Make my haemodynamic monitor GREEN: sustainable monitoring solutions.

Anaesthesiologists overwhelmingly favour pulse wave analysis techniques as their primary method to monitor cardiac output during high-risk noncardiac surgery. In patients with a radial arterial catheter in place, pulse wave analysis techniques have the advantage of instantly providing non-operator-dependent and continuous haemodynamic monitoring information. Green pulse wave analysis techniques working with any standard pressure transducer are as reliable as techniques requiring dedicated pressure transducers. They have the advantage of minimising plastic waste and related carbon dioxide emissions, and also significantly reducing hospital costs. The future integration of pulse wave analysis algorithms into multivariable bedside monitors, obviating the need for standalone haemodynamic monitors, could lead to wider use of haemodynamic monitoring solutions by further reducing their cost and carbon footprint.

Arteriovenous Oscillometric Plethysmography for Fistula Functional Testing.

INTRODUCTION: The aim of the presented prospective observational study was to evaluate the effect of fistula flow on peripheral wave morphology and pulse wave velocity by means of the oscillometric Vicorder®-device with the purpose of fistula surveillance. METHODS: Digitized and normalized curves of 53 haemodialysis patients at the fistula and non-fistula arm were analysed. Slope parameters and the areas under the curve of characteristic sections of pulse waves as well as the power spectrum of the pulse waves and their first and second derivatives were computed. Furthermore, the amplitude of volumetric change (AMP) was assessed. Duplex sonography served as a reference method. RESULTS: In the comprehensive set of novel pulse wave parameters significant inter-arm differences were demonstrated and a significant delay of the systolic maximum at the fistula arm in comparison to the non-fistula arm (204 ± 3.4 vs. 162 ± 5.3 ms, p < 0.001) was proven. Unexpectedly, pulse wave velocity apparently did not differ between both arms (7.85 vs. 8.05 m/s at the fistula/non-fistula side, p = 0.942). The inter-arm differences of the slope parameters were more pronounced in forearm than in upper arm fistulas. Finally, we showed that the inter-arm difference of AMP correlated with volume flow (r = 0.326 with p = 0.017). CONCLUSION: Pulse waves as assessed by oscillometric pulse wave analysis have distinct features at fistula and non-fistula arms. This is due to enhanced arteriovenous flow, i.e. in both the brachial artery and the fistula vein. The analysis of those alterations has the potential to assess fistula function.

Association of cardiorespiratory fitness level with vascular function and subclinical atherosclerosis in the elderly.

PURPOSE: Physical exercise is crucial for healthy aging and plays a decisive role in the prevention of atherosclerotic cardiovascular disease (ASCVD). A higher level of cardiorespiratory fitness (CRF) in the elderly is associated with lower cardiovascular and all-cause mortality. This study investigated the association of CRF level with vascular function and cardiovascular risk factors in the elderly. METHODS: We examined 79 apparently healthy and physically active subjects aged > 55 years (64 ± 4 years). Cardiovascular functional parameters assessed included brachial and central blood pressure (BP), pulse wave velocity (PWV), augmentation index (Aix), and ankle-brachial index. Sonography of the common carotid artery was performed. CRF level was determined by a cardiopulmonary exercise test, and everyday activity was quantified with an accelerometer. RESULTS: All participants had a higher CRF level than the reported age-specific normative values. Twenty-nine subjects had subclinical atherosclerosis of the common carotid artery. Compared with participants without atherosclerosis, they were older (p = 0.007), displayed higher brachial systolic BP (p = 0.006), and higher central systolic BP (p = 0.014). Lower brachial (p = 0.036) and central (p = 0.003) systolic BP, lower PWV (p = 0.004), lower Aix (p < 0.001), lower body fat percentage (< 0.001), and lower LDL cholesterol (p = 0.005) were associated with a higher CRF level. CONCLUSIONS: In this cohort of healthy and physically active individuals, subjects with subclinical atherosclerosis displayed higher systolic brachial and central BP. A higher CRF level was associated with enhanced vascular function, consistent with an influence of CRF on both BP and vascular function in the elderly.

Association of central blood pressure with an exaggerated blood pressure response to exercise among elite athletes.

