Search Results
Results 501 - 550 of 1119
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Hansen C L - - 1998
Myocardial perfusion imaging with coronary vasodilators is routinely used for patients with suspected coronary disease who are unable to exercise. Since these agents work by increasing blood flow without significantly changing myocardial oxygen demand, they generally do not produce ischemia. A minority of patients show evidence of ischemia which some ...
Assayag P - - 1998
OBJECTIVE: Both aging and myocardial ischemia are associated with alterations of calcium-regulating proteins. We investigated the effects of graded levels of low-flow ischemia on myocardial function and on SR Ca(2+)-ATPase (SERCA2), Na(+)-Ca2+ exchanger (NCX) and ryanodine receptor (RyR2), at mRNA and protein levels in both adult and senescent myocardium. METHODS: ...
Hacker T A - - 1998
Previously, we reported, alterations in glucose metabolism in a 4 day model of chronic coronary stenosis similar to those described in patients with hibernating hearts. The purpose of this study was 2 fold: (1) to identify whether an acute model of mild, sustained ischemia could effect similar changes, and (2) ...
Fleisher L A - - 1998
The intraoperative management of the high-risk patient has received a great deal of attention and research during the past decade. Based on the available evidence, there appears to be no one best anesthetic technique or agent. More importantly, the goals of intraoperative management are to avoid myocardial ischemia, which include ...
Gannedahl P - - 1998
OBJECTIVE: To elucidate the relation of changes in computerized vectorcardiographic trend parameters indicating perioperative myocardial ischemia with perioperative cardiac complications. DESIGN: Prospective clinical study. SETTING: A single university hospital. PARTICIPANTS: Thirty-eight patients undergoing elective abdominal aortic surgery. INTERVENTIONS: Computerized vectorcardiography recorded during surgery and for 48 hours postoperatively. MEASUREMENTS AND ...
Nakata T - - 1998
Antimyosin monoclonal antibody is a specific marker of impaired sarcolemmal integrity resulting not only from ischemia but also from non-ischemic myocardial injury, such as infection, inflammatory, or immunologic reactions, and alcohol or drug intoxication. In addition, antimyosin accumulation has been demonstrated in some forms of cardiomyopathy with unknown as well ...
Munyao N - - 1998
To investigate whether sublethal ischemia preserves neuronal function otherwise lost after stroke, anesthesized rabbits were subjected to clamping of abdominal aorta to cause lumbar spinal cord ischemia. An occlusion period of 12.5 min was followed 12 or 48 h later by a second occlusion for 30 min. When scored 24 ...
Stierle U - - 1998
Generalized (multiple) arterio-systemic fistulae are fistulae arising from all three major coronary arteries and drain into the left ventricle are rare and the clinical and hemodynamic sequelae are incompletely understood. This communication is based on the clinical and hemodynamic data of a series of patients (eight cases out of 7262 ...
Bigi R - - 1998
Prevalence and prognostic significance of painful and silent ischemia detected by exercise electrocardiography (ECG) and dobutamine stress echocardiography (DSE) were evaluated in 407 consecutive patients recovering from acute myocardial infarction. Painful ischemia assessed by both tests was not associated with different clinical characteristics of patients; on the other hand, it ...
MacLeod R S - - 1998
Despite the widespread use of electrocardiogram (ECG), changes in cardiac activity resulting from ischemia or altered recovery characteristics sometimes remain electrocardiographically "silent" or are first detectable by techniques that measure ventricular contractility, such as ultrasound or blood pressure. Especially local changes in repolarization can go undetected when ECG electrodes do ...
Fleg Jerome L. - - 1998
Although clinically manifest CAD is present in about one-fourth of individuals older than 65 years, a like proportion of additional persons have asymptomatic coronary artery stenoses, manifest only by inducible myocardial ischemia. A major challenge to contemporary cardiology is to detect the subset of such asymptomatic subjects at highest risk ...
Grisold M - - 1998
The compound 2,3,5,6-Tetramethylpyrazine (TMP; Ligustrazine), a flavouring component and sweetness enhancer for beverages constitutes a commonly used food additive. Now we studied the effect of TMP on coronary artery dilation during ischemia: In our experiments we used isolated, Langendorff-perfused guinea pig hearts, arrested with K(+)-rich Normal Tyrode solution (in mM: ...
