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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 ...
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 ...
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 ...
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 - - 2013
Background: 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. Methods: In patients undergoing cardiac catheterization mean blood pressure (MBP) in the ...
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 ...
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 ...
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 ...
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 ...
Yoganathan Ajit P - - 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 patient-specific MAC MVs. Replicated ...
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 ...
Briasoulis Alexandros - - 2013
The beneficial effects of nebivolol on arterial stiffness and endothelial dysfunction are well documented in untreated hypertensive patients and differ from nonvasodilatory β-blockers. This study tests the hypothesis that the addition of nebivolol in predominantly African American patients with type 2 diabetes already receiving maximally tolerated doses of renin-angiotensin system ...
Williams Bryan B Institute of Cardiovascular Science, University College London, 170 Tottenham Court Rd, London W1T 7HA, UK. - - 2013
Elevated brachial blood pressure (BP) is associated with increased cardiovascular risk and predicts morbidity and mortality in humans. Recently, 24-hour ambulatory BP monitoring and assessment of central aortic BP have been introduced to improve BP phenotyping. The Ambulatory Central Aortic Pressure (AmCAP) study combines these approaches and describes, for the ...
Nichols Wilmer W - - 2013
OBJECTIVE:: 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, ...
Markus Marcello Ricardo Paulista - - 2013
BACKGROUND: The effects of smoking on central aortic pressures and the age-related increase in left ventricular mass (LVM) are largely unknown. We studied the relationship between smoking, arterial distensibility, central aortic pressures and left ventricular mass in two population-based studies. METHODS: Data was obtained from two German population-based studies (KORA ...
Nemes Attila - - 2013
INTRODUCTION: There is an interaction between the left ventricle (LV) and the vascular system, which plays a crucial role in determining cardiac output. LV twist could be evaluated by three-dimensional speckle-tracking echocardiography (3DSTE) as the net difference of counterclockwise apical and clockwise basal LV rotations during systole. Aortic elasticity parameters ...
Convelbo Channing - - 2013
OBJECTIVES: Leaflet injury has been documented to occur during the deployment of valved stents (VSs). The pathological aspects, however, of this injury are difficult to quantify. Conversely, the hydraulic conductance of a (pericardial) membrane may be easily determined. The impact of crimping and deployment of VS on this parameter was ...
Sahіn Durmuş Yildiray - - 2013
Background. Abnormal left ventricular (LV) geometric patterns, particularly concentric LV hypertrophy, are associated with a greater risk of hypertensive complications. The aim of this study was to investigate the association between LV myocardial performance index (LVMPI) and aortic distensibility (AD) with different LV geometric patterns in patients with newly diagnosed ...
Kuzeytemiz Mustafa - - 2013
The purpose of this study was to evaluate the effect of blood pressure (BP) rhythm on aortic functions in patients with metabolic syndrome. Seventy patients with newly diagnosed hypertension who fulfilled the metabolic syndrome criteria according to the Third Report of the National Cholesterol Education Program Expert Panel on Detection, ...
McGreevy Cora - - 2013
Background. Pulse wave velocity measured using the Vicorder(®) apparatus is a non-invasive indicator of arterial stiffness. The objective of this study was to assess its repeatability in older patients when used by medical professionals with limited experience of the technique. Methods. Aortic pulse wave velocity (aPWV) was measured using the ...
Booysen Hendrik L - - 2013
AIMS:: We sought to determine whether within normal/high-normal blood pressure (BP) ranges (120-139/80-89 mmHg), aortic BP may further refine BP-related cardiovascular risk assessment, as determined from target organ changes. METHODS:: In 1169 participants from a community sample of African ancestry, 319 (27%) of whom had a normal/high-normal BP, aortic BP was ...
O'Rourke Michael F - - 2013
Current guidelines on isolated systolic hypertension (ISH) suggest the same treatment to patients of all ages. Application of these guidelines in youth with ISH may not be appropriate, as presently no data show adverse outcome or benefit of drug therapy in this group. Simple noninvasive tonometric techniques now enable physicians ...