PURPOSE: The systolic blood pressure/workload (SBP/MET) slope was recently reported to be a reliable parameter to identify an exaggerated blood pressure response (eBPR) in the normal population and in athletes. However, it is unclear whether an eBPR correlates with central blood pressure (CBP) and vascular function in elite athletes. METHODS: We examined 618 healthy male elite athletes (age 25.8 ± 5.1 years) of mixed sports with a standardized maximum exercise test. CBP and vascular function were measured non-invasively with a validated oscillometric device. The SBP/MET slope was calculated and the threshold for an eBPR was set at > 6.2 mmHg/MET. Two groups were defined according to ≤ 6.2 and > 6.2 mmHg/MET, and associations of CBP and vascular function with the SBP/MET slope were compared for each group. RESULTS: Athletes with an eBPR (n = 180, 29%) displayed a significantly higher systolic CBP (102.9 ± 7.5 vs. 100 ± 7.7 mmHg, p = 0.001) but a lower absolute (295 ± 58 vs. 384 ± 68 W, p < 0.001) and relative workload (3.14 ± 0.54 vs. 4.27 ± 1.1 W/kg, p < 0.001) compared with athletes with a normal SBP/MET slope (n = 438, 71%). Systolic CBP was positively associated with the SBP/MET slope (r = 0.243, p < 0.001). In multiple logistic regression analyses, systolic CBP (odds ratio [OR] 1.099, 95% confidence interval [CI] 1.045-1.155, p < 0.001) and left atrial volume index (LAVI) (OR 1.282, CI 1.095-1.501, p = 0.002) were independent predictors of an eBPR. CONCLUSION: Systolic CBP and LAVI were independent predictors of an eBPR. An eBPR was further associated with a lower performance level, highlighting the influence of vascular function on the BPR and performance of male elite athletes.

Implications of pulse wave velocity and central pulse pressure in heart failure with reduced ejection fraction.

BACKGROUND: Carotid-femoral pulse wave velocity (cfPWV) and central pulse pressure (PP) are recognised as significant indicators of vascular health and predictors of cardiovascular outcomes. In this study, associations between central hemodynamics and left ventricular (LV) echocardiographic parameters were investigated in subjects with heart failure with reduced ejection fraction (HFrEF), comparing the results to healthy individuals. METHODS AND RESULTS: This cross-sectional prospective controlled study included 50 subjects with HFrEF [mean LV ejection fraction (EF) 26 ± 6.5%] and 30 healthy controls (mean LVEF 65.9 ± 5.3%). Pulse wave analysis (PWA) and carotid-femoral pulse wave velocity (cfPWV) were used to measure central hemodynamics and arterial stiffness. The HFrEF group displayed higher cfPWV (8.2 vs. 7.2 m/s, p = 0.007) and lower central (111.3 vs. 121.7 mmHg, p = 0.001) and peripheral (120.1 vs. 131.5 mmHg, p = 0.002) systolic blood pressure. Central pulse pressure (PP) was comparable between the two groups (37.6 vs. 40.4 mmHg, p = 0.169). In the HFrEF group, cfPWV significantly correlated with left ventricular end-diastolic volume (LVEDV) index (mL/m2) and LVEF, with LVEDV index being a significant independent predictor of cfPWV (R2 = 0.42, p = 0.003). Central PP was significantly associated with heart rate, LVEF and LVEDV index, with the latter being a significant independent predictor of central PP (R2 = 0.41, p < 0.001). These correlations were not observed in healthy controls. CONCLUSIONS: Significant associations between central hemodynamic measures and LV echocardiographic parameters were identified, suggesting the potential to use PWA and cfPWV as possible tools for managing HFrEF.

What is the context?Heart failure with reduced ejection fraction (HFrEF) affects millions of people worldwide.Vascular health plays a significant role in the development and progression of HFrEF.This study investigates two indicators of arterial stiffness­pulse wave velocity (PWV) and central pulse pressure (PP)­and their impact on the functioning of the heart in HFrEF patients compared to healthy individuals.What is new?The study found that higher carotid-femoral PWV and central PP, which typically indicate worse vascular health, were associated with better heart function in HFrEF patients. This paradoxical finding suggests that in the context of HFrEF, traditional markers of vascular health may have different implications.The study included non-invasive methods to evaluate these indicators, offering a potential new additional approach for monitoring and managing HFrEF.What is the impact?We could possibly use non-invasively evaluated PWV and central PP (measures of vascular function) as markers of left ventricular function assessment in HFrEF.