Sanyal S - - 1998
During the management of acute myocardial infarction, we observed that clinical and electrocardiographic indications of myocardial ischemia worsened upon nitroglycerin infusion and were promptly relieved upon streptokinase infusion. Subsequent coronary angiography revealed diffuse ectasia with no significant stenosis. We discuss the possible pathophysiologic mechanisms by which nitroglycerin might exacerbate ischemia ...
Coronel R - - 1997
BACKGROUND: An intracoronary thrombus during regional ischemia is related to life-threatening arrhythmias. The electrophysiological consequences of a thrombus are unknown. METHODS AND RESULTS: In open chest pigs, regional ischemia was induced by intracoronary injection of a thrombus (protocol 1). In protocol 2, coronary ligation was followed by injection of heparinized ...
Matot I - - 1997
STUDY OBJECTIVE: To study the incidence of myocardial ischemia and related hemodynamic alterations in sedated patients undergoing fiberoptic bronchoscopy (FOB). DESIGN: Prospective study. SETTING: Tertiary care, university hospital. PATIENTS: Twenty-nine patients, age 50 years or older, undergoing elective FOB. INTERVENTIONS: Myocardial ischemia was assessed by continuous ECG monitoring beginning 30 ...
Whetzel T P - - 1997
The primary critical ischemia time of the hairless mouse ear was determined using a probit analysis. An atraumatic clamp was used across the pedicle base of the ear to induce total ischemia at 0, 2, 4, 6, 7, 7.5, 8.0, 8.5, 9.0, 9.5, and 12 hours of normothermic ischemia. Seventy-seven ...
Hosokawa R - - 1997
To evaluate the clinical utility of 123I-(rho-iodophenyl)-3-R,S-methylpentadecanoic acid (123I-BMIPP) for ischemic heart disease, we investigated the metabolic fate of 123I-BMIPP in canine models with mild and severe ischemia and evaluated the clinical utility of this tracer. METHODS: Using open-chest dogs under anesthesia, we assembled a system that would release all ...
Seeberger M D - - 1997
New segmental wall motion abnormalities (SWMA) detected by echocardiography are considered sensitive and specific markers of myocardial ischemia. However, we have observed new SWMA during pacing-induced reductions in left ventricular filling, which resolved immediately with cessation of the atrial pacing and simultaneous restoration of filling. Therefore, we designed this study ...
Stone P H - - 1997
Myocardial ischemia identified by ambulatory electrocardiography (AECG), exercising treadmill testing, (ETT), or 12-lead electrocardiogram at rest is associated with an adverse prognosis, but the effect of improving these ischemic manifestations by treatment on outcome is unknown. The Asymptomatic Cardiac Ischemia Pilot (ACIP) study was a National Heart, Lung, and Blood ...
Hecker R B - - 1997
This case study describes myocardial ischemia and stunning after the topical application of phenylephrine-soaked pledgets (0.25%) in a 63-year-old female undergoing elective endoscopic sinus surgery. The patient had no previous history of cardiovascular disease or illicit drug use. Transient myocardial ischemia was associated with acute hypertension, chest pain, and S-T ...
Dhein S - - 1997
Acetylsalicylic acid often is used in the treatment and prophylaxis of regional myocardial ischemia and infarction. However, only little is known about its electrophysiological effects and on possible proarrhythmic effects of the drug. Thus, the aim of this study was to evaluate the electrophysiological effects of acetylsalicylic acid in normal ...
Jensen S M - - 1997
On-line computerized vectorcardiography (cVCG) is increasingly being used for continuous monitoring of myocardial ischemia, however, little is known about factors other than ischemia causing electrocardiographic abnormalities. This paper describes how three important cVCG parameters, STC-VM, ST-VM and QRS-VD, are affected by different body positions, myocardial ischemia, contrast injection and increasing ...
Watanabe I - - 1997
INTRODUCTION: This study was designed to determine the role of increased extracellular potassium [K+]e on action potential duration (APD) in the in situ porcine heart during acute regional no-flow ischemia. METHODS AND RESULTS: In open chest, anesthetized swine, an arterial shunt from the carotid artery to the mid-left anterior descending ...
Ebert T J - - 1997
Sevoflurane is associated with less tachycardia and coronary vasodilation than isoflurane and thus might be associated with less myocardial ischemia. This multicenter study examined the incidence of myocardial ischemia and adverse cardiac outcomes in adults (40-87 yr) with cardiac disease having elective noncardiac surgery. Patients were randomized to receive either ...
Sakamoto K - - 1997
During myocardial ischemia, the extracellular potassium concentration increases in a triphasic pattern, an initial early increase, a constant phase, and a late increasing phase. The aim of this study was to determine whether diltiazem inhibits the late increasing phase by maintaining glycolytic adenosine triphosphate (ATP) synthesis in ischemic myocardium. The ...
