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Gao Mingwu - - 2013
Pulse wave velocity (PWV) is the most important index of arterial stiffness. It is conventionally estimated by noninvasively measuring central and peripheral blood pressure (BP) and/or velocity (BV) waveforms and then detecting the foot-tofoot time delay between the waveforms wherein wave reflection is presumed absent. We developed techniques for improved ...
Lamata Pablo - - 2013
To describe the assessment of the spatiotemporal distribution of relative aortic pressure quantifying the magnitude of its three major components. Nine healthy volunteers and three patients with aortic disease (bicuspid aortic valve, dissection, and Marfan syndrome) underwent 4D-flow CMR. Spatiotemporal pressure maps were computed from the CMR flow fields solving ...
Taylor Jennifer L - - 2013
Elevated central pressures and arterial stiffness are associated with increased peripheral resistance and higher sympathetic nervous system activity. Additionally, consumption of a meal is known to be sympathoexcitatory. However, the acute effects of a meal on aortic wave reflection and stiffness are unknown. Therefore, we tested the hypothesis that aortic ...
Ozdemir Emrah - - 2013
The relationship between cardiovascular diseases and the diurnal blood pressure (BP) rhythm was researched in many studies. It has been demonstrated that the nondipping pattern has been associated with target organ damage and worsened cardiovascular outcomes. The aim of our study was to assess the relationship between aortic elasticity parameters ...
Quail Michael A - - 2013
Central aortic systolic pressure (CASP) is a more accurate measure of load and cardiovascular risk than brachial pressure. Unfortunately, CASP is difficult to measure using current methods. In this study we report three methods of determining CASP by combining MR-derived aortic area curves with different models of the pressure-area relationship. ...
Taviani Valentina V Department of Radiology, University of Cambridge, Cambridge, - - 2014
To use a simplified hemodynamic model and Fourier-encoded velocity data to measure pulse pressure (PP) in the descending aorta. A one-dimensional, cylindrically localized pulse sequence with Fourier velocity encoding (FVE) was used to obtain time-dependent velocity distributions along the descending aorta. Numerical evaluation of a simplified hemodynamic model, based on ...
Mosadegh Bobak - - 2013
One strategy for actuating soft machines (e.g., tentacles, grippers, and simple walkers) uses pneumatic inflation of networks of small channels in an elastomeric material. Although the management of a few pneumatic inputs and valves to control pressurized gas is straightforward, the fabrication and operation of manifolds containing many (>50) independent ...
Gómez-Marcos Manuel A - - 2013
To examine the relationship between ambulatory blood pressure monitoring parameters (ABPM) and electrocardiographic criteria for left-ventricular hypertrophy (LVH) in adults. This study analyzed 1,544 subjects from the EVIDENT study (mean age = 55±14 years; 61% women). A standard electrocardiograph (ECG) and 10 criteria were used to detect LVH. Office and ...
Stergiotou Iosifina - - 2013
To assess carotid and aortic intima-media thickness (IMT) in term growth restricted newborns with and without prenatal signs of severity. This was a prospective study comprising 67 cases diagnosed prenatally and 134 normally grown newborns. Cases were sub-classified into small-for-gestational age (SGA) with no signs of severity and those with ...
Myles Valtresa - - 2013
Background: Hypertension is a known risk factor for aortic stenosis. The elevated blood pressure increases the transvalvular load and can elicit inflammation and extracellular matrix (ECM) remodeling. Elevated cyclic pressure and the vasoactive agent angiotensin II (Ang II) both promote collagen synthesis, an early hallmark of aortic sclerosis. In the ...
Mittal S R - - 2013
A case of mild to moderate aortic regurgitation with presystolic closure of mitral valve and presystolic mitral regurgitation is reported. This echocardiographic finding is a reliable marker of significantly increased LV end-diastolic pressure.
Mason R Preston - - 2013
Clinical trials have shown that amlodipine reduces cardiovascular events at a rate that is not predicted by changes in brachial arterial pressure alone. These findings may be explained, in part, by the pleiotropic effects of amlodipine on endothelial cell (EC) function. In this study, we elucidated the effect of amlodipine ...
Vrachatis D - - 2013
Biomarkers derived noninvasively from the aortic blood pressure (BP) waveform provide information regarding cardiovascular (CV) risk independently of brachial BP (bBP). Although body position has significant impact on the assessment of bBP, its effect on aortic hemodynamics remains unknown. This study investigated the changes in both brachial and aortic hemodynamics, ...