Arterial Stiffness and Heart Failure With Preserved Ejection Fraction.

Heart failure with preserved ejection fraction (HFpEF) is prevalent and associated with a poor prognosis, imposing a significant burden on society. Arterial stiffness is increasingly recognized as a crucial factor in the pathophysiology of HFpEF, affecting diagnosis, management, and prognosis. As a hallmark of vascular aging, arterial stiffness contributes to increased afterload on the left ventricle (LV), leading to diastolic dysfunction, a key feature of HFpEF. Elevated arterial stiffness is linked with common cardiovascular risk factors in HFpEF, such as hypertension, diabetes and obesity, exacerbating the progression of disease. Studies have demonstrated that patients with HFpEF exhibit significantly higher levels of arterial stiffness compared to those without HFpEF, highlighting the value of arterial stiffness measurements as both diagnostic and prognostic tools. Moreover, interventions aimed at reducing arterial stiffness, whether through pharmacological therapies or lifestyle modifications, have shown potential in improving LV diastolic function and patient outcomes. Despite these advancements, the precise mechanisms by which arterial stiffness contributes to HFpEF are still not fully understood, necessitating the need for further research.

Temporal Convolutional Neural Network-Based Prediction of Vascular Health in Elderly Women Using Photoplethysmography-Derived Pulse Wave during Exercise.

(1) Background: The objective of this study was to predict the vascular health status of elderly women during exercise using pulse wave data and Temporal Convolutional Neural Networks (TCN); (2) Methods: A total of 492 healthy elderly women aged 60-75 years were recruited for the study. The study utilized a cross-sectional design. Vascular endothelial function was assessed non-invasively using Flow-Mediated Dilation (FMD). Pulse wave characteristics were quantified using photoplethysmography (PPG) sensors, and motion-induced noise in the PPG signals was mitigated through the application of a recursive least squares (RLS) adaptive filtering algorithm. A fixed-load cycling exercise protocol was employed. A TCN was constructed to classify flow-mediated dilation (FMD) into "optimal", "impaired", and "at risk" levels; (3) Results: TCN achieved an average accuracy of 79.3%, 84.8%, and 83.2% in predicting FMD at the "optimal", "impaired", and "at risk" levels, respectively. The results of the analysis of variance (ANOVA) comparison demonstrated that the accuracy of the TCN in predicting FMD at the impaired and at-risk levels was significantly higher than that of Long Short-Term Memory (LSTM) networks and Random Forest algorithms; (4) Conclusions: The use of pulse wave data during exercise combined with the TCN for predicting the vascular health status of elderly women demonstrated high accuracy, particularly in predicting impaired and at-risk FMD levels. This indicates that the integration of exercise pulse wave data with TCN can serve as an effective tool for the assessment and monitoring of the vascular health of elderly women.

Development of a Personalized Multiclass Classification Model to Detect Blood Pressure Variations Associated with Physical or Cognitive Workload.

Comprehending the regulatory mechanisms influencing blood pressure control is pivotal for continuous monitoring of this parameter. Implementing a personalized machine learning model, utilizing data-driven features, presents an opportunity to facilitate tracking blood pressure fluctuations in various conditions. In this work, data-driven photoplethysmograph features extracted from the brachial and digital arteries of 28 healthy subjects were used to feed a random forest classifier in an attempt to develop a system capable of tracking blood pressure. We evaluated the behavior of this latter classifier according to the different sizes of the training set and degrees of personalization used. Aggregated accuracy, precision, recall, and F1-score were equal to 95.1%, 95.2%, 95%, and 95.4% when 30% of a target subject's pulse waveforms were combined with five randomly selected source subjects available in the dataset. Experimental findings illustrated that incorporating a pre-training stage with data from different subjects made it viable to discern morphological distinctions in beat-to-beat pulse waveforms under conditions of cognitive or physical workload.

VEGF Polymorphisms (VEGF-936 C/T, VEGF-634 G/C and VEGF-2578 C/A) and Cardiovascular Implications in Long COVID Patients.

