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Results 451 - 500 of 1326
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Nakaigawa Y - - 1997
We have studied the effects of i.v. bolus doses of magnesium sulphate (MgSO4) 60, 90 and 120 mg kg-1 on haemodynamic state, the coronary circulation and myocardial metabolism in nine dogs anaesthetized with pentobarbitone and fentanyl. MgSO4 produced dose-dependent decreases in arterial pressure, heart rate, left ventricular dP/dtmax and left ...
Rowbotham D S - - 1997
N-acetylcysteine improves survival in established acute liver failure following paracetamol overdose by reducing the incidence of multiorgan failure. These benefits are thought to be related to decreased tissue hypoxia by the enhancement of both oxygen delivery and oxygen extraction. Similar findings have been recorded in critically ill patients from an ...
Vergroesen I - - 1997
OBJECTIVE: Introduction and measurement of human myocardial oxygen supply:demand ratio as a reference for quantification of coronary microvascular vasodilating drug effects in clinical studies. Myocardial oxygen consumption is the major determinant of coronary blood flow; therefore, the true vasodilating properties of coronary vasodilating drugs that may have an effect on ...
Di Salvo T G - - 1997
BACKGROUND: The purpose of this study was to identify predictors of survival in patients referred for heart transplantation evaluation who had a peak oxygen uptake of 10 to 14 ml/kg/min measured during initial cardiopulmonary exercise testing. METHODS: Seventy-two patients were identified retrospectively from a database of 304 patients who underwent ...
Okuyama T - - 1997
BACKGROUND: Stimulation of myocardial alpha 1-adrenoceptors has been shown to exert positive inotropic effects through a cyclic AMP-independent mechanism. The purpose of this study was to examine if alpha 1-adrenoceptor stimulation is able to attenuate myocardial depression produced by exposure to halothane, and to test if alpha 1-adrenoceptor stimulation alters ...
Chen W - - 1997
1H NMR spectroscopy was used to detect the proximal histidyl Ndelta proton signal of deoxymyoglobin from canine hearts in vivo during graded myocardial ischemia. The NMR signal intensity provided an indicator of intracellular oxygenation in myocardium. The relationship between the myocardial blood flow and the deoxymyoglobin concentration was successfully measured ...
Phillips R A - - 1997
This study was undertaken to determine if shivering after cardiac surgery threatens stability during early surgical recovery. Twenty-six subjects were monitored for 6 postoperative hours to identify effects of increasing shivering severity on cardiac effort and peripheral oxygenation. Analyses show that there is an increase in effort and a decrease ...
Hsi W L - - 1997
The purpose of this study was to examine whether submaximal oxygen pulse divided by body weight (O2 pulse/BW) during an incremental exercise test discriminated between trained and untrained men, correlated to left ventricular ejection fraction (LVEF) at rest in post-myocardial infarction patients, and was sensitive and specific in detecting ventricular ...
Bagger J P - - 1997
Cytoprotection or metabolic modulation is a new principle in the treatment of angina pectoris. The effect of ranolazine (a cytoprotective drug) on ischemic threshold, coronary sinus blood flow, and myocardial metabolism was evaluated by means of two pacing sequences in nine male patients with coronary artery disease (CAD) and in ...
Sherman A J - - 1997
OBJECTIVES: This study sought to determine whether modest short-term reductions in coronary flow can produce subsequent proportionate reductions in myocardial function and O2 consumption compatible with myocardial hibernation. BACKGROUND: Acute studies indicate that myocardial energy utilization can be downregulated during moderate flow reduction. Whether this apparently beneficial adjustment persists into ...
Buckman R F RF - - 1997
OBJECTIVE: To compare the coronary and cerebral perfusion achieved using a novel method of minimally-invasive, direct cardiac massage to that obtained using bimanual, open-chest cardiac massage. DESIGN: Prospective, controlled animal study with repeated measures. SETTING: University research laboratory. SUBJECTS: Large domestic swine. INTERVENTIONS: Aortic, coronary sinus, jugular venous and pulmonary ...
Möbert J - - 1997
Isoprostanes are a family of prostaglandin-related compounds formed from arachidonic acid in a cyclooxygenase-independent manner as products of free radical-initiated lipid peroxidation. To elucidate the biological activity of the F2-and E2-isoprostanes, 8-iso-prostaglandin F2alpha (8-iso-PGF2alpha) and 8-iso-prostaglandin E2 (8-iso-PGE2), we measured hemodynamic effects in isolated perfused guinea pig hearts after cumulative ...
