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Results 401 - 450 of 1761
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Losert Heidrun - - 2007
AIMS: To investigate the potential for finding an alternative for the 'pulse check' during CPR, we studied the use of thoracic impedance measured via the defibrillator pads for circulation assessment during CPR. MATERIALS AND METHODS: Transthoracic impedance, ECG and arterial pressures were recorded on 69 patients with a resulting data ...
Aslan Sahin - - 2007
Hypothermia is generally defined as a core body temperature less than 35 degrees C (95 degrees F), and is one of the most common environmental emergencies encountered by emergency physicians. A 32-year-old male hunter was admitted to the hospital with altered mental status. He remained unconscious, Glasgow Coma Scale (GCS) ...
Kawakami Manri - - 2007
Aim: In general, cirrhotic patients are known to have a low prevalence of cardiovascular disease. Cirrhosis is often accompanied by diabetes mellitus, while blood pressure and serum cholesterol levels are low in liver cirrhosis. We examined the atherosclerosis of patients with chronic liver disease by two phases of atherosis "lipid ...
Protogerou Athanase D - - 2007
It is well established that in young and healthy individuals central (aortic or carotid) systolic and pulse pressures are different from peripheral (brachial) corresponding pressures as a consequence of progressive changes in arterial stiffness and pressure wave reflections along the arterial tree. There is evidence indicating that in interventions with ...
Lawrence-Snyder Marion - - 2007
Sequential-pulse (or dual-pulse) laser-induced breakdown spectroscopy (DP-LIBS) with an orthogonal spark orientation is described for elemental analysis of bulk aqueous solutions at pressures up to approximately 138 x 10(5) Pa (138 bar). The use of sequential laser pulses for excitation, when compared to single-pulse LIBS excitation (SP-LIBS), provides significant emission ...
Protogerou Athanase D - - 2007
BACKGROUND: Brachial pulse pressure (PP) is physiologically higher than central PP. This PP amplification, which protects the heart from increased afterload, is related to the progressive increase of arterial stiffness along the vascular tree and subsequent changes in pressure wave reflections. The PP amplification increases with high heart rate (HR), ...
Smith J C - - 2007
BACKGROUND: Alström syndrome (AS) is a rare autosomal recessive condition characterized by retinal degeneration, childhood obesity, and severe insulin resistance. Dilated cardiomyopathy of unknown aetiology is a well-recognized and potentially lethal complication. The aim of this study was to investigate the relationship between vascular function, hyperinsulinaemia and cardiac performance in ...
Kaye Gerry - - 2007
AIMS: To measure changes in transventricular impedance during arrhythmias. METHODS AND RESULTS: Patients were studied during electrophysiological studies. A quadrapolar catheter was positioned at the right ventricular apex (RVA) and a decapolar catheter within the coronary sinus (CS). Transventricular impedance was measured by injecting a subthreshold biphasic rectangular pulse of ...
Mulè Giuseppe - - 2007
BACKGROUND: Pulse pressure is largely dependent on arterial stiffness. Recent studies have documented reduced large artery compliance in nondiabetic subjects with metabolic syndrome (MS). The aim of our study was to analyze, in a group of patients with essential hypertension and without diabetes mellitus, the influence of MS on clinic ...
Swamy Gokul - - 2007
We have developed a new technique to estimate the clinically relevant aortic pressure waveform from multiple, less invasively measured peripheral artery pressure waveforms. The technique is based on multichannel blind system identification in which two or more measured outputs (peripheral artery pressure waveforms) of a single-input, multi-output system (arterial tree) ...
Douniama, C.
A chronically high blood pressure (BP) may lead to arteriosclerosis and consequently is a risk factor for apoplectic stroke and cardiac infarction the main death causes in industrial countries. Hence, blood pressure recently has become one of the most relevant parameters for the assessment of a patients health status. For ...
Wakabayashi Ichiro - - 2007
Pulse pressure is known to be a potent risk factor for cardiovascular disease. However, it has not been determined whether pulse pressure is associated with cerebrovascular disease in patients with diabetes mellitus. The purpose of the present study was to investigate association of pulse pressure with carotid atherosclerosis in patients ...