The COVID-19 pandemic has raised awareness of the virus's long-term non-pulmonary consequences. This study examined the relationship between genetic polymorphisms of VEGF and cardiac dysfunction and subclinical atherosclerosis in patients recovering from COVID-19. This study included 67 patients previously diagnosed with COVID-19. VEGF-936C/T, VEGF-634G/C, and VEGF-2578C/A statuses were determined. Conventional echocardiography and arterial parameters assessments were performed at inclusion and at six months after the first assessment. For VEGF-936C/T, dominant and over-dominant models showed a significant increase in ejection fraction at six months after COVID (p = 0.044 and 0.048) and was also a predictive independent factor for the augmentation index (ß = 3.07; p = 0.024). The dominant model showed a rise in RV-RA gradient (3.702 mmHg) (p = 0.028 95% CI: 0.040-7.363), with the over-dominant model indicating a greater difference (4.254 mmHg) (p = 0.025 95% CI: 0.624-7.884). The findings for VEGF-634G/C were not statistically significant, except for a difference in TAPSE during initial evaluation, using the codominant model. For VEGF-2578C/A, a difference in ventricular filling pressure (E/E'ratio) was best described under the recessive model. Our research suggests that the VEG-936C/T genotype may impact the baseline level and subsequent changes in cardiac function and subclinical atherosclerosis. These findings offer valuable insights into the complex correlation between genetic polymorphisms and cardiovascular disfunction in long COVID patients.

Cuffless Blood Pressure Measurement.

Cuffless blood pressure (BP) measurement has become a popular field due to clinical need and technological opportunity. However, no method has been broadly accepted hitherto. The objective of this review is to accelerate progress in the development and application of cuffless BP measurement methods. We begin by describing the principles of conventional BP measurement, outstanding hypertension/hypotension problems that could be addressed with cuffless methods, and recent technological advances, including smartphone proliferation and wearable sensing, that are driving the field. We then present all major cuffless methods under investigation, including their current evidence. Our presentation includes calibrated methods (i.e., pulse transit time, pulse wave analysis, and facial video processing) and uncalibrated methods (i.e., cuffless oscillometry, ultrasound, and volume control). The calibrated methods can offer convenience advantages, whereas the uncalibrated methods do not require periodic cuff device usage or demographic inputs. We conclude by summarizing the field and highlighting potentially useful future research directions.

A pilot study: Exploring the influence of COVID-19 on cardiovascular physiology and retinal microcirculation.

BACKGROUND: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) affects the cardiovascular system. The current study investigated changes in heart rate (HR), blood pressure (BP), pulse wave velocity (PWV), and microcirculation in patients recovering from Coronavirus disease 2019 (COVID-19) infection. METHODOLOGY: Out of 43 initially contacted COVID-19 patients, 35 (30 males, 5 females; age: 60 ± 10 years; and body mass index (BMI): 31.8 ± 4.9) participated in this study. Participants were seen on two occasions after hospital discharge; the baseline measurements were collected, either on the day of hospital discharge if a negative PCR test was obtained, or on the 10th day after hospitalization if the PCR test was positive. The second measurements were done 60 days after hospitalization. The vascular measurements were performed using the VICORDER® device and a retinal blood vessel image analysis. RESULTS: A significant increase in systolic BP (SBP) (from 142 mmHg, SD: 15, to 150 mmHg, SD: 19, p = 0.041), reduction in HR (from 76 bpm, SD: 15, to 69 bpm, SD: 11, p = 0.001), and narrower central retinal vein equivalent (CRVE) (from 240.94 µm, SD: 16.05, to 198.05 µm, SD: 17.36, p = 0.013) were found. Furthermore, the trends of increasing PWV (from 11 m/s, SD: 3, to 12 m/s, SD: 3, p = 0.095) and decreasing CRAE (from 138.87 µm, SD: 12.19, to 136.77 µm, SD: 13.19, p = 0.068) were recorded. CONCLUSION: The present study investigated cardiovascular changes following COVID-19 infection at two-time points after hospital discharge (baseline measurements and 60 days post-hospitalization). Significant changes were found in systolic blood pressure, heart rate, and microvasculature indicating that vascular adaptations may be ongoing even weeks after hospitalization from COVID-19 infection. Future studies could involve conducting additional interim assessments during the active infection and post-infection periods.

