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Results 351 - 400 of 1763
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Sommerfield Andrew J AJ Department of Diabetes, Royal Infirmary of Edinburgh, 51 Little France Crescent, Edinburgh, Scotland, - - 2007
To examine the effects of intravenous insulin and acute hypoglycemia on arterial wall stiffness and central hemodynamic responses in adults with and without type 1 diabetes. In 30 young male volunteers [10 nondiabetic (Group 1); 10 with type 1 diabetes, <5 yr duration (Group 2); 10 with type 1 diabetes, ...
Blyth Kevin G - - 2007
In the Framingham studies, systemic arterial pulse pressure correlated linearly with morbidity and mortality. Right ventricular (RV) systolic dysfunction and pulmonary circulation stiffening result in abnormalities of pulmonary arterial (PA) pulse pressure in PA hypertension (PAH). We investigated the prognostic potential of PA pulse pressure in 67 patients with PAH ...
Khir A W - - 2007
In a previous paper we demonstrated that the linear portion of the pressure-velocity loop (PU-loop) corresponding to early systole could be used to calculate the local wave speed. In this paper we extend this work to show that determination of the time at which the PU-loop first deviates from linearity ...
Segers Patrick - - 2007
Assessment of timing and magnitude of wave reflection is ideally based on wave separation analysis (WSA). In clinical practice, however, waveform analysis (WFA) is often used to study wave reflection, with different coexisting approaches to assess 'landmarks' on the waveform which are indicative for return of the reflected wave. The ...
Chen S S M - - 2008
OBJECTIVES: To determine the relation of ambulatory systolic blood pressure to aortic obstruction and more extensive vascular dysfunction, assessed by central aortic, peripheral conduit arterial and resistance vessel function. METHODS: 12 adults (5 native, 7 recoarctation) were studied before, and 2 weeks and 6 months after aortic stenting. Systolic blood ...
Mangiafico R A - - 2008
Osteoporosis has been associated with cardiovascular disease. We found increased augmentation index, a measure of wave reflections and arterial stiffness, and central pressures in osteoporotic postmenopausal women. They also showed a higher estimated aortic pulse wave velocity, indicating a stiffer aorta. These changes may increase cardiovascular risk in postmenopausal osteoporosis. ...
Papaioannou Theodore G - - 2007
BACKGROUND: Wave reflections are implicated increasingly in clinical research. AIMS: The purpose of the present study was to investigate whether wave reflection indices are reproducible when measured repeatedly (more than twice) at longer time intervals, namely hour-to-hour and week-to-week, in healthy subjects; something that has not yet been examined. METHODS: ...
Cheng Li-Tao - - 2007
Although the augmentation index (AIx) is widely used to evaluate arterial stiffness in clinics and research, some conflicting data exist in regard to its validity. We therefore performed a series of studies to test the validity of AIx. The first study in 196 peritoneal dialysis patients showed that AIx in ...
Virtanen M P O - - 2008
We evaluated the relationship between the variability in the left ventricular mass index (LVMI) and different hemodynamic factors. LVMI was associated with blood pressure and, in one subgroup, strongly to arterial pulse wave velocity (PWV). High physical activity was connected to increased LVMI, and a combination of low stroke index ...
Yildiz Mustafa - - 2007
This study aims to investigate arterial distensibility by using carotid-femoral (aortic) pulse wave velocity measurements in patients with cardiac syndrome X. The authors studied 10 patients with cardiac syndrome X (mean age 49.4 +/-7.5, 39 to 67 years old, 3 men) and 10 healthy subjects (mean age 50.0 +/-10.5, 38 ...
Tsui Po-Hsiang - - 2007
Augmentation index (AIx) calculated from the pressure waveform of an artery is widely used to quantify the arterial stiffness and evaluate the cardiovascular risk. The key for calculating AIx is to locate the inflection point on the waveform signal, which is caused by the wave reflection. This study applies the ...
Sakka S G - - 2007
BACKGROUND: Recently, continuous monitoring of cardiac output (CO) based on pulse contour analysis (Vigileo) has been introduced into practice. In this clinical study, we evaluated the accuracy of this system by comparing it with the transpulmonary thermodilution technique (TPID) in septic patients. METHODS: We studied 24 mechanically ventilated patients with ...
Hope Sarah A - - 2007
1. Arteries become stiffer with increasing age and various disease states. A complete description of arterial mechanical properties in vivo is not possible, although a number of methods have been used. 2. Detailed discussion in the present review is limited to pulse wave velocity and estimates of central waveform morphology ...
