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Results 251 - 300 of 1326
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Nicholls Tim P - - 2006
BACKGROUND: The aims of this study were to describe the early time course of hemodynamic and tissue perfusion and oxygenation patterns in survivors and nonsurvivors after head injury; to suggest physiologic mechanisms responsible for the observed patterns; and to evaluate postinjury parameters that might be useful for treatment. The hypothesis ...
Rosano Giuseppe M C - - 2005
Diabetic patients with ischaemic heart disease have a greater amount of myocardial ischaemia, often silent, and an increased incidence of heart failure compared to nondiabetic patients. This is the result of altered myocardial metabolism and accelerated atherogenesis with involvement of peripheral coronary segments causing chronic hypoperfusion and diffuse hybernation. In ...
Suzuki Takeshi - - 2005
OBJECTIVE: Since beta-blocker therapy is known to be effective in patients with an injured heart, such as infarction, we designed the present study to examine the protective effects of infusion of the beta1-selective blocker esmolol on myocardial function in peritonitis-induced septic rats using an isolated working heart preparation. DESIGN: Randomized ...
Kirkeby-Garstad I - - 2005
BACKGROUND: An acute increase in oxygen demand can be compensated for either by increased cardiac index (CI) or increased oxygen extraction, resulting in reduced mixed venous oxygen saturation (SvO2). We tested the hypothesis that post-operative cardiac dysfunction may explain why oxygen extraction alone is increased during early mobilization after cardiac ...
Thoennissen Nils H - - 2005
OBJECTIVE: Microembolic signals (MES) can be detected by transcranial Doppler sonography (TCD). To identify gaseous microemboli the inhalation of oxygen is an established method in patients with prosthetic heart valves. Time domain analysis of sample volume length (SVL) and of frequency modulation showed promising results in the discrimination between solid ...
Lepore John J - - 2005
BACKGROUND: Irreversible, severe pulmonary hypertension (PH) can produce right heart failure and early mortality after cardiac transplantation. We hypothesized that dipyridamole, an inhibitor of Type 5 phosphodiesterase, would augment the ability of inhaled nitric oxide (NO) to identify reversibility of PH. METHODS: In 9 patients with congestive heart failure (CHF) ...
Shoemaker William C - - 2005
OBJECTIVES: The aims were a) to noninvasively monitor acute emergency trauma patients beginning within 1 hr after admission to the emergency department; b) to prospectively predict outcome; and c) to evaluate the relative effectiveness of various modes of therapy. DESIGN: Prospective outcome prediction study using a mathematical search and display ...
Matschke Klaus - - 2005
INTRODUCTION: The influence of heart rate on cardiac output, oxygen consumption, and myocardial activity has been widely investigated. However, the influence of heart rate on myocardial oxygen tension (pO2) remains unclear. Since the introduction of flexible pO2 micro catheters to measure partial oxygen tension in a working muscle, it is ...
Lei Biao - - 2005
Nitric oxide (NO) inhibits myocardial glucose transport and metabolism, although the underlying mechanism(s) and functional consequences of this effect are not clearly understood. We tested the hypothesis that NO inhibits the activation of AMP-activated protein kinase (AMPK) and translocation of cardiac glucose transporters (GLUTs; GLUT-4) and reduces lactate production. Ischemia ...
Conti C Richard - - 2005
The basic principle of enhanced external counterpulsation (EECP) is diastolic augmentation of arterial pressure, lowering of systolic arterial pressure along with increasing venous return. EECP is a noninvasive procedure involving sequential inflation and rapid deflation of compressive cuffs wrapped around the patient's calves, thighs, and lower abdomen, timed to the ...
Mahle William T - - 2005
BACKGROUND: Indications for extracorporeal membrane oxygenation therapy have expanded to include cardiopulmonary arrest and support after congenital heart surgery. Data from a national registry have reported that cardiac patients have the poorest survival of all extracorporeal membrane oxygenation recipients. Concerns have been raised about the appropriateness of such an aggressive ...
Burkhoff Daniel - - 2005
Despite the availability of interventional catheterization for patients with acute coronary syndromes, there is an unavoidable delay until the occluded coronary artery(s) can be revascularized, during which time persistent ischemia may lead to irreversible myocardial damage despite subsequently high patency rates. Accordingly, there has been an intense effort to develop ...
