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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 ...
Herrmann Tarrah A TA The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA 30332, - - 2013
Mitral annular calcification (MAC) involves calcium deposition in the fibrous annulus supporting the mitral valve (MV). When calcification extends onto the leaflets, valve opening can be restricted. The influence of MAC MV geometry on Doppler gradients is unknown. This study describes a novel methodology to rapid-prototype subject-specific MAC MVs. Replicated ...
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 KL Department of Integrative Physiology, University of Colorado Boulder, Boulder, Colorado;, †Intramural Research Program, Laboratory of Cardiovascular Science, National Institute on Aging, National Institutes of Health, Baltimore, Maryland;, ‡Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, Exeter, United Kingdom, §Division of Renal Diseases and Hypertension, University of Colorado Denver Anschutz Medical Center, Aurora, - - 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 ...
Goubergrits L - - 2013
Aortic coarctation (CoA) accounting for 3-11% of congenital heart disease can be successfully treated. Long-term results, however, have revealed decreased life expectancy associated with abnormal hemodynamics. Accordingly, an assessment of hemodynamics is the key factor in treatment decisions and successful long-term results. In this study, 3D angiography whole heart (3DWH) ...
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 ...
Ng K P - - 2013
Patients with chronic kidney disease (CKD) and renal transplant recipients (RTR) have increased cardiovascular risk. The value of measuring central pulse pressure (cPP) over brachial pulse pressure (pPP) is not known. Central PP was measured in 597 patients (364 CKD:233 RTR). In multivariate analysis, age and female gender positively correlated ...
Gregory Shaun D - - 2013
Aortic insufficiency (AI) is usually repaired prior to rotary blood pump (RBP) implantation but can develop during support due, in part, to the sustained RBP-induced high pressure gradient across the aortic valve. Repair of the aortic valve before or during RBP support predisposes these critically ill patients to even higher ...
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 ...
Diab Mahmoud - - 2013
We compared the haemodynamic performance of two pericardial aortic prostheses with the stent either on the outside (Perimount), or the inside (Mitroflow) of the valve cusps, with regard to sizing strategies and valve dimensions. We analysed discharge echoes from all patients who received an isolated Perimount (n = 537) or ...
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 ...
Figueroa A - - 2013
Increased wave reflection (augmented pressure (AP) and augmentation index (AIx)) and reduced muscle strength may increase cardiovascular risk in postmenopausal women. We evaluated the effects of whole-body vibration exercise training (WBVET) on aortic haemodynamics and leg muscle strength. Twenty-eight postmenopausal women (age, 56±3 years; brachial systolic blood pressure (SBP) 138±12 mm Hg; ...
Armentano Ricardo L - - 2013
Wave reflection is an important factor that influences pressure wave morphology and becomes more significant with aging, when cardiovascular risk increases. A pressure wave, measured at any location in the arterial tree, can be decomposed into its forward and backward components and depends on the corresponding amplitude and shifting time ...
Hashem Mohamed O - - 2013
Diastolic counter-pulsation has been used to provide circulatory augmentation for short term cardiac support. The success of intra-aortic balloon pump (IABP) therapy has generated interest in long term counter-pulsation strategies to treat heart failure patients. The authors have been developing a totally implantable extra aortic pulsation device for the circulatory ...
Delles Michael - - 2013
Several approaches for the non-invasive MRI-based measurement of the aortic pressure waveform over the heart cycle have been proposed in the last years. These methods are normally based on time-resolved, two-dimensional phase-contrast sequences with uni-directionally encoded velocities (2D PC-MRI). In contrast, three-dimensional acquisitions with tridirectional velocity encoding (4D PC-MRI) have ...
Nichols Wilmer W WW Division of Cardiovascular Medicine, University of Florida College of Medicine, Gainesville, Florida 32601, - - 2013
Wave reflections augment central aortic SBP and increase systolic pressure time integral (SPTI) thereby increasing left ventricular (LV) afterload and myocardial oxygen (MVO2) demand. When increased, such changes may contribute to myocardial ischemia and angina pectoris, especially when aortic diastolic time is decreased and myocardial perfusion pressure jeopardized. Accordingly, we ...
Tuzun Egemen - - 2013
Aortic valve regurgitation, fusion and thrombosis are commonly reported clinical complications after continuous flow ventricular assist device implantations; however, the complex interaction between reduced pulsatile flow physiology and aortic valve functions has not been studied experimentally. To address this, a continuous flow left ventricular assist device was implanted in four ...
Karatzi Kalliopi - - 2013
Moderate consumption of beer is associated with lower cardiovascular (CV) risk. The goal of this study was to determine the effect of beer consumption on CV risk. To explore the underlying mechanisms, we studied the acute effects of the constituents of beer (alcohol and antioxidants), on established predictors of CV ...
Bertram C D - - 2013
Our published model of a lymphatic vessel consisting of multiple actively contracting segments between non-return valves has been further developed by the incorporation of properties derived from observations and measurements of rat mesenteric vessels. These included (1) a refractory period between contractions, (2) a highly nonlinear form for the passive ...
Storre Jan H - - 2013
When supplemental oxygen is added to noninvasive positive pressure ventilation (NPPV) using non-ICU ventilators, it is usually introduced with a preset flow rate into the ventilatory circuit at a site next to the ventilator; however, the impact of different CO2 exhalation systems and leaks on actual inspired FiO2 and gas ...
Loerakker S - - 2013
Tissue engineering represents a promising technique to overcome the limitations of the current valve replacements, since it allows for creating living autologous heart valves that have the potential to grow and remodel. However, also this approach still faces a number of challenges. One particular problem is regurgitation, caused by cell-mediated ...