Wimmer Neil J - - 2007
White coat hypertension (WCH) is considered by some but not all investigators to be a benign condition without increased cardiovascular risk. Pulse wave analysis is a noninvasive method to measure how the reflected pressure wave interacts with central aortic blood pressure (BP) and to assess how it is related to ...
Eguchi Kazuo - - 2007
The authors examined the relationship of clinic and self-measured pulse pressure with target organ damage in 597 treated hypertensive patients without clinical evidence of renal dysfunction or a history of heart failure. The cross-sectional relationships of plasma brain natriuretic peptide (BNP) and urinary albumin/creatinine ratio with clinic and self-monitored pulse ...
Delerme Samuel - - 2007
PURPOSE: Noninvasive methods that could predict preload responsiveness are lacking. Our objective was to evaluate variations in pulse oximetry plethysmographic (POP) waveform amplitude (deltaPOP) induced by passive leg raising (PLR). METHODS: We attached a pulse oximeter to the middle finger of 25 spontaneously breathing volunteers at several time points: baseline ...
Sum K S - - 2007
Distributions of sound pressure and intensity on the surface of a flat impedance strip flush-mounted on a rigid baffle are studied for a grazing incident plane wave. The distributions are obtained by superimposing the unperturbed wave (the specularly reflected wave as if the strip is rigid plus the incident wave) ...
Lamia Bouchra - - 2007
OBJECTIVE: Peripheral arterial pulse pressure is increasingly used to assess hemodynamic status. Our aim was to test the respective influence of arterial stiffness, stroke volume, peripheral resistance, and various hemodynamic and demographic variables on peripheral pulse pressure in critically ill patients. DESIGN: Prospective study. SETTING: Medical intensive care unit of ...
Schofield Richard S - - 2007
BACKGROUND: Chronic heart failure (HF) is associated with increased central arterial pulse-wave reflections, which may contribute to increased myocardial oxygen demand. Although the treatment of HF via left-ventricular assist device (LVAD) placement has recently become widespread, the effects of LVAD therapy on central arterial pulse-wave reflections are unknown. METHODS: Central ...
Vyas Mitul - - 2007
BACKGROUND: Increased aortic stiffness contributes to systolic hypertension and increased cardiovascular risk. The augmentation index (AI), ie, the percentage of central pulse pressure attributed to reflected wave overlap in systole, was proposed as a noninvasive indicator of increased arterial stiffness. We evaluated this hypothesis by investigating relations between AI and ...
Levy Daniel - - 2007
BACKGROUND: Increased arterial stiffness and higher plasma natriuretic peptide and homocysteine levels are associated with elevated risk for cardiovascular disease. Little is known about the relations of natriuretic peptides and homocysteine to arterial wall stiffness in the community. METHODS AND RESULTS: We assessed the relations of plasma N-terminal atrial natriuretic ...
Nagasaki Toshiki - - 2007
OBJECTIVE: Subclinical hypothyroidism affects 5-15% of the population and is associated with increased cardiovascular morbidity, although this is controversial. We recently reported a significant increase in brachial-ankle pulse wave velocity (baPWV), a parameter of arterial stiffening and an independent predictor for cardiovascular events, in subclinical hypothyroidism. The current study was ...
Protogerou Athanase D - - 2007
Isolated systolic hypertension is predominantly observed in the elderly because of increased arterial stiffness. Aggressive treatment leads to excessive lowering of diastolic blood pressure and favors the presence of a J-shaped curve association with mortality. We investigated whether, in the elderly, this pattern of association is a simple epiphenomenon of ...
Mahmood Feroze - - 2007
INTRODUCTION: In the perioperative arena, pronounced changes in cardiac loading conditions can make assessment of diastolic parameters difficult. A number of Doppler techniques have been introduced to assess perioperative diastolic function. OBJECTIVES: To compare transmitral flow propagation velocity (Vp) with other pulse-wave Doppler echocardiographic assessments of diastolic function in patients ...
Roman Mary J - - 2007
Brachial blood pressure is predictive of cardiovascular outcome; however central pressure may better represent the load imposed on the coronary and cerebral arteries and thereby bear a stronger relationship to vascular damage and prognosis. Relations of brachial and central pressures to carotid artery hypertrophy (intimal-medial thickness and vascular mass), extent ...
