICP.MethodsAdult patients (age > 18 years) undergoing surgery for an unruptured intracranial aneurysm without any other neurological co-morbidities were included. Patients had a telemetric ICP sensor inserted, and ICP was measured in four different positions: supine, lateral recumbent, standing upright, and 45-degree sitting, at day 1, 14, 30, and 90 following the surgery.ResultsICP in each position did not change with time after surgery. Median ICP was 6.7 mmHg and median PWA 2.1 mmHg in the supine position, while in the upright standing position median ICP was − 3.4 mmHg and median PWA was 1.9 mmHg. After standardization of the measurements from the transducer site to the external acoustic meatus, the median ICPmidbrain was 8.3 mmHg in the supine position and 1.2 mmHg in the upright standing position.ConclusionOur study provides insights into normal ICP dynamics in healthy adults following a uncomplicated surgery for an unruptured aneurysm. These results suggest a slightly wider normal reference range for invasive intracranial pressure than previously suggested, and present the first normal values for PWA in different positions. Further studies are, however, essential to enhance our understanding of normal ICP.Trial registration The study was preregistered at www.clinicaltrials.gov (NCT03594136) (11 July 2018)

Experimental research on the reflection and response characteristics of pressure pulse waves for different gas pipeline blockage materials

AbstractNatural gas pipelines are exposed to complex production and transportation environments, leading to blockages of varying compositions and forms due to various factors. This paper proposes a pressure pulsing wave‐based pipe blockage detection method, and a series of pipeline blockage detection experiments of different materials are carried out, including hydrate blockage, ice blockage, paraffin blockage, and water blockage. Through the blockage detection calculation theory and the reflection and transmission characteristics during pressure wave emission, the blockage position, length, and section blockage rate under different blockage materials are obtained, and the influence of different blockage materials on the reflection and transmission signal characteristics of the pressure pulse wave is analyzed. The results show that the solid blocking material does not noticeably impact the reflectivity and reflective properties of pressure waves, and different cross‐sectional shapes have a noticeable impact on the reflectivity of the pressure wave. The reflected wave waveform of the liquid blockage material is visible but irregular. The average error of blockage location is 0.78%.

Age and Sex Differences in the Contribution of Mean Arterial Pressure to Pulse Pressure Before Middle Age.

A lower ability to buffer pulse pressure (PP) in the face of increasing mean arterial pressure (MAP) may underlie the disproportionate increase in systolic blood pressure (SBP) in women from young adulthood through middle-aged relative to men. To evaluate the contribution of MAP to the change in PP and pressure wave contour in men and women from young adulthood to middle age. Central pressure waveform was obtained from radial artery applanation tonometry in 312 hypertensive patients between 16 to 49 years (134 women, mean age 35 ± 9 years), 185 of whom were on antihypertensive treatment. Higher MAP levels (≥ 100 mmHg) were significantly associated with higher brachial and central SBP (P < 0.001), PP (P < 0.001), incident wave (P = 0.005), AP (P < 0.001), and PWV (P < 0.001) compared to lower MAP levels. The relationship between MAP and brachial PP (P < 0.001), central PP (P < 0.001), incident wave (P < 0.001), and AP (P < 0.01), but not PWV, strengthens with age. The age-related increase in the contribution of MAP to brachial PP (P < 0.001), central PP (P < 0.001), and incident wave (P < 0.001) was more prominent in women than in men beginning in the fourth decade. In multiple regression analyses, MAP remained a significantly stronger predictor of central PP and incident wave in women than in men, independent of age, heart rate, and antihypertensive treatment. In turn, age remained a significantly stronger predictor of central PP and incident wave in women than in men, independent of MAP, heart rate, and antihypertensive treatment. Women of reproductive age showed a steeper increase in PP with increasing MAP, despite comparable increases in arterial stiffness in both sexes. The difference was driven by a greater contribution of MAP to the forward component of the pressure wave in women.

