Search Results
Results 501 - 550 of 1069
< 6 7 8 9 10 11 12 13 14 15 16 >
Hu Xiaojun - - 2003
BACKGROUND: Previous studies have shown that viable but stunned myocardium displays contractile reserve and exhibits cardiac cycle-dependent variations of integrated backscatter (CVIB), whereas infarcted myocardium does not. HYPOTHESIS: This study was designed to clarify whether assessment of the acoustic properties of the myocardium can predict contractile reserve in patients with ...
Javadpour Maryam M - - 2003
The thin filament protein cardiac troponin T (cTnT) is an important regulator of myofilament activation. Here we report a significant change in cardiac energetics in transgenic mice bearing the missense mutation R92Q within the tropomyosin-binding domain of cTnT, a mutation associated with a clinically severe form of familial hypertrophic cardiomyopathy. ...
Paz Y - - 2003
OBJECTIVE: The internal thoracic artery (ITA) is the most important graft in coronary artery bypass grafting. Its distal region is, however, prone to vasospasm. We studied the effects of nitroglycerin (NTG) and isosorbide-dinitrate (DSDN) on distal segments of left versus right ITA. METHODS: Rings of distal segments (6 to 9 ...
Wunderlich Carsten - - 2003
Elevated cardiac levels of nitric oxide (NO) generated by inducible nitric oxide synthase (iNOS) have been implicated in the development of heart failure. The surprisingly benign phenotype of recently generated mice with cardiac-specific iNOS overexpression (TGiNOS) provided the rationale to investigate whether NO scavenging by oxymyoglobin (MbO2) yielding nitrate and ...
Rapezzi Claudio - - 2003
Since a depressed contractility has long been considered the primary defect in patients with heart failure, the use of inotropic agents has been regarded as a logical approach to treat this syndrome. Despite this conceptual framework, these drugs have not yet established themselves in the treatment of chronic heart failure ...
Cremers Bodo - - 2003
Although there are some data on the cardiovascular profile of bupropion, a non-nicotine-based pharmacotherapy for smoking cessation, detailed studies of its specifically cardiac effects are lacking. In particular, the direct action of this agent on human myocardial contractility is not known. Therefore, we investigated the effects of bupropion on human ...
Conde Garcia E A - - 2003
Many pharmacological effects have been ascribed to extracts of Psidium guajava L. (guava) leaves. However, in spite of its widespread use in Brazilian folk medicine and a reasonable number of scientific reports about it, we could not find any study dealing with its action on the mammalian myocardium. In the ...
Zaugg C E - - 2003
Carnitine is essential for mitochondrial metabolism of long-chain fatty acids and thus for myocardial energy production. Accordingly, carnitine deficiency can be associated with cardiomyopathy. To better understand this disease, we determined myocardial function and energy metabolism in a rat model of carnitine deficiency. Carnitine deficiency was induced by a 3- ...
Klockgether-Radke A P - - 2003
BACKGROUND AND OBJECTIVE: Benzodiazepines may cause hypotension and are reported to interfere with smooth vascular muscle activity. The aim was to elucidate the influence of three different benzodiazepines on the vascular reactivity of coronary arteries. METHODS: Using the model of isolated vessels, we studied the impact of midazolam (0.15, 1.5, ...
Barnes Edward - - 2003
Myocardial stunning refers to the contractile dysfunction that occurs following an episode of acute ischaemia, despite the return of normal blood flow. The phenomenon was initially identified in animal models, where it has been very well characterised, and there was initial doubt about whether a similar syndrome occurred in humans, ...
Frangogiannis N G - - 2003
Myocardial hibernation refers to a state of persistent regional ventricular dysfunction, in patients with coronary artery disease that is reversible with revascularization. It is part of the spectrum of pathophysiological responses to myocardial ischemia and is a particularly important concept in understanding the development and progression of ischemic cardiomyopathy. Hibernating ...
Houser Steven R - - 2003
This review examines the evidence for and against the hypothesis that abnormalities in cardiac contractility initiate the heart failure syndrome and drive its progression. There is substantial evidence that the contractility of failing human hearts is depressed and that abnormalities of basal Ca2+ regulation and adrenergic regulation of Ca2+ signaling ...
Takahara Akira - - 2003
Y-27632, (+)-(R)-trans-4-(1-aminoethyl)-N-(4-pyridyl) cyclohexanecarboxamide dihydrochloride monohydrate, is a selective Rho-associated kinase inhibitor, which has been suggested to possess multiple clinical applications based on the in vitro observations. Since information regarding in vivo cardiovascular effects of Y-27632 is still limited, we assessed them using the halothane-anesthetized, closed-chest canine model. Administration of Y-27632 ...
