Search Results
Results 251 - 300 of 1760
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Huang Ying - - 2008
PURPOSE: To investigate the potential clinical application of tissue Doppler imaging (TDI) for motion measurement of the aortic wall in healthy and hypertensive adults. METHOD: We used TDI to examine 53 hypertensive and 29 sex-matched healthy adults. Maximum velocity of the first and second systolic wall expansion peaks (S1, S2), ...
Franklin Stanley S - - 2008
Arterial stiffness of the large, elastic conduit arteries is considered a risk marker of vascular aging, as well as a new biomarker of cardiovascular (CV) disease. Arterial stiffness also plays an important role in the development of isolated systolic hypertension (ISH) in the middle-aged and elderly population. ISH is characterized ...
Swamy Gokul - - 2008
We introduce a patient- and time-specific technique to estimate the clinically more relevant aortic pressure (AP) waveform and beat-to-beat relative changes in cardiac output (CO) from multiple peripheral artery pressure (PAP) waveforms distorted by wave reflections. The basic idea of the technique is to first estimate the AP waveform by ...
Casey Darren P - - 2008
The relative contribution of sympathetic nervous system (SNS)-induced increase in peripheral vascular resistance on central artery blood pressure (BP) and aortic wave reflection (augmentation index; AIx) is not completely understood. Central BP and wave reflection characteristics were measured using radial artery applanation tonometry before, during a 3-min cold pressor test ...
Schnabel Renate - - 2008
Inflammation causes vascular dysfunction and perpetuates proatherosclerotic processes. We hypothesized that a broad panel of inflammatory biomarkers and single nucleotide polymorphisms in inflammatory genes is associated with vascular stiffness. We assessed 12 circulating inflammatory biomarkers (C-reactive protein, fibrinogen, interleukin-6, intercellular adhesion molecule-1, lipoprotein-associated phospholipase-A2 [mass and activity], monocyte chemoattractant protein-1, ...
McEniery Carmel M CM Clinical Pharmacology Unit, University of Cambridge, Addenbrooke's Hospital Box 110, Cambridge CB2 2QQ, United Kingdom. - - 2008
Pulse pressure varies throughout the arterial tree, resulting in a gradient between central and peripheral pressure. Factors such as age, heart rate, and height influence this gradient. However, the relative impact of cardiovascular risk factors and atheromatous disease on central pressure and the normal variation in central pressure in healthy ...
Malik A Rauoof AR Division of Cardiovascular Diseases, Mayo Clinic, 200 First Street Southwest, Rochester, MN 55905, - - 2008
Vascular reactivity may affect the stiffness characteristics of the arterial wall. We investigated the association between forearm microcirculatory and conduit artery function and measures of arterial stiffness in 527 asymptomatic non-Hispanic white adults without known cardiovascular disease. High-resolution ultrasonography of the brachial artery (ba) was performed to assess forearm microcirculatory ...
Tronvik E - - 2008
BACKGROUND: Many antihypertensive drugs are also used as migraine prophylactics, but the relationship between blood pressure and headache is not been well understood. The objective of the present study was to explore the association between blood pressure and headache prevalence, and the effect of antihypertensive medication on this relationship, using ...
Edwards David G - - 2008
Cardiovascular events are more common in the winter months, possibly because of hemodynamic alterations in response to cold exposure. The purpose of this study was to determine the effect of acute facial cooling on central aortic pressure, arterial stiffness, and wave reflection. Twelve healthy subjects (age 23 +/- 3 yr; ...
Najjar Samer S - - 2008
This study sought to evaluate whether pulse wave velocity (PWV), a noninvasive index of arterial stiffness, is a predictor of the longitudinal changes in systolic blood pressure (SBP) and of incident hypertension. Although arterial stiffness is believed to underlie, in part, the age-associated changes in SBP, particularly at older ages, ...
Foo Jong Y A - - 2009
Sympathetic responses to provocative tests have shown to provide an early prognosis of abnormalities in the human autonomic nervous system. Photoplethysmographic signal characteristics have been studied to identify vascular diseases. However, knowledge about the pulse-added arterial volume of the photoplethysmographic waveforms during these clinical investigations is limited. In all, 16 ...
Lee Sang-Hak - - 2008
Arterial stiffness is significantly correlated with cardiovascular risk in patients with hypertension. Although arterial stiffness increases with age and other vascular risk factors, the effect of heart rhythm on arterial stiffness is uncertain. The aim of this study was to determine whether the presence of atrial fibrillation is associated with ...
