Search results for "Mean blood pressure"
showing 10 items of 19 documents
Evaluation of the pulse wave arrival time as a marker for blood pressure changes in critically ill infants and children
1995
Objective. Pulse arrival time (PAT), which is the interval between the R wave of the electrocardiogram (ECG) and the arrival of the pulse wave peripherally, has been reported to be suitable for use as an indirect measure of blood pressure change. The purpose of this study was to evaluate, in critically ill infants and children, the degree to which 1/PAT covaries with systolic, diastolic, and mean blood pressure, as well as heart rate.Methods. A laboratory device was used to calculate PAT in real time from the ECG and the plethysmographic curve of pulse oximetry used for routine monitoring. Calculated PAT and corresponding blood pressures and heart rate were stored on hard disk. A total of 1…
Evaluation of regional haemodynamics and alterations of vascular wall of the lower limbs in hypertensive subjects
1995
This study was designed to analyse the relationship between arterial hypertension and changes in arterial blood flow and vascular wall damage of the lower limbs in hypertensive patients with various degrees of hypertension. Six hundred and fifty-four hypertensive patients (421 males and 233 females) aged 35 to 70 years and 88 healthy subjects (63 males and 25 females) aged 39 to 60 years were studied. Strain-gauge plethysmography of the lower limbs was used to calculate arterial calf blood flow (RF), arterial calf blood flow after post-ischaemic hyperaemia (PF), basal and minimal vascular resistances (BVR and MVR), time to reach peak flow (tPF), time until 50% reduction of peak flow (tT1/2)…
Baroreflex control of heart rate during sleep in severe obstructive sleep apnoea: effects of acute CPAP
2006
Baroreflex control of heart rate during sleep (baroreflex sensitivity; BRS) has been shown to be depressed in obstructive sleep apnoea (OSA), and improved after treatment with continuous positive airway pressure (CPAP). Whether CPAP also acutely affects BRS during sleep in uncomplicated severe OSA is still debatable. Blood pressure was monitored during nocturnal polysomnography in 18 patients at baseline and during first-time CPAP application. Spontaneous BRS was analysed by the sequence method, and estimated as the mean sequence slope. CPAP did not acutely affect mean blood pressure or heart rate but decreased cardiovascular variability during sleep. Mean BRS increased slightly during CPAP…
Rapid left ventricular filling in untreated hypertensive subjects with or without left ventricular hypertrophy
1992
In this study, independent contribution of age, HR, BMI, casual and ambulatory blood pressure, LVM and LVEF in evaluating diastolic filling have been investigated in 34 never-treated hypertensive patients and in 15 healthy normotensive subjects. All the subjects were free from coronary artery disease, valvular disease, heart failure, renal disease and psychiatric problems. All the hypertensive subjects (never treated) were subgrouped according to presence or absence of LVH. The PFR decreased significantly and tPFR increased significantly in hypertensive patients in comparison with normotensive subjects and they did not change in the presence vs absence of LVH. The PFR was inversely correlat…
Central obesity and hypertensionThe role of plasma endothelin
1996
Hypertension and central obesity are two conditions closely linked, but the mechanisms responsible for obesity-associated hypertension are still unclear. In the last few years, several studies addressed the role of endothelin-1 (ET-1) in the development and maintenance of hypertension. This study was designed to evaluate plasma ET-1 in normotensive and hypertensive central obese subjects compared with a lean healthy group. Our final goal was to analyze the relationship between plasma ET-1, blood pressure, and left ventricular structure and function in central obese subjects (both normotensives and hypertensives). ET-levels have been assessed by the radioimmunoassay method in 20 lean normote…
The spectrum of circadian blood pressure changes in type I diabetic patients.
2001
Background The objective of the present study was to characterize the spectrum of circadian blood pressure changes in type I diabetes at different stages of nephropathy by using two monitorings in each patient in order to avoid intra-individual variability. Patients and methods A total of 80 type I diabetic subjects and the same number of age, sex and awake mean blood pressure (BP)-matched controls were included. According to urinary albumin excretion, there were 57 normoalbuminurics, 15 persistent microalbuminurics and eight proteinurics. Two 24 h ambulatory blood pressure monitorings were performed at the same urinary albumin excretion stage in absence of antihypertensive treatment for ea…
Relationships between 24 h blood pressure load and target organ damage in patients with mild-to-moderate essential hypertension.
2001
Objective: To analyse the relationships between 24 h blood pressure load (the percentage of systolic/diastolic blood pressures exceeding 140/90 mmHg while awake and 120/80 mmHg during sleep) and some indices of hypertensive target organ involvement, independently of the mean level of 24 h blood pressure. Methods: One hundred and thirty patients with mild-to-moderate hypertension underwent 24 h ambulatory blood pressure monitoring, ocular fundus examination, microalbuminuria assay and two-dimensional guided M-mode echocardiography. The study population was divided into subsets according to the systolic and diastolic 24 h blood pressure load values predicted from the regression equation relat…
Sympathetic Activity and Blood Pressure Pattern in Autosomal Dominant Polycystic Kidney Disease Hypertensives
1998
To study the potential role of sympathetic activity in the pathogenesis of arterial hypertension associated with autosomal dominant polycystic kidney disease (ADPKD) and to analyze its relationship with 24-hour blood pressure pattern, plasma catecholamines and 24-hour ambulatory blood pressure monitoring were evaluated in 30 ADPKD hypertensive patients (of which 17 without and 13 with renal failure) and in 50 essential hypertensives. The groups were matched for sex, body mass index, known duration of hypertension, and clinic blood pressure. Plasma catecholamines, determined in resting position, were higher in ADPKD patients without renal failure than in essential hypertensives. Nighttime di…
Pulsatile and steady 24-h blood pressure components as determinants of left ventricular mass in young and middle-aged essential hypertensives
2003
In order to explore the relations between left ventricular mass (LVM) and the pulsatile (pulse pressure) and steady (mean pressure) components of the blood pressure (BP) curve, 304 young and middle-aged essential hypertensive patients were studied by means of 24-h ambulatory BP monitoring and echocardiography. In the overall study population, both the BP components showed significant correlations with LVM. These correlations were unevenly distributed in the subgroups of subjects younger and in those older than 50 years. While in this latter subgroup, in multivariate analysis, both 24-h mean BP (24-MBP) (beta = 0.27; P = 0.008) and 24-h pulse pressure (24-h PP) (beta = 0.23; P = 0.02) were a…
Optical coherence tomography-based retinal vessel analysis for the evaluation of hypertensive vasculopathy
2013
Purpose Evaluation of retinal vessels in cardiovascular disease traditionally relies upon funduscopy, but more recently digital photo analysis has expanded the spectrum. As spectral domain optical coherence tomography (OCT) allows an in-vivo assessment of retinal tissue and its vessels on a histological scale, our study aimed at using this tool for the analysis of the retinal vasculature. Methods Circumferential peripapillary OCT scans (3DOCT-2000; Topcon Inc., Tokyo, Japan), with centration on the optic nerve head, were taken from 20 eyes (20 participants) with normal blood pressure and 20 eyes (20 participants) with arterial hypertension above 120 mmHg (mean blood pressure). The diameter …