Vessel Stiffness Research Articles

A Multiscale Mathematical Model for the Fetal Blood Circulation of the Second Half of Pregnancy.

Doppler ultrasound is a commonly used method to assess hemodynamics of the fetal cardiovascular system and to monitor the well-being of the fetus. Indices based on the velocity profile are often used for diagnosis. However, precisely linking these indices to specific underlying physiology factors is challenging. Several influences, including wave reflections, fetal growth, vessel stiffness, and resistance distal to the vessel, contribute to these indices. Understanding these data is essential for making informed clinical decisions. Mathematical models can be used to investigate the relation between velocity profiles and physiological properties. This study presents a mathematical model designed to simulate velocity wave propagation throughout the fetal cardiovascular system, facilitating the assessment of factors influencing velocity-based indices. The model combines a one-fiber model of the heart with a 1D wave propagation model describing the larger vessels of the circulatory system and a lumped parameter model for the microcirculation. Fetal growth from 20 to 40 weeks of gestational age is incorporated by adjusting cardiac and circulatory parameter settings according to scaling laws. The model's results, including cardiac function, cardiac output distribution, and volume distribution, show a good agreement with literature studies for a growing healthy fetus from 20 to 40 weeks. In addition, Doppler indices are simulated in various vessels and agree with literature as well. In conclusion, this study introduces a novel closed-loop 0D-1D mathematical model that has been verified against literature studies. This model offers a valuable platform for analyzing factors influencing velocity-based indices in the fetal cardiovascular system.

A comparative study of postadrenalectomy hyperuricemia and renal impairment in patients with unilateral primary aldosteronism: does histopathology subtype matter?

BackgroundPrimary aldosteronism (PA), which is present in 5–18% of hypertensive patients, is a leading cause of secondary hypertension. Adrenalectomy is often recommended for patients with unilateral primary aldosteronism (uPA), yielding good long-term outcomes. PA patients without hyperuricemia and chronic renal failure before adrenalectomy were enrolled in this cohort study. Serum uric acid (SUA) and renal filtration were measured one year post-adrenalectomy. Their relationships with pathologic features, histopathological subtype (classical or nonclassical (HISTALDO consensus)), and vessel stiffness were explored. The aim of this cohort study is to evaluate the correlation between post-adrenalectomy serum uric acid (SUA) levels and estimated glomerular filtration rate (eGFR) with the pathologic features delineated by the HISTALDO consensus. Additionally, the study seeks to assess the impact of these biochemical markers on peripheral vessel stiffness and brachial-ankle pulse wave velocity (baPWV) at a one-year follow-up visit.MethodsThis prospective cohort study included patients (N = 100) diagnosed with uPA who underwent adrenalectomy from Jan 1, 2007 to Dec 31, 2022.ResultsAt follow-up, elevated SUA, hyperuricemia, and a > 25% eGFR decrease were significantly more common in the classical than the nonclassical group. The incidence of postoperative hyperuricemia, herein referred to as post-adrenalectomy hyperuricemia (PAHU), was 29% (29/100) overall, 34.8% (23/66) in the classical group and 17.6% (6/34) in the nonclassical group. The incidence of eGFR reduction > 25% was 33% (33/100), 43.9% (29/66), and 11.8% (4/34), respectively. baPWV decreased more in the classical group than the nonclassical group.ConclusionFor PA patients with PAHU and/or renal impairment, we suggest monitoring SUA, pH, urine uric acid, and urine crystals and performing a KUB study and peripheral vascular and renal sonography (on which pure uric acid stones in the KUB are radiolucent) to determine whether drug intervention is required for cases of asymptomatic PAHU, especially patients in male gender, classical histopathology, or renal impairment.

Pulse transmission time and amplitude of digital pulse wave determined by fingertip plethysmography as a surrogate marker of brachial artery flowmediated dilatation.

