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Results 451 - 500 of 1690
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Bak Z - - 2000
BACKGROUND: Preoperative acute normovolemic hemodilution may compromise oxygen transport. The aims of our study were to describe the hemodynamic effects of normovolemic hemodilution and to determine its effect on systolic and diastolic cardiac function by multiplane transesophageal echocardiography. METHODS: In eight anesthetized patients (aged 13-51 yr) without heart disease, hemoglobin ...
Esquivel J - - 2000
BACKGROUND: Heated intraoperative intraperitoneal chemotherapy achieves high peritoneal concentrations with limited systemic absorption and has become an important tool in the management of patients with peritoneal carcinomatosis from low-grade malignancies such as pseudomyxoma peritonei and in selected cases of high-grade tumors such as colon adenocarcinoma. When the closed abdomen technique ...
Rosenberg P - - 2000
Evaluation of the hemodynamic response in heart failure is a useful adjunct in clinical management. Invasive monitoring has been the accepted gold standard of hemodynamic assessment but carries with it significant associated risks. Noninvasive hemodynamic assessment in heart failure previously has been either unreliable or difficult to obtain. Bioimpedance relies ...
Larsen F S - - 2000
OBJECTIVE: To evaluate whether changes in cardiac output influence cerebral perfusion directly. In fulminant hepatic failure, the circulation is characterized by wide variations in cardiac output and cerebral blood flow (CBF). DESIGN: A retrospective, interindividual analysis of CBF and cardiac output (part 1) and a prospective evaluation of cerebral perfusion, ...
Porat E - - 2000
BACKGROUND: Hemodynamic instability during heart displacement in off-pump multivessel coronary artery bypass grafting might be related to right heart dysfunction. The Enabler (HemoDynamics Systems Ltd, Upper Yoqneam, Israel) is a cannula pump that expels blood from the right atrium into the pulmonary artery. We studied the hemodynamic changes and the ...
Andropoulos D B - - 2000
OBJECTIVE: To assess the effects of transesophageal echocardiography (TEE) on hemodynamic variables during cardiac surgery in small infants. DESIGN: A prospective clinical study. SETTING: A medical college-affiliated tertiary care children's hospital. PARTICIPANTS: Twenty-three infants weighing 2 to 5 kg undergoing cardiac surgery. INTERVENTIONS: Baseline heart rate, arterial pressure, and central ...
Wright J R - - 2000
The effect of physiological changes in systemic blood pressure on the force output of working abductor pollicis (AP) muscle was studied in six normal subjects. Supramaximal tetanic stimulation at the ulnar nerve produced repeated isometric contractions at 1-s intervals. Force output declined gradually with time. During the train of contractions, ...
Grigioni M - - 2000
Foetal cardiac surgery is the ultimate goal in the treatment of congenital cardiac malformations. The aim of our research is to elucidate some of the features of the necessarily invasive experimental protocol to be used in an animal model of foetal cardiac surgery. In particular, we assessed the foetal placental ...
Opasich C - - 2000
Part of the management of refractory heart failure is treatment aimed at preventing organ damage due to inadequate oxygen delivery, improving hemodynamics, and maximizing cardiac output while maintaining only mildly elevated ventricular filling pressures The aim of this paper is to review the most updated indications on intravenous inotropic agents, ...
McCaffery J M - - 2000
Individuals differ in the cardiac and vascular processes that underlie blood pressure elevations evoked by environmental stimuli; such differences may reflect variability in sympathoadrenal response. We separated 108 healthy, young-adult males into those with predominant elevations in either cardiac output or peripheral resistance when exposed to psychological challenges. We then ...
Tone O - - 2000
The authors examined the correlations between cerebral blood flow (CBF) during the stage of vasospasm following subarachnoid hemorrhage and four parameters, namely, cardiac output (cardiac index), mean arterial blood pressure, age, and the Glasgow coma scale score. Forty-two patients who were diagnosed to have subarachnoid hemorrhage were included in this ...
Haryadi D G - - 2000
OBJECTIVE: Evaluation in animals of a non-invasive and continuous cardiac output monitoring system based on partial carbon-dioxide (CO2) rebreathing indirect Fick technique. METHODS: We have developed a non-invasive cardiac output (NICO) monitoring system, based on the partial rebreathing method. The partial rebreathing technique employs a differential form of the Fick ...
