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Fluids and Barriers of the CNS May 2021Idiopathic normal pressure hydrocephalus (iNPH) and late-onset idiopathic aqueductal stenosis (LIAS) are two forms of chronic adult hydrocephalus of different aetiology....
BACKGROUND
Idiopathic normal pressure hydrocephalus (iNPH) and late-onset idiopathic aqueductal stenosis (LIAS) are two forms of chronic adult hydrocephalus of different aetiology. We analysed overnight intracranial pressure (ICP) monitoring to elucidate ICP waveform changes characteristic for iNPH and LIAS to better understand pathophysiological processes of both diseases.
METHODS
98 patients with iNPH and 14 patients with LIAS from two neurosurgical centres were included. All patients underwent diagnostic overnight computerised ICP monitoring with calculation of mean ICP, ICP heartbeat related pulse wave amplitude calculated in the frequency domain (AMP) and the time domain (MWA), index of cerebrospinal compensatory reserve (RAP) and power of slow vasogenic waves (SLOW).
RESULTS
ICP was higher in LIAS than iNPH patients (9.3 ± 3.0 mmHg versus 5.4 ± 4.2 mmHg, p = 0.001). AMP and MWA were higher in iNPH versus LIAS (2.36 ± 0.91 mmHg versus 1.81 ± 0.59 mmHg for AMP, p = 0.012; 6.0 ± 2.0 mmHg versus 4.9 ± 1.2 mmHg for MWA, p = 0.049). RAP and SLOW indicated impaired reserve capacity and compliance in both diseases, but did not differ between groups. INPH patients were older than LIAS patients (77 ± 6 years versus 54 ± 14 years, p < 0.001).
CONCLUSIONS
ICP is higher in LIAS than in iNPH patients, likely due to the chronically obstructed CSF flow through the aqueduct, but still in a range considered normal. Interestingly, AMP/MWA was higher in iNPH patients, suggesting a possible role of high ICP pulse pressure amplitudes in iNPH pathophysiology. Cerebrospinal reserve capacity and intracranial compliance is impaired in both groups and the pressure-volume relationship might be shifted towards lower ICP values in iNPH. The physiological influence of age on ICP and AMP/MWA requires further research.
Topics: Adult; Age of Onset; Aged; Aged, 80 and over; Blood Pressure; Female; Humans; Hydrocephalus; Hydrocephalus, Normal Pressure; Intracranial Pressure; Male; Middle Aged
PubMed: 34039383
DOI: 10.1186/s12987-021-00259-y -
Heart, Lung & Circulation Nov 2021Aortic valve stenosis (AS) is no longer considered to be a disease of fixed left ventricular (LV) afterload (due to an obstructive valve), but rather, functions as a... (Review)
Review
Aortic valve stenosis (AS) is no longer considered to be a disease of fixed left ventricular (LV) afterload (due to an obstructive valve), but rather, functions as a series circuit with important contributions from both the valve and ageing vasculature. Patients with AS are frequently elderly, with hypertension and a markedly remodelled aorta. The arterial component is sizable, and yet, the contribution of ventricular afterload has been difficult to determine. Arterial stiffening increases the speed of propagation of the blood pressure wave along the central arteries (estimated as the pulse wave velocity), which results in an earlier return of reflected waves. The effect is to augment blood pressure in the proximal aorta during systole, increasing the central pulse pressure and, in turn, placing even greater afterload on the heart. Elevated global LV afterload is known to have adverse consequences on LV remodelling, function and survival in patients with AS. Consequently, there is renewed focus on methods to estimate the relative contributions of local versus global changes in arterial mechanics and valvular haemodynamics in patients with AS. We present a review on existing and upcoming methods to quantify valvulo-arterial impedance and thereby global LV load in patients with AS.
Topics: Aged; Aging; Aortic Valve; Aortic Valve Stenosis; Blood Pressure; Humans; Hypertension; Pulse Wave Analysis; Ventricular Function, Left
PubMed: 34274230
DOI: 10.1016/j.hlc.2021.05.108 -
American Journal of Physiology. Heart... Jun 2023The central aortic pressure waveform, while simple in form, is complex in its physiological interpretation. Although general agreement has been reached on the contour... (Review)
Review
The central aortic pressure waveform, while simple in form, is complex in its physiological interpretation. Although general agreement has been reached on the contour and mechanisms responsible for pressure waveforms in the ascending aorta of healthy humans, in recent years there has been increasing interest in the contour of the pressure wave in elderly patients with aortic valve stenosis (AS). As aortic valve leaflets succumb to fibrosis and calcification, they increase opposition to forward flow. This results in a protracted pressure rise and manifests as the classical finding of pulsus parvus et tardus. Equally, changes to arterial properties (including elasticity and geometry) and pulse wave velocity (PWV) with age, heart failure, or hypertension can cause profound changes to the contour. Increased accessibility of methods to measure the central aortic pressure waveform, as well as the rapid uptake of transcatheter aortic valve implantation technologies, has created a renewed focus on better understanding of characteristic perturbations to the waveform in elderly patients with AS. In this review, we investigate the evolution of our understanding of the central aortic pressure waveform in varying AS disease states to highlight the importance of the physiological and biological basis for alterations in this waveform.