Greenwald S E - - 2007
Conduit arteries become stiffer with age due to alterations in their morphology and the composition of the their major structural proteins, elastin and collagen. The elastic lamellae undergo fragmentation and thinning, leading to ectasia and a gradual transfer of mechanical load to collagen, which is 100-1000 times stiffer than elastin. ...
Quinsac C - - 2007
Arterial blood pressure and velocity pulse wave speed are important biomarkers of arterial stiffness and cardiovascular disease risk in man. Arterial wave speed is usually assessed using pulse wavefront movement over a known finite portion of the arterial tree. In our pilot study we assess a new technique for determining ...
Danchin Nicolas - - 2007
Central pulse pressure is more likely to reflect the haemodynamic conditions to which the heart and coronary arteries are subjected than is peripheral pulse. We reviewed the data currently available on the correlations between central pulse pressure and both the presence and extent of coronary artery disease, as well as ...
Baruch Martin - - 2007
A non-invasive wrist sensor, BPGuardian (Empirical Technologies C., Charlottesville, VA) has been developed that provides continuous pressure readings by de-convolving the radial arterial pulse waveform into its constituent component pulses (Pulse Decomposition Analysis). Results agree with the predictions of the model regarding the temporal and amplitudinal behavior of the component ...
Crilly Mike - - 2007
OBJECTIVE: To estimate the repeatability of radial pulse wave analysis (PWA) in measuring central systolic and diastolic blood pressures (cSBP/cDBP), pulse pressure (cPP), augmentation pressure (cAP) and pulse pressure amplification (PPA). METHODS: After 15 min supine rest, 20 ambulant patients (aged 27-82 years; four female) underwent four SphygmoCor PWA measurements ...
Pasovic Mirza - - 2007
The nonlinear parameter B/A, better know as the Beyer parameter, is a measure of the nonlinearity between variations of the pressure and density. Because of these variation propagating wave is distorted. Media with the different Beyer parameter, will distort wave differently. In our work we are trying to measure this ...
Wakabayashi Ichiro - - 2007
INTRODUCTION: Pulse pressure is a potent risk factor for atherosclerotic disease. The purpose of this cross-sectional study was to determine whether pulse pressure is associated with blood coagulation and fibrinolysis in patients with diabetes. MATERIALS AND METHODS: The relationships between pulse pressure and atherosclerotic risk factors, including blood coagulation and ...
Aletti Federico - - 2007
Arterial pressure variability is a relatively unexplored topic among the various and detailed studies of cardiovascular variability. A deeper analysis of components and contributions carried by diastolic and pulse pressure may provide a unique insight on the potential systemic effects due to vasomotor activity and response at the level of ...
Borresen Malene L - - 2007
BACKGROUND: In young ADPKD patients, we have previously found an impaired endothelium-dependent relaxation in small resistance vessels but a normal flow-mediated dilatation of the brachial artery. The present study investigated arterial stiffness in early ADPKD by pulse-wave analysis (PWA) and measurement of pulse-wave velocity (PWV). METHODS: 18 young normotensive ADPKD ...
Feng J - - 2007
Wave intensity (WI) is a hemodynamics index, which is the product of changes in pressure and velocity across the wave-front. Wave Intensity Analysis, which is a time domain technique allows for the separation of running waves into their forward and backward directions and traditionally uses the measured pressure and velocity ...
Amar Jacques - - 2007
Blood pressure is a complex phenomenon that can be divided into two components: a steady and a pulsatile component. The pulsatile component is estimated by the pulse pressure which is mainly influenced by the large artery stiffness. The purpose of this review was to describe the relation between pulse pressure, ...
Rivas-Vilchis José F - - 2007
Indices obtained from the second derivative of the digital volume pulse waveform have been proposed to characterize vascular aging, arterial rigidity, and the effects of vasoactive drugs. The purpose of this study was to assess the effects of manual needling of PC6 on SD(DVP) indices in healthy and untreated hypertensive ...
Stancanelli Benedetta - - 2007
BACKGROUND: In patients with end-stage renal disease pulse wave velocity (PWV) has been widely assessed, but its behavior in mild to moderate chronic kidney disease (CKD) has been less investigated. We evaluated PWV in mild to moderate CKD. METHODS: We studied 31 patients with grade II-IV CKD. Aortic PWV (aPWV), ...