Michaels Andrew D - - 2005
BACKGROUND: Levosimendan is a calcium-sensitizing agent and an inodilator under current investigation in the treatment of decompensated heart failure. The effects of intravenous levosimendan on the human coronary vasculature, together with myocardial wall stress and oxygen uptake, have not been adequately studied. METHODS AND RESULTS: Ten adult patients underwent right- ...
Giordano Frank J - - 2005
A constant supply of oxygen is indispensable for cardiac viability and function. However, the role of oxygen and oxygen-associated processes in the heart is complex, and they and can be either beneficial or contribute to cardiac dysfunction and death. As oxygen is a major determinant of cardiac gene expression, and ...
Hare Joshua M - - 2005
There is growing evidence that the altered production and/or spatiotemporal distribution of reactive oxygen and nitrogen species creates oxidative and/or nitrosative stresses in the failing heart and vascular tree, which contribute to the abnormal cardiac and vascular phenotypes that characterize the failing cardiovascular system. These derangements at the integrated system ...
Steinhauer Tad - - 2005
The heart pumps blood through a system of blood vessels under the control of an electric conduction system to deliver oxygen to all cells of the body. When the blood volume becomes greater than the limited volume capacity of the vascular system, the patient develops hypertension. When the myocardium does ...
Portman Michael A - - 2005
Thyroid acting through ligand binding to nuclear receptors modifies myocardial respiratory kinetics and oxidative phosphorylation in the heart. Direct nongenomic action of thyroid hormone on high-energy phosphate concentrations and respiratory kinetics has never been proven in vivo but might be responsible for observed changes in oxygen utilization efficiency immediately after ...
Frostfeldt Gunnar - - 2005
BACKGROUND: Early reperfusion is an established therapeutic objective in acute myocardial infarction (MI). The relationship of regional myocardial microcirculation and metabolism toward outcome in acute human MI is not well known. METHODS AND RESULTS: In 8 patients, positron emission tomography (PET) was performed with oxygen 15-labeled water at 3 hours, ...
Maekawa Takuji - - 2005
PURPOSE: We investigated the effects of propofol on contractility and oxygen balance in acute ischemic myocardium and compared them with those of normal myocardium using a coronary microembolization model in dogs. METHODS: In open-chest dogs, the left anterior descending coronary artery (LAD) was perfused through an extracorporeal bypass from the ...
Ouattara Alexandre - - 2005
BACKGROUND: Terlipressin, a synthetic analog of arginine-vasopressin (AVP), has been proposed as an effective vasopressive therapy in catecholamine-resistant vasodilatory shock. Although beneficial effects of terlipressin on systemic arterial pressure have been clearly demonstrated, its intrinsic effects on coronary circulation and myocardial performances remain unknown. METHODS: The authors compared the coronary ...
Ejike J Chiaka - - 2005
Previous work from this laboratory using near-infrared optical spectroscopy of myoglobin has shown that approximately 20% of the myocardium is hypoxic in buffer-perfused hearts that are perfused with fully oxygenated buffer at 37 degrees C. The present study was undertaken to determine cardiac myoglobin saturation in buffer-perfused hearts when cardiac ...
Bilkovski Robert N - - 2004
PURPOSE OF REVIEW: The management of the traumatically injured patient has evolved during the past half century despite continually high morbidity and mortality rates. The management of the trauma victim requires timely intervention and damage control in an attempt to maintain normal hemodynamic parameters and adequate systemic perfusion. There is ...
Allamaneni Shyam S R - - 2004
Increased levels of reactive oxygen species (ROS) are associated with clinical varicoceles; however, its correlation with varicocele grade and testis size is unknown. In our study, seminal ROS levels showed significant correlation with left varicocele grade and significantly elevated seminal ROS levels were seen in men with left varicocele grade ...
Setty Srinath - - 2004
OBJECTIVE: The present study examined the role of nitric oxide (NO) in oxygen demand-supply balance in hypoperfused canine right ventricular myocardium. METHODS: The right coronary artery of anesthetized, open-chest dogs was perfused at pressures of 80, 60, and 40 mm Hg, and right ventricular myocardial oxygen consumption, right coronary blood ...
Nicholson Christopher - - 2004
BACKGROUND: Patients with acute cardiac chest pain receive oxygen as part of their treatment. Oxygen is given in the belief it will help to correct the oxygen demand - supply imbalance of acute myocardial ischaemia. AIMS AND OBJECTIVES: The aim was to review the evidence base for the use of ...