Koutnik Andrew P - - 2013
Impaired leg arterial stiffness (pulse wave velocity, PWV) and vasodilatory function are found after stroke. Acute passive vibration (PV) decreases leg PWV (legPWV) and pressure wave reflection (aortic augmentation index, aAIx) in healthy men. Our objective was to evaluate the effects of acute PV on aAIx and PWV in the ...
Wohlfahrt Peter - - 2013
Carotid-femoral pulse wave velocity (PWV), as a parameter of aortic stiffness, is an established marker of cardiovascular risk. There has been increasing use of arterial stiffness parameters combining aortic and muscular stiffness or a parameter derived from PWV - the stiffness index beta (BETA = ln(systolic/diastolic pressure) × 2 blood viscosity/pulse pressure × PWV(2)). The aim ...
Pullan M - - 2013
Mitral regurgitation is frequently classified as mild, moderate or severe based on echocardiography. Patients with mild mitral regurgitation are usually managed medically. We hypothesise that mild mitral regurgitation as assessed volumetrically can in fact be severe when analysed from a bioenergetics point of view. The conservation of energy predicts that ...
Causey Marlin Wayne - - 2013
Aortic occlusion is accompanied by a hyperdynamic cardiovascular response secondary to increased systemic vascular resistance and increased cardiac output. This study was designed primarily to determine the safety and cardiovascular response to hydrogen sulfide (H2S; HS) administration with supraceliac aortic cross-clamp and, secondarily, on short-duration resuscitation. A validated porcine model ...
Jamalian Samira - - 2013
Any disruption of the lymphatic system due to trauma or injury can lead to edema. There is no effective cure for lymphedema, partly because predictive knowledge of lymphatic system reactions to interventions is lacking. A well-developed model of the system could greatly improve our understanding of its function. Lymphangions, defined ...
Eeftinck Schattenkerk Daan W - - 2013
The vasodilating beta-blocker nebivolol is thought to be superior in lowering wave reflection and central blood pressure (BP) compared to nonvasodilating beta-blockers. The results from studies comparing nebivolol with either metoprolol or atenolol, with or without hydrochlorothiazide (HCTZ), are not unequivocal. We examined the effects of nebivolol 5 mg and metoprolol ...
Muraru Denisa - - 2013
Reference ranges of ascending aorta diameters (AAoD) for two-dimensional echocardiography (2DE) using inner edge (IE) convention are lacking, preventing the comparison of AAoD measurements by 2DE with those obtained by other imaging modalities. We used harmonic imaging 2DE to prospectively study 218 healthy volunteers (56% women, 42 ± 15 years, ...
Khan Bobby V BV Atlanta Vascular Research Foundation, Atlanta, Ga., - - 2013
Sixty-six self-identified African-American subjects with stage 1 and 2 hypertension and characteristics of the cardiometabolic syndrome were treated with amlodipine/olmesartan (A/O) versus losartan/hydrochlorothiazide (L/H) for 20 weeks in an open-label, active comparator fashion. Subjects not meeting a blood pressure (BP) value of <125/75 mm Hg on either regimen at week ...
Catalano Mariella - - 2013
A number of conditions have been associated with functional changes of large arteries. The aim of this study was to evaluate the factors associated with aortic stiffness in patients with peripheral arterial disease (PAD). The authors studied 86 patients with PAD (ankle-brachial pressure index [ABPI] ≤0.9) and 86 controls. Aortic ...
Lockie Tim - - 2013
We report on two cases that illustrate an important caveat in the measurement of fractional flow reserve (FFR) in coronary arteries. To obtain accurate FFR measurements, two fundamental requirements must be fulfilled. One is to minimize microvascular resistance; the other is that there is no damping of the proximal aortic ...
Zhang Junzhi - - 2013
On/off solenoid valves with PWM control are widely used in all types of vehicle electro-hydraulic control systems respecting to their desirable properties of reliable, low cost and fast acting. However, it can hardly achieve a linear hydraulic modulation by using on/off valves mainly due to the nonlinear behaviors of valve ...
Sharman James E - - 2013
Arm cuff blood pressure (BP) may overestimate cardiovascular risk. Central aortic BP predicts mortality and could be a better method for patient management. We sought to determine the usefulness of central BP to guide hypertension management. This was a prospective, open-label, blinded-end point study in 286 patients with hypertension randomized ...