Is There a Role for Imaging Youth at Risk of Atherosclerosis?

PURPOSE OF REVIEW: Cardiovascular (CV) risk factors such as dyslipidemia, hypertension, diabetes, and obesity are associated with an increased risk for CV events in adults. Noninvasive measures of vascular health are associated with these CV events and can potentially help risk stratify children with CV risk factors. The purpose of this review is to summarize recent literature regarding vascular health in children with cardiovascular risk factors. RECENT FINDINGS: Adverse changes in pulse wave velocity, pulse wave analysis, arterial distensibility, and carotid intima-media thickness are seen in children with CV risk factors supporting potential utility in risk stratification. Assessing vascular health in children can be challenging due to growth-related changes in vasculature, multiple assessment modalities, and differences in normative data. Vascular health assessment in children with cardiovascular risk factors can be a valuable tool for risk stratification and help identify opportunities for early intervention. Future areas of research include increasing normative data, improving conversion of data between different modalities, and increasing longitudinal studies in children linking childhood risk factors to adult CV outcomes.

Arterial stiffness for the early prediction of pre-eclampsia compared with blood pressure, uterine artery Doppler and angiogenic biomarkers: a prospective cohort study.

OBJECTIVE: Our aim was to evaluate the ability of arterial stiffness parameters to predict pre-eclampsia early compared with peripheral blood pressure, uterine artery Doppler and established angiogenic biomarkers. DESIGN: Prospective cohort study. SETTING: Tertiary care antenatal clinics in Montreal, Canada. POPULATION: Women with singleton high-risk pregnancies. METHODS: In the first trimester, arterial stiffness was measured by applanation tonometry, along with peripheral blood pressure and serum/plasma angiogenic biomarkers; uterine artery Doppler was measured in the second trimester. The predictive ability of different metrics was assessed through multivariate logistic regression. MAIN OUTCOME MEASURES: Arterial stiffness (carotid-femoral pulse wave velocity, carotid-radial pulse wave velocity) and wave reflection (augmentation index, reflected wave start time), peripheral blood pressure, ultrasound indices of velocimetry and circulating angiogenic biomarker concentrations. RESULTS: In this prospective study, among 191 high-risk pregnant women, 14 (7.3%) developed pre-eclampsia. A first-trimester 1 m/s increase in carotid-femoral pulse wave velocity was associated with 64% increased odds (P < 0.05), and a 1-millisecond increase in time to wave reflection with 11% decreased odds for pre-eclampsia (P < 0.01). The area under the curve of arterial stiffness, blood pressure, ultrasound indices and angiogenic biomarkers was 0.83 (95% confidence interval [CI] 0.74-0.92), 0.71 (95% CI 0.57-0.86), 0.58 (95% CI 0.39-0.77), and 0.64 (95% CI 0.44-0.83), respectively. With a 5% false-positive rate, blood pressure had a sensitivity of 14% for pre-eclampsia and arterial stiffness a sensitivity of 36%. CONCLUSIONS: Arterial stiffness predicted pre-eclampsia earlier and with greater ability than blood pressure, ultrasound indices or angiogenic biomarkers.

The characteristics of elevated blood pressure in abdominal obesity correspond to primary hypertension: a cross-sectional study.

BACKGROUND: Obesity-related hypertension and the associated metabolic abnormalities are considered as a distinct hypertensive phenotype. Here we examined how abdominal fat content, as judged by waist:height ratio, influenced blood pressure and hemodynamic profile in normotensive subjects and never-treated hypertensive patients. METHODS: The 541 participants (20-72 years) underwent physical examination and laboratory analyses and were divided into age and sex-adjusted quartiles of waist:height ratio. Supine hemodynamics were recorded using whole-body impedance cardiography, combined with analyses of radial tonometric pulse wave form and heart rate variability. RESULTS: Mean waist:height ratios in the quartiles were 0.46, 0.51, 0.55 and 0.62. Radial and aortic blood pressure, systemic vascular resistance, pulse wave velocity, markers of glucose and lipid metabolism, leptin levels and C-reactive protein were higher in quartile 4 when compared with quartiles 1 and 2 (p < 0.05 for all). Cardiac index was lower in quartile 4 versus quartile 1, while no differences were seen in heart rate variability, augmentation index, plasma renin activity, and aldosterone concentration between the quartiles. Linear regression analyses showed independent associations of abdominal obesity with higher aortic systolic and diastolic blood pressure, systemic vascular resistance, and pulse wave velocity (p < 0.05 for waist:height ratio in all regression models). CONCLUSION: Higher waist:height ratio was associated with elevated blood pressure, systemic vascular resistance, and arterial stiffness, but not with alterations in cardiac sympathovagal modulation or activation of the circulating renin-angiotensin-aldosterone system. Although obesity-related elevation of blood pressure has distinct phenotypic features, these results suggest that its main characteristics correspond those of primary hypertension. TRIAL REGISTRATION: ClinicalTrails.gov NCT01742702 (date of registration 5th December 2012).

