Search Results
Results 501 - 550 of 1760
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Papaioannou Theodore G - - 2006
BACKGROUND: Various factors are implicated in the circadian pattern of cardiovascular vulnerability. The exact mechanisms involved in the peak incidence of cardiovascular events occurring during the early morning hours after awaking are not completely known. The purpose of our study was to investigate the circadian variation of timing and intensity ...
Tartière J-M - - 2006
Pulse wave velocity (PWV), the carotid augmentation index (AIx), and pulse pressure (PP) may be prognostic factors in heart failure, but the possible influence of the ejection fraction (EF) and other simple haemodynamic variables on them has not been investigated in this setting. Noninvasive methods were used to measure carotid-radial ...
Mukkamala Ramakrishna - - 2006
A clinical method for monitoring cardiac output (CO) should be continuous, minimally invasive, and accurate. However, none of the conventional CO measurement methods possess all of these characteristics. On the other hand, peripheral arterial blood pressure (ABP) may be measured reliably and continuously with little or no invasiveness. We have ...
Vlachopoulos Charalambos - - 2006
OBJECTIVE: Large-artery stiffness and arterial wave reflections have been identified as independent markers and prognosticators of cardiovascular risk. Mental stress is a novel risk factor for coronary artery disease and has been associated with left ventricular dysfunction, myocardial ischemia and infarction, and sudden cardiac death. The purpose of this study ...
Carter S A - - 2006
AIM: Our aim was to determine how the risk associated with presence of low transcutaneous oxygen tension (tcPO2) for subsequent major amputation in patients with skin ulcers or gangrene and peripheral arterial disease, compares with the risks associated with low peripheral pressures and low amplitude of pulse waves. Secondly, we ...
Colin E - - 2006
AIM: The purpose of this study was to examine the effects of a cycle competition on the large arteries stiffness, 24-hours after the end of the effort. METHODS: Two males elite cyclists were studied before and after performing a stage-race. Their heart rate (HR) was measured continuously during the two ...
Zhang Xiaoming - - 2006
Arterial wall stiffness can be associated with various diseases. Arteriosclerosis involves the buildup of plaques within artery walls that stiffen the arteries. The stiffness of an artery can be assessed by measurement of the pulse wave velocity (PWV). Usually, PWV is estimated using the foot-to-foot method. However, the foot of ...
Li Yan - - 2006
We hypothesized that 1 minus the slope of diastolic on systolic pressure during 24-hour ambulatory monitoring (ambulatory arterial stiffness index [AASI]) might reflect arterial stiffness. We compared AASI with established measures of arterial stiffness and studied its distribution in Chinese and European populations. We used 90207 SpaceLabs monitors and the ...
Segers P - - 2006
Early return of reflected pressure waves increases the load on central arteries and may increase the risk of aortic rupture in patients with Marfan's syndrome (MFS). To assess whether wave reflection is elevated in MFS, we used ultrasound and MRI to measure central pressure and flow waveforms in 26 patients ...
Frimodt-Møller M - - 2006
OBJECTIVE: Applanation tonometry for pulse-wave analysis (PWA) and determination of pulse-wave velocity (PWV) is a non-invasive method for assessment of the central aortic pressure waveform and indices of arterial stiffness. The objective of this study was to examine the influence of eating and smoking on PWA and PWV measurements in ...
McCombie Devin B - - 2006
A method for estimating pulse wave velocity (PWV) using circulatory waveform signals derived from multiple photoplethysmograph (PPG) sensors is described. The method employs two wearable in-line PPG sensors placed at a known distance from one another at the ulnar and digital artery. A technique for calibrating the measured pulse wave ...
Aguado-Sierra J - - 2006
Pulse wave velocity is related to arterial stiffness. Pulse wave velocity changes with age and disease and is a useful indicator of cardiovascular disease. Different methods are used for evaluating pulse wave velocity in systemic vessels, but none is applicable to coronary arteries. In this study we first compare values ...
Sollers John J JJ - - 2006
Reduced arterial compliance has been implicated as a risk factor for future cardiovascular events in hypertensive patients. Recently, several non-invasive techniques have been used to access arterial compliance. However, comparisons of these techniques with older individuals and African-Americans have not been done. In the present study, beat-to-beat blood pressure was ...