Cannesson Maxime - - 2008
BACKGROUND: Respiratory variations in the pulse oximeter plethysmographic waveform amplitude (deltaPOP) are sensitive to changes in preload and can predict fluid responsiveness in mechanically ventilated patients. However, they cannot be easily calculated from a bedside monitor. Pleth variability index (PVI, Masimo Corp., Irvine, CA) is a new algorithm that automatically ...
Abhayaratna Walter P - - 2008
OBJECTIVE: An age-dependent relationship between aortic and left ventricular (LV) stiffening has been observed in community-based adults. Our aim was to compare the performances of wave reflection-dependent (pulse pressure) and independent [carotid-femoral pulse wave velocity (PWV)] indexes of aortic stiffness to detect preclinical LV diastolic dysfunction. METHODS: In this case-control ...
Tsioufis Costas - - 2008
OBJECTIVE: In the present study we assessed the impact of metabolic syndrome (MS) and its components on markers of cardiovascular and renal damage in a population of essential hypertensives. METHODS: A total of 651 consecutive, untreated and non-diabetic hypertensives (age 54 +/- 12 years, 340 males) who were included in ...
Muxfeldt Elizabeth S - - 2008
The ambulatory arterial stiffness index (AASI) is a recently proposed index derived from 24-h ambulatory blood pressure monitoring (ABPM) for the evaluation of arterial stiffness. In this cross-sectional study we investigated whether AASI reflects arterial stiffness in patients with resistant hypertension by comparing AASI and ambulatory pulse pressure (PP) with ...
Seidlerová Jitka - - 2008
We investigated the heritability and familial aggregation of various indexes of arterial stiffness and wave reflection and we partitioned the phenotypic correlation between these traits into shared genetic and environmental components. Using a family-based population sample, we recruited 204 parents (mean age, 51.7 years) and 290 offspring (29.4 years) from ...
Nichols Wilmer W WW Division of Cardiovascular Medicine, Department of Medicine, University of Florida College of Medicine, Gainesville, FL 32610, USA. - - 2008
Brachial systolic and pulse blood pressures (BPs) are better predictors of adverse cardiovascular (CV) events than diastolic BP in individuals older than 50 years. The principal cause of increased systolic and pulse BP is increased stiffness of the elastic arteries as a result of degeneration and hyperplasia of the arterial ...
Teixeira L S - - 2008
OBJECTIVES: To establish reference curves for ductus venosus blood flow velocities during the first trimester and compare them with previously published curves. METHODS: This was a cross-sectional and retrospective study performed between January 1998 and January 2003. The following inclusion criteria were used: singleton pregnancy, velocity measurements taken when the ...
Olafiranye Oladipupo - - 2008
Studies have found less cardiovascular risk reduction in patients treated with beta-blockers (BBs) compared with other agents. We compared the severity of aortic atherosclerosis, arterial stiffness, and wave reflection in patients treated and not treated with BBs. Seventy-two patients, 37 treated with BBs and 35 not treated, referred for transesophageal ...
Vyssoulis Gregory P - - 2008
The purpose of the present study was to assess angiotensin receptor blocker (ARB) treatment on arterial stiffness in select hypertensive patients and define possible differences between smokers and nonsmokers. The authors evaluated 81 consecutive, nondiabetic patients (mean age, 52 years; 47 men) with uncomplicated essential hypertension with high plasma renin ...
Oyamada Jun - - 2008
BACKGROUND: There are limited data regarding whether the ratio of the peak transmitral flow velocity during early diastole (E) to the peak mitral annular velocity during early diastole (Ea) obtained by tissue Doppler imaging (TDI) and the plasma levels of the B-type natriuretic peptide (BNP) are useful for evaluating the ...
Munir Shahzad - - 2008
Exercise markedly influences pulse wave morphology, but the mechanism is unknown. We investigated whether effects of exercise on the arterial pulse result from alterations in stroke volume or pulse wave velocity (PWV)/large artery stiffness or reduction of pressure wave reflection. Healthy subjects (n = 25) performed bicycle ergometry. with workload ...
Macedo Maria L - - 2008
Normal pregnancy is associated with profound alterations in the maternal cardiovascular system. The aim of the present study was to assess noninvasively, using applanation tonometry, the maternal central aortic blood pressures (BP), effects of wave reflection and arterial stiffness (aortic and brachial pulse wave velocity) in normal pregnancy. This was ...