Frisby Claudine L - - 2007
Administration of abdominal radiotherapy results in small intestinal motor dysfunction. We have developed a rat radiation enteritis model that, after exposure in vivo, shows high-amplitude, long-duration (HALD) pressure waves in ex vivo ileal segments. These resemble in vivo dysmotility where giant contractions migrate both antegradely and retrogradely. Mediation of these ...
Brennan J Matthew - - 2007
BACKGROUND: Rapid prediction of the effect of volume expansion is crucial in unstable patients receiving mechanical ventilation. Both radial artery pulse pressure variation (DeltaPP) and change of aortic blood flow peak velocity are accurate predictors but may be impractical point-of-care tools. PURPOSES: We sought to determine whether respiratory changes in ...
Townsend Raymond R - - 2007
PURPOSE OF REVIEW: The use of peripheral pressure wave recording devices to estimate central vessel pressure profiles has grown over the past decade. This review will briefly recount the history behind this technology and discuss where it fits into the measurement of vascular properties that may predict outcomes such as ...
Novellas Rosa - - 2007
Resistive index (RI) and pulsatility index (PI) are indirect measurements of blood flow resistance that may be measured by pulsed wave Doppler ultrasonography. Chemical restrain may potentially alter the indices although it is required to perform ultrasonography in some patients. The purpose of this study was to describe values for ...
Matsumae Tomoji - - 2007
Aortic pulse wave velocity (Ao-PWV) and ankle-brachial blood pressure index (ABPI) are significant prognostic factors in patients with end-stage renal disease (ESRD). Diabetes mellitus (DM) promotes changes in arterial walls, including marked increases in Ao-PWV and decreases in ABPI. To determine the prevalence of peripheral arterial occlusive disease (PAOD) as ...
Jiang Xiong-Jing - - 2007
BACKGROUND: In recent studies, benefit has been shown for angiotensin-converting enzyme (ACE) inhibitors and calcium antagonists over a beta-blocker in hypertension, through a greater reduction in aortic than brachial systolic and pulse pressure. No data are available on diuretics, even though these are the preferred initial treatment of patients with ...
Holm Sverre - - 2008
Two methods for analyzing intracranial pressure (ICP) waveforms were compared. The frequency domain (FD) method converts the signal from the time domain to the frequency domain by a fast Fourier transform (FFT), while the time domain (TD) method calculates peak-to-peak value of the pulse waveform directly from the time samples. ...
Mitchell Gary F GF Cardiovascular Engineering, Inc., Waltham, MA 02453, USA. - - 2007
The Prevention of Events with Angiotensin Converting Enzyme inhibition (PEACE) trial evaluated angiotensin-converting enzyme inhibition with trandolapril versus placebo added to conventional therapy in patients with stable coronary disease and preserved left ventricular function. The PEACE hemodynamic substudy evaluated effects of trandolapril on pulsatile hemodynamics. Hemodynamic studies were performed in ...
Vlachopoulos Charalambos V - - 2007
The effect of habitual cocoa consumption on arterial stiffness and wave reflection indexes, as well as on peripheral and central blood pressure, was assessed in 198 healthy subjects. In conclusion, higher cocoa intake was an independent determinant of low arterial stiffness and wave reflection indexes and was also independently associated ...
Bos Willem J W - - 2007
OBJECTIVES: Mean arterial pressure at the upper arm is traditionally calculated by adding one-third of the pulse pressure to the diastolic pressure. We questioned the general validity of this formula. METHODS: We used previously recorded resting intrabrachial pressure and Riva-Rocci Korotkoff blood pressure measurements in 57 subjects (study A) and ...
Okura Takafumi - - 2007
Aortic stiffness measured by aorta-iliac or carotid-femoral pulse wave velocity (PWV) predicts all-cause and cardiovascular mortality. Brachial-ankle PWV (baPWV) has been developed as a more convenient assessment of arterial stiffness. However, the problem with clinical use of baPWV is that the index itself is closely dependent on blood pressure. Recently, ...
Drighil Abdenasser - - 2007
BACKGROUND: Increased QT dispersion (QTd) has been associated with an increased risk for ventricular arrhythmias and sudden death in the general population and in various clinical states. METHODS: We investigated the impact of hemodialysis (HD) on QT, QTd, and T-wave amplitude in subjects with end-stage renal failure. Data on 49 ...