Bjarnegråd N - - 2006
Systemic lupus erythematosus (SLE) is a connective tissue disease where inflammatory activity affects several organ systems. An increased risk of cardiovascular disease has been identified in these patients, even after correction for traditional risk factors. The aim of the present study was to evaluate arterial stiffness and central hemodynamics in ...
Unno Naoki - - 2006
PURPOSE: To evaluate the efficiency of the form PWV/ABI (pulse wave velocity/ankle brachial pressure index) for measuring penile blood pressure (PBP) and the penile brachial pressure index (PBI). METHODS: We measured PBP and the PBI using both form PWV/ABI and Doppler ultrasonography in 40 men with surgical disorders. RESULTS: By ...
Muehlsteff J - - 2006
This paper investigates the specific contributions of the pre-ejection period (PEP) and pulse transit time (PTT) for blood pressure estimation based on the pulse wave methodology. We show that in short-term physical stress tests, PEP dominates PTT variations raising the question of a suitable blood pressure calibration. A model using ...
Byrd Israel A - - 2006
Interactions between paced wavefronts and monomorphic ventricular tachycardia (VT) dictate antitachycardia pacing outcomes. Monomorphic VTs were initiated in isolated rabbit hearts (n=6) that were endocardially cryoablated to limit viable tissue to the visible epicardium and the ablated apex served as an anatomic anchor. Preparations were optically mapped during single and ...
Jachymczyk Tomasz - - 2006
BACKGROUND: The aim of our study was to assess the relationship between blood pressure and arterial stiffness in Polish centenarians. MATERIALS AND METHODS: We examined 59 centenarians with the mean age of 101.3 years. Peripheral blood pressure was estimated upon mean value of three measurements and arterial stiffness by pulse ...
McNames J - - 2006
Cardiovascular signals such as arterial blood pressure (ABP), pulse oximetry (SpO2) and central venous pressure (CVP) contain useful information such as heart rate, respiratory rate, and pulse pressure variation (PPV). We present a statistical state-space model of cardiovascular signals that can be used with the extended Kalman filter or smoother ...
Hashimoto Junichiro - - 2006
BACKGROUND: Wave reflection augments central blood pressure (BP) in late systole, thus increasing cardiac afterload. We examined the relationship between late systolic pressure augmentation in the peripheral radial artery pulse wave and the existence of left ventricular hypertrophy (LVH) in hypertension. METHODS: Brachial BP, radial augmentation index (AI(r)), and carotid-femoral ...
Chua C P - - 2006
Pulse arrival time and the amplitude of the finger photoplethysmogram were used to track blood pressure continuously over 10-minute intervals. The measures were recorded with a holter-oximeter from a sample of 8 young, healthy human subjects in the supine and standing positions. Results indicate that, with individual calibration, systolic and ...
Swamy Gokul - - 2006
We introduce a blind identification technique to reconstruct the clinically more relevant central aortic pressure waveform from multiple less invasively measured peripheral arterial pressure waveforms. We conducted initial testing of the technique in two swine in which peripheral arterial pressure waveforms from the femoral and radial arteries and reference central ...
Austin Daniel - - 2006
We describe a novel algorithm to estimate the pulse pressure variation index (PPV) from arterial blood pressure signals (ABP). PPV has been shown to be one of the best predictors of fluid responsiveness in mechanically ventilated subjects. Our PPV algorithm uses a non-linear technique for envelope estimation, eliminating the need ...
Foo Jong Yong Abdiel - - 2006
Study of cardiac functions has shown to be important in understanding the prognosis and pathogenesis of vascular diseases. A physiologic parameter termed pulse transit time (PTT) has been studied intensively to be used as an indirect marker of such pathologic conditions. It is defined as the time it takes a ...
Shiburi Cleopatra P - - 2006
BACKGROUND: Measurements of blood pressure (BP) together with applanation tonometry at the radial and femoral arteries allow for reproducible assessments of various indexes of arterial stiffness, including peripheral (PP(p)) and central (PP(c)) pulse pressures, peripheral (AI(p)) and central (AI(c)) augmentation indexes, and aortic pulse wave velocity (PWV). In the absence ...
Park Seong Uk - - 2006
Arterial stiffness is an important, independent determinant of cardiovascular risk. Pulse wave velocity (PWV) has been used as a valuable index of arterial stiffness and as a surrogate marker for atherosclerosis. Chunghyul-dan (CHD) has anti-hyperlipidemic activity, anti-inflammatory activity and anti-atherogenic effects. To determine its clinical effect on increased arterial stiffness, ...