Vogt Achim M - - 2003
In the current study on human hibernating myocardium (HHM), we tested the hypothesis that increased glycolysis might exert a positive effect during a supply-demand balance situation by augmentation of myocardial energy formation. In 14 patients HHM was preoperatively detected by clinical methods and validated by the recovery of contractile function ...
Noguchi Teruo - - 2003
In non-failing human myocardium, V1 myosin comprises a small amount (<10%) of the total myosin content, whereas end-stage failing hearts contain nearly 100% V3 myosin. It has been suggested that this shift in V1 myosin isoform content may contribute to the contractile deficit in human myocardial failure. To test this ...
Cremers Bodo - - 2003
Lysophosphatidic acid (LPA) is a phospholipid messenger, which is released from activated platelets and leukocytes. This study examined the effects of LPA on myocardial contractility and characterized the signal transduction pathway involved in these effects. Functional effects of LPA were determined in isolated, electrically driven human myocardial preparations and rat ...
Koch A - - 2003
OBJECTIVE: To determine if bradycardia during hyperbaric exposure is accompanied by a negative influence on myocardial contractility. METHODS: Accelerometer-based registration of myocardial compression waves with Seismocardiography (SCG) for noninvasive contractility monitoring. Comparative pulmonary artery (PA) catheter study (9 ICU-patients, mean = 67ys) with ejection-fraction (EF) equivalent versus sum of g-values ...
Squires Jeffrey E - - 2003
Blunted beta-adrenergic inotropism in stunned myocardium is restored by pharmacological (N-acetylcysteine) and metabolic (pyruvate) antioxidants. The ketone body acetoacetate is a natural myocardial fuel and antioxidant that improves contractile function of prooxidant-injured myocardium. The impact of acetoacetate on postischemic cardiac function and beta-adrenergic signaling has never been reported. To test ...
Xiao Shouzhong - - 2002
Although a very close relationship between the amplitude of the first heart sound (S1) and the cardiac contractility have been proven by previous studies, the absolute value of S1 can not be applied for evaluating cardiac contractility. However, we were able to devise some indicators with relative values for evaluating ...
Wagner Kay-Dietrich - - 2002
In this study we analyzed the susceptibility of contractile function of the myocardium to hypoxia-reoxygenation after infarction. For this purpose, the contractility of isolated papillary muscles from rats was studied at high oxygen tension (pO2 80 kPa) and during hypoxia (pO2 3 kPa) with subsequent reoxygenation at variable intervals between ...
Müller Frank U - - 2003
Congestive heart failure is the common endpoint of various cardiac diseases representing a leading cause of cardiovascular mortality in Western countries. Characteristic functional alterations of the failing heart are explained by expressional changes of myocardial regulatory proteins; however, little is known about underlying mechanisms regulating cardiac gene expression in the ...
Amedeo Modesti Pietro - - 2002
The role of angiotensin II in pressure overload is still debated because notwithstanding its effects on myocyte contractility angiotensin II is not an obligatory factor for the development of hypertrophy. To define the role of angiotensin II in acute pressure overload we studied the effects of AT1 blockade (valsartan 80mg ...
Mukherjee Rupak - - 2002
BACKGROUND: Adrenomedullin has been demonstrated to cause systemic vasodilation, and increased plasma adrenomedullin levels have been observed in cardiovascular disease states such as heart failure. While adrenomedullin receptors have been localized to the myocardium, the effects of adrenomedullin on human myocyte contractility remained unknown. METHODS AND RESULTS: Left ventricular myocytes ...
Chakraborti Sajal - - 2002
A considerable number of experimental, epidemiological and clinical studies are now available which point to an important role of Mg2+ in the etiology of cardiovascular pathology. In human subjects, hypomagnesemia is often associated with an imbalance of electrolytes such as Na+, K+ and Ca2+. Abnormal dietary deficiency of Mg2+ as ...
Min Jiang-Yong - - 2002
We monitored myocardial function in postinfarcted wild-type (WT) and transgenic (TG) mouse hearts with overexpression of the cardiac Na(+)/Ca(2+) exchanger. Five weeks after infarction, cardiac function was better maintained in TG than WT mice [left ventricular (LV) systolic pressure: WT, 41 +/- 2; TG, 58 +/- 3 mmHg; P < ...