Ghomeshi H R - - 1997
OBJECTIVE: Our objective was to test the effects of exogenous L-aspartate and L-glutamate on myocardial energy metabolism during ischemia-reperfusion. METHODS: Phosphorus 31-magnetic resonance spectroscopy was used to observe cellular energetics and intracellular pH in isolated pig hearts perfused with blood (group A, n = 8) or blood enriched with 13 ...
Mrozek R - - 1997
OBJECTIVE: The aim of the study was to assess gastric mucosal pH during certain parts of a major cardiac procedure (hypo- and normothermic), and then throughout the first postoperative day. METHODS: Gastric mucosal pH was measured using a tonometer, in 15 patients subjected to elective CABG procedures. The patients were ...
Michalewicz L - - 1997
The calcium antagonists are a class of heterogeneous drugs, with a wide spectrum of direct and indirect cardiac effects that vary a great deal from one drug to another and depend upon formulation and duration of action. Calcium antagonists act by decreasing total peripheral resistance to lower arterial pressure. As ...
Cohn P F - - 1997
Non-invasive treatment continues to be the mainstay of anti-ischaemic therapy. The imbalance between myocardial oxygen supply and demand provides the basis for myocardial ischaemia, which may present as symptomatic, asymptomatic or, in most cases, a mixture of the two. Both symptomatic and silent ischaemia are major prognostic indicators in patients ...
Berry J M - - 1997
Whole-body hyperthermia (WBH) is a well-described investigational adjunct to systemic chemotherapy for the treatment of advanced malignancies. The hemodynamic consequences of this physiologic state may include tachycardia, which can produce acute myocardial ischemia in patients with coronary artery disease. Ischemic heart disease is currently considered a contraindication to WBH. We ...
Layland M - - 1997
OBJECTIVE: To determine the relationship between gastrointestinal intramucosal pH and myocardial oxygenation during isovolemic hemodilution in dogs with critical coronary artery stenoses. DESIGN: Prospective sequential evaluation of ileal intramucosal pH and regional myocardial function of a critically perfused area of myocardial tissue in a canine model of normovolemic hemodilution. SETTING: ...
Sherman A J - - 1997
BACKGROUND: Although cardiac myocytes and coronary vascular endothelium are known to express a constitutive form of NO synthase, the in vivo effects of tonic endogenous production of NO on myocardial O2 consumption and contractile performance remain unclear. METHODS AND RESULTS: The effects of blockade of NO synthase were determined in ...
Cheong K F - - 1997
Oxygen consumption values calculated by Fick's principle (cVO2) were compared to simultaneously obtained values measured by indirect calorimetry (mVO2) in two groups of patients; post-coronary artery bypass graft (post-CABG) and septic shock. In both groups of patients, oxygen consumption values derived using indirect calorimetry were higher than that from Fick's ...
Takaoka H - - 1997
Although conventional inotropic agents such as catecholamines increase myocardial oxygen consumption, a newly developed inotropic agent, a Ca2+ sensitizer, may be able to increase cardiac output with less myocardial oxygen consumption. By using right-side heart catheterization, we assessed the ratio of the increase in myocardial oxygen consumption per unit increase ...
Rabindranauth P - - 1997
We tested the hypothesis that increasing myocardial cyclic GMP levels would reduce myocardial O2 consumption and that renal hypertension (One Kidney-One Clip, 1K1C)-induced cardiac hypertrophy would change this relationship. Four groups of anesthetized open-chest New Zealand white rabbits (N = 26) were utilized. Either vehicle or 3-morpholinosydnonimine (SIN-1) (10(-4) M, ...
Hammar N - - 1997
OBJECTIVES: Little is known about the possible influence of different kinds of alcohol drinking pattern on the risk of acute myocardial infarction. In this study the association between average daily alcohol consumption, as well as large intakes of alcohol on single occasions, and myocardial infarction incidence was investigated. DESIGN: A ...
Barzaghi N - - 1997
Cardiopulmonary failure occurred in a 62-year-old patient a few hours after emergency cardiac retransplantation. Venoarterial extracorporeal membrane oxygenation was required to support biventricular dysfunction; thereafter, inhaled nitric oxide was given for residual hypoxemia and pulmonary hypertension. We report survival after venoarterial extracorporeal membrane oxygenation and inhaled nitric oxide treatment for ...
Graf B M - - 1997
BACKGROUND: The local anesthetic bupivacaine is an equal mixture of two optically active isomers known to exert different cardiotoxic profiles in vivo. Enantiomer-specific forms of bupivacaine may have differential effects on cardiovascular function, specifically on cardiac electrophysiology. The authors' aim was to determine if there were any direct functional differences ...