Dekleva Milica - - 2004
BACKGROUND: The role of hyperbaric oxygen in patients with acute myocardial infarction is controversial, ranging from not beneficial to having a favorable effect. This randomized study was conducted to further assess the benefit of hyperbaric oxygen treatment after thrombolysis on left ventricular function and remodeling in patients with acute myocardial ...
Dworschak Martin - - 2004
Nitric oxide (NO) supplementation may modify myocardial oxygen consumption and vascular function after ischemia. We investigated the effects of the NO donor, S-nitroso human serum albumin (S-NO-HSA), on cardiac oxygen metabolism during controlled reperfusion on normothermic cardiopulmonary bypass after severe myocardial ischemia. Pigs randomly received either S-NO-HSA or human serum ...
Santos José L JL Servicio de Cardiología, Hospital Universitario de Salamanca, Salamanca, - - 2004
We describe a 54-year-old man who was HIV-positive, admitted for cardiogenic shock complications inferior myocardial infarction. He was treated with primary percutaneous transluminal angioplasty (PCTA) and stent deployment in mid right coronary artery. After a few days thrombotic occlusion of the stent occurred, and the problem recurred during implantation of ...
Zhang Jianyi - - 2005
NO and O(2) compete at cytochrome-c oxidase, thus potentially allowing NO to modulate mitochondrial respiration. We previously observed a decrease of myocardial phosphocreatine (PCr)/ATP during very high cardiac work states, corresponding to an increase in cytosolic free ADP. This study tested the hypothesis that NO inhibition of respiration contributes to ...
Kim M A - - 2004
SETTING: University-affiliated general hospital. OBJECTIVE: To evaluate the pump performance of right heart before and after exercise in post-tuberculosis emphysema. DESIGN: In patients with post-tuberculosis or primary emphysema (similar lung volumes), body plethysmography, arterial blood gas analysis and echocardiography were performed at rest and after exercise. Right heart pump performance ...
Molavi Behzad - - 2004
PURPOSE OF REVIEW: The adoption of immediate reperfusion strategies to treat acutely occluded coronary arteries and the emergence of high-resolution molecular biology techniques have drawn attention to oxidative stress and reactive oxygen species generation in the cardiovascular system. Recent evidence suggests that oxidative stress is a common denominator in many ...
Kemming G I - - 2004
BACKGROUND: Hemodilution reduces hematocrit (Hct) and blood oxygen content. Tissue oxygenation is mainly preserved by increased cardiac output. As myocardial O2-demands increase, coronary vasodilatation becomes necessary to increase myocardial blood flow. Myocardial ischemia occurs at a critical Hct-value (Hctcrit), with accompanying exhaustion of coronary reserve. Hyperoxic ventilation is known to ...
Eriksson Ove - - 2004
Levosimendan is a novel drug developed for treatment of decompensated heart failure. Levosimendan is a calcium sensitizer that increases contractile force of the myocardium by enhancing the sensitivity of myofilaments to calcium without increasing intracellular calcium concentration. The present study was carried out to investigate whether levosimendan induces any changes ...
Foo K - - 2004
AIMS: To compare major determinants of myocardial oxygen demand (heart rate, blood pressure and rate pressure product) in patients with and without diabetes admitted with acute coronary syndromes. METHODS: A cross-sectional study of the relation between diabetes and haemodynamic indices of myocardial oxygen demand in 2542 patients with acute coronary ...
Inglessis Ignacio - - 2004
OBJECTIVES: We sought to determine whether or not inhaled nitric oxide (NO) could improve hemodynamic function in patients with right ventricular myocardial infarction (RVMI) and cardiogenic shock (CS). BACKGROUND: Inhaled NO is a selective pulmonary vasodilator that can decrease right ventricular afterload. METHODS: Thirteen patients (7 males and 6 females, ...
Aghajani Ebrahim - - 2004
OBJECTIVE: Myocardial oxygen consumption (MVO2) in the septic myocardium is increased despite reduced left ventricular mechanical work. We investigated the mechanism behind this energetic inefficiency in the septic myocardium. METHODS: To clarify whether energy consumption in basal metabolism or excitation-contraction (EC) coupling is elevated in the septic myocardium, we separated ...
Zheng Jie - - 2004
PURPOSE: To explore the relationship of myocardial T(2) and oxygenation for the quantification of myocardial oxygen extraction fraction (OEF). MATERIALS AND METHODS: A proposed myocardial T(2)-OEF relationship was evaluated by computer simulation and in nine normal dogs in vivo. The relationship was based on a simplified two-compartment T(2) model. In ...