Laleg Taous-Meriem - - 2007
"Arterial blood pressure analysis based on scattering transform I" introduces a new method based on the scattering transform for a one dimensional Schrödinger equation to reconstruct the arterial blood pressure waves and separate its systolic and diastolic parts. In this article, we propose to analyse the parameters computed from this ...
Soveri Inga - - 2007
BACKGROUND: Cardiovascular mortality is high in hemodialysis (HD) patients. Early arterial pressure wave reflections, reflecting arterial stiffness and the endogenous nitric oxide synthesis inhibitor asymmetric dimethylarginine (ADMA) levels predict mortality in HD patients. Therefore, we aimed to study changes in ADMA levels and central arterial pressure waveform during HD. METHODS: ...
Jankowski Piotr - - 2007
Pulse pressure (PP) is traditionally believed to increase cardiovascular risk because of an increase in afterload leading to left ventricular hypertrophy. It has also been emphasized that low diastolic blood pressure, being in part responsible for high PP, leads to an impairment of myocardial perfusion with all its adverse consequences. ...
Talts Jaak - - 2007
A theoretical study has been performed to assess how the pulse pressure variation affects results of the arterial compliance measurement. Two asymmetric arctangent models for the arterial pressure-volume (P-V) relationship have been used by applying model-based and amplitude-based compliance estimation techniques. The results demonstrate that for near-zero transmural pressure the ...
McCombie Devin B - - 2007
A technique for calibrating non-invasive peripheral arterial sensor signals to peripheral arterial blood pressure (BP) is proposed. The adaptive system identification method utilizes a measurable intra-arterial hydrostatic pressure change in the sensor outfitted appendage to identify the transduction dynamics relating the peripheral arterial blood pressure and the measured arterial sensor ...
Laleg Taous-Meriem - - 2007
This article presents a new method for analyzing arterial blood pressure waves. The technique is based on the scattering transform and consists in solving the spectral problem associated to a one-dimensional Schrödinger operator with a potential depending linearly upon the pressure. This potential is then expressed with the discrete spectrum ...
Tsatsaris Athanasios - - 2007
To investigate the role of infrasound aortic pressure waves (IPW) in atherosclerotic plaque rupture. Atherosclerotic plaques have been simulated partly, in two dimensions, as being short or long Conical Intersections (CIS), that is to say elliptic, parabolic or hyperbolic surfaces. Consequently, the course and reflection of the generated aortic pressure ...
Smulyan Harold - - 2007
This chapter traces the history of nitroglycerin from the initial nitration of glycerol to its widespread clinical use. The pharmacologic differences between nitroglycerin and nitric oxide are described, as well as their similar mechanisms of action. The vasoactivity of nitroglycerin requires a biochemical transformation, the nature of which remains incompletely ...
Lee Tao Yu - - 2007
OBJECTIVES: The aim of this study was to investigate the changes of regional tissue Doppler velocity after volume removal following regular hemodialysis (HD) in uremic patients. Is tissue Doppler velocity really preload-independent? BACKGROUND: Diastolic dysfunction was divided into four stages: normal pattern, abnormal relaxation pattern, pseudonormalization pattern, and restrictive pattern. ...
Gilani Masood - - 2007
Systemic inhibition of nitric oxide (NO) synthesis raises blood pressure, and endothelial dysfunction with reduced NO bioactivity is a precursor of atherosclerosis. Pre-hypertensive blood pressures place patients at increased risk for cardiovascular morbid events. Whether NO deficiency contributes to this increased risk has not been explored. Constitutive NO release was ...
Verdecchia Paolo - - 2007
Brachial pulse pressure (PP) is an established risk marker for cardiovascular disease. PP is largely determined by the stroke volume in young subjects, although the progressive amplification of pulse wave from central to peripheral arteries could make brachial PP not representative of the central PP in the young. With advancing ...
Mitsutake Ryoko - - 2007
BACKGROUND: The coronary artery calcification (CAC) score determined by multi-detector row computed tomography (MDCT) predicts the onset of coronary artery disease (CAD). In addition, pulse wave velocity (PWV) also predicts the mortality of CAD. Therefore, the aim of this study was to assess whether or not the CAC score is ...