Redón Josep - - 2013
Introduction. The main objective was to compare the mean change in augmentation index of hypertensive patients treated with nebivolol or atenolol. Methods. Multicenter, double-blind randomized study conducted in six Spanish centers. We enrolled outpatients between the ages of 40 and 65 years with mild or moderate essential hypertension (systolic blood ...
Li Jack Z - - 2013
Acute aortic syndromes are among the most lethal of the cardiovascular diseases. Delays in recognition, diagnosis, and treatment are associated with increases in mortality. Signs and symptoms are sometimes subtle and atypical, and a high index of suspicion is useful to guide the diagnostic evaluation. Uncontrolled hypertension remains the most ...
Kamimura Daisuke - - 2013
Background: A small proximal aortic diameter (AoD) is thought to be associated with a higher characteristic impedance of the proximal aorta. However, there has been no evidence of a relationship between directly evaluated AoD and directly measured central aortic pressure or the outcome of patients with cardiovascular diseases. Methods and ...
Karmonik Christof - - 2013
Objectives: To evaluate hemodynamic changes during aneurysmal dilatation in chronic type B aortic dissections compared to hemodynamic parameters in the healthy aorta with the use of computational fluid dynamics (CFD). Methods: True lumen (TL)/false lumen (FL) dimensional changes, changes in total pressure (TP), and wall shear stress (WSS) were evaluated ...
Harada Kenji - - 2013
-Presence of syncope in aortic valve stenosis (AS) predicts a grave prognosis. However, the evaluation of AS severity has been limited to valve-specific factors such as aortic valve area and mean transaortic pressure gradient. Recently, valvuloarterial impedance (Zva) was proposed for estimation of the global left ventricular afterload. Therefore, because ...
Papaioannou Theodore G - - 2013
Surrogates of aortic wave reflection and arterial stiffness, such as augmentation index (AIx), augmentation pressure, pulse wave velocity (PWV) and pulse pressure amplification (PPampl) are independent predictors of cardiovascular risk. A novel ambulatory, brachial cuff-based oscillometric device has been recently developed and validated, yielding 24-h assessment of the aforementioned parameters ...
Charitaki Evangelia - - 2013
Haemodialysis patients have an increased prevalence of hypertension and risk of cardiovascular mortality and stroke. Higher dialysate calcium concentrations have been reported to cause both an acute and chronic increase in arterial stiffness. We therefore looked at changes in arterial stiffness in established haemodialysis patients to determine whether there was ...
Pase Matthew P - - 2013
Central (aortic) blood pressures differ from brachial pressures and may be more relevant to the study of cognitive function, given that blood is delivered to the brain through the central large arteries. Pulse-pressure amplification reflects the augmentation of blood pressure between the central and peripheral arteries, which diminishes with aging. ...
Wang Zhengjia - - 2013
The liquid drop captured at the capillary end, which is observed in capillary valve and pendant drop technique, is investigated theoretically and experimentally. Because of contact line pinning of the lower meniscus, the lower contact angle is able to rise from the intrinsic contact angle (θ∗) so that the external ...
Srivastava Uma U Department of Anaesthesia and Critical Care, S N Medical College, Agra, Uttar Pradesh, - - 2013
Invention of oxygen cylinder was one of the most important developments in the field of medical practice. Oxygen and other gases were compressed and stored at high pressure in seamless containers constructed from hand-forged steel in1880. Materials technology has continued to evolve and now medical gas cylinders are generally made ...
Ortiz Tatiana de Arruda - - 2013
To evaluate the performance of manual resuscitators (MRs) used in Brazil in accordance with international standards. Using a respiratory system simulator, four volunteer physiotherapists employed eight MRs (five produced in Brazil and three produced abroad), which were tested for inspiratory and expiratory resistance of the patient valve; functioning of the ...
Theilade Simone - - 2013
Non-invasive measurements of 24 h ambulatory central aortic systolic pressure (24 h-CASP) and central pulse pressure (24 h-CPP) are now feasible. We evaluate the relationship between 24 h central blood pressure and diabetes-related complications in patients with type 1 diabetes. The study was cross-sectional, including 715 subjects: 86 controls (C), ...