Theilade Simone - - 2013
OBJECTIVE: Central blood pressure may be a better risk marker than brachial blood pressure and can be measured noninvasively by tonometric devices. We investigate whether tonometric measurements are feasible in patients with diabetes and whether the degree of albuminuria or increased arterial stiffness affects measurements. PATIENTS AND METHODS: In 676 ...
Xu Chong-En - - 2013
OBJECTIVES: To investigate effects of high-dose ulinastatin on the release of proinflammatory cytokines and lung injury in patients with aortic dissection after cardiopulmonary bypass (CPB) under deep hypothermic circulatory arrest (DHCA). DESIGN: A prospective, randomized and double-blinded study. SETTING: A teaching hospital. PARTICIPANTS: Thirty-six patients with acute type-A aortic dissection ...
Wang Jiun-Jr - - 2013
BACKGROUND: Impedance cardiography (ICG) is a noninvasive technique used to estimate left ventricular (LV) stroke volume (SV) using thoracic impedance (ΔZ). It remains controversial, partly because ICG parameters have not been successfully related to hemodynamic events. We hypothesized that the change in ΔZ may be proportional to the variation in ...
Chopard Romain - - 2013
Two-dimensional transthoracic echocardiography (2D-TTE) is the reference technique for evaluating aortic stenosis (AS) but may be unreliable in some cases. We aimed to assess whether the use of a pressure wire to measure simultaneous transaortic gradient and aortic valve area (AVA) could be helpful in patients in whom initial noninvasive ...
Bahraseman Hamidreza Ghasemi - - 2013
The aim of this study was to measure the cardiac output and stroke volume for a healthy subject by coupling an echocardiogram Doppler (echo-Doppler) method with a fluid-structure interaction (FSI) simulation at rest and during exercise. Blood flow through aortic valve was measured by Doppler flow echocardiography. Aortic valve geometry ...
Nar Gokay - - 2013
This study has attempted to evaluate the relationship between aortic stiffness, blood pressure (BP) and serum endothelin-1 (ET-1) levels in patients with essential HT. Totally 152 subjects, consisting of 103 patients diagnosed with HT at least 1 year previously and 49 healthy individuals, were enrolled in this study. They were ...
Arjunon Sivakkumar - - 2013
The aortic valve (AV) experiences a complex mechanical environment, which includes tension, flexure, pressure, and shear stress forces due to blood flow during each cardiac cycle. This mechanical environment regulates AV tissue structure by constantly renewing and remodeling the phenotype. In vitro, ex vivo and in vivo studies have shown ...
Chen Duanduan - - 2013
Conservative medical treatment is commonly first recommended for patients with uncomplicated Type-B aortic dissection (AD). However, if dissection-related complications occur, endovascular repair or open surgery is performed. Here we establish computational models of AD based on radiological three-dimensional images of a patient at initial presentation and after 4-years of best ...
Nguy Lisa - - 2013
Rats with adenine-induced chronic renal failure (A-CRF) develop metabolic and cardiovascular abnormalities resembling those in patients with chronic kidney disease. The aim of this study was to investigate the mechanisms of hypertension in this model and to assess aortic stiffness in vivo. Male Sprague-Dawley rats were equipped with radiotelemetry probes ...
Bazemore Taylor C - - 2013
Abrupt onset of renal ischemia is associated with increased blood pressure (BP), but it is unknown whether BP remains elevated in patients with chronic severe atherosclerotic renal artery stenosis (RAS). Patients undergoing coronary angiography who had concurrent renal angiography were divided into 3 groups: severe (stenosis ≥70% diameter reduction), moderate ...
Stec David E - - 2013
BACKGROUNDModerate (approximately 2-fold) increases in plasma unconjugated bilirubin levels are able to attenuate the development of angiotensin II (Ang II)-dependent hypertension. To determine the specific role of decreases in superoxide production to the blood pressure-lowering effects of moderate hyperbilirubinemia (MHyB), we performed this study, in which the Nicotinamide adenine dinucleotide ...
Popescu Andreea Catarina - - 2013
Objectives: The left ventricular (LV) response to combined pressure and volume overload [aortic stenosis (AS) and aortic regurgitation (AR)] versus pressure overload (isolated AS) has not been systematically studied. We aimed to assess LV remodeling, functional and hemodynamic consequences in patients with mixed aortic valve disease versus patients with isolated ...
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