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Results 351 - 400 of 1699
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Feissel Marc - - 2004
OBJECTIVE: To investigate whether the respiratory variation in inferior vena cava diameter (DeltaD(IVC)) could be related to fluid responsiveness in mechanically ventilated patients. DESIGN: Prospective clinical study. SETTING: Medical ICU of a non-university hospital. PATIENTS: Mechanically ventilated patients with septic shock (n=39). INTERVENTIONS: Volume loading with 8 mL/kg of 6% ...
Blyton Diane M - - 2004
STUDY OBJECTIVES: Recent studies suggest a specific association between intrauterine growth restriction that commonly occurs in preeclampsia and decreased maternal cardiac output. Sleep is associated with marked hypertension in preeclampsia. We therefore aimed to determine how sleep influences other hemodynamic parameters in preeclampsia, specifically to determine if sleep-induced exacerbation of ...
Laszlo Gabriel - - 2004
The measurement of cardiac output was first proposed by Fick, who published his equation in 1870. Fick's calculation called for the measurement of the contents of oxygen or CO2 in pulmonary arterial and systemic arterial blood. These values could not be determined directly in human subjects until the acceptance of ...
Al-Said Haffor
Obstructive sleep apnea (OSA) relates to cardiovascular diseases. This study evaluated oxygenation and the ventilatory responses to hypercapnea in OSA in whom cardiac output is elevated. Sleep studies were conducted using CASE system. From an arterial line, blood pressure was monitored directly by blood pressure transducer and blood samples were ...
Sheriff Don D - - 2004
A change in cardiac output induced by a change in cardiac performance is accompanied by opposite changes in cardiac filling pressure owing to the resistive and capacitive properties of blood vessels. The inverse relationship between cardiac output and cardiac filling pressure provides a passive (hydraulic) regulatory mechanism that functions to ...
Fernández J A - - 2004
BACKGROUND: Cardiovascular changes during drainage of pericardial effusion are not well understood, and most studies are of systemic effects and not of right ventricular performance. Thoracoscopy is not widely used to drain pericardial effusions because of haemodynamic changes in relation to the use of single lung ventilation. PATIENTS AND METHODS: ...
Hsu Cheung-Hwa - - 2004
Automatic physiological control of the pneumatic Phoenix-7 total artificial heart (TAH) occupies a pivotal position for clinical application of the device. We developed a fuzzy logic automatic control algorithm for the Phoenix-7. The object of the automatic control system is to regulate the cardiac output at a level desirable for ...
Mukkamala R R Department of Electrical and Computer Engineering, Michigan State University, East Lansing, MI, - - 2004
We have developed a novel technique for monitoring cardiac output (CO) changes by mathematically analyzing a single peripheral arterial blood pressure (ABP) waveform. In contrast to all previous techniques, our technique analyzes the ABP waveform over time scales greater than a cardiac cycle in which complex wave reflections are attenuated. ...
Danzi Sara - - 2003
Thyroid hormone has well-recognized effects on the cardiovascular system and blood pressure regulation. Blood pressure is altered across the entire spectrum of thyroid disease. The effects of hyperthyroidism include increased cardiac output, contractility, tachycardia, widened pulse pressure, decreased systemic vascular resistance, and increased basal metabolic rate. The manifestations of hypothyroidism ...
Wada Yukoh - - 2003
The aim of this study was to clarify the relationship between cardiac sympathetic nervous activity (SNA) assessed by radioiodinated metaiodobenzylguanidine (123I-MIBG), an analogue of norepinephrine and cardiovascular functions in patients with chronic heart failure (CHF). Subjects were 17 patients with CHF. A dose of 111 MBq of 123I-MIBG was administered ...
Mahajan Aman - - 2003
Conventional methods of cardiac output monitoring using pulmonary artery catheters may not be feasible in patients with congenital heart disease because of patients' small size or aberrant anatomy. We studied the accuracy of a new device, which uses pulse contour analysis to measure continuous cardiac output, in children and adults ...
McMullen Julie R - - 2003
An unresolved question in cardiac biology is whether distinct signaling pathways are responsible for the development of pathological and physiological cardiac hypertrophy in the adult. Physiological hypertrophy is characterized by a normal organization of cardiac structure and normal or enhanced cardiac function, whereas pathological hypertrophy is associated with an altered ...
Diroll Anne - - 2003
The outcome objectives for EG were met. In order for her blood pressure to improve, cardiac output had to improve. In her case, this could only be accomplished by reducing the vascular volume through aggressive ultrafiltration. Starling's Law and Laplace's Theorem provide the key to understanding this concept, namely that ...