Oscillometric pulse wave analysis for detecting low flow arteriovenous fistula.

BACKGROUND: Pulse wave analysis may be useful to assess fistula function. We aimed to prospectively evaluate if convenient oscillometric devices are applicable to detect flow below 500 ml/min in a real life clinical setting. METHODS: Pulse waves were recorded ambilaterally with the vicorder® device at the brachial artery in 53 patients on haemodialysis with native fistula. Primary variables consisted of the mean slope between the systolic maximum and the diacrotic notch (Slope2), the sum of the mean slopes in the four characteristic sections of pulse waves (Slope∑) and the amplitude of relative volumetric change in the measuring cuff at the upper arm (AMP). Fistula flow was measured with the use of duplex sonography using a standardized approach. RESULTS: Parameter values above or below the median indicated measurement at the non-fistula side, with sensitivities/specificities of 0.79/0.79 (p < 0.001) for Slope 2, 0.64/0.64 (p = 0.003) for Slope∑ and 0.81/0.81 (p < 0.001) for AMP if measurements at the fistula and non-fistula arm were considered. ROC-analyses of parameter values measured at the fistula to detect low flow demonstrated AUCs (with CI) of 0.652 (0.437-0.866, p = 0.167) for Slope2, 0.732 (0.566-0.899, p = 0.006) for Slope∑ and 0.775 (0.56-0.991, p = 0.012) for AMP. The point with maximal youden's index was regarded as optimal cut-off, which corresponded to sensitivities and specificities of 0.8/0.56 for slope2, 0.86/ 0.56 for Slope∑ and 0.93/0.78 for AMP. CONCLUSION: Functional surveillance with oscillometry is a promising clinical application to detect a low fistula flow. Among all investigated pulse wave parameters AMP revealed the highest diagnostic accuracy.

Comparison of invasive and non-invasive measurements of cardiac index and systemic vascular resistance in living-donor liver transplantation: a prospective, observational study.

BACKGROUND: Based on the controversy surrounding pulmonary artery catheterization (PAC) in surgical patients, we investigated the interchangeability of cardiac index (CI) and systemic vascular resistance (SVR) measurements between ClearSight™ and PAC during living-donor liver transplantation (LDLT). METHODS: This prospective study included consecutively selected LDLT patients. ClearSight™-based CI and SVR measurements were compared with those from PAC at seven LDLT-stage time points. ClearSight™-based systolic (SAP), mean (MAP), and diastolic (DAP) arterial pressures were also compared with those from femoral arterial catheterization (FAC). For the comparison and analysis of ClearSight™ and the reference method, Bland-Altman analysis was used to analyze accuracy while polar and four-quadrant plots were used to analyze the trending ability. RESULTS: From 27 patients, 189 pairs of ClearSight™ and reference values were analyzed. The CI and SVR performance errors (PEs) exhibited poor accuracy between the two methods (51.52 and 51.73%, respectively) in the Bland-Altman analysis. CI and SVR also exhibited unacceptable trending abilities in both the polar and four-quadrant plot analyses. SAP, MAP, and DAP PEs between the two methods displayed favorable accuracy (24.28, 21.18, and 26.26%, respectively). SAP and MAP exhibited acceptable trending ability in the four-quadrant plot between the two methods, but not in the polar plot analyses. CONCLUSIONS: During LDLT, CI and SVR demonstrated poor interchangeability, while SAP and MAP exhibited acceptable interchangeability between ClearSight™ and FAC.