Cay Serkan - - 2006
BACKGROUND: Angina with normal coronary arteries, cardiac syndrome X, is a diagnosis of exclusion. The exact mechanism of this clinical syndrome remains unclear. Although the prognosis is as good as equal to that of the normal population, symptoms related to the syndrome largely impair quality of life. Aortic pulse and ...
Yildiz Mustafa - - 2006
The aim of the present study was to investigate the effects of melatonin administration on arterial distensibility by using carotid-femoral (aortic) pulse wave velocity (PWV) measurements in healthy young men. Ten men were studied (five men in the melatonin group and five men in the placebo group) by physicians. Carotid-femoral ...
Mitchell Gary F - - 2005
BACKGROUND: Aortic stiffness and small-artery structure and function share various risk factors; however, relations between these 2 measures of vascular function are complex and incompletely understood. METHODS AND RESULTS: We examined hyperemic forearm blood flow, an indicator of microvascular structure and function, and aortic stiffness in 2045 participants (1107 women, ...
Separovi?-Hanzevacki Jadranka - - 2005
AIM: To determine if Color Doppler myocardial imaging could provide evidence of diastolic dysfunction in patients with hypertension whose pulse-wave Doppler parameters were normal. METHOD: The study included 33 patients (mean age 48+/-7.3 years) and a control group of 13 sex- and age-matched healthy individuals. Patients were divided into two ...
Sharman J E - - 2005
BACKGROUND: Brachial blood pressure predicts cardiovascular outcome at rest and during exercise. However, because of pulse pressure amplification, there is a marked difference between brachial pressure and central (aortic) pressure. Although central pressure is likely to have greater clinical importance, very little data exist regarding the central haemodynamic response to ...
Ishikawa Joji - - 2005
Collagen metabolism in the extracellular matrix (ECM) is related to the pathogenesis of cardiovascular stiffness and remodeling in hypertension. We evaluated the association between collagen metabolism markers and the newly developed parameter, brachial-ankle pulse wave velocity (baPWV), in older hypertensive patients with left ventricular hypertrophy (LVH). We performed echocardiography and ...
Mahmud Azra - - 2005
Adiponectin, an anti-inflammatory adipocytokine, is reduced in hypertension, diabetes, and coronary artery disease (CAD). Arterial stiffness, as aortic pulse wave velocity (PWV) in hypertension and diabetes, and as augmentation index (AIx) in CAD, is independently associated with cardiovascular mortality. We explored the relationship between adiponectin and arterial stiffness in essential ...
Ghosh Sudip K - - 2006
Manometrically measured peristaltic pressure amplitude displays a well-defined trough in the upper esophagus. Whereas this manometric "transition zone" (TZ) has been associated with striated-to-smooth muscle fiber transition, the underlying physiology of the TZ and its role in bolus transport are unclear. A computer model study of bolus retention in the ...
Pishchalnikov Yuri A - - 2005
Measurements using a fiber-optic probe hydrophone, high-speed camera, and B-mode ultrasound showed attenuation of the trailing negative-pressure phase of a lithotripter shock pulse under conditions that favor generation of cavitation bubbles, such as in water with a high content of dissolved gas or at high pulse repetition rate where more ...
Nakazato Keiko - - 2005
PURPOSE: To assess the arterial stiffness in patients with branch retinal vein occlusion (BRVO). METHODS: Brachial-ankle pulse wave velocity (PWV) and ankle-brachial index were measured in 10 patients with BRVO (mean age 67.9 +/- 7.5 years) and in 18 age-matched controls (mean age 66.9 +/- 6.8 years). The controls were ...
Jagomägi Kersti - - 2005
Finger arterial compliance has been studied on the beat-to-beat basis by using the digital arterial pressure and volume waveforms and performing measurements at zero transmural pressure during arm elevation in 11 volunteers. Continuous non-invasive finger blood pressure was measured by applying the Finapres monitor and the finger volume pulses were ...
Mitchell Gary F GF Cardiovascular Engineering, Inc, Waltham, MA 02453, USA. - - 2005
Augmentation index (AI), a measure of enhanced wave reflection, has been proposed as a bedside measure of aortic stiffness. However, because AI is potentially sensitive to various factors other than vessel wall stiffness, the utility of AI as a stiffness indicator may be limited. To assess relations between AI and ...