Fluid-solid coupling model and analysis on pulse wave propagation properties of iliac artery

In this work, we investigated the influence of the bifurcation geometry of the iliac artery on the propagation properties of the pulse wave, and applied software to establish the straight bifurcation and curved bifurcation bi-directional fluid-solid coupling finite element analysis models based on the iliac artery, and compared and analyzed the influence of the bifurcation angle of the blood vessel on the propagation characteristics of the pulse wave. It was found that the bifurcation geometry had a significant effect on the pulse wave propagation in the iliac arteries, and the pressure and velocity pulse wave amplitudes predicted by these two models had a good agreement with that before the vessel bifurcation in a cardiac cycle. The curvilinear bifurcation model predicted the pulse wave amplitude to be lower and the pressure drop to be smaller after the bifurcation, which was more in line with the actual situation of the human body. In addition, the bifurcation point is accompanied by the stress concentration phenomenon in the vessel wall, and there is a transient increase in the velocity pulse waveform amplitude, which was consistent with the fact that the bifurcation site is prone to phenomena such as arterial stenosis and hardening. The preliminary results of this paper will provide some reference for the use of pulse waveforms in the diagnosis of arterial diseases.

Correlation between the cardiometabolic index and arteriosclerosis in patients with type 2 diabetes mellitus

BackgroundThe cardiometabolic index (CMI) is a new metric derived from the triglyceride-glucose index and body mass index and is considered a potential marker for cardiovascular risk assessment. This study aimed to examine the correlation between the CMI and the presence and severity of arteriosclerosis in patients with type 2 diabetes mellitus (T2DM).MethodsThis study involved 2243 patients with T2DM. The CMI was derived by dividing the triglyceride level (mmol/L) by the high-density lipoprotein level (mmol/L) and then multiplying the quotient by the waist-to-height ratio. Multivariate logistic regression was used to analyze the correlations between the CMI and BMI blood biomarkers, blood pressure, and brachial-ankle pulse wave velocity (baPWV).ResultsPatients were categorized into three groups based on their CMI: Group C1 (CMI < 0.775; n = 750), Group C2 (CMI: 0.775–1.355; n = 743), and Group C3 (CMI > 1.355; n = 750). Increased BMI, fasting glucose, insulin (at 120 min), total cholesterol (TC), and baPWV values were observed in Groups C2 and C3, with statistically significant trends (all trends P < 0.05). The CMI was positively correlated with systolic blood pressure (r = 0.74, P < 0.001). Multivariate analysis revealed that an increased CMI contributed to a greater risk for arteriosclerosis (OR = 1.87, 95%CI: 1.66–2.10, P < 0.001). Compared to the C1 group, the C2 group and C3 group had a greater risk of developing arteriosclerosis, with ORs of 4.55 (95%CI: 3.57–5.81, P<0.001) and 5.56 (95%CI: 4.32–7.17, P<0.001), respectively. The association was notably stronger in patients with a BMI below 21.62 kg/m² than in those with a BMI of 21.62 kg/m² or higher (OR = 4.53 vs. OR = 1.59).ConclusionsThese findings suggest that the CMI is a relevant and independent marker of arteriosclerosis in patients with T2DM and may be useful in the risk stratification and management of these patients.

An innovative approach for assessing coronary artery lesions: Fusion of wrist pulse and photoplethysmography using a multi-sensor pulse diagnostic device

Coronary heart disease (CHD) is a leading cause of mortality globally and poses a significant threat to public health. Coronary angiography (CAG) is a gold standard for the clinical diagnosis of CHD, but its invasiveness restricts its widespread application. In this study, we utilized a pulse diagnostic device equipped with pressure and photoelectric sensors to synchronously and non-invasively capture wrist pressure pulse waves and fingertip photoplethysmography (FPPG) of patients undergoing CAG. The extracted features were utilized in constructing random forest-based models to assessing the severity of coronary artery lesions. Notably, Model 3, incorporating both wrist pulse and FPPG features, surpassed Model 1 (solely utilizing wrist pulse features) and Model 2 (solely utilizing FPPG features). Model3 achieved an Accuracy, Precision, Recall, and F1-score of 78.79%, 78.69%, 78.79%, and 78.70%, respectively. Compared to Model1 and Model2, Model 3 exhibited improvements by 4.55%, 5.25%, 4.55%, and 5.12%, and 6.06%, 6.58%, 6.06%, and 6.54% respectively. This fusion of wrist pulse and FPPG features in Model 3 highlights the advantages of multi-source information fusion for model optimization. Additionally, this research provides invaluable insights into the novel development of diagnostic devices imbued with TCM principles and their potential in managing cardiovascular diseases.