Dart Anthony M - - 2008
This study examined the importance of aortic dimensions in determining pulse pressure in elderly hypertensives participating in the 2nd Australian National Blood Pressure Study, including a substantial number not previously receiving blood pressure lowering medication. Aortic dimensions were determined by ultrasound at the transverse arch and at the insertion of ...
Mitchell Gary F - - 2008
Pulse pressure increases with advancing age particularly in women. As a result, women have a higher pulse pressure than men from midlife onward. Higher pulse pressure in older women as compared to men is often attributed to increased aortic wall stiffness and premature wave reflection. To evaluate this hypothesis, we ...
Tuncer Mustafa - - 2008
INTRODUCTION: P-wave dispersion (PWD) has been shown to be a non-invasive electrocardiographic predictor for development of atrial fibrillation (AF). Thus, it may be possible to decrease AF risk through improvement in PWD. Our objective was to compare the effects of cilazapril and atenolol on P-wave duration and dispersion in patients ...
Chemla Denis - - 2008
Total arterial stiffness plays a contributory role throughout aging and in numerous cardiovascular diseases, including hypertension. Aortic stiffening is responsible for an increased characteristic impedance (ie, the impedance to the left ventricular pulsatile flow), thus increasing the forward pressure-wave amplitude that contributes to pulse pressure elevation. Aortic stiffening also increases ...
De Silva D - - 2008
Arterial stiffness, a known risk factor for atherosclerosis, can be measured directly with carotid-femoral pulse wave velocity (CPWV) and indirectly with central pulse pressure (CPP). We aimed to compare central and brachial pulse pressures, and to profile CPWV and CPP among ischemic stroke patients. We studied 198 consecutive prospective ethnic ...
Heffernan Kevin S - - 2008
BACKGROUND AND AIMS: Arterial stiffening with aging causes early return of reflected arterial pressure waves from peripheral arteries and augmentation of these waves on incident aortic pressure waves. The purpose of this study was to examine the relationship between pressure wave reflection and augmentation from peripheral arteries and peripheral sympathetic ...
Shimizu Motohiro - - 2008
Recent studies have revealed the clinical usefulness of central blood pressure (BP) as an index of risk for cardiovascular disease. The arterial pulse waveform is the sum of the forward pressure wave generated by left ventricular ejection and a backward propagating wave that is subsequently reflected from the peripheral site, ...
Michikawa Takehiro - - 2008
OBJECTIVES: This study evaluated the association between job strain and subclinical indicators of arteriosclerosis simultaneously in the cerebral artery, the aorta, and the carotid artery. METHODS: The participants in this cross-sectional study consisted of 352 male factory workers between the ages of 24.9 to 55.8 (mean 41.7) years who had ...
Roytvarf Alexander - - 2008
The energetic balance of forces in the cardiovascular system is vital to the stability of blood flow to all physiological systems in mammals. Yet, a large-scale, theoretical model, summarizing the energetic balance of major forces in a single, mathematically closed system has not been described. Although a number of computer ...
Casey Darren P - - 2008
BACKGROUND: Age is associated with increases in elastic artery stiffness and pulse wave velocity, which cause profound changes in arterial pressure waves, including increases in the augmentation index (AIx) and wasted left ventricular (LV) energy. We examined the impact of aging on the central blood pressure (BP) waveform and wave ...
Gambillara Veronica - - 2008
BACKGROUND: With advancing age arteries stiffen, reducing arterial compliance and leading to the development of systolic hypertension and to a substantial increase in pulse pressure. An augmented pulse pressure can be a predictor of the development of hypertension, which has been linked to several cardiovascular diseases including atherosclerosis, and to ...
Papaioannou Theodore G - - 2008
BACKGROUND: Augmentation Index (AIx) is related to cardiovascular diseases, risk, and mortality. AIx is associated with heart rate but the effect of aortic stiffness on this relationship has not been studied. The purpose of our study was to investigate the relationship between AIx and heart rate at different aortic stiffness ...
Chen Ju-Yi - - 2008
BACKGROUND: Although premature ventricular complex (PVC) occurs frequently, its predisposing factors have rarely been studied. We examined the connection between PVC and aortic stiffness. METHODS: We recruited 200 consecutive patients (< 50 years, 95 men, mean age 36 +/- 10 years) who received a 24-hour ambulatory electrocardiography examination for palpitation ...