Rabkin Simon W - - 2013
The objective was to evaluate coronary blood flow (CBF) in patients with systemic arterial hypertension (HTN) and to compare it with CBF in patients with aortic regurgitation (AR). A systematic literature search was conducted using the reference terms "coronary blood flow" and either "aortic regurgitation" or "hypertension." The selection criteria ...
Satoh Shinji - - 2013
We investigated gender differences in factors influencing the electrocardiographic (ECG) findings of left ventricular hypertrophy (LVH) in patients with severe aortic stenosis (AS). The functional and geometric responses of the left ventricle to chronic pressure overload, such as hypertension and AS, have been reported to be different between men and ...
Hintsala Heidi - - 2013
Short- and long-term exposures to cold increase blood pressure and may explain the higher wintertime cardiovascular morbidity and mortality. Hypertensive subjects may be more susceptible to adverse cold-related cardiovascular health effects. The aim of our study was to assess the effect of short-term cold exposure on central aortic blood pressure ...
Eleid Mackram F MF Division of Cardiovascular Diseases and Internal Medicine, Mayo Clinic College of Medicine, Rochester, - - 2013
Low-gradient severe aortic stenosis with preserved ejection fraction is an increasingly recognized entity, and symptomatic patients may benefit from aortic valve replacement. However, systemic hypertension frequently coexists with low-gradient severe aortic stenosis, which itself may cause elevated left ventricular (LV) filling pressures with resultant symptoms of dyspnea. Symptomatic patients with ...
Iida Masato - - 2013
Cystatin C, a cathepsin inhibitor, is involved in the remodeling of human aortic valve and left ventricle (LV). Objective Cystatin C may be related to the severity of aortic regurgitation (AR). We measured cystatin C and CRP in hypertensive patients with mild-to-moderate AR (n=120) and in those without AR (n=128). ...
Jablonski Kristen L - - 2013
Systolic BP and large elastic artery stiffness both increase with age and are reduced by dietary sodium restriction. Production of the natriuretic hormone marinobufagenin, an endogenous α1 Na+,K+-ATPase inhibitor, is increased in salt-sensitive hypertension and contributes to the rise in systolic BP during sodium loading. The hypothesis was that dietary ...
Schlöglhofer Thomas - - 2013
Purpose: Investigations of the circulatory system in vitro use mock circuits that require valves to mimic the cardiac situation. Whereas mechanical valves increase water hammer effects due to inherent stiffness and do not allow the use of pressure lines or catheters, bioprosthetic valves are expensive and of limited durability in ...
Katsi Vasiliki - - 2013
Systemic hypertension and aortic valve stenosis (AVS) are both age-related diseases. The pathophysiology of AVS shares some similarities with essential hypertension, which might be the link between the two diseases. Although AS is usually related with low blood pressure levels, approximately one third of patients with severe AS suffer from ...
Syedain Zeeshan H - - 2013
A novel tissue-engineered heart valve (TEHV) was fabricated from a decellularized tissue tube mounted on a frame with three struts, which upon back-pressure cause the tube to collapse into three coapting "leaflets." The tissue was completely biological, fabricated from ovine fibroblasts dispersed within a fibrin gel, compacted into a circumferentially ...
Gaddum Nicholas R - - 2013
Thoracic pulse wave velocity (PWV) variation due to modulated trans-mural pressure (TMP) may indicate mechanical properties of the aorta. Our aim was to measure beat-to-beat thoracic PWV and TMP to observe its normal variation during respiratory maneuvers. We validated PWV measurements from a real-time velocity projection MRI scan in a ...
Alihanoglu Yusuf I - - 2013
The aim of this study was to investigate impact of central blood pressure (BP) levels and sex on the difference between central and upper arm oscillometric BP values. Oscillometric arterial BP measurements of 675 patients were simultaneously compared with values measured from the ascending aorta. The patients were divided into ...
Mihl Casper - - 2013
Both iodine delivery rate (IDR) and iodine concentration are decisive factors for vascular enhancement in computed tomographic angiography. It is unclear, however, whether the use of high-iodine concentration contrast media is beneficial to lower iodine concentrations when IDR is kept identical. This study evaluates the effect of using different iodine ...
Luong Quang Minh - - 2013
Glaucoma drainage device (GDD) implantation is an effective method of lowering the intraocular pressure (IOP). Commonly used GDDs can be classified into nonvalved and valved. Although a stable IOP is critical, currently available devices often cause extreme IOP fluctuations: nonvalved GDDs suffer from a risk of hypotony (IOP < 5 ...
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