Topics: Humans; Aged; Arterial Pressure; Pulse Wave Analysis; Hypertension; Arteries; Aortic Valve Stenosis; Blood Pressure
PubMed: 37000607
DOI: 10.1152/ajpheart.00050.2023 -
Vascular Health and Risk Management 2023The compliance of the distal arteries depends on their vasoconstrictor tone and distensibility and is sensitive to endothelial function and aging. C2, a component of...
INTRODUCTION
The compliance of the distal arteries depends on their vasoconstrictor tone and distensibility and is sensitive to endothelial function and aging. C2, a component of the Windkessel model, is a measure of distal arterial compliance, and establishes the magnitude of the pressure rise during early diastole. It is calculated from the diastolic portion of the radial pulse wave using sophisticated analyses. C2 is used as a cardiovascular risk indicator since it decreases with aging, high blood pressure, and diabetes. Here, we propose an alternative method to assess the distal arteries distensibility by measuring the amplitude of the oscillation that occurs at the beginning of diastole.
METHODS
Peripheral pulse wave was evaluated noninvasively by applanation tonometry in 511 individuals (264 women) aged between 13 and 70 years. Diastolic amplitude (DA) was measured as the peak-to-peak amplitude of the diastolic oscillation. Radial augmentation index (RAIx) and pulse wave velocity (PWV) were also calculated.
RESULTS
DA decreased approximately 2% per decade of life between 16 and 70 years from 19% to 7%, and was higher in men than in women (p<0.0001). Linear regression analysis identified RAIx as the strongest predictor of AD (p<0.0001), followed by age and height. Sex modified the age-related decrease in DA (p< 0.001). By applying the method to measure DA from previously published data, we found a strong linear correlation with C2.
CONCLUSION
DA decreased linearly with age in a reciprocal manner to the increase in radial augmentation index, was greater in men than women, and was independent of blood pressure and heart rate, as previously reported for C2. We propose that measuring DA could provide an alternative index to evaluate distal arterial compliance and aging.
Topics: Male; Humans; Female; Adolescent; Young Adult; Adult; Middle Aged; Aged; Diastole; Pulse Wave Analysis; Arteries; Aging; Blood Pressure
PubMed: 37038502
DOI: 10.2147/VHRM.S381452 -
Clinical and Experimental Hypertension... Dec 2023Microcirculatory endothelial dysfunction is a complex phenomenon that contributes to the development of cardiovascular disease. However, the relationship between...
BACKGROUND
Microcirculatory endothelial dysfunction is a complex phenomenon that contributes to the development of cardiovascular disease. However, the relationship between microcirculatory endothelial dysfunction and macrovascular disease remains incompletely understood. Fluid overload is a risk factor for cardiovascular mortality in patients undergoing peritoneal dialysis. Therefore, we investigated the effects of chronic fluid overload on both the microcirculation and macrocirculation in these patients.
METHODS
Thirty patients undergoing peritoneal dialysis were included in this cross-sectional study. We measured their central blood pressure and pulse wave velocity, assessed their microvascular endothelial function using drug-induced iontophoresis with laser Doppler flowmetry, and determined the amount of fluid overload using bioimpedance. We conducted a Spearman correlation analysis, univariate analysis, and stepwise multivariate regression models to determine the associations among the hemodynamic parameters.
RESULTS
Acetylcholine-induced iontophoresis with laser Doppler flowmetry showed a correlation with both brachial and central pulse pressure (PP), but not with pulse wave velocity. Fluid overload was associated with both central and brachial PP and remained an independent predictor of central PP even after adjusting for multiple factors. However, fluid overload was not associated with microcirculatory endothelial function.
CONCLUSION
In peritoneal dialysis patients, we observed a significant association between central PP and microvascular endothelial function, indicating a connection between macrocirculation and microcirculation. However, conclusive evidence regarding fluid overload as a mediator between these circulatory systems is lacking. Further research is needed to investigate this relationship.
Topics: Humans; Blood Pressure; Microcirculation; Cross-Sectional Studies; Pulse Wave Analysis; Peritoneal Dialysis
PubMed: 37842909
DOI: 10.1080/10641963.2023.2267192 -
The Journals of Gerontology. Series A,... Jul 2023Dysfunction in blood vessel dynamics may contribute to changes in muscle measures. Therefore, we examined associations of vascular health measures with grip strength and...