Hashimoto Junichiro - - 2008
BACKGROUND: Wave reflection during the systole increases left ventricular (LV) pressure, tension-time index (TTI) and myocardial oxygen requirement. The purpose of this study was to extract that component of extra myocardial oxygen requirement that is due to early systolic wave reflection, define it as wasted effort (DeltaE(w)), and examine its ...
Petrie Colin J - - 2009
In patients with atherosclerotic disease, a high pulse pressure is an important predictor of cardiovascular events. However, in patients with chronic heart failure (CHF) a low pulse pressure is related to worse outcome, although no distinction was made between ischaemic and non ischaemic heart failure. We therefore aimed to compare ...
Qasem Ahmed - - 2008
Aortic pulse wave velocity (PWV), calculated from pulse transit time (PTT) using 2 separate pulse recordings over a known distance, is a significant biomarker of cardiovascular risk. This study evaluates a novel method of determining PTT from waveform decomposition of central aortic pressure using a single pulse measurement. Aortic pressure ...
Swamy Gokul - - 2008
We developed a new technique to estimate the aortic pressure (AP) waveform from a single peripheral artery pressure (PAP) waveform. The technique 1) employs a parallel tube model of the arterial tree to establish a transfer function relating PAP to AP with unknown parameters; 2) estimates the parameters from the ...
Boari Gianluca E M - - 2008
OBJECTIVE: It has been previously demonstrated that structural alterations of subcutaneous small resistance arteries of hypertensive patients, as indicated by an increased media to lumen (M/L) ratio, is the most potent predictor of cardiovascular events. The aim of the present study was to identify possible determinants of small resistance artery ...
Reddy Anilkumar K - - 2008
The Little dwarf mouse lives 30% longer than its age-matched wild-type (WT) mouse. We determined aortic input impedance in 21 (8 Little, 13 WT) 4 month-old mice. Modulus of impedance was calculated from the Fourier transformed aortic pressure (P) and average luminal flow velocity (V(avg)) as |Z(i)| = |P|/|V(avg)|. Characteristic ...
Sola Josep - - 2008
The continuous separate monitoring of cardiac and vascular functions provide important insights on cardiovascular regulation. In the last years several attempts have failed at demonstrating the feasibility of using Pulse Wave Velocity as a surrogate indicator of arterial blood pressure. Upon the hypothesis that the cause of PWV unreliability is ...
Cay Serkan - - 2008
BACKGROUND: Diabetes mellitus and impaired fasting glucose (IFG) are associated with future cardiovascular disorders. Aortic pulse pressure (PP) and fractional pulse pressures (FPPs) are strong and independent indicators of the risk of coronary heart disease. These conditions have been reported to be associated with endothelial dysfunction. In the present study, ...
Vergnaud Anne Claire - - 2008
OBJECTIVES: The ESH2003 report (J Hypertens 2003, 21:1011-1053) has classified brachial blood pressure into six groups reflecting the consistently increasing cardiovascular risk caused by high blood pressure. Chronically treated hypertensive individuals with well-controlled blood pressure retain higher cardiovascular risk than normotensive untreated individuals. Differences between these groups in arterial stiffness, ...
Doyle Arthur - - 2008
BACKGROUND: Arterial stiffness is associated with adverse cardiovascular outcomes, particularly in end-stage renal disease (ESRD). One mechanism linking arterial stiffness with cardiovascular events may be the changes in pressure wave reflection on ventricular ejection and coronary perfusion during diastole. We illustrate this using MRI to describe aortic elastic properties and ...
Hahn Jin-Oh - - 2008
This paper presents a new system identification approach to the reconstruction of central aortic blood pressure signal by exploiting a non-invasive peripheral blood pressure measurement. This technique, which is called the 'adaptive' transfer function, is able to reconstruct the aortic blood pressure signal by characterizing the aortic-to-peripheral cardiovascular dynamics solely ...
Rosa J - - 2008
Arterial wall stiffness is considered an independent cardiovascular risk factor. Aim of this study was to evaluate relationship between clinical, 24-hour, average day-time and night-time blood pressure (BP) and measures of arterial stiffness assessed by pulse wave velocity (PWV) (using SphygmoCor applanation tonometer) in essential hypertension (severe-resistant (RH, n=29) and ...
McNames James - - 2008
Cardiovascular signals such as arterial blood pressure (ABP), pulse oximetry (POX), and intracranial pressure (ICP) contain useful information such as heart rate, respiratory rate, and pulse pressure variation (PPV). We present a novel state-space model of cardiovascular signals and describe how it can be used with the extended Kalman filter ...
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