Hashimoto Junichiro - - 2007
BACKGROUND: Studies have required large numbers of patients to associate regression of left ventricular (LV) mass with a decrease in brachial cuff blood pressure (BP) in the treatment of hypertension. Hence, we prospectively examined potential superiority of pulse wave analysis over conventional BP measurement in predicting treatment-induced LV mass reduction. ...
Curtis Stephanie L - - 2007
In human heart failure the role of wave generation by the ventricle and wave reflection by the vasculature is contentious. The aim of this study was to compare wave generation and reflection in normal subjects with patients with stable compensated heart failure. Twenty-nine normal subjects and 67 patients with heart ...
Casey Darren P - - 2007
Large elastic artery stiffness increases with age and menopause is a mitigating factor in women. High-intensity resistance training (RT) increases arterial stiffness in young men and women. However, the effects of moderate intensity RT on central aortic pressure wave reflection in healthy postmenopausal women are unknown. Healthy sedentary normotensive postmenopausal ...
Tentolouris Nicholas - - 2007
BACKGROUND AND AIM: Reduction in aortic distensibility occurs early in the atherosclerosis process and carries a poor prognosis. Metabolic syndrome is common and it is associated with increased cardiovascular mortality. The aim of this cross-sectional study was to investigate the association between metabolic syndrome and aortic distensibility. METHODS AND RESULTS: ...
Knez Wade L - - 2008
Central hemodynamics such as ascending aortic blood pressure (BP), wave reflection and myocardial perfusion are clinically important in the context of cardiovascular health. Ultra-endurance athletes may be at greater risk of cardiovascular abnormalities due to chronically increased physiological stress placed on the cardiovascular system. This study was a cross-sectional investigation ...
Safar Michel E - - 2007
Whereas large arteries dampen oscillations resulting from intermittent ventricular ejection, small arteries steadily deliver optimal blood flow to various organs as the heart. The transition from pulsatile to steady pressure is influenced by several factors as wave travel, damping, and reflections, which are mainly determined by the impedance mismatch between ...
Wright Stephen A - - 2007
Structural and functional changes in wall and endothelial components of arterial blood vessels underlie the accelerated vascular disease progression in systemic lupus erythematosus (SLE). Using pulse contour analysis we sought to determine if subclinical vascular abnormalities could be identified in a well-characterised cohort of patients with SLE who had no ...
Aydos Sena Erdogan - - 2007
Telomeres--tandem repeats at the ends of mammalian chromosomes--serve as clocks that pace cellular aging in vitro and in vivo and they may be a major determinant of human aging, not only at the cellular level but also at the organ and perhaps systemic levels. In industrialized nations, pulse pressure rises ...
Zieman Susan J - - 2007
Arterial stiffening and endothelial dysfunction are hallmarks of aging, and advanced glycation endproducts (AGE) may contribute to these changes. We tested the hypothesis that AGE crosslink breakers enhance endothelial flow-mediated dilation (FMD) in humans and examined the potential mechanisms for this effect. Thirteen adults (nine men, aged 65 +/- 2 ...
Lind Lars - - 2008
BACKGROUND: Only a few previous studies have investigated endothelium-dependent vasodilation in the metabolic syndrome (MetS). In the Prospective Study of the Vasculature in Uppsala Seniors (PIVUS) study, different techniques to assess vasodilation in conduit and resistance arteries were evaluated in relation to the MetS and insulin resistance. METHODS: In this ...
Reesink Koen D - - 2007
Central blood pressure waveforms contain specific features related to cardiac and arterial function. We investigated posture-related changes in ventriculoarterial hemodynamics by means of carotid artery (CA) pulse wave analysis. ECG, brachial cuff pressure, and common CA diameter waveforms (by M-mode ultrasound) were obtained in 21 healthy volunteers (19-30 yr of ...
Mitchell Gary F GF Cardiovascular Engineering Inc, Waltham, Mass 02453, USA. - - 2007
Atrial fibrillation (AF) is responsible for considerable morbidity and mortality, making identification of modifiable risk factors a priority. Increased pulse pressure, a reflection of aortic stiffness, increases cardiac load and may increase AF risk. To examine relations between pulse pressure and incident AF. Prospective, community-based observational cohort in Framingham, Mass, ...
Allen John - - 2007
Photoplethysmography (PPG) is a simple and low-cost optical technique that can be used to detect blood volume changes in the microvascular bed of tissue. It is often used non-invasively to make measurements at the skin surface. The PPG waveform comprises a pulsatile ('AC') physiological waveform attributed to cardiac synchronous changes ...
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