Farrell A P - - 2000
Vertebrate hearts from fish to mammals secrete peptide hormones with profound natriuretic, diuretic, and vasodilatory activity; however, the specific role of these cardiac natriuretic peptides (NPs) in homeostasis is unclear. NPs have been suggested to be involved in salt excretion in saltwater teleosts, whereas they are proposed to be more ...
Held C M - - 2000
A rule-based system was designed to control the mean arterial pressure (MAP) and the cardiac output (CO) of a patient with congestive heart failure (CHF), using two vasoactive drugs: sodium nitroprusside (SNP) and dopamine (DPM). The controller has three different modes, that engage according to the hemodynamic state. The critical ...
Nemec P - - 2000
The piggyback technique in venous outflow tract reconstruction has been proposed as an alternative to the conventional technique in liver transplantation. Maintaining caval flow during the anhepatic phase with hemodynamic stability is regarded as one of the main advantages of this method. Between November 1994 and November 1998, the piggyback ...
Nakagawara M - - 2000
A new, portable instrument has been developed for simultaneous monitoring of blood pressure, cardiac output and other cardiovascular haemodynamic variables. The measurements are based on the volume-compensation method and the transthoracic electrical admittance method. The instrument is small and light and can be carried by the subject. The portable unit ...
Dittrich S - - 2000
OBJECTIVE: Evaluation of the acute hemodynamic changes during peritoneal dialysis in patients with low cardiac output syndrome and acute renal failure after open heart surgery. PATIENTS: Three newborns and three infants after corrective surgery of congenital heart disease with post cardiotomy dialysis. Five of these had an open thorax during ...
Shimoyama M - - 1999
BACKGROUND: Cardiac hypertrophy is a fundamental adaptive response to hemodynamic overload; how mechanical load induces cardiac hypertrophy, however, remains elusive. It was recently reported that activation of a calcium-dependent phosphatase, calcineurin, induces cardiac hypertrophy. In the present study, we examined whether calcineurin plays a critical role in pressure overload-induced cardiac ...
Goldstein L J - - 1999
OBJECTIVES: This study was conducted to determine the response time of the Opti-Q continuous cardiac output (CCO) device to a step change in cardiac. DESIGN: Prospective study. SETTING: University hospital animal lab. MODEL: Female sheep. INTERVENTIONS: In ten animals, cardiac output was altered suddenly by opening and closing a peripheral ...
Stevenson R S - - 1999
OBJECTIVE: To determine whether cardiac output can be augmented by preferentially activating cardiac adrenergic efferent neurons. DESIGN: Elicited cardiac output responses were compared when cardiac myocytes were directly stimulated by a beta1-adrenoceptor agonist versus when they were indirectly influenced by beta2- adrenergic-sensitive cardiac efferent neurons. ANIMALS AND METHODS: The beta1-adrenoceptor ...
Yuste J - - 1999
Mechanically recovered poultry meat (MRPM) was inoculated with Listeria innocua 910 CECT at a level of approximately 10(8) CFU g(-1). Vacuum-packaged samples were treated by combinations of pressure (350, 400, 450 and 500 MPa), time (5, 10, 15 and 30 min) and temperature (2, 10 and 20°C) and later stored ...
Felici F - - 1999
BACKGROUND: Hiking is the special manoeuvre, which the dinghy sailor uses to counterbalance the capsizing effect of the wind on the boat. In the present research the work required of the heart by this exercise was studied in the laboratory using a boat simulator. METHODS: Seven Laser male sailors selected ...
Fuhrman B P - - 1999
The treatment of cardiogenic shock using inotropic agents and vascular volume expansion places an added burden on the heart. The resultant increase in cardiac work may cause myocardial ischemia and lead to cardiac arrest. Extracorporeal membrane oxygenation (ECMO) may be used to treat cardiogenic shock. It supports systemic circulation, assures ...
Gullberg N - - 1999
BACKGROUND: Based on early studies in the lamb, and in spite of more recent studies in humans, it has been the received opinion that neonates and infants can not change their stroke volume significantly, but are mainly dependent on changes in heart rate, to change cardiac output. To further evaluate ...
Hwang B - - 1999
Cardiac after-load, neurohumoral reaction and the secondary cardiac hypertrophy were studied in six groups of Sprague-Dawley (SD) rats with abdominal aortic constriction. We found that abdominal aortic constriction above the renal arteries decreased the heart rate and cardiac output, and increased the pulse pressure. These abnormalities would return to normal ...