Clarenbach Christian F CF Sleep Disorders Center and Pulmonary Division, University Hospital Zurich, Zurich, - - 2013
Preliminary evidence supports an association between obstructive sleep apnea (OSA) and thoracic aortic dilatation, although potential causative mechanisms are incompletely understood; these may include an increase in aortic wall transmural pressures, induced by obstructive apneas and hypopneas. In patients undergoing cardiac catheterization, mean blood pressure (MBP) in the thoracic aorta ...
Sen Omer - - 2013
OBJECTIVES: Arterial hypertension leads to instability and heterogeneity in atrial conduction by these hemodynamic and morphological changes in heart and aorta. These changes can be evaluated by transthoracic echocardiography. The aim of this study was to evaluate the correlation of aortic elastic parameters and atrial electromechanical delay (AEMD) parameters in ...
Costantino Marco Fabio - - 2013
Purpose: The effect of Transcatheter Aortic Valve Implantation (TAVI) on left ventricular (LV) geometry and function was compared to traditional aortic replacement (AVR) by major surgery. METHODS: 45 patients with aortic stenosis (AS) undergoing TAVI and 33 AVR were assessed by standard echo Doppler the day before and 2 months ...
Hartung Julia Christine - - 2013
AIM: Positive end-expiratory pressure (PEEP) valves are used together with self-inflating bags (SIB) to provide a preset PEEP during manual ventilation. It has recently been shown that these valves deliver highly variable levels of PEEP. We hypothesised that material fatigue due to repeated thermo-sterilisation (TS) may contribute to varying reliability ...
Soender Trine K - - 2013
Ventriculo-arterial coupling (VAC) has been shown to be impaired in patients with type 2 diabetes mellitus (type 2 DM) and hypertension, and to improve with antihypertensive treatment. We examined if VAC in patients with type 2 DM and hypertension improved after a period of intensified antihypertensive treatment. VAC was estimated as the ratio of effective arterial ...
Lim Young-Hyo - - 2013
The proximal portion of the abdominal aorta (AA) is characterized by minimal arteriosclerosis compared with other aortic segments. To assess the clinical usefulness of this characteristic, the correlation between ultrasonographically measured proximal AA stiffness and brachial-ankle pulse wave velocity (baPWV) was examined. 285 subjects were analyzed, half with hypertension and ...
Glavan Ana C - - 2013
This paper describes the fabrication of pressure-driven, open-channel microfluidic systems with lateral dimensions of 45-300 microns carved in omniphobic paper using a craft-cutting tool. Vapor phase silanization with a fluorinated alkyltrichlorosilane renders paper omniphobic, but preserves its high gas permeability and mechanical properties. When sealed with tape, the carved channels ...
Pagel Paul S - - 2013
OBJECTIVE: Transmitral blood flow produces a vortex ring that enhances the hydraulic efficiency of early left ventricular (LV) filling. The effect of pressure-overload hypertrophy on the duration of LV vortex ring formation (vortex formation time [VFT]) is unknown. The current investigation tested the hypothesis that chronic LV pressure-overload hypertrophy produced ...
Li Zhi-Yong - - 2013
BACKGROUND: Ambulatory arterial stiffness index (AASI) has been proposed as a new measure of arterial stiffness for predicting cardio-cerebro-vascular morbidity and mortality. However, there has been no research on the direct relationships between AASI and arterial stiffness-determining factors. METHODS: We utilized beat-to-beat intra-aortic blood pressure (BP) telemetry to characterize AASI ...
Briasoulis Alexandros - - 2013
The contribution of sympathetic activation in the development of hypertension is supported by early experimental evidence based on surgical denervation of sino-aortic baroreceptors or lesions of the central relay station of the baroreflex, the nucleus tractus solitarii. Disruption of this area of the brain was associated with an immediate increase ...
Schramm Christoph - - 2013
BACKGROUND:The accuracy of measurement of the continuous noninvasive arterial blood pressure (CNAP) technique is unknown during sudden cardiocirculatory arrest.METHODS:In 33 patients undergoing elective transfemoral aortic valve implantation procedures under analgesic sedation, invasive arterial blood pressure (IAP) was compared with a CNAP device during episodes of severe hypotension (functional cardiocirculatory arrests ...
Dai Bing - - 2013
Abstract Background: Early studies have found better clinical efficiency when a nebulizer was used with noninvasive positive pressure ventilation (NPPV), compared with spontaneous breathing without NPPV. However, very limited research addressed factors that might affect aerosol delivery. This study aimed to investigate the influence of exhalation valves and nebulizer positions ...
Khir Ashraf William - - 2013
It has been observed that operating the intra-aortic balloon at an angle to the horizontal resulted in a reduction of the volume displaced toward the coronary arteries and compromised afterload reduction. Therefore, the aim of this work is to examine whether changing the current balloon shape, which has not been ...
Figueroa Arturo - - 2013
Postmenopausal women have increased arterial stiffness (brachial-ankle pulse wave velocity [baPWV]) and wave reflection. L-Citrulline supplementation reduces baPWV but not brachial blood pressure. Peripheral vasodilators decrease wave reflection amplitude or second systolic peak (SBP2) in radial artery and aorta, which are related to aortic systolic blood pressure (SBP). We examined ...
Spielvogel David - - 2013
Selective antegrade cerebral perfusion (SACP) for aortic arch surgery has evolved considerably since it was first reported. Various pressure rates have been investigated through animal models, as has the effect of warmer perfusate temperatures and hematocrit. Clinical research into pH management, the role of unilateral and bilateral perfusion, and core ...
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