Kofidis T - - 2002
INTRODUCTION: Myocardial infarction followed by heart failure represents one of the major causes of morbidity and mortality, particularly in industrialized countries. Engineering and subsequent transplantation of contractile artificial myocardial tissue and, consequently, the replacement of ischemic and infarcted areas of the heart provides a potential therapeutic alternative to whole organ ...
Thomas James A - - 2002
Both large burns and severe gram-negative sepsis are associated with acute myocardial contractile dysfunction. Because others have reported that burn injury may be followed by transient endotoxemia, we hypothesized that bacterial endotoxin induces contractile impairment after burn trauma. We tested this hypothesis in two rodent models. In each model, postburn ...
Iqbal Mobeen - - 2002
OBJECTIVES: To determine the time course for myocardial production of nitric oxide, peroxynitrite, and glutathione, to determine the activities of the myocardial antioxidant enzymes glutathione peroxidase, superoxide dismutase, and glutathione reductase throughout endotoxemia and into recovery, and to correlate the levels of these variables to left ventricular contractility in endotoxemia. ...
Burmeister Lynn A - - 2002
Subclinical thyrotoxicosis is defined as a below normal thyrotropin (TSH) in association with a normal total and free thyroxine (T4) and triiodothyronine (T3). It may be caused by thyroid hormone treatment or by endogenous thyroid disease. The degree of thyrotoxicosis may be estimated by the level of TSH suppression. Subclinical ...
Heusch Gerd - - 2002
Patients with chronic coronary artery disease frequently have contractile dysfunction that recovers upon reperfusion. The concept of myocardial hibernation views the observed reduction in contractile function not as the result of an ongoing energetic deficit, but as an adaptive down-regulation that serves to maintain myocardial integrity and viability. In the ...
Elsässer Albrecht - - 2002
OBJECTIVES: We tested the hypothesis that severe alterations in myocardial energy metabolism play an important role in the pathophysiology of human hibernating myocardium (HHM). BACKGROUND: It is well established that a disturbed myocardial energy metabolism results in impairments of contractile performance, structure and viability. All of these are important characteristics ...
Du Xiao-Jun - - 2002
Ca(2+) signaling plays a central role in cardiac contractility and adaptation to increased hemodynamic demand. We have generated mice with a targeted deletion of the S100A1 gene coding for the major cardiac isoform of the large multigenic S100 family of EF hand Ca(2+)-binding proteins. S100A1(-/-) mice have normal cardiac function ...
Kuhn M - - 2002
To investigate how permanent inhibition of guanylyl cyclase A receptor (GC-A) affects cardiac function. Hearts of GC-A-/- and corresponding wild type mice (GC-A+/+) were characterised by histological, western blotting, and northern blotting analyses. Cardiac function was evaluated in isolated, working heart preparations. At 4 months of age, GC-A-/- mice had ...
Sugiyama Atsushi - - 2002
Chronotropic, inotropic and coronary effects of Y-27632 ((+)-(R)-trans-4-(1-aminoethyl)-N-(4-pyridyl) cyclohexanecarboxamide dihydrochloride, monohydrate), a specific inhibitor of Rho-associated coiled-coil forming protein serine/threonine kinase (ROCK), were assessed using canine isolated, blood-perfused heart preparations. Y-27632 slightly enhanced sinoatrial automaticity and significantly increased coronary blood flow, while it decreased ventricular contraction. The concentrations of Y-27632 ...
Fang Zhibin - - 2002
Acute myocardial ischemia was induced by intravenous injection of pituitrin, and electroacupuncture (EA) was applied at the Heart and Lung Meridians (HM and LM), 3 points on each meridian. The changes in the left intraventricular pressure (LVP), the maximum rise rate of intraventricular pressure (LVP dp/dtmax), the area of cardiac ...
Saavedra Walter F - - 2002
Inhibition of xanthine oxidase (XO) in failing hearts improves cardiac efficiency by an unknown mechanism. We hypothesized that this energetic effect is due to reduced oxidative stress and critically depends on nitric oxide synthase (NOS) activity, reflecting a balance between generation of nitric oxide (NO) and reactive oxygen species. In ...
Kanzaki Hideaki - - 2002
BACKGROUND: Although right ventricular (RV) contractility is important in determining functional capacity, few quantification methods are clinically available. RV dP/dt(max) can be assessed by Doppler echocardiography by using tricuspid regurgitation (TR) but is not routinely used because of its dependency on a Doppler incident angle and preload. Doppler-derived dP/dt/P(max) is ...