Urine sodium excretion is related to extracellular water volume but not to blood pressure in 510 normotensive and never-treated hypertensive subjects.

PURPOSE: High sodium intake is an accepted risk factor for hypertension, while low Na+ intake has also been associated with increased risk of cardiovascular events. In this cross-sectional study, we examined the association of 24-h urinary Na+ excretion with haemodynamics and volume status. MATERIALS AND METHODS: Haemodynamics were recorded in 510 normotensive and never-treated hypertensive subjects using whole-body impedance cardiography and tonometric radial artery pulse wave analysis. The results were examined in sex-specific tertiles of 24-h Na+ excretion, and comparisons between normotensive and hypertensive participants were also performed. Regression analysis was used to investigate factors associated with volume status. The findings were additionally compared to 28 patients with primary aldosteronism. RESULTS: The mean values of 24-h urinary Na+ excretion in tertiles of the 510 participants were 94, 148 and 218 mmol, respectively. Average tertile age (43.4-44.7 years), office blood pressure and pulse wave velocity were corresponding in the tertiles. Plasma electrolytes, lipids, vitamin D metabolites, parathyroid hormone, renin activity, aldosterone, creatinine and insulin sensitivity did not differ in the tertiles. In supine laboratory recordings, there were no differences in aortic systolic and diastolic blood pressure, heart rate, cardiac output and systemic vascular resistance. Extracellular water volume was higher in the highest versus lowest tertile of Na+ excretion. In regression analysis, body surface area and 24-h Na+ excretion were independent explanatory variables for extracellular water volume. No differences in urine Na+ excretion and extracellular water volume were found between normotensive and hypertensive participants. When compared with the 510 participants, patients with primary aldosteronism had 6.0% excess in extracellular water (p = .003), and 24-h Na+ excretion was not related with extracellular water volume. CONCLUSION: In the absence of mineralocorticoid excess, Na+ intake, as evaluated from 24-h Na+ excretion, predominantly influences extracellular water volume without a clear effect on blood pressure.

We evaluated sodium intake in 510 subjects by measuring their 24-h sodium excretion to the urine and examined whether sodium intake was related with alterations in cardiovascular function and fluid balance. All participants were without blood pressure lowering medications.Blood pressure was recorded by a device that senses the radial artery pulsations form the wrist. The amount of blood pumped by the heart, the transfer of pressure waves following cardiac contractions and body fluid status were evaluated using bioimpedance, a method recording changes in body electrical resistance.For the analyses, the participants were divided into tertiles according to their 24-h sodium excretions. We also compared results between normotensive and hypertensive subjects.The 24-h sodium excretion in the tertiles corresponded to about 6 g, 9 g and 13 g of salt intake per day, respectively. There were no differences between the tertiles in age, routine laboratory analyses, blood pressure, large arterial stiffness, amount blood pumped by the heart and resistance to blood flow in the arteries. However, there was more extracellular fluid in the highest versus the lowest tertile of sodium excretion. Further statistics indicated that extracellular fluid volume in the body was mainly determined by body size, but it was also moderately influenced by sodium intake.No differences in 24-h sodium excretion and extracellular water volume were found between normotensive and hypertensive participants.In subjects not using blood pressure lowering medications, sodium intake predominantly influences the amount of extracellular fluid without a clear effect on blood pressure.

Evaluation of Arterial Stiffness and Carotid Intima-Media Thickness in Children with Primary and Renal Hypertension.

Hypertension is an increasing disease in children and the risk of endothelial damage and target organ damage increases in the presence of additional risk factors such as obesity. In our study, the effect of hypertension on early atherosclerotic changes and target organ damage in children was investigated. Twenty four-hour ambulatory pulse wave analysis was performed by oscillometric method in 71 children aged 8-18 years, 17 of whom were diagnosed with primary hypertension without obesity, 18 had both primary hypertension and obesity, and 16 had renal hypertension. Twenty healthy normotensive children were included as the control group. Carotid intima-media thickness (CIMT) and Left Ventricular Mass Index were measured. Central systolic blood pressure (cSBP), central diastolic blood pressure (cDBP), systolic blood pressure (SBP) and diastolic blood pressure (DBP) were higher in the primary hypertension group compared to controls (p = 0.001, p = 0.005, p = 0.001, p = 0.009, respectively), cSBP was higher in the renal hypertension group than the control group (p = 0.018). There was no difference between the groups in terms of pulse wave analysis parameters, CIMT, or left ventricular mass index (p > 0.05). Pulse wave velocity was positively correlated with SBP, DBP, cSBP, cDBP (p < 0.001). Augmentation index was positively correlated with DBP and cDBP (p = 0.01, p = 0.002, respectively). Our findings show that high blood pressure is associated with arterial stiffness and target organ damage beginning in childhood. The detection of early atherosclerotic vascular changes using pulse wave analysis allows to take necessary precautions such as lifestyle changes to prevent target organ damage in hypertensive children.