Bailey B - - 1997
Chlorinated hydrocarbons are well known to produce ventricular arrhythmias because of myocardial sensitization to endogenous catecholamines, but cases of myocardial ischemia have not been described frequently. We report 2 cases of myocardial ischemia after exposure to chlorinated hydrocarbons. The first patient developed an asymptomatic myocardial infarction after inhalation of 1,1,1-trichloroethane ...
Drew B J - - 1997
To determine the frequency, duration, magnitude, and possible adverse effects of ischemia during intracoronary ultrasonography, real-time standard 12-lead electrocardiograms were recorded before, during, and after ultrasonography. Ischemia was defined as new-onset ST segment deviation of > or = 1 mm in one or more leads, measured at J + 80 ...
Lipton R B - - 1997
We report two patients with exertional headaches beginning with vigorous exercise and relieved by rest. Neurologic evaluation and neuroimaging were normal in both. During exercise stress testing, the onset of the patients' typical headaches correlated with ECG changes indicative of myocardial ischemia. In both patients coronary angiography revealed three-vessel disease, ...
Deedwania P C - - 1997
Myocardial ischemia occurs frequently during daily life and has a circadian pattern similar to that reported for myocardial infarction and sudden death. Because of the increased risk of myocardial ischemia in the morning hours, it has been suggested that the administration of anti-ischemic medication before bedtime may be more effective ...
Fisman D N - - 1997
Polyvalent intravenous immunoglobulin (IVIg) is considered to be standard therapy for a variety of autoimmune and idiopathic disorders. Several reports have emphasized the temporal association between administration of IVIg and thrombotic events. Recent experience with a patient who suffered a large myocardial infarction shortly after receiving IVIg led the authors ...
Cinca J - - 1997
BACKGROUND: The myocardium bordering a healed infarction undergoes electrophysiological and autonomic neural derangements that may interact with a new ischemic episode to promote arrhythmias. Therefore, peri-infarction ischemia may be more arrhythmogenic than ischemia at a distance from the infarct zone, but this is not known. METHODS AND RESULTS: Forty-two anesthetized ...
Seeberger M D - - 1997
A major reason for the relatively low sensitivity of Holter electrocardiography (ECG) for detecting ischemia is that the sensitivity of bipolar leads used for Holter ischemia monitoring has not been systematically evaluated, making lead selection difficult. Therefore, this study evaluated the sensitivity of 6 bipolar Holter leads for detecting ischemia ...
Tzivoni D - - 1997
OBJECTIVES: The purpose of this study was to assess whether the severity of myocardial ischemia would be attenuated by repeated daily ischemic episodes, recorded by ambulatory electrocardiographic monitoring (AEM). BACKGROUND: Repetitive ischemic episodes induced by brief coronary occlusions in animal experiments and in humans during balloon coronary angioplasty produce preconditioning. ...
Brosius F C FC - - 1997
Persistently ischemic myocardium exhibits increased glucose uptake which may contribute to the preservation of myocardial function and viability. Little is known about the specific molecular events which are responsible for this increase in uptake. Therefore, we investigated whether myocardial ischemia induces the gene expression of the major cardiac facilitative glucose ...
Alfonso F - - 1997
Coronary angioscopy was used to elucidate the underlying substrate of the culprit lesion in 20 patients with postinfarction ischemia and in 19 patients with other types of unstable angina. Plaque characteristics were similar in both groups, but red thrombi and occlusive thrombi were more frequently seen in patients with postinfarction ...
Maurer I - - 1997
Cardiac ischemia is associated with an impairment in long-chain fatty acid metabolism. We studied carnitine palmitoyltransferase (CPT) in left ventricular biopsies of 6 transplant recipients with ischemia due to atherosclerosis, 4 patients with dilated cardiomyopathy, and 5 donor hearts. Total CPT activity was not significantly different between the three groups ...
Boley S J - - 1997
This article has traced the evolution of our knowledge of mesenteric ischemia from the initial stage of recognition of the condition and its manifestations, through the phase of treatment after the fact-resection of gangrenous intestine, to our present-day attempts to diagnose and treat the ischemic episode before death of the ...
Eltchaninoff H - - 1997
It has been shown that brief episodes of myocardial ischemia can render the heart more resistant to a prolonged subsequent ischemic episode. This phenomenon, called "preconditioning," has been described in human beings during coronary angioplasty with the use of clinical, electrocardiographic (ECG), or metabolic parameters. The goal of this study ...