Kamp Otto - - 2003
This was a double-blind, randomized, prospective study comparing the effects of nebivolol and atenolol on systolic diastolic left ventricular function in patients with essential hypertension. A significant difference was seen in stroke volume between these 2 drugs. The blood pressure lowering effect of atenolol was strongly related to cardiac output ...
Giuliano Karen K - - 2003
BACKGROUND: Cardiac output is an extremely important measurement in the care of critically ill patients, but the accuracy of measurement is unknown when patients are in positions other than flat and supine. OBJECTIVE: The purpose of this study was to compare the effects of varying degrees of backrest elevation on ...
Kini SH, Pednekar SJ, ...
A 30 years old female, mother of a three-year-old child, presented with breathlessness and chest pain for four days and orthopnoea for last two days. She had no past history of cardiac, renal or thyroid disease. On examination, she was orthopnoeic, with a respiratory rate of 44/minute and pulse rate ...
Are Chandrakanth - - 2003
OBJECTIVE: In a porcine model, we demonstrated that laparoscopic Nissen fundoplication causes a significant drop in cardiac output (30%) because it exposes both the peritoneal cavity and the mediastinum to CO(2) under pressure. To determine if this occurs in humans, we examined cardiovascular physiology during laparoscopic Nissen fundoplication. Because of ...
Summers Richard L - - 2003
The evaluation of the hemodynamic state of the severely ill patient is a common problem in emergency medicine. While conventional vital signs offer some insight into delineating the circulatory pathophysiology, it is often impossible to determine the true clinical state from an analysis of blood pressure and heart rate alone. ...
Robel-Tillig Eva - - 2003
BACKGROUND: Small for gestational age neonates with prenatal hemodynamic disturbances are at increased risk for neonatal morbidity. Investigations of fetal cardiac function have proved some functional impairments. The aim of the study was to investigate postnatal cardiac adaptation in these neonates in comparison with neonates without prenatal hemodynamic impairments. METHODS ...
Bengel Frank M - - 2003
Using noninvasive imaging, we have previously demonstrated that myocardial efficiency is impaired in hypothyroidism and improves after establishing euthyroid conditions. Little is known about the effects of abnormally elevated thyroid hormone exposure on cardiac metabolic performance. We studied 10 patients without evidence of heart disease in mild hyperthyroidism, and after ...
Yu Ming - - 2003
The changes in blood pressure, cardiac output, and total peripheral conductance evoked by the novel hypotensive arginine vasopressin (AVP) - like peptide, d(CH2)5[D-Tyr(Et)2,Arg3,Val4,Arg7,Eda9]AVP (HYPO-AVP), were recorded in conscious unrestrained Sprague-Dawley rats implanted with radiotelemetry pressure transducers and ultrasonic transit-time flowprobes. Intravenous infusions of 0.6, 1.0, 2.0, and 4.0 microg x ...
Cotter Gad - - 2003
The heart is a muscular mechanical pump with an ability to generate both flow (cardiac output) and pressure. The product of flow output and systemic arterial pressure is the rate of useful work done, or power output. Cardiac pumping capability can be defined as the cardiac power output (CPO(max)) achieved ...
Gidlewski Josh - - 2003
Ultrasonography is a safe, noninvasive, sensitive, and specific tool for evaluation of the heart and pericardium in patients with cardiac neoplasia. In small animals, the incidence of cardiac neoplasia is low. In dogs, hemangiosarcoma and chemocdectoma are the two most common types of cardiac neoplasia. In cats, lymphosarcoma is the ...
Linton N W F - - 2003
BACKGROUND AND OBJECTIVE: The aim was to study the rapid changes in cardiac output and systemic vascular resistance produced by intravenous epinephrine (5 microg) on a beat-by-beat basis. METHODS: Ten patients were studied during cardiac surgery. Radial or brachial arterial pressure was recorded continuously during intravenous administration of epinephrine (5 ...
Rao Ramesh R - - 2003
A model-based control methodology was developed for automated regulation of mean arterial pressure and cardiac output in critical care subjects using inotropic and vasoactive drugs. The control algorithm used a multiple-model adaptive approach in a model predictive control framework to account for variability and explicitly handle drug rate constraints. The ...