Saavedra Walter F - - 2002
Inhibition of cardiomyocyte-specific ATP-sensitive potassium (K(ATP)) channels prolongs the action potential during intense ischaemia with attendant antiarrhythmic effects. However, this is accompanied by contractile depression in some models. These changes may be particularly troublesome in dilated cardiomyopathic hearts that display basal systolic dysfunction, limited energy reserve, and prolonged repolarization favouring ...
Heger Jacqueline - - 2002
Nitric oxide (NO), a potent regulator of myocardial contractility, has been implicated in the development of heart failure; however, no study exists describing the relation between expression of inducible nitric oxide synthase (iNOS), formation of NO in vivo, and cardiac contractility. We have therefore generated transgenic (TG) mice overexpressing iNOS ...
van der Velden J - - 2002
In failing human myocardium changes occur, in particular, in isoform composition and phosphorylation level of the troponin T (TnT) and troponin I (TnI) subunits of the actin filament and the myosin light chains (MLC-1 and -2), but it is unclear to what extent they influence cardiac performance. This overview concentrates ...
de Simone Giovanni - - 2002
In all conditions altering wall stress and mechanical stretching, LV performance becomes insufficient at the distance, due to a number of structural and functional alterations ultimately impairing pump function, but not invariably due to reduced inotropic state. Among them, structural alteration of the normal myocardial architectures might play a key ...
Jacob R - - 2002
In the early years after foundation (1927) of the German Society for Circulation Research, physiological topics were often predominant at the annual meetings. At that time, besides methodological questions of blood pressure measurement, sphygmography and phonocardiography, many lectures and discussions were concerned with problems of electrocardiogaphy, the transmitters and effects ...
Pósa Ildikó - - 2002
The effects of glibenclamide (GB, CAS 10238-21-8) and those of the latest low daily dose sulphonylurea compound, glimepiride (GM, CAS 93479-97-1) on myocardial haemodynamics and pyruvate-lactate metabolism of healthy and alloxan-diabetic dogs (n = 6 in six groups) were compared. Mean arterial blood pressure, heart rate, blood flow of the ...
Bi Xiaojun - - 2002
To evaluate the effects of left ventricular contractility on the changes of average image intensity (AII) of the myocardial integrated backscatter (IB) and cyclic variation in IB (CVIB), 7 adult mongrel dogs were studied. The magnitude of AII and CVIB were measured from myocardial IB carves before and after dobatamine ...
Brunner F - - 2001
BACKGROUND: The major source of nitric oxide (NO) in the heart is the constitutive form of NO synthases (eNOS, NOS III) that is expressed in vascular endothelium and cardiac myocytes. NO mediates endothelium-dependent vasodilation and may modulate cardiac function. We examined the role of NO in hearts from transgenic (TG) ...
Alipov N N - - 2001
The possibility of using contraction and relaxation indices for evaluation of inotropic and loositropic influences on the heart was studied in experiments on cats. Increased pre- and afterload were used as the stimuli, which are simultaneously loading and reflexogenic. Under conditions of preserved innervation both stimuli elevated the indices selected ...
Schulz R - - 2001
During normoperfusion, both contractile function and myocardial blood flow are heterogeneously distributed throughout the left ventricle. Midwall segment shortening is greater at the apex than at the base of the left ventricle, and it is greater in the anterior than in the posterior wall. Also, transmural heterogeneity of myocardial deformation ...
Dinarello C A - - 2001
BACKGROUND: Interleukin 18 (IL18) is related to the IL1 family by structure, receptors, signalling molecules, and function. IL18 induces gene expression and synthesis of tumour necrosis factor (TNF), IL1, Fas ligand, several chemokines, and vascular adhesion molecules. Similar to IL1beta, IL18 is synthesised as a biologically inactive precursor molecule lacking ...
Karsanov N V - - 2001
Experiments with hybrid myocardial fibers showed that abnormalities of actin (basic protein of fine sarcomer threads) are responsible for reduced contraction rate, decreased developed force, and low efficiency of cardiomyocyte contraction in chronic heart failure caused by dilatation and ischemic cardiomyopathies and infective allergic myocarditis. Wastefulness of the contractile process ...
Ambrosio G - - 2001
The phenomenon of myocardial stunning has been observed in all animal species studied. The possible occurrence of myocardial stunning in man has been demonstrated after either regional ischemia (such as exercise-induced angina, vasospastic or unstable angina) or after global ischemia (i.e., after cardioplegic arrest during cardiac surgery, or cardiac arrest, ...
< 6 7 8 9 10 11 12 13 14 15 16 >