Edwards David G - - 2006
The purpose of this study was to determine the effects of acute cold exposure on the timing and amplitude of central aortic wave reflection and central pressure. We hypothesized that cold exposure would result in an early return of reflected pressure waves from the periphery and an increase in central ...
McEniery Carmel M - - 2005
OBJECTIVES: The aim of the current investigation was to test the hypothesis that age-related changes in augmentation index (AIx) are more prominent in younger individuals (<50 years), whereas changes in aortic stiffness per se are more marked in older individuals (>50 years). BACKGROUND: Aging exerts a number of deleterious changes ...
Aboy Mateo - - 2005
Beat detection algorithms have many clinical applications including pulse oximetry, cardiac arrhythmia detection, and cardiac output monitoring. Most of these algorithms have been developed by medical device companies and are proprietary. Thus, researchers who wish to investigate pulse contour analysis must rely on manual annotations or develop their own algorithms. ...
Gedik R G - - 2005
The aim of the present study is to investigate changes in blood pressure, pulse rate and temperature before and after periodontal surgery. The study included 127 normal healthy patients (43 males, 84 females) with age range 9 to 65 years (mean age: 26 +/- 12 years) who underwent periodontal surgery. ...
Sharma Gyanendra K - - 2005
BACKGROUND: Increased arterial stiffness is an early indicator of vascular disease. Several methods may be used to determine arterial stiffness. One method obtains an arterial stiffness index from the vascular dynamics of oscillometric-derived brachial artery pressure. METHODS: To determine the test-retest repeatability of the CardioVision MS-2000, 47 healthy hospital employees ...
Reddy Anilkumar K - - 2005
We have developed a high-frequency, high-resolution Doppler spectrum analyzer (DSPW) and compared its performance against an adapted clinical Medasonics spectrum analyzer (MSA) and a zero-crossing interval histogram (ZCIH) used previously by us to evaluate cardiovascular physiology in mice. The aortic velocity (means +/- SE: 92.7 +/- 2.5 versus 82.2 +/- ...
Kim Jin-Tae - - 2005
PURPOSE: Unintentional intravascular bupivacaine injection is known to be associated with treatment-resistant cardiovascular collapse. Therefore, it is important for safe anesthetic management to establish an early sign of bupivacaine-induced cardiac depression with available monitoring. We hypothesized that bupivacaine induced-cardiac depression in dogs could be detected early by analyzing the electrocardiogram ...
Monnet Xavier - - 2005
The pulse oximetry plethysmographic signal resembles the peripheral arterial pressure waveform, and the degree of respiratory variation in the pulse oximetry wave is close to the degree of respiratory arterial pulse pressure variation. Thus, it is tempting to speculate that pulse oximetry can be used to assess preload responsiveness in ...
Bonamy Anna-Karin Edstedt - - 2005
Preterm birth might induce permanent changes in vascular structure and function as well as in blood pressure. To elucidate this hypothesis and underlying mechanisms in girls born before term, the authors correlated neonatal data, including estradiol levels, with vascular function and structure and with blood pressure after puberty. In a ...
Murakami Tomoaki - - 2005
BACKGROUND: Despite the relative successes in cardiac surgical repair, early onset of heart disease (hypertension, myocardial infarction, cardiac failure, and sudden death) is a common late complication in patients who have undergone repair of occlusive aortic vessels. Many hypotheses for the cause of this complication have been proposed, but these ...
Cullen John P - - 2005
We investigated the effect of ethanol on the pulse pressure-induced expression of PAI-1 and MMP-2/9 in human smooth muscle cells (SMC). Human SMC were exposed to static or pulse pressure (25 mL/min; pulse pressure 106/50 mm Hg) conditions for 24 h in the absence or presence of ethanol (0.1-100 mM). ...
Jourdan Claudia - - 2005
OBJECTIVE: Sonographic evaluation of arterial wall morphology and elasticity is increasingly accepted as a non-invasive tool in cardiovascular assessment. Several studies suggest that intima-media thickness (IMT) and arterial elasticity indices may sensitively reflect different vasculopathic processes in children. However, normative values and the impact of adolescent growth are largely unknown. ...
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