Real-time tracking of radial artery vessel wall using a Kalman filter-based ultrasound single-plane wave RF signal time-frequency information fusion algorithm

ObjectiveThe goal of our study was to achieve real-time dynamic tracking of the radial artery vessel wall in everyday life, which is crucial for blood pressure estimation and cardiovascular disease prediction. MethodsThe algorithm integrates time–frequency information from ultrasound single-plane wave RF (radiofrequency) signals and consists of three main components: feature frame ROI (region of interest) selection, inter-frame cross-correlation and intra-frame autocorrelation, and feature frame Kalman filtering. ResultsExperimental validation on a silicone gel ultrasound phantom with simulated blood vessels demonstrates an average diameter estimation error of less than 0.5% compared to ground truth values. Comparative experiments show similar relative errors (2.83%, 2.43%) to the optical flow method, with a computational speed 7.32 times faster. The algorithm accurately aligns extracted pulse waves with pressure pulse waves at six local feature points per cycle. ConclusionThe proposed method achieves a favorable balance between speed and accuracy in tracking the radial artery vessel wall. It holds significant potential for real-time monitoring of physiological health parameters, offering precise and dynamic tracking capabilities. SignificanceThis algorithm addresses the challenges of non-invasive real-time tracking, benefiting blood pressure estimation and cardiovascular disease prediction. Its integration of time–frequency information and efficient computational speed make it valuable for the scientific community and public in monitoring physiological health parameters.

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 parameters for atherosclerosis, taking into consideration blood's dynamic viscosity and compressibility. Pressure and velocity pulse-wave propagation were investigated through the application of a 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 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.

Experimental Studies of Hydrodynamic and Energy Characteristics of a High-Voltage Electrochemical Explosion in Limited Liquid Volumes

In this paper, the dependence of the charging voltage, stored electrical energy, and the mass of the combusted exothermic mixture on electrical, energy and hydrodynamic characteristics of a high-voltage electrochemical explosion (HVEE) in limited volumes of liquid on is experimentally studied. A comparison with other methods of initiating an electric discharge under similar conditions was made. The results established that the HVEE makes it possible to carry out a high-voltage electric discharge with low energy losses (less than 9%) and to realize an electrical breakdown mode close to aperiodic. It has been found that HVEE can generate pressure waves with an amplitude up to 37% and a pulse up to 45% larger (at a charging voltage of 25 kV or higher) than that of an electric explosion of an initiating metallic conductor of optimum length under the same initial conditions. It was found that an increase in the charging voltage leads to an increase in the amplitude and pulse of the generated pressure wave along a linear dependence. A compre-hensive analysis of the dependences of the energy and hydrodynamic characteristics showed that the main influence on the formation of the pressure wave pulse during the HVEE is provided by both the stored electrical energy and the interconnection between the electrical parameters of the discharge circuit and the mass of the burning exothermic mixture, which determines the shape of the discharge characteristics.

Sex Differences in Heart Rate Variability and Vascular Function Following High-Intensity Interval Training in Young Adults.

High-intensityintervaltraining (HIIT) issuperiortoothertrainingstrategies in both male andfemalehealthyindividuals. Understanding sex-specificdifferences in cardiac auto-regulation maycontributetothe optimal trainingstrategiesfor HIIT. The presentstudyaimedtoidentifysexdifferences in heart rate variability (HRV) andvascularfunctionfollowing HIIT in youngadults. Twenty-fourphysicallyactiveyoung male andfemaleadults (M: 12, F: 12, age: 19.5 yr, BMI: 22.1 kg·m-2) volunteeredtoparticipate in thestudy. Participantsperformed 10 boutsof HIIT including 20 s of high-intensitycycling at 115-130% Wmaxfollowedby 100 s ofrecovery. The cardiac auto-regulationsincluding HRV andvascularfunctionweremeasured at five different time points. The R-R interval, rMSSD, and SDNN wererecoveredfaster in malesthan in females after 15 min of HIIT. Thereweresexdifferences in theautonomicnervoussystemwhereln LF andln HF activitiesalongwithsympathovagalbalance (ln LF/HF) weregreater in femalescomparedwithmalesimmediatelyand 15 min after HIIT. However, nosignificantdifferences in bloodpressureand brachial-ankle pulse wavevelocitywereobservedbetween male andfemaleparticipants. Overall, HRV was moreactivated in femalesthan in malesfollowing HIIT, but theacuteresponse in vascularfunction was not different betweensexes. In futurestudies, sex-specificadaptationsofcardiacautoregulationfollowingrepeated HIIT mayneedtobeperformed.

