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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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, ...

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 ...

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 ...

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 ...

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 ...

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, ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

BACKGROUND:In this study, we compared the effects of 3 frequently used arterial blood pressure-regulating agents on brain (rScO2), renal (SrO2), and muscle (SmO2) oxygen saturation, during aortic coarctation repair in children. Based on the reported adverse effect of sodium nitroprusside (SNP) on left-sided rScO2 during aortic coarctation repair, we tested ...

Abnormal aortic function in hypertension is generally attributed to accelerated breakdown of elastin in the aorta, leading to dilatation of the lumen and stiffening of the wall as elastin is replaced with stiffer collagen. Aortic stiffness is an independent predictor of cardiovascular risk and all-cause and cardiovascular mortality. Vascular stiffening ...

: To evaluate whether the relationship between early glomerular dysfunction and left-ventricular mass (LVM) occurs in a community sample and whether this relationship depends on haemodynamic factors. : In 621 randomly selected participants from a community sample (332 were normotensive), estimated glomerular filtration rate (eGFR), LVM and dimensions were determined ...

Patient inflating valves combined with self-inflating bags are known to all anaesthetists as resuscitation devices and are familiar as components of draw-over anaesthesia systems. Their variants are also commonplace in transfer and home ventilators. However, the many variations in structure and function have led to difficulties in their optimal use, ...

BackgroundExperimental and clinical data suggest that statins exert anti-inflammatory and antiproliferative actions on vasculature beyond their lipid-lowering properties. Whether these pleiotropic effects of statins translate into a beneficial effect on arterial stiffness is not clear. This study aimed to evaluate the potential effects of low-dose atorvastatin treatment on arterial stiffness ...

BACKGROUND: Patients who underwent surgery for aortic coarctation (COA) have an increased risk of arterial hypertension. We aimed at evaluating (1) differences between hypertensive and non-hypertensive patients and (2) the value of cardiopulmonary exercise testing (CPET) to predict the development or progression of hypertension. METHODS: Between 1999 and 2010, CPET ...

INTRODUCTION: Hypertension is an established risk factor for atrial fibrillation. Understanding the association of blood pressure (BP) levels and aortic distensibility with P wave indices (PWIs) and PR interval, intermediate phenotypes of atrial fibrillation, could provide insights into underlying mechanisms. METHODS: This analysis included 3180 men and women aged 45-84years ...

Despite the apparently successful surgical repair of aortic coarctation, subsequent cardiovascular complications have sometimes been encountered. Aortic pressure wave reflection is one of the risk factors for developing cardiovascular diseases, and an enhancement of the pressure wave reflection has been reported in patients after aortic arch repair. To clarify this ...

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 ...

A thirteen-year-old boy presented with severe systemic hypertension. His upper limb blood pressure measured 190/100mmHg and lower limb blood pressure measured 98/64mmHg. The brachial pulses were bounding and femoral pulses were not palpable. Echocardiography and magnetic resonance angiography confirmed middle aortic syndrome. There was severe diffuse thoraco-abdominal coarctation with continuous ...

OBJECTIVE: The aim of this study was to determine the influence of aortic annulus (AA) diameter and the ratio of the sinotubular junction (STJ) diameter to the AA diameter on aortic valve hemodynamics and tissue mechanics and to suggest optimal values. METHODS: Sixteen cases of aortic roots with AA diameters ...

Purpose:To evaluate the relationship between pulse wave velocity (PWV) from the aortic arch and subsequent cerebral microvascular disease independent of other baseline cardiovascular risk factors among the participants in the multiethnic Dallas Heart Study.Materials and Methods:Each subject gave written consent to participate in this HIPAA-compliant, institutional review board-approved prospective study. ...

For the left ventricle (LV) to function as an effective pump it must be able to fill from a low left atrial pressure. However, this ability is lost in patients with heart failure. We investigated LV filling by measuring the cardiac blood flow using 2D phase contrast magnetic resonance imaging ...

An existing lumped-parameter model of multiple lymphangions (lymphatic vascular segments) in series is adapted for the incorporation of recent physiological measurements of lymphatic vascular properties. The new data show very marked nonlinearity of the passive pressure-diameter relation during distension, relative to comparable blood vessels, and complex valve behaviour. Since lymph ...

OBJECTIVE:: The results from the ASCOT CAFÉ study demonstrated the inferiority of beta blockers in reducing central aortic blood pressure. In this study, we wanted to demonstrate whether or not second-generation beta blockers with higher beta 1 selectivity, namely bisoprolol, may counterbalance the effect of bradycardia through reduced reflection wave ...