Ingwall Joanne S - - 2004
The requirement of chemical energy in the form of ATP to support systolic and diastolic work of the heart is absolute. Because of its central role in cardiac metabolism and performance, the subject of this review on energetics in the failing heart is ATP. We briefly review the basics of ...
Vlahović Alja - - 2004
BACKGROUND: It has been shown that transient increase in left ventricular stiffness, assessed by Doppler-derived early filling deceleration time, occurs during the first 24 to 48 hours after myocardial infarction but returns to normal within several days. It has been reported that hyperbaric oxygen treatment has a favorable effect on ...
Adler Alexandra - - 2004
We investigated the role of nitric oxide (NO) in the control of myocardial O(2) consumption in the hearts of female Xenopus frogs, which lack a coronary vascular endothelium and in which the endocardial endothelium is the only source of NO to regulate cardiac myocyte function. Hence, frogs are an ideal ...
Hou Mingxiao - - 2004
Circulating levels of the potent vasoconstrictor peptide endothelin-1 (ET-1) are increased in congestive heart failure (CHF). Coronary blood flow and myocardial oxygen consumption (MVO2) are decreased in some models of CHF. This study tested the hypothesis that ET-1 induced coronary vasoconstriction limits oxygen availability in the failing heart. The effects ...
Vasiliauskas Donatas - - 2004
STUDY OBJECTIVE: The aim of the study was to evaluate the impact of a long-term (6-month) correct breathing stereotype on minute ventilation, capillary blood gases and acid-base balance in post-myocardial infarction patients. METHODS: Fifty-five men (age 57.2 +/- 12.5) were examined 2 months later after myocardial infarction. Spirometry and assessment ...
Nikolaidis Lazaros A - - 2004
To investigate the metabolic cost of catecholamine use in heart failure, we administered intravenous dobutamine or norepinephrine to dogs with moderate and severe LV dysfunction until LV contractile function was restored to normal levels. Both drugs were associated with significant increases in myocardial O(2) consumption, increased coronary blood flow requirements ...
Hirata Kumiko - - 2004
Epidemiologic studies suggest that tea consumption decreases the risk for cardiovascular events. However, there has been no clinical report examining the effects of tea consumption on coronary circulation. The purpose of this study was to evaluate the effects of black tea on coronary flow velocity reserve (CFVR) using transthoracic Doppler ...
Mukamal Kenneth J - - 2004
BACKGROUND: Previous studies have generally suggested no effect of coffee consumption on the risk of acute myocardial infarction. The effect of coffee consumption on prognosis after acute myocardial infarction is uncertain. METHODS: In an inception cohort study, we observed 1935 patients who were hospitalized with a confirmed acute myocardial infarction ...
Kaye David M - - 2004
The aim of the present study was to investigate the effects of CPAP (continuous positive airway pressure) support on myocardial energetics in patients with CHF (congestive heart failure). CPAP has been shown to decrease left ventricular afterload and to produce favourable short- and long-term haemodynamic and neurohormonal benefits in CHF ...
Michiels Carine - - 2004
As the average age in many countries steadily rises, heart infarction, stroke, and cancer become the most common causes of death in the 21st century. The causes of these disorders are many and varied and include genetic predisposition and environmental influences, but they all share a common feature in that ...
Sandstedt Bengt - - 2004
OBJECTIVE: Ventricular fibrillation (VF) is life-threatening because of its haemodynamic and metabolic effects. The purpose was to examine if VF also has primary effects per se. We therefore investigated the early effects of VF on myocardial blood flow, metabolic characteristics and catecholamine concentrations in patients undergoing surgery for aortic stenosis. ...
Samuels Louis - - 2004
The traditional extracorporeal membrane oxygenation circuit uses a centrifugal pump. These pumps require close monitoring and are subject to complications. In addition, they do not take advantage of the potential benefits of pulsatile flow. These extracorporeal membrane oxygenation circuits use a single pump with an inline oxygenator. If cardiac failure ...
Misfeld Martin - - 2004
OBJECTIVE: In coronary artery bypass surgery various parameters have been used to monitor patients clinical status. Direct monitoring of myocardial oxygenation can be performed by measuring intramyocardial partial oxygen tension pressure (p ti O2). This study was performed to determine the perioperative time course of this parameter in correlation to ...
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