To assess the changes in blood vessel stiffness and digital pulse wave amplitude because of flowmediated dilatation, and to explore how these two variables change when endothelial dysfunction is experimentally induced. The experimental study was conducted at the departments of physiology at the College of Medicine, Mustansiriyah University, and the College of Medicine, Al-Iraqia University, Baghdad, Iraq, from October 14, 2021, to May 31, 2022, and comprised healthy young males who were subjected to the flow-mediated dilatation technique on the left brachial artery. Pulse transit time and the amplitude of the digital pulse wave were measured during reactive hyperaemia for 2.5 minutes from the left middle finger using a piezoelectric pressure sensor and a simultaneous Lead I electrocardiogram. Endothelial dysfunction (ED) was induced by oscillatory and retrograde shear rates. The correlation between variables was calculated in Excel running on the Windows operating system. There were 10 second-year medical students with mean age 22±0 years and mean body mass index 25.7±4.8kg/m2. During reactive hyperaemia, pulse transit time was significantly increased by 3-5% in both normal endothelium and experimentally induced endothelial dysfunction relative to the pre-occluded artery, and the difference was not significant (p>0.05). Digital pulse wave amplitude increased significantly in normal endothelium relative to the pre-occluded artery (p<0.05), but not in experimentally-induced endothelial dysfunction (p>0.05). The pulse transit time and digital pulse wave amplitudes of the photo plethysmography signal may be used to detect changes in vessel wall diameter and tone throughout the reactive hyperaemia process. Digital pulse wave amplitude was better able to detect experimentally-induced endothelial dysfunction, as assessed by the flowmediated dilatation protocol, than pulse transit time.

Assessment of modifiable risk factors and vascular wall stiffness in young people

Objective: to study the characteristics of vascular stiffness in young people, taking into account the presence of the main modifiable risk factors (FR) for the development of cardiovascular diseases (CVD). Materials and methods: a survey was conducted of 38 practically healthy young people (18 boys, 20 girls) — university students, whose average age was 19.8±1.45 years. By filling in the modified diagnostic charts, the subjects assessed the presence of the main behavioral CVD disorders. Volumetric sphygmography on the VaSera-1000 device (Fukuda Denschi, Japan) was used to assess the stiffness of the main vessels and blood pressure (BP) levels in the basins of the upper and lower extremities. Results: in the examined individuals, despite their young age and the documented absence of cardio-vascular pathology, all the main cardiovascular diseases were revealed: an increased body mass index (BMI≥25 kg/m2), smoking, psychosocial factors, sedentary lifestyle, unbalanced diet, alcohol consumption, which were present in various combinations. Vascular stiffness indices — the cardio-ankle index and the biological age of the vessels — were within the normal range, while the ankle-shoulder index was reduced in 24% of the students. Conclusion: the results obtained indicate the need for primary prevention of CVD by lifestyle modification, even in young people, since the FR detected in them and the tendency to change vascular stiffness indicators can subsequently act as triggers for the early onset of diseases of the circulatory system

Transcriptomic and Multi-scale Network Analyses Reveal Key Drivers of Cardiovascular Disease.

Cardiovascular diseases (CVDs) and pathologies are often driven by changes in molecular signaling and communication, as well as in cellular and tissue components, particularly those involving the extracellular matrix (ECM), cytoskeleton, and immune response. The fine-wire vascular injury model is commonly used to study neointimal hyperplasia and vessel stiffening, but it is not typically considered a model for CVDs. In this paper, we hypothesize that vascular injury induces changes in gene expression, molecular communication, and biological processes similar to those observed in CVDs at both the transcriptome and protein levels. To investigate this, we analyzed gene expression in microarray datasets from injured and uninjured femoral arteries in mice two weeks post-injury, identifying 1,467 significantly and differentially expressed genes involved in several CVDs such as including vaso-occlusion, arrhythmia, and atherosclerosis. We further constructed a protein-protein interaction network with seven functionally distinct clusters, with notable enrichment in ECM, metabolic processes, actin-based process, and immune response. Significant molecular communications were observed between the clusters, most prominently among those involved in ECM and cytoskeleton organizations, inflammation, and cell cycle. Machine Learning Disease pathway analysis revealed that vascular injury-induced crosstalk between ECM remodeling and immune response clusters contributed to aortic aneurysm, neovascularization of choroid, and kidney failure. Additionally, we found that interactions between ECM and actin cytoskeletal reorganization clusters were linked to cardiac damage, carotid artery occlusion, and cardiac lesions. Overall, through multi-scale bioinformatic analyses, we demonstrated the robustness of the vascular injury model in eliciting transcriptomic and molecular network changes associated with CVDs, highlighting its potential for use in cardiovascular research.