Antihypertensive treatment with hydrochlorothiazide-hydralazine combination aggravates medial vascular calcification in CKD rats with mineral bone disorder.

Arterial stiffness and medial vascular calcification, leading to isolated systolic blood pressure (BP), are major cardiovascular risk factors in patients with chronic kidney disease (CKD) and mineral bone disorders (MBD). The impact of BP on MBD-induced medial vascular calcification in CKD remains uncertain. We investigated whether BP reduction improves arterial stiffness and medial vascular calcification in a rat model of CKD-MBD. CKD was induced in Wistar rats by subtotal nephrectomy. Then, MBD was generated by a Ca/P-rich diet with calcitriol supplementation to induce medial vascular calcification. Two antihypertensive treatments were evaluated: (1) the angiotensin AT1 receptor antagonist losartan, and (2) the combination of the thiazide diuretic hydrochlorothiazide and the direct vasodilator hydralazine (HCTZ/HY). After 5 weeks, mean BP (MBP), pulse pressure (PP), and pulse wave velocity (PWV) were determined. Vascular calcification was assessed in the thoracic aorta. While MBP was similar in CKD-MBD and control CKD rats, PP and PWV were increased in CKD-MBD rats. The heightened arterial stiffness in CKD-MBD rats was associated with diffused medial calcification along the thoracic aorta. Although both losartan and HCTZ/HY reduced MBP in CKD-MBD rats, losartan did not affect PP and PWV nor medial vascular calcification, whereas HCTZ/HY, unexpectedly, further increased arterial stiffness and medial vascular calcification. In the rat model of CKD-MBD, antihypertensive treatment with losartan did not affect arterial stiffness or medial vascular calcification. However, HCTZ/HY treatment aggravated arterial stiffness and vascular calcification despite a similar reduction of MBP, suggesting a blood pressure-independent mechanism for vascular calcification.

Cuffless Blood Pressure Measurement Using Smartwatches: A Large-Scale Validation Study.

This study aimed to evaluate the performance of cuffless blood pressure (BP) measurement techniques in a large and diverse cohort of participants. We enrolled 3077 participants (aged 18-75, 65.16% women, 35.91% hypertensive participants) and conducted followed-up for approximately 1 month. Electrocardiogram, pulse pressure wave, and multiwavelength photoplethysmogram signals were simultaneously recorded using smartwatches; dual-observer auscultation systolic BP (SBP) and diastolic BP (DBP) reference measurements were also obtained. Pulse transit time, traditional machine learning (TML), and deep learning (DL) models were evaluated with calibration and calibration-free strategy. TML models were developed using ridge regression, support vector machine, adaptive boosting, and random forest; while DL models using convolutional and recurrent neural networks. The best-performing calibration-based model yielded estimation errors of 1.33 ± 6.43 mmHg for DBP and 2.31 ± 9.57 mmHg for SBP in the overall population, with reduced SBP estimation errors in normotensive (1.97 ± 7.85 mmHg) and young (0.24 ± 6.61 mmHg) subpopulations. The best-performing calibration-free model had estimation errors of -0.29 ± 8.78 mmHg for DBP and -0.71 ± 13.04 mmHg for SBP. We conclude that smartwatches are effective for measuring DBP for all participants and SBP for normotensive and younger participants with calibration; performance degrades significantly for heterogeneous populations including older and hypertensive participants. The availability of cuffless BP measurement without calibration is limited in routine settings. Our study provides a large-scale benchmark for emerging investigations on cuffless BP measurement, highlighting the need to explore additional signals or principles to enhance the accuracy in large-scale heterogeneous populations.