BACKGROUND
Dysfunction in blood vessel dynamics may contribute to changes in muscle measures. Therefore, we examined associations of vascular health measures with grip strength and gait speed in adults from the Framingham Heart Study.
METHODS
The cross-sectional study (1998-2001) included participants with 1 measure of grip strength (kg, dynamometer) or gait speed (4-m walk, m/s) and at least 1 measure of aortic stiffness (carotid-femoral pulse wave velocity, brachial pulse pressure, and brachial flow pulsatility index) or brachial artery structure and function (resting flow velocity, resting brachial artery diameter, flow-mediated dilation %, hyperemic brachial blood flow velocity, and mean arterial pressure [MAP]) assessed by tonometry and brachial artery ultrasound. The longitudinal study included participants with ≥1 follow-up measurement of gait speed or grip strength. Multivariable linear regression estimated the association of 1 standard deviation (SD) higher level of each vascular measure with annualized percent change in grip strength and gait speed, adjusting for covariates.
RESULTS
In cross-sectional analyses (n = 2 498, age 61 ± 10 years; 56% women), higher resting brachial artery diameter (β ± standard error [SE] per 1 SD: 0.59 ± 0.24, p = .01) and MAP (β ± SE: 0.39 ± 0.17, p = .02) were associated with higher grip strength. Higher brachial pulse pressure (β ± SE: -0.02 ± 0.01, p = .07) was marginally associated with slower gait speed. In longitudinal analyses (n = 2 157), higher brachial pulse pressure (β ± SE: -0.19 ± 0.07, p = .005), was associated with slowing of gait speed but not with grip strength.
CONCLUSIONS
Higher brachial artery pulse pressure (measure of aortic stiffness) was associated with loss of physical function over ~11 years, although we found no evidence that microvascular function contributed to the relation.
Topics: Humans; Female; Aged; Male; Longitudinal Studies; Cross-Sectional Studies; Pulse Wave Analysis; Blood Pressure; Vascular Stiffness; Brachial Artery
PubMed: 37183502
DOI: 10.1093/gerona/glad097 -
Scientific Reports Feb 2023The associations between blood pressure and cannabis use remain inconsistent. The purpose of our study was to examine gender stratified associations of cannabis use and...
The associations between blood pressure and cannabis use remain inconsistent. The purpose of our study was to examine gender stratified associations of cannabis use and blood pressure [systolic, diastolic blood pressure (BP), pulse pressure (PP)] levels among the general UK Biobank population based study. Among 91,161 volunteers of the UK Biobank population, cannabis use status was assessed by questionnaire and range as heavy, moderate, low and never users. Associations between cannabis use and BP were estimated using multiple gender linear regressions. In adjusted covariates models, lifetime heavy cannabis use was associated with decrease in both SBP, DBP and PP in both genders, but with a higher effect among women (for SBP in men, b = - 1.09 (0.27), p < 0.001; in women, b = - 1.85 (0.36), p < 0.001; for DBP in men, b = - 0.50 (0.15), p < 0.001; in women, b = - 0.87 (0.17), p < 0.001; and for PP in men, b = - 0.60 (0.20), p < 0.001; in women, b = - 0.97 (0.27), p < 0.001. Among men, lower SBP and DBP levels were observed with participants without dyslipidemia and lower PP in participants with high income levels. Among women, lower SBP, DBP and PP were observed with current smokers, moderate/low alcohol levels and participants without dyslipidemia. Current cannabis use was associated with lower SBP levels in men (b = - 0.63 (0.25), p = 0.012) and in women (b = - 1.17 (0.31), p < 0.001). Same results were observed for DBP and PP. Negative association between BP in men was found but not in women. The small association in BP differences between heavy users and never users remains too small to adopt cannabis-blood pressure public policy in clinical practice.
Topics: Humans; Male; Female; Blood Pressure; Cannabis; Hallucinogens; Social Class; Hypertension
PubMed: 36740601
DOI: 10.1038/s41598-022-22841-6 -
BMC Emergency Medicine Aug 2023Septic shock medical treatment relies on a bundle of care including antibiotic therapy and hemodynamic optimisation. Hemodynamic optimisation consists of fluid expansion...
BACKGROUND
Septic shock medical treatment relies on a bundle of care including antibiotic therapy and hemodynamic optimisation. Hemodynamic optimisation consists of fluid expansion and norepinephrine administration aiming to optimise cardiac output to reach a mean arterial pressure of 65mmHg. In the prehospital setting, direct cardiac output assessment is difficult because of the lack of invasive and non-invasive devices. This study aims to assess the relationship between 30-day mortality and (i) initial pulse pressure (iPP) as (ii) pulse pressure variation (dPP) during the prehospital stage among patients cared for SS by a prehospital mobile intensive care unit (MICU).