Upton R N - - 1999
Indicator dilution theory predicts that the first-pass pulmonary and systemic arterial concentrations of a drug will be inversely related to the cardiac output. For high-clearance drugs, these first-pass concentrations may contribute significantly to the measured arterial concentrations, which would therefore also be inversely related to cardiac output. We examined the ...
Healey C - - 1999
OBJECTIVES: This study compared 2-mL bolus thermodilution cardiac output measurements with standard 10-mL bolus measurements. DESIGN: Cardiac output was measured with the new 2-mL bolus technique and the 10-mL standard thermodilution technique in a perspective series. We describe a system that automatically cools and injects 2-mL boluses of saline into ...
Saari J T - - 1999
Dietary copper deficiency in animals is often associated with cardiac enlargement and anemia. In this study we examined the hypothesis that anemia leads to a high cardiac output state that results in work-induced (physiological) cardiac hypertrophy. Blood pressure was measured by carotid cannulation and cardiac output was measured by aortic ...
Kurita T - - 1999
OBJECTIVE: The lithium dilution technique for the measurement of cardiac output by the central injection of lithium chloride was introduced by Linton et al. in 1993. In the present report, we compare lithium dilution cardiac output measurement (LD) by the peripheral injection of lithium chloride (pLD) and by central venous ...
Boone T - - 1999
This study was conducted to determine the cardiovascular effects of 15 minutes of hot tub immersion at 39 degrees C. Five college-age subjects (4 males and 1 female) volunteered to participate in this study. Assessments were made while sitting first in a chair for 5 minutes and then in the ...
Stenslokken KO - - 1999
Endothelin-1 (ET-1) has been shown to cause a considerable increase in the vascular resistance of fish gills. In trout, recent evidence suggest that this is the result of pillar cell contraction in the gill lamellae. Using epi-illumination microscopy to observe the gill lamellae of anaesthetised Atlantic cod (Gadus morhua), we ...
Bos W J - - 1999
BACKGROUND: Arteriovenous (AV) fistulas used for hemodialysis access may affect cardiac load by increasing the preload while decreasing the afterload. In dogs, AV fistulas have also been shown to affect coronary perfusion negatively. We investigated the net effect of AV fistulas on cardiac oxygen supply and demand. METHODS: Aortic pressure ...
Pandeya S - - 1999
Satisfactory hemodialysis access flow (Qa) is necessary for dialysis adequacy. However, high access flows are postulated to increase cardiac output (CO). The relationship between Qa and CO is not well defined. The purpose of this study was to observe the relationship between Qa and CO and to evaluate the effect ...
Nyström E U - - 1999
Bupivacaine-induced cardiovascular collapse is a feared complication because of the difficulty in restoring stable circulation (1). Early recognition is important so that the injection of bupivacaine can be discontinued. We used an animal model of near-cardiac arrest from bupivacaine infusion to identify the sequence of hemodynamic events that precedes bupivacaine-induced ...
Dexter S P - - 1999
BACKGROUND: Peritoneal insufflation to 15 mmHg diminishes venous return and reduces cardiac output. Such changes may be dangerous in patients with a poor cardiac reserve. The aim of this study was to investigate the hemodynamic effects of high (15 mmHg) and low (7 mmHg) intraabdominal pressure during laparoscopic cholestectomy (LC) ...
Stenqvist O - - 1999
BACKGROUND: End-stage liver disease is accompanied by a hyperkinetic circulation sometimes combined with hypoxaemia. Nitric oxide overproduction has been described as a possible cause by dilating the vasculature and decreasing cardiac afterload. The aim of this study was to evaluate haemodynamics, ventilation/perfusion matching, alveolar and alveolar dead space ventilation and ...
Wideman R F RF - - 1999
Female broilers were evaluated at 4, 5, and 6 wk of age (1.2, 1.8, and 2.3 kg BW, respectively) to assess changes in cardiac output and related hemodynamics associated with BW gain, and to evaluate cardiopulmonary hemodynamic adjustments occurring secondary to i.v. injections of epinephrine (0.1 mg/ kg BW). Cardiac ...