Narins C R - - 1997
OBJECTIVES: This study was undertaken to better understand the functional and prognostic significance of silent relative to symptomatic ischemia. BACKGROUND: Previous studies have reached conflicting conclusions as to whether painless ischemia identified during noninvasive cardiac testing is related to a lesser extent of myocardial ischemia or a different prognosis than ...
Patel D J - - 1997
BACKGROUND: Transient ischemia in stable coronary disease peaks in the morning, reflecting increased myocardial oxygen demand and coronary vasomotor tone after walking. In acute coronary syndromes, however, ischemia may result from transient thrombus formation or coronary spasm at the site of a ruptured plaque. We report on the pathophysiological mechanisms ...
Sorimachi T - - 1997
The protective effect of prior ischemia on focal cerebral infarction produced by permanent middle cerebral artery (MCA) occlusion was studied in a gerbil model. Forebrain ischemia for 2 and 5 minutes at an interval of 48 hours was used as the prior ischemic insult. Forty-eight hours after the second forebrain ...
Ascheim D D - - 1997
INTRODUCTION: Vasodepressor syncope is a common cause of syncope, but the initiating event that triggers the vasodepressor response remains incompletely understood. Although ischemia due to acute right coronary occlusion may precipitate hypotension and bradycardia through the Bezold-Jarisch reflex, an ischemic precipitant for the common vasodepressor faint has not been previously ...
- - 1997
BACKGROUND: Mivazerol hydrochloride is a new alpha 2-adrenoceptor agonist. In vitro and animal studies have demonstrated both sympatholytic and antiischemic properties. To evaluate the safety and efficacy of mivazerol in patients during perioperative stress, this multicenter phase II clinical trial studied hemodynamic stability and myocardial ischemia in patients with coronary ...
Sharaf B L - - 1997
OBJECTIVES: The purpose of this Asymptomatic Cardiac Ischemia Pilot (ACIP) data bank study was to characterize angiographic features of coronary pathology of patients enrolled in the ACIP study. BACKGROUND: Ischemia during ambulatory electrocardiographic (AECG) monitoring is associated with increased morbidity and mortality. Reports relating AECG ischemia to severity or complexity ...
Ch'en F - - 1997
Arrhythmias are caused by the interdependent processes of change in energy metabolism and alterations in sarcolemmal ion gradients that occur during ischemia. Depletion of energy metabolites and increased proton concentrations in ischemic heart may underlie the observed phenomena of reduced contractile force and also of malignant ventricular arrhythmias that can ...
de Mol B A - - 1997
The Björk-Shiley convexo-concave artificial heart valve has a significant risk of failure which is often fatal.Elective explantation has a mortality of approximately 5%. Follow-up studies provide the basis for clinical decision making whether or not to explant the valve. So far, the contribution of technical, organizational, ethical, and professional considerations ...
Okazaki Y - - 1997
BACKGROUND: OG-VI is a solution composed of 30 mmol/l inosine, 30 mmol/l sodium 5'-guanylate, 30 mmol/l cytidine, 22.5 mmol/l uridine, and 7.5 mmol/l thymidine, which is known to improve myocardial stunning. OBJECTIVE: To study the effect of OG-VI on myocardial energy and carbohydrate metabolism during ischemia. METHODS: Ischemia was induced ...
Cohn P F - - 1997
Silent myocardial ischemia, whether it occurs at rest or during exercise, is associated with an unfavorable prognosis and may lead to sudden cardiac death. Agents used to treat silent myocardial ischemia have included nitrates, beta-blockers, and calcium antagonists (CAs). Despite treatment with traditional anti-ischemic agents, studies have shown that up ...
Wong D H - - 1996
STUDY OBJECTIVE: To determine the incidence of new episodes of myocardial ischemia in patients undergoing transurethral resection of the prostate (TURP). DESIGN: Prospective, nonrandomized study. SETTING: Veterans Administration medical center. PATIENTS: 39 patients undergoing elective TURP. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Myocardial ischemia was detected with a 3-channel ambulatory ...
Parthenakis F - - 1996
This study investigated the relationship between silent myocardial ischaemia during daily life and ventricular ectopic activity in patients with angiographically confirmed coronary artery disease and preserved left ventricular function. We studied 45 patients (37 men, 8 women, aged 42-70 years) who satisfied the above criteria. All underwent 72-h continuous electrocardiographic ...
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