Karasawa F - - 2003
BACKGROUND AND OBJECTIVE: Phosphodiesterase-III inhibitors and dobutamine effectively improve cardiac function in patients with cardiac failure, but they are limited by possible hypotensive effects. We tested the hypothesis that dopamine contributes to stabilizing milrinone-induced haemodynamic changes. METHODS: Nine patients undergoing major surgery were anaesthetized using nitrous oxide and oxygen supplemented ...
Lindström P - - 2003
AIM: Oliguria is seen during elevated intraperitoneal pressure, but the physiological mechanisms are not yet clarified. The purpose of the present study was to investigate the changes in renal function, cardiac output and distribution of systemic blood flow (BF) that occur in connection with an elevation of intra-abdominal pressure (IAP) ...
McNamara Mary Ellen - - 2003
CONTEXT: Admission to the hospital for a diagnostic cardiac catheterization can be perceived as a threat to one's health status. Autonomic nervous system arousal, particularly the sympathetic division, can elicit negative physiological and psychological human responses as a reaction to this threat. OBJECTIVE: The purpose of this study was to ...
Katz A M - - 2003
Heart failure has traditionally been viewed as a hemodynamic syndrome characterized by fluid retention, high venous pressure, and low cardiac output. Over the past decade, however, it has become clear that because of deterioration and progressive dilatation (remodeling) of the diseased heart, this is also a rapidly fatal syndrome. The ...
Anning Luke - - 2003
BACKGROUND AND PURPOSE: Manual hyperinflation is a physiotherapy technique that improves static compliance and mobilizes secretions, but has the potential to alter haemodynamic function. The aim of the present study was to investigate the effects of manual hyperinflation on haemodynamic function in a healthy animal model, without the usual confounding ...
Reuter D A - - 2003
BACKGROUND AND OBJECTIVE: The efficacy of the Trendelenburg position, a common first step to treat suspected hypovolaemia, remains controversial. We evaluated its haemodynamic effects on cardiac preload and performance in patients after cardiac surgery. METHODS: Twelve patients undergoing mechanical ventilation of the lungs who demonstrated left ventricular 'kissing papillary muscles' ...
Meck Janice V - - 2003
Intravenous injections of the indirect sympathetic amine, tyramine, are used as a test of peripheral adrenergic function. The authors measured the time course of increases in ejection fraction, heart rate, systolic and diastolic pressure, popliteal artery flow, and greater saphenous vein diameter before and after an injection of 4.0 mg/m(2) ...
Gonzalez Jésus - - 2003
Bedside cardiac output determination is a common preoccupation in the critically ill. All available methods have drawbacks. We wished to re-examine the agreement between cardiac output determined using the thermodilution method (QTTHERM) and cardiac output determined using the metabolic (Fick) method (QTFICK) in patients with extremely severe states, all the ...
Clow Kathy A - - 2003
Pregnant animals are less able to maintain mean arterial pressure (MAP) during hemorrhage compared with nonpregnant animals, but the hemodynamic basis of this difference is unknown. The hypothesis that pregnancy attenuates responses of cardiac output, as well as total peripheral resistance (TPR) and femoral conductance, to hemorrhage was tested in ...
Yamamoto Natsuo - - 2002
A 51-year-old woman suffering from dyspnoea and refractory bilateral pleural effusions is discussed. The effusion was characterized as a transudate and cardiac decompensation and renal insufficiency were initially suspected. Diuretic agents were not effective and the patient required bilateral chest water-sealed drainage tubes for 4 months, after exclusion of neoplastic ...
Lanni Susan M - - 2002
OBJECTIVE: The purpose of this study was to determine whether supine hypotensive syndrome is caused by a decreased baroreflex gain that results in inadequate compensatory responses to restore cardiac output. STUDY DESIGN: Ten third-trimester gravid women with symptoms that were suggestive of supine hypotensive syndrome and 10 control subjects without ...
Benallal Habib - - 2002
PURPOSE: The aim of this investigation was to evaluate a breathing lung model to estimate arterial gas partial pressures and cardiac output at rest and during exercise. METHODS: A mathematical model was used to describe variations in gas fractions, alveolar volume, and gas exchange in the pulmonary capillaries during the ...
Jellema Wilbert T - - 2002
The cardiovascular derangement that results from the administration of endotoxin in healthy subjects is qualitatively similar to what is observed in patients in septic shock. The biological response to endotoxin is attributed in part to cytokine release. In experimental endotoxemia, recombinant bactericidal/permeability increasing protein (rBPI(23)) has shown a protective effect ...