METHODS
From May 09th, 2016 to December 02nd, 2021, septic shock patients requiring MICU intervention were retrospectively analysed. iPP was calculated as the difference between systolic blood pressure (SBP) and diastolic blood pressure (DBP) at the first contact between the patient and the MICU team prior to any treatment and, dPP as the difference between the final PP (the difference between SBP and DBP at the end of the prehospital stage) and iPP divided by prehospital duration. To consider cofounders, the propensity score method was used to assess the relationship between (i) iPP < 40mmHg, (ii) positive dPP and 30-day mortality.
RESULTS
Among the 530 patients analysed, pulmonary, digestive, and urinary infections were suspected among 43%, 25% and 17% patients, respectively. The 30-day overall mortality rate reached 31%. Cox regression analysis showed an association between 30-day mortality and (i) iPP < 40mmHg; aHR of 1.61 [1.03-2.51], and (ii) a positive dPP; aHR of 0.56 [0.36-0.88].
CONCLUSION
The current study reports an association between 30-day mortality rate and iPP < 40mmHg and a positive dPP among septic shock patients cared for by a prehospital MICU. A negative dPP could be helpful to identify septic shock with higher risk of poor outcome despite prehospital hemodynamic optimization.
Topics: Humans; Blood Pressure; Retrospective Studies; Shock, Septic; Intensive Care Units; Emergency Medical Services
PubMed: 37626302
DOI: 10.1186/s12873-023-00864-0 -
BMC Pediatrics Jan 2022Abnormal fetal growth is associated with increased cardiovascular risk in adulthood. We investigated the effect of fetal programming on arterial health and morphology...
BACKGROUND
Abnormal fetal growth is associated with increased cardiovascular risk in adulthood. We investigated the effect of fetal programming on arterial health and morphology during early childhood.
METHODS
We examined 90 children (median age 5.81 years, interquartile range: 5.67; 5.95), born small for gestational age with fetal growth restriction, large or appropriate for gestational age (SGA, N = 23, LGA, N = 19, AGA N = 48). We measured body composition, anthropometrics, blood pressure, pulse wave velocity (PWV), lipids, glucose and inflammatory markers, and assessed carotid, brachial, radial and femoral arterial morphology and stiffness using very-high resolution ultrasound (46-71 MHz).
RESULTS
LGA showed increased anthropometry, lean body mass and body mass index. SGA displayed decreased anthropometry and lean body mass. Blood pressure, PWV, carotid artery stiffness and blood work did not differ groupwise. Differences in lumen diameters, intima-media thicknesses (IMT) and adventitia thicknesses disappeared when adjusted for lean body mass and sex. In multiple regression models arterial dimensions were mainly predicted by lean body mass, with birth weight remaining associated only with carotid and brachial lumen dimensions, and not with IMTs. Carotid-femoral PWV was predicted by height and blood pressure only. No independent effect of adiposity was observed.
CONCLUSIONS
Arterial dimensions in childhood associate with current anthropometrics, especially lean body mass, and sex, explaining differences in arterial layer thickness. We found no signs of fetal programming of cardiovascular risk or arterial health in early childhood.
Topics: Adult; Blood Pressure; Carotid Arteries; Carotid Intima-Media Thickness; Child; Child, Preschool; Gestational Age; Humans; Pulse Wave Analysis; Ultrasonography
PubMed: 35031019
DOI: 10.1186/s12887-021-02951-2 -
BMJ Case Reports Jul 2021A 74-year-old man with a history of chronic alcohol use presented with progressive exertional dyspnoea and weight gain. On physical examination, he was noted to have...
A 74-year-old man with a history of chronic alcohol use presented with progressive exertional dyspnoea and weight gain. On physical examination, he was noted to have wide pulse pressure, elevated jugular venous pressure, and alternating flushing and blanching of the nail beds in concert with the cardiac cycle, known as Quincke's pulse. Transthoracic echocardiography demonstrated normal biventricular systolic function and valvular function, but noted a dilated inferior vena cava. Right heart catheterisation revealed elevated filling pressures, high cardiac output and low systemic vascular resistance, consistent with high-output heart failure. Whole blood concentration of thiamine was low, confirming the diagnosis of wet beriberi. The patient abstained from alcohol use and was started on thiamine replacement therapy, resulting in narrowing of the pulse pressure over time and complete resolution of symptoms without the need for diuretic therapy.
Topics: Aged; Beriberi; Blood Pressure; Echocardiography; Heart Failure; Humans; Male; Thiamine
PubMed: 34301700
DOI: 10.1136/bcr-2021-241654