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Results 251 - 300 of 803
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Ogoh S - - 2007
AIMS: Cardiac failure and ischaemic heart disease patients receive standard of care cardiac beta(1)-adrenergic blockade medication. Such medication reduces cardiac output and cerebral blood flow. It is unknown whether the beta(1)-adrenergic blockade-induced reduction of cardiac output in the presence of an exercise-induced reduction in cardiac-arterial baroreflex gain affects cerebral blood ...
Rowland T - - 2007
Traditional findings of circulatory responses to a bout of static exercise include an abrupt rise in systolic and diastolic blood pressure, small increases in cardiac output with no rise in stroke volume, and unaltered systemic vascular resistance. These characteristics are not, however, consistent with current concepts of circulatory adjustments to ...
Shah Amy - - 2007
BACKGROUND: Cardiovascular and cerebrovascular disease is 2-3 times more common in bipolar patients than the general population. Asymptomatic bipolar patients have electrocardiogram abnormalities at high rates. The question of heart function in asymptomatic bipolar subjects arises. METHODS: This study examined the impact of exhaustive exercise on cardiac function in untrained ...
Keren Hanan - - 2007
Noninvasive cardiac output (CO) measurement can