Zhang X - - 1997
BACKGROUND: ACE inhibitors potentiate kinin-nitric oxide (NO)-dependent coronary vascular dilation, and NO can modulate myocardial oxygen consumption. Whether ACE inhibitors also affect myocardial O2 consumption has not been established. METHODS AND RESULTS: Production of nitrite, a metabolite of NO in aqueous solution, in coronary microvessels and O2 consumption in myocardium ...
Niki K - - 1997
We evaluated the effects of disopyramide in terms of the balance between myocardial oxygen supply and demand in patients with hypertrophic obstructive cardiomyopathy (HOCM). The myocardial oxygen supply was evaluated by measuring coronary flow velocity and the myocardial oxygen demand was assessed by the pressure-volume area (PVA). The time velocity ...
Matsubara T - - 1997
BACKGROUND: The effects of oxygen free radicals on coronary vasoreactivity remain unknown. OBJECTIVE: To examine whether oxygen free radicals increase coronary arterial tone and sensitivity to vasoconstrictor stimulation in closed-chest dogs. METHODS: Oxygen radicals were generated by the reaction of xanthine plus xanthine oxidase (XXO) and effects of these substances ...
Moser D K - - 1997
BACKGROUND: Advanced heart failure is characterized by activation of the sympathetic nervous system and intense vasoconstriction. Biofeedback-relaxation techniques have been used successfully to treat conditions with similar pathophysiological features. OBJECTIVES: The purpose of this study was to determine if conscious control of skin temperature via a biofeedback-relaxation technique could produce ...
Walley K R - - 1997
We tested the hypothesis that the onset of myocardial anaerobic metabolism is fundamentally different from the whole body and other organs, where the onset of anaerobic metabolism occurs at a critical oxygen extraction ratio--not at a critical venous PO2. We measured oxygen saturation and PO2 of arterial and coronary venous ...
Grinberg O Y - - 1997
Oxygen is essential for normal cardiac function and plays an important role in cardiac regulation. Electron paramagnetic resonance (EPR) oximetry appears to have some significant advantages for measuring oxygen tension (pO2) in the beating heart. This study presents the serial measurement of myocardial pO2 by EPR oximetry in the isolated ...
Wu S J - - 1996
Myocardial stunning refers to reversible postischemic myocardial dysfunction persisting after reperfusion. We report a patient who presented with biventricular failure, but exhibited neither definite electrocardiographic change nor elevation of serum cardiac enzyme levels in the post-cardiotomy period. The presentation was indicative of myocardial stunning. The patient's hemodynamics could not be ...
Myles P S - - 1996
We studied the relationship between oxygen delivery (DO2) and consumption (VO2) in twenty patients undergoing cardiac surgery, in order to determine if VO2 was dependent on DO2 (pathological oxygen supply dependence). We measured VO2 from expired gas analysis (VO2G) and compared this to that calculated using the reverse Fick method ...
Tzivoni D - - 1996
Myocardial ischaemia in daily life varies according to a circadian rhythm and is induced by many factors, including both increased myocardial oxygen demand and changes in coronary tone. In most patients, ischaemia is induced by a combination of different contributing factors, although the relative contribution of each mechanism varies from ...
Chen J W - - 1996
To determine the possible mechanism of the ischemic-like electrocardiogram (ECG) during exercise in the presence of anginal chest pain and normal coronary angiograms, both a treadmill exercise test (TET) and coronary hemodynamic study were prospectively performed in 33 consecutive patients (18 females and 15 males, aged 48 +/- 10 years) ...
Licker M - - 1996
Twenty-three patients undergoing elective coronary artery bypass graft surgery with moderate hypothermic bypass, under opiate-benzodiazepine anaesthesia were investigated during the first 7 h following surgery. Patients with recent myocardial infarct (< 6 weeks), reduced left ventricular ejection fraction (< 40%) or requiring inotropic support were excluded. During the first 3 ...
Yu M - - 1996
A relationship between survival and high cardiac index and oxygen delivery (DO2) has been documented for patients of all ages. Debate continues whether achieving these parameters decreases mortality or whether these parameters merely reflect better physiologic reserve. Younger patients who spontaneously generate high DO2 have low mortality rates and do ...
Keeley E C - - 1996
PURPOSE: Nicotine replacement therapy has become a popular therapy for smokers attempting to stop smoking. Unfortunately, some subjects continue to smoke while receiving it. Since nicotine is believed to be the primary constituent of cigarette smoke responsible for its acute adverse effects on myocardial oxygen supply and demand, concomitant nicotine ...