Kelly Martin G - - 2002
STUDY OBJECTIVE:s: Induced sputum is used to investigate pulmonary diseases. Low-output ultrasonic nebulizers have become available and have potential advantages over high-output nebulizers. We hypothesized that a low-output nebulizer would give comparable results to a high-output nebulizer, with an acceptable safety profile. DESIGN: Randomized, crossover study. SETTING: University teaching hospital. ...
Dhingra Vinay K - - 2002
STUDY OBJECTIVE:s: Individual comparison of cardiac output via intermittent thermodilution and Fick technique over a wide range of cardiac outputs. DESIGN: Prospective clinical investigation. SETTING: Multidisciplinary ICUs of two teaching hospitals in Vancouver, British Columbia. PARTICIPANTS: Eighteen critically ill patients who had pulmonary and systemic arterial catheters and in whom ...
Remmen Jaap J - - 2002
Non-invasive continuous monitoring of cardiac output could be very useful in clinical care and in research settings, particularly in elderly subjects. We studied whether Finapres arterial pulse wave analysis with Modelflow is a reliable non-invasive method for the assessment of cardiac output in healthy elderly subjects. We compared Modelflow cardiac ...
Romano Salvatore M - - 2002
OBJECTIVE: To evaluate the reliability, by comparison with established techniques, of a new method to assess cardiac output, called pressure recording analytical method (PRAM), deriving from the analysis of the arterial pressure profile in the time domain the arterial-pressure-blood flow relationship. DESIGN: Criterion standard. SETTING: Hemodynamics laboratory at an university ...
Jolma Catherine D CD Department of Pediatrics, The University of Arizona, 1501 N. Campbell Avenue, PO Box 245073, Tucson, AZ 85724-5073, - - 2002
Nicotine is known to have many physiologic effects. The influence of nicotine delivered in chewing gum upon cardiac hemodynamics and conduction has not been well-characterized. We studied the effects of nicotine in nonsmoking adults (6 male, 5 female; ages 23-36 years) using a double-blind, randomized, cross-over study. Subjects chewed nicotine ...
Messerli Franz H - - 2002
Hypertension, by definition, is a hemodynamic disorder. A high cardiac output and a normal systemic vascular resistance characterize the young hypertensive patient. As hypertension progresses, resistance becomes progressively elevated and cardiac output returns to normal. The elderly patient with hypertension has very high systemic vascular resistance and low cardiac output. ...
Marcisz Czesław - - 2002
BACKGROUND: Hyperthyroidism affects the circulatory system, producing an increase in cardiac output and an enhanced vascular bed volume. These phenomena are important in the regulation of blood pressure. The present study was designed to evaluate the effects of short- and long-term treatment of hyperthyroidism on arterial pressure, taking into account ...
Hashimoto Tomoki - - 2002
Brain arteriovenous malformation (BAVM) resection can result in an acute increase in cerebral blood flow (CBF) of unclear etiology. This observational study investigated the relationship between changes in CBF and cardiac output (CO) in patients undergoing microsurgical resection of BAVMs. In 20 patients undergoing a BAVM resection during an isoflurane-based ...
Jonas Max M - - 2002
Lithium dilution cardiac output (LiDCO trade mark; LiDCO, London, UK) is a minimally invasive indicator dilution technique for the measurement of cardiac output. It was primarily developed as a simple calibration for the PulseCO trade mark (LiDCO, London, UK) continuous arterial waveform analysis monitor. The technique is quick and simple, ...
Yazawa K - - 2002
BACKGROUND: Upper gastrointestinal endoscopy (UGIE) may cause some cardiac stress. The effect of sedation on hemodynamics during UGIE has not been fully studied, and therefore the aim of this study was to clarify whether or not sedation can reduce cardiac stress dufing UGIE. METHODS: Eight normal male volunteers undergoing UGIE ...
Bailey James M - - 2002
BACKGROUND: Treatment of elevated blood pressure is frequently necessary after cardiac surgery to minimize postoperative bleeding and to attenuate afterload changes associated with hypertension. The purpose of this study was to investigate the pharmacodynamics and pharmacokinetics of a short-acting calcium channel antagonist, clevidipine, in the treatment of hypertension in postoperative ...
Scott-Douglas Nairne W - - 2002
BACKGROUND: Changes in intestinal vascular capacitance during acute volume loading and hemorrhage have not been described. OBJECTIVES: To determine the effects of volume loading and hemorrhage on the intestinal vascular pressure-volume relationship and cardiac output. PATIENTS AND METHODS: In 11 alpha-chloralose-anesthetized dogs, a pneumatic portal venous constrictor and catheter were ...
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