Pirk J - - 1999
OBJECTIVE: This is an experimental work designed to determine, using the isolated perfused rat heart, the effect of the ultra-short acting beta-blocker esmolol on cardiac arrest and cardiac function recovery following esmolol withdrawal. METHODS: Changes in heart rate, coronary flow, diastolic pressure and the rate pressure product were evaluated on ...
Shekerdemian L S - - 1999
OBJECTIVES: We hypothesized that a period of cuirass negative pressure ventilation (NPV) would augment the cardiac output of patients in the early postoperative period after complete correction of tetralogy of Fallot (TOF). BACKGROUND: Diastolic right ventricular dysfunction can lead to a low-output state in an important minority of patients after ...
Raso J - - 1999
The influence of several factors (amplitude of ultrasonic waves, external static pressure, temperature and viscosity of medium) acting, either individually or in combination, on the amount of power transferred to a liquid medium during ultrasonication (power output) was measured by calorimetry. At constant amplitude (150 microns) and pressure (200 kPa), ...
Carstensen E L - - 1999
By ignoring the effects of nonlinear propagation, current exposimetry protocols may yield significant underestimates of the acoustic pressure in situ. This problem can be avoided simply by (1) extrapolating pressures linearly from low amplitude measurements in water and (2) linearly derating these values to obtain estimates of fields in situ. ...
Putzke J D - - 1998
BACKGROUND: Cognitive deficits among heart transplant candidates have been well documented. This study was designed to examine the hypothesis that impaired cognitive test performance among heart transplant candidates may be attributed, in part, to decreased cerebral perfusion secondary to poor cardiac function. METHODS AND RESULTS: Sixty-two patients participated in the ...
Kiely J L - - 1998
BACKGROUND: Some previous reports have indicated beneficial cardiac effects of nasal continuous positive airway pressure (NCPAP) in patients with severe congestive heart failure (CHF), but others have reported deleterious cardiac effects, particularly among patients in atrial fibrillation (AF). The aim of this study was to determine if differences in cardiac ...
Pypendop B H - - 1998
To characterize the hemodynamic effects of medetomidine administered intravenously at doses ranging from 1 to 20 microg/kg, and to determine whether these effects are dose dependent. Prospective randomized multidose trial. Twenty-five clinically normal male beagles (5 groups of 5), aged 1 to 4 years and weighing 13.5 +/- 1.7 kg. ...
Tanaka H - - 1998
Stiffening of central arteries is believed to contribute to the increase in the incidence of cardiovascular disease with age, presumably through its adverse influence on arterial blood pressure. We found that (1) the physiologic link between age-related increases in arterial stiffness and blood pressure appears to be elevated systemic vascular ...
Martino M N - - 1998
In high-pressure-assisted freezing, samples are cooled under pressure (200 MPa) to - 20 °C without ice formation then pressure is released (0.1 MPa) and the high super-cooling reached (approx. 20 °C), promotes uniform and rapid ice nucleation. The size and location of ice crystals in large meat pieces (Longissimus dorsi ...
Brahimi M - - 1998
1. Coronary ischaemic disease and congestive heart failure are the principal causes of mortality in patients with peripheral vascular disease. Whether cardiac hypertrophy is present and even more pronounced in peripheral vascular disease than in other populations has never been explored.2.Twenty-five hypertensive patients were investigated, 11 without and 14 with ...
Young L E - - 1998
OBJECTIVE: To evaluate temporal hemodynamic effects of dobutamine in horses anesthetized with halothane. ANIMALS: 8 adult Thoroughbreds. PROCEDURE: Anesthesia was induced by i.v. administration of romifidine and ketamine and maintained using halothane in oxygen. After 60 minutes, dobutamine was administered i.v. for 60 minutes at 4 micrograms/kg of body weight/min. ...
White R J - - 1998
Early in spaceflight, an apparently paradoxical condition occurs in which, despite an externally visible headward fluid shift, measured central venous pressure is lower but stroke volume and cardiac output are higher, and heart rate is unchanged from reference measurements made before flight. This paper presents a set of studies in ...
Cooper S J - - 1998
A 1-m-long RF-pumped HCN waveguide laser is described. Output power optimizations were performed with mixtures of methane, nitrogen, and helium in the ratios 1:2:0, 1:1:0, 2:1:0, and 8:3:36. The variation of output power as a function of gas pressure, flow rate, waveguide wall temperature, and RF driving power was studied. ...
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