Aortic pulse wave morphology in individuals after chronic stroke: interarm comparison wave morphology after chronic stroke.

CONTEXT: Vascular changes can be a risk factor for recurrent and new events of stroke. However, few information is known regarding the variables related to aortic pulse wave morphology in stroke individuals. OBJECTIVE: To analyze aortic pulse wave morphology (arterial stiffness indices, hemodynamics and vascular variables) and to compare the paretic and non-paretic sides in individuals after chronic stroke. DESIGN: In this cross-sectional study stroke individuals had arterial stiffness indices, hemodynamics and vascular variables assessed with brachial artery oscillometry. T-test (CI95%) was used in order to compare the variables between the paretic and non-paretic sides. RESULTS: Twenty individuals were included, 65% men (60.3 SD 16.7 years). The following variables: (mean difference [CI95%]): coefficient of reflection (-2.33 [-4.60 to -0.07]), peak of ejection wave, P1 (5.32 [2.75 to 7.90] and peak of ejection wave, P2 (6.17 [2.55 to 9.78]), central diastolic blood pressure (mean difference [IC95%]): (-3.75 [-6.09 to -1.40]), central systolic blood pressure (-6.17 [-9.74 to -2.59]), mean arterial pressure (-4.46 [-7.08 to -1.84]), peripheral diastolic blood pressure (-3.48 [-5.94 to -1.02]) and peripheral systolic blood pressure (-5.53 [-9.54 to -1.52]) were higher in paretic than non-paretic side. Hemodynamics parameters were similar in both sides. CONCLUSIONS: In this study we demonstrated, for the first time, that many parameters from aortic pulse wave were higher in paretic compared with non-paretic side in individuals after chronic stroke, suggesting that peripheral vascular changes affect heart-vascular coupling in these individuals.

Bridging vascular physiology to vascular medicine: an integrative laboratory class.

Vascular diseases of the legs are highly prevalent and constitute an important part of medical curricula. The understanding of these diseases relies on strongly interwoven aspects of vascular physiology and vascular medicine. We aimed to connect these within a horizontally integrated laboratory class on vascular physiology of the leg that was designed in cooperation between the departments of physiology and vascular surgery. Conceptually, we applied examination techniques of vascular medicine to visualize physiological parameters that are altered by the most frequent diseases. This facilitates integrative discussions on malfunctions, trains diagnostic skills, and bridges to vascular medicine. In four experiments, we use oscillometry and impedance venous occlusion plethysmography to address key aspects of the arterial and venous system of the legs: 1) arterial pulse wave, 2) arterial systolic blood pressure, 3) venous capacitance and venous outflow, and 4) reactive hyperemia. After the experiments, physiological vascular function, the associated diseases, their impact on the recorded parameters, and diagnostic options are discussed. To allow reproduction, we describe the course structure and the experimental setup in detail. We present the experimental data of a cohort of medical students and document learning success and student satisfaction. All experiments were feasible and provided robust data on physiologically and clinically relevant vascular functions. The activity was perceived positively by the students and led to a substantial improvement of knowledge. With this work, we offer a template for reproduction or variation of a proven concept of horizontally integrated teaching of vascular physiology of the leg.NEW & NOTEWORTHY This article presents an integrative laboratory class on vascular physiology bridging to vascular medicine. The four experiments rely on oscillometry and venous occlusion plethysmography. We describe in detail this new class regarding structure, experimental setup, and experimental procedure, and we give insight into the applied materials. Moreover, we present the experimental data of 74 students and a quantitative evaluation of the students' learning success and acceptance.