Cavaliere F - - 1996
OBJECTIVE: To investigate the utility of the arterial-venous PCO2 gradient (P(a-v)CO2) as a marker of the increased risk of postoperative complications in the early postoperative hours following myocardial revascularization. EXPERIMENTAL DESIGN: Prospective study. SETTING: The Postoperative Intensive Care Unit (ICU) of a University Hospital. PATIENTS: Thirty patients (28 males and ...
Holm C - - 1996
A high proportion of the mortality and morbidity associated with endoscopic procedures may be of cardiopulmonary origin. For this reason, the appropriate degree of monitoring and prophylactic measures to be used in the sedated patient undergoing endoscopy has become a topic of discussion during recent years. The development of myocardial ...
DiPierro F V - - 1996
BACKGROUND: Triiodothyronine (T3) administration after cardiopulmonary bypass has been shown to significantly improve cardiac performance. The present study was undertaken to elucidate the effects of T3, when administered as an intravenous bolus, on both cardiac energetics and stroke work-oxygen utilization (EW/LVVO2) efficiency. METHODS: In both unstressed and stressed hearts, energetics ...
Habler O P - - 1996
The influence of severe acute normovolemic hemodilution (ANH) on myocardial contractility (MC) was investigated in 14 splenectomized, anesthetized dogs. MC was assessed by the maximum rate of left ventricular pressure increase (LVdp/dt(max)), end-systolic elastance (Ees), and preload recruitable stroke work (PRSW) (conductance catheter, left ventricular pressure-volume relationship). Measurements of myocardial ...
Xie Y W - - 1996
The mechanism responsible for the regulation of cardiac function by endogenous nitric oxide (NO) remains unclear. In this investigation, O2 consumption by freshly isolated myocardial muscle segments from the left ventricular free wall of canine hearts was quantified by a Clark-type O2 electrode at 37 degrees C. S-nitroso-N-acetylpenicillamine (SNAP, 9 ...
Gurevicius J - - 1996
This study evaluated changes in coronary blood flow (CBF), myocardial oxygen consumption (MVo2), and myocardial segmental shortening (SS) during intracoronary administrations of enflurane in in situ canine hearts. The left anterior descending coronary artery (LAD) of 11 anesthetized and mechanically ventilated dogs was perfused at constant perfusion pressure (80 mm ...
Leaf D A - - 1996
Environmental exposure to inhaled carbon monoxide (CO) increases coronary artery disease risk. Sudden cardiac death, a frequent manifestation of coronary artery disease, is usually a result of ventricular dysrhythmia. The effect of exposure to CO at sea level (CO/SL) and simulated high (2.1 km) altitudes (CO/HA) on the incidence of ...
Marques-Vidal P - - 1996
The effect of alcohol consumption was assessed in 561 men with myocardial infarction and 643 healthy controls recruited from France and Northern Ireland between 1988 and 1991 in the ECTIM Study (Enquête Cas-Témoins de I'Infarctus du Myocarde). In total, patients consumed less wine than did controls, while non-wine-derived alcohol consumption ...
Pedersen H K - - 1996
RATIONALE AND OBJECTIVES: We investigated the possible cardiac effects of oxygen addition to contrast media (CM) during coronary arteriography in dogs that did and did not have ischemic heart failure. METHODS: Acute ischemic heart failure was induced by injecting small plastic microspheres into the left coronary artery of 18 dogs. ...
Lee D - - 1996
Carbon monoxide intoxication usually disturbs the normal human biochemical respiratory chain cascade from which high affinity of carboxyhemoglobin to oxygen causes ischemic insult to the human tissues and cells. Ubiquitous injuries to human cells have already been well documented for a long period of time. Here we reported a 42-year-old ...
Roekaerts P M - - 1996
The central sympatholytic effect of alpha 2 agonists may be beneficial during myocardial ischemia, but could be opposed by their peripheral vasoconstrictive effect. We studied the effects of mivazerol during periods of moderate coronary artery stenosis in anesthetized dogs. Mivazerol decreased heart rate (from 125 +/- 6 to 106 +/- ...
Alexi-Meskishvili V - - 1996
A 7-day newborn girl with d-transposition of the great arteries (d-TGA) and complex coronary anatomy developed global myocardial dysfunction after arterial switch operation despite establishment of an effective coronary circulation. Extracorporeal membrane oxygenation was used for circulatory support for 163 h after the operation. On day 7 after surgery she ...
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