Evaluation of carotid artery elasticity and its influencing factors in non-obese PCOS patients using a technique for quantitative vascular elasticity measurement.

To evaluate the intima-media thickness (IMT) and elasticity of the carotid artery in non-obese polycystic ovary syndrome (PCOS) patients using a quantitative technique for vascular elasticity measurement and to explore the influencing factors. Sixty non-obese patients without metabolic and cardiovascular diseases who were diagnosed with PCOS in the Women and Children's Hospital of Chongqing Medical University from January to December 2022 were prospectively selected (case group), and 60 healthy volunteers matched for body mass index were included as the control group. Body weight, height, heart rate, blood pressure, and waist-to-hip ratio were recorded. Fasting blood samples were drawn from the elbow vein to measure hormone levels including total testosterone (TT), sex hormone-binding globulin (SHBG), fasting plasma glucose (FPG), fasting insulin (FINS), lipids, and homocysteine (Hcy). The insulin resistance index (HOMA-IR) and free androgen index (FAI) were calculated. Ultrasound elastography was used to measure the IMT and elastic function parameters of the right carotid artery, including vessel diameter, wall displacement, stiffness coefficient, and pulse wave velocity. Differences in various parameters between the two groups were analyzed, and correlations between the carotid stiffness coefficient and other serological indicators were assessed using Spearman correlation analysis. No significant differences in age, body mass index, heart rate, systolic blood pressure, and diastolic blood pressure were observed between the two groups (all P>0.05), while the waist-to-hip ratio (WHR) was higher in the case group than in the control group (P<0.05).The hormone level serological indicators TT and FAI were higher in the case group than in the control group, and SHBG was lower in the case group than in the control group (all P<0.05). The metabolism-related serum indicators LDL-C, HDL-C, FPG, triglycerides, and total cholesterol levels were not statistically different between the two groups (all P>0.05), and serum FINS, HOMA-IR, and Hcy levels were significantly higher in the case group than in the control group (all P<0.05).No significant difference in carotid artery diameter was observed between the case group and control group (P>0.05). The carotid artery displacement in the case group was significantly smaller than that in the control group (P<0.05), and carotid IMT, hardness coefficient, and pulse wave propagation velocity were greater in the case group than in the control group (all P<0.05). The carotid elastic stiffness coefficient was positively correlated with WHR, TT, SHBG, FAI, FINS, HOMA-IR and Hcy to varying extents and negatively correlated with SHBG. In non-obese PCOS patients with no metabolic or cardiovascular disease, the carotid stiffness coefficient was increased and correlated with indicators of hyperandrogenism, insulin resistance, and hyperhomocysteinemia.