Yambe Minoru - - 2007
OBJECTIVES: This observational study was conducted to compare the significance of the relationship between arterial stiffness and progression to higher blood pressure categories among middle-aged Japanese men with high normal blood pressure (HNP), normal blood pressure (NRP) and optimal blood pressure (OPP). METHODS AND RESULTS: During the 3-year observational period, ...
Vlachopoulos C V - - 2007
OBJECTIVE: Aortic stiffness and wave reflections are important markers and prognosticators of cardiovascular risk. Caffeine increases acutely aortic stiffness and wave reflections. Furthermore, chronic coffee consumption is associated with increased aortic stiffness and wave reflections in normotensive subjects. In the present study, we aimed to assess the association between chronic ...
Feng J - - 2007
Earlier work of wave dissipation in flexible tubes and arteries has been carried out predominantly in the frequency domain and most of the studies used the measured pressure waveform for presenting the results. In this work we investigate the pattern of wave dissipation in the time domain using the separated ...
Watabe Daisuke - - 2006
BACKGROUND: Whether arterial stiffness per se contributes to left ventricular hypertrophy (LVH) independently of blood pressure (BP) remains unknown. We examined the relationship between pulse wave velocity (PWV) and LVH in a large population. METHODS: The PWV was measured between the brachial and ankle regions (baPWV) of 798 individuals. We ...
Kemeny A - - 2006
A new optical device was developed that measures blood pressure noninvasively, in small human subjects (neonates and premature infants) and small animals (Roeder RAR. Transducer for indirect measurement of blood pressure in small human subjects and animals, Purdue University, BME; 2003.: xi, 50 p.). The ability of this device to ...
Natalini Giuseppe - - 2006
In the present study, we compared indices of respiratory-induced variation obtained from direct arterial blood pressure measurement with analogous indices obtained from the plethysmogram measured by the pulse oximeter to assess the value of these indices for predicting the cardiac output increase in response to a fluid challenge. Thirty-two fluid ...
Kim E J - - 2007
Blood pressure (BP) is one of the most important contributing factors to pulse wave velocity (PWV), a classic measure of arterial stiffness. Although there have been many non-invasive studies to show the relation between arterial stiffness and BP, the results are controversial. The aim of this study is to evaluate ...
Hobson Tracy N - - 2007
The left atrium (LA) acts as a booster pump during late diastole, generating the Doppler transmitral A wave and contributing incrementally to left ventricular (LV) filling. However, after volume loading and in certain disease states, LA contraction fills the LV less effectively, and retrograde flow (i.e., the Doppler Ar wave) ...
Sasoh A - - 2006
The effect of ambient pressure on the interaction between a laser plasma bubble and a shock wave involving a Richtmyer-Meshkov instability was experimentally studied via framing Schlieren visualization. A sharp plasma interface could be formed without any separation material that causes undesired disturbances. The fundamental vortex structure which was produced ...
Zhang Xiaoming - - 2006
Arterial wall stiffness can be associated with various diseases. The stiffness of an artery can be measured with the pulse wave velocity (PWV) using the "foot-to-foot" method. However, the foot of the pressure pulse is not very clear, due to reflected waves. The blood pressure pulse generated by the heart ...
Natalini Giuseppe - - 2006
We analyzed ventilation-induced changes in arterial blood pressure and photoplethysmography from waveforms obtained by monitoring 57 patients in the operating room and intensive care unit. Analysis of systolic and pulse pressure variations during positive pressure ventilation, DeltaUp, DeltaDown, and changes in the preejection period on both arterial and photoplethysmographic waveforms ...
Boussuges Alain - - 2006
BACKGROUND: Since thermoneutral head-out water immersion induces an increase in central blood volume and cardiac output along with a decrease in peripheral vascular resistance, we examined here whether thermoneutral immersion leads rapidly to an increase in arterial compliance. METHODS: Changes in hemodynamic status and arterial compliance induced by thermoneutral head-out ...
Zachary James F - - 2006
Arterial injury resulting from the interaction of contrast agent (CA) with ultrasound (US) was studied in rabbit auricular arteries and assessed by histopathologic evaluation and s-thrombomodulin concentrations. Three sites on each artery were exposed (2.8 MHz, 5-min exposure duration, 10-Hz pulse repetition frequency, 1.4-mus pulse duration) using one of three ...
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