P229 INFLUENCE OF ASTHMA ON BLOOD PRESSURE OF CHILDREN AND ADOLESCENTS: THE ASMAVIX PROJECT

Background and Objectives: Asthma is a prevalent disease in children and the chronic inflammatory may affect blood vessel stiffness and blood pressure (BP). Systolic BP increases progressively along the childhood tending to reach stable values at the beginning of adulthood. Higher BP levels in infancy predispose to hypertension development hypertension in adulthood. Our aim was to investigate the influence of asthma on the age-dependent BP increase in children and adolescents. Methods Asthmatic (Asth, n = 166), 7-15 years (67% boys) attending to Public Health Units of Vitória (an industrialized city of the coastal plain of southeastern Brazil) were included. Non-asthmatic children (N-Asth, n =50; 33% boys) living in the neighborhood of Asth were used as controls. Clinic and laboratory exams were performed in an outpatient clinic at the University Hospital. BP was measured with an oscillometric device (Onrom HBP 1100) and large artery stiffness was estimated by carotid-to-femoral pulse wave velocity (cf-PWV; Complior SP-2). The 90th percentile of systolic or diastolic BP was used to identify high BP considering gender, age, and height. Age-dependent BP increase was determined by linear regression with and without adjustment for covariates (gender and body mass index). Statistical significance was set at p&lt;0.05. Results Asth and N-Asth groups were similar (p&gt;0.05) considering age (11.7 ± 2.3 vs 11.1 ± 2.1 years), body mass index (20.2 ± 4.2 vs 20.3 ± 5.7 kg/m2), systolic (102 ± 11 vs 104 ± 10 mmHg) and diastolic (62 ± 7 vs 63 ±8 mmHg) BP. However, cf-PWV was higher in Asth (48.9 ± 9.0 vs 44.0 ± 9.1 cm/s; p&lt;0.01). The crude age-dependent systolic BP increase was 34% higher in the Asth group (1.74 mmHg/year; 95%CL 1.06;2.43 vs 1.37 mmHg/year; 95% CL 0.02;2.72). This difference remained similar after adjusting for gender and body mass index (1.47 mmHg/year; 95%CL 0.80; 2.14 vs 1.10; -0.47;2.67). The percentage of children with elevated BP was higher in the Asth group (10.2% vs 4.0%). Conclusion: The higher stiffness of large arteries seems to accelerate the systolic BP increase along childhood and adolescence and may predispose to an earlier onset of hypertension in adulthood. Acknowledgment: This study was supported with grants from ArcelorMittal, CNPq and Fapes.

Pulse Wave Velocity: Methodology, Clinical Applications, and Interplay with Heart Rate Variability.

Pulse wave velocity (PWV) has been established as a promising biomarker in cardiovascular diagnostics, providing deep insights into vascular health and cardiovascular risk. Defined as the velocity at which the mechanical wave propagates along the arterial wall, PWV represents a useful surrogate marker for arterial vessel stiffness. PWV has garnered clinical attention, particularly in monitoring patients suffering from vascular diseases such as hypertension and diabetes mellitus. Its utility extends to preventive cardiology, aiding in identifying and stratifying cardiovascular risk. Despite the development of various measurement techniques, direct or indirect tonometry, Doppler ultrasound, oscillometric analysis, and magnetic resonance imaging (MRI), methodological variability and lack of standardization lead to inconsistencies in PWV assessment. In addition, PWV can be estimated through surrogate parameters, such as pulse arrival or pulse transit times, although this heterogeneity limits standardization and, therefore, its clinical use. Furthermore, confounding factors, such as variations in sympathetic tone, strongly influence PWV readings, thereby necessitating careful control during assessments. The bidirectional relationship between heart rate variability (HRV) and PWV underscores the interplay between cardiac autonomic function and vascular health, suggesting that alterations in one could directly influence the other. Future research should prioritize the standardization and increase comparability of PWV measurement techniques and explore the complex physiological variables influencing PWV. Integrating multiple physiological parameters such as PWV and HRV into algorithms based on artificial intelligence holds immense promise for advancing personalized vascular health assessments and cardiovascular care.

Activity and function of the endothelial sodium channel is regulated by the effector domain of MARCKS like protein 1 in mouse aortic endothelial cells.

The endothelial sodium channel (EnNaC) plays an important role in regulating vessel stiffness. Here, we investigated the regulation of EnNaC in mouse aortic endothelial cells (mAoEC) by the actin cytoskeleton and lipid raft association protein myristoylated alanine-rich C-kinase substrate like protein 1 (MLP1). We hypothesized that mutation of specific amino acid residues within the effector domain of MLP1 or loss of association between MLP1 and the anionic phospholipid phosphate PIP2 would significantly alter membrane association and EnNaC activity in mAoEC. mAoEC transiently transfected with a mutant MLP1 construct (three serine residues in the effector domain replaced with aspartate residues) showed a significant decrease in EnNaC activity compared to cells transfected with wildtype MLP1. Compared to vehicle treatment, mAoEC treated with the PIP2 synthesis blocker wortmannin showed less colocalization of EnNaC and MLP1. In other experiments, Western blot and densitometric analysis showed a significant decrease in MLP1 and caveloin-1 protein expression in mAoEC treated with wortmannin compared to vehicle. Finally, wortmannin treatment decreased sphingomyelin content and increased membrane fluidity in mAoEC. Taken together, our results suggest constitutive phosphorylation of MLP1 attenuates the function of EnNaC in aortic endothelial cells by a mechanism involving a decrease in association with MLP1 and EnNaC at the membrane, while deletion of PIP2 decreases MARCKS expression and overall membrane fluidity.

Oxidative DNA damage promotes vascular aging associated with changes in extracellular matrix-regulating proteins.

Vascular aging is characterized by vessel stiffening, with increased deposition of extracellular matrix (ECM) proteins including collagens. Oxidative DNA damage occurs in vascular aging, but how it regulates ECM proteins and vascular stiffening is unknown. We sought to determine the relationship between oxidative DNA damage and ECM regulatory proteins in vascular aging. We examined oxidative DNA damage, the major base excision repair (BER) enzyme 8-Oxoguanine DNA Glycosylase (Ogg1) and its regulators, multiple physiological markers of aging, and ECM proteomics in mice from 22-72w. Vascular aging was associated with increased oxidative DNA damage, and decreased expression of Ogg1, its active acetylated form, its acetylation regulatory proteins P300 and CBP, and the transcription factor Foxo3a. Vascular stiffness was examined in vivo in control, Ogg1-/-, or mice with vascular smooth muscle cell-specific expression of Ogg1+ (Ogg1) or an inactive mutation (Ogg1KR). Ogg1-/- and Ogg1KR mice showed reduced arterial compliance and distensibility, and increased stiffness and pulse pressure, whereas Ogg1 expression normalised all parameters to 72w. ECM proteomics identified major changes in collagens with aging, and downregulation of the ECM regulatory proteins Protein 6-lysyl oxidase (LOX) and WNT1-inducible-signaling pathway protein 2 (WISP2). Ogg1 overexpression upregulated LOX and WISP2 both in vitro and in vivo, and downregulated Transforming growth factor β1 (TGFb1) and Collagen 4α1 in vivo compared with Ogg1KR. Foxo3a activation induced Lox, while Wnt3 induction of Wisp2 also upregulated LOX and Foxo3a, and downregulated TGFβ1 and fibronectin 1. In humans, 8-oxo-G increased with vascular stiffness, while active OGG1 reduced with both age and stiffness. Vascular aging is associated with oxidative DNA damage, downregulation of major BER proteins, and changes in multiple ECM structural and regulatory proteins. Ogg1 protects against vascular aging, associated with changes in ECM regulatory proteins including LOX and WISP2.

Determinants of hand pulse wave velocity and hand pulse transit time in healthy adults

Arterial pulse wave velocity (PWV) is recognized as a convenient method to assess peripheral vascular stiffness. This study explored the clinical characteristics of hand PWV (hPWV) and hand pulse transit time (hPTT) in healthy adults (sixty males = 42.4 ± 13.9 yrs; sixty-four females = 42.8 ± 13.9 yrs) voluntarily participated in this study. The arterial pulse waveform and the anatomical distance from the radial styloid process to the tip of the middle finger of both hands were recorded in the sitting position. The hPWV was calculated as the traversed distance divided by hPTT between those two points. Male subjects showed significantly greater hPWV, systolic blood pressure, and pulse pressure than age-matched female subjects, while the hPTT was not significantly different between genders. Multiple linear regression analysis showed that gender is a common determinant of hPWV and hPTT, and that age and heart rate (HR) were negatively correlated with hPWV and hPTT, respectively. We conclude that male subjects have greater hPWV than female subjects. Ageing is associated with decreased hPWV, while increased HR is associated with a smaller hPTT. The hPWV and hPTT might be used as non-invasive indices to characterise the ageing and arterial stiffness of peripheral blood vessels.

Flexural pulse wave velocity in blood vessels.

Arteriosclerosis is a major risk factor for cardiovascular disease and results in arterial vessel stiffening. Velocity estimation of the pulse wave sent by the heart and propagating into the arteries is a widely accepted biomarker. This symmetrical pulse wave propagates at a speed which is related to the Young's modulus through the Moens Korteweg (MK) equation. Recently, an antisymmetric flexural wave has been observed in vivo. Unlike the symmetrical wave, it is highly dispersive. This property offers promising applications for monitoring arterial stiffness and early detection of atheromatous plaque. However, as far as it is known, no equivalent of the MK equation exists for flexural pulse waves. To bridge this gap, a beam based theory was developed, and approximate analytical solutions were reached. An experiment in soft polymer artery phantoms was built to observe the dispersion of flexural waves. A good agreement was found between the analytical expression derived from beam theory and experiments. Moreover, numerical simulations validated wave speed dependence on the elastic and geometric parameters at low frequencies. Clinical applications, such as arterial age estimation and arterial pressure measurement, are foreseen.

Prepregnancy physiology and subsequent preterm preeclampsia

BackgroundPreeclampsia is a common pregnancy complication with debated etiology. ObjectiveTo evaluate the contribution of prepregnancy physiology, biochemistry and anthropometrics to the subsequent development of preterm preeclampsia. Study DesignOne-hundred twenty-four participants were recruited through open recruitment and targeted mailings. Participants included 81 nulliparous women and 43 with a history of preterm preeclampsia. We characterized cardiovascular function, metabolic profile, and body composition in 100 non-pregnant women who went on to subsequent pregnancy. Measures included plasma volume, baseline cardiovascular function and cardiovascular response to volume challenge, body composition and circulating biochemical measures. Pregnancy outcome was obtained through chart review. Prepregnancy metrics for women who developed preterm preeclampsia were compared with measurements for those who did not, with adjustment for a history of prior preterm preeclampsia. Logistic regression modeling was used to identify the strongest prepregnancy factors associated with preterm preeclampsia. ResultsPregnancy outcomes included 11 women with preterm preeclampsia, 7 women with term preeclampsia, 20 women with other hypertension affecting their pregnancy, and 62 with uncomplicated pregnancies. We observed no difference in maternal age, study cycle day, lean body mass, uterine hemodynamics, or flow mediated dilation across groups. Women with preterm preeclampsia had greater android fat content 3215+1143 vs. 1918+1510 grams (p=0.002), faster supine pulse, 77+7 vs. 67+10 beats per minute (p=0.001), higher supine diastolic blood pressure 82+6 vs. 68+6 mmHg (p< 0.001), increased cardiac output 5.6+1.1 vs. 4.6+1 L/min (p=0.002), faster aortic-popliteal pulse wave velocity 4.5+0.7 vs. 3.8+0.5 m/sec (p<0.001), and exaggerated cardiac output response to volume challenge 20+9 vs. 9+12 L/min (p=0.002) compared to those with other pregnancy outcomes. Women who developed preterm preeclampsia also had reduced renal vascular resistance index 0.86+0.08 vs. 0.97+0.12 (p=0.005) compared with other pregnancy outcomes when assessed prior to pregnancy. Women with subsequent preterm preeclampsia had higher serum c-reactive protein 10.7+12.5 vs. 4.1+5.8mg/mL (p=0.003) and greater insulin resistance, as assessed by HOMA-IR calculation 2.2+1.1 vs. 1.2+0.9 (p<0.001). ConclusionPrepregnancy physiology is linked to subsequent preterm preeclampsia. The same factors associated with metabolic syndrome are more prominent in patients who develop preterm pre-eclampsia than those who do not, including increased vessel stiffness, low vascular compliance, high cardiac output, reduced renal vascular resistance index, insulin resistance and increased android fat, all consistent with subclinical features of the metabolic syndrome.

Customisable Silicone Vessels and Tissue Phantoms for In Vitro Photoplethysmography Investigations into Cardiovascular Disease.

Age-related vessel deterioration leads to changes in the structure and function of the heart and blood vessels, notably stiffening of vessel walls, increasing the risk of developing cardiovascular disease (CVD), which accounts for 17.9 million global deaths annually. This study describes the fabrication of custom-made silicon vessels with varying mechanical properties (arterial stiffness). The primary objective of this study was to explore how changes in silicone formulations influenced vessel properties and their correlation with features extracted from signals obtained from photoplethysmography (PPG) reflectance sensors in an in vitro setting. Through alterations in the silicone formulations, it was found that it is possible to create elastomers exhibiting an elasticity range of 0.2 MPa to 1.22 MPa. It was observed that altering vessel elasticity significantly impacted PPG signal morphology, particularly reducing amplitude with increasing vessel stiffness (p < 0.001). A p-value of 5.176 × 10-15 and 1.831 × 10-14 was reported in the red and infrared signals, respectively. It has been concluded in this study that a femoral artery can be recreated using the silicone material, with the addition of a softener to achieve the required mechanical properties. This research lays the foundation for future studies to replicate healthy and unhealthy vascular systems. Additional pathologies can be introduced by carefully adjusting the elastomer materials or incorporating geometrical features consistent with various CVDs.

Assessment of the Stiffness of Small Arterial Vessels of Superficial Biotissues and Their Spectral-Temporal Diffuse Light Reflection Profiles

Assessment of the Stiffness of Small Arterial Vessels of Superficial Biotissues and Their Spectral-Temporal Diffuse Light Reflection Profiles

Acupressure Therapy for Chronic Pain in Elderly Patient with Hypertension Stage II: A Case Study

In the aging process, various changes occur regarding biology, cognition, and psychosocial life. The elderly are easily affected by diseases such as non-communicable (degenerative) diseases such as hypertension. As a result of aging, it can reduce the elasticity of the blood vessel walls and cause stiffness in the blood vessels; as a result, blood pressure in the elderly tends to increase. This study aims to determine the impact of applying acupressure therapy to chronic pain problems in the elderly. The research method used in this study was a descriptive case study. The research was conducted for five days on one patient with hypertension and chronic pain at an Elderly Residential Home. Acupressure therapy was carried out once a day for 20 minutes. Evaluation of the implementation is given using the NRS pain scale. The result of Acupressure therapy showed that the level of chronic pain was decreased from the NRS scale 5 to the NRS scale 2, blood pressure 140/80 mmHg, pulse rate 85 x/minutes, respiration rate 18 times per minute, and SpO2 96. This study recommends that acupressure therapy can be applied to treat chronic pain in hypertension patients as a complementary therapy.

Carotid wave analysis in young adults with a history of adolescent anorexia nervosa: a case control study

BackgroundAnorexia nervosa (AN) is associated with abnormalities that may increase the risk of future cardiovascular disease. This study assessed the cardiovascular health of individuals who recovered from AN during adolescence by conducting wave power analysis.MethodsFormer AN patients discharged from the Royal Children’s and Monash Children’s Hospitals (N = 17) in Melbourne, Australia underwent ultrasound imaging of the right carotid artery. Wave power analysis was conducted to assess biomechanical interactions of the cardiovascular system. Patient measures were compared to healthy controls (N = 51).ResultsEighty-eight percent of the former AN patients and controls were female, aged approximately 25 years, with a healthy body mass index. Mean carotid flow and pulsatility index were not different between groups. Carotid arterial strain and distensibility were lower, and the wave speed and beta stiffness index higher in the former AN patients. Characteristic impedance was not different nor were the forward and backward wave amplitudes. However, wave reflection indices (ratios of backward-to-forward compression wave area, and wave-related effect on pressure and hydraulic power) were 12–18% lower in the former AN patients (p < 0.05).ConclusionsIncreased carotid artery stiffness and reduced wave reflection are evident in young adults who recovered from adolescent AN. This may relate to an adaptive process that helps to maintain or restore flow and characteristic impedance despite increased vessel stiffness, with this warranting future investigation.

Arterial stiffness assessment using PPG feature extraction and significance testing in an in vitro cardiovascular system

Cardiovascular diseases (CVDs) remain the leading cause of global mortality, therefore understanding arterial stiffness is essential to developing innovative technologies to detect, monitor and treat them. The ubiquitous spread of photoplethysmography (PPG), a completely non-invasive blood-volume sensing technology suitable for all ages, highlights immense potential for arterial stiffness assessment in the wider healthcare setting outside specialist clinics, for example during routine visits to a General Practitioner or even at home with the use of mobile and wearable health devices. This study employs a custom-manufactured in vitro cardiovascular system with vessels of varying stiffness to test the hypothesis that PPG signals may be used to detect and assess the level of arterial stiffness under controlled conditions. Analysis of various morphological features demonstrated significant (p < 0.05) correlations with vessel stiffness. Particularly, area related features were closely linked to stiffness in red PPG signals, while for infrared PPG signals the most correlated features were related to pulse-width. This study demonstrates the utility of custom vessels and in vitro investigations to work towards non-invasive cardiovascular assessment using PPG, a valuable tool with applications in clinical healthcare, wearable health devices and beyond.

Pulsatile microvascular cerebral blood flow waveforms change with intracranial compliance and age.

Diffuse correlation spectroscopy (DCS) is an optical method to measure relative changes in cerebral blood flow (rCBF) in the microvasculature. Each heartbeat generates a pulsatile signal with distinct morphological features that we hypothesized to be related to intracranial compliance (ICC). We aim to study how three features of the pulsatile rCBF waveforms: the augmentation index (AIx), the pulsatility index, and the area under the curve, change with respect to ICC. We describe ICC as a combination of vascular compliance and extravascular compliance. Since patients with Chiari malformations (CM) () have been shown to have altered extravascular compliance, we compare the morphology of rCBF waveforms in CM patients with age-matched healthy control (). AIx measured in the supine position was significantly less in patients with CM compared to healthy controls (). Since physiologic aging also leads to changes in vessel stiffness and intravascular compliance, we evaluate how the rCBF waveform changes with respect to age and find that the AIx feature was strongly correlated with age (, , and , ). These results suggest that the AIx measured in the cerebral microvasculature using DCS may be correlated to changes in ICC.

Ultrasound elastography to quantify average percent pressure-normalized strain reduction associated with different aortic endografts in 3D-printed hydrogel phantoms

ObjectiveStrain has become a viable index for evaluating abdominal aortic aneurysm stability after endovascular aneurysm repair (EVAR). In addition, literature has shown that healthy aortic tissue requires a degree of strain to maintain homeostasis. This has led to the hypothesis that too much strain reduction conferred by a high degree of graft oversizing is detrimental to the aneurysm neck in the seal zone of abdominal aortic aneurysms after EVAR. We investigated this in a laboratory experiment by examining the effects that graft oversizing has on the pressure-normalized strain (ερ+¯/pulse pressure [PP]) reduction using four different infrarenal EVAR endografts and our ultrasound elastography technique. Approximate graft oversizing percentages were 20% (30 mm phantom-graft combinations), 30% (28 mm phantom-graft combinations), and 50% (24 mm phantom-graft combinations). MethodsAxisymmetric, 10% by mass polyvinyl alcohol phantoms were connected to a flow simulator. Ultrasound elastography was performed before and after implantation with the four different endografts: (1) 36 mm polyester/stainless steel, (2) 36 mm polyester/electropolished nitinol, (3) 35 mm polytetrafluoroethylene (PTFE)/nitinol, and (4) 36 mm nitinol/polyester/platinum-iridium. Five ultrasound cine loops were taken of each phantom-graft combination. They were analyzed over two different cardiac cycles (end-diastole to end-diastole), yielding a total of 10 maximum mean principal strain (ερ+¯) values. ερ+¯ was divided by pulse pressure to yield pressure-normalized strain (ερ+¯/PP). An analysis of variance was performed for graft comparisons. We calculated the average percent ερ+¯/PP reduction by manufacturer and percent oversizing. These values were used for linear regression analysis. ResultsResults from one-way analysis of variance showed a significant difference in ερ+¯/PP between the empty phantom condition and all oversizing conditions for all graft manufacturers (F(3, 56) = 106.7 [graft A], 132.7 [graft B], 106.5 [graft C], 105.7 [graft D], P < .0001 for grafts A-D). There was a significant difference when comparing the 50% condition with the 30% and 20% conditions across all manufacturers by post hoc analysis (P < .0001). No significant difference was found when comparing the 20% and 30% oversizing conditions for any of the manufacturers or when comparing ερ+¯/PP values across the manufacturers according to percent oversize. Linear regression demonstrated a significant positive correlation between the percent graft oversize and the all-graft average percent ερ+¯/PP reduction (R2 = 0.84, P < .0001). ConclusionsThis brief report suggests that a 10% increase in graft oversizing leads to an approximate 5.9% reduction in ερ+¯/PP on average. Applied clinically, this increase may result in increased stiffness in axisymmetric vessels after EVAR. Further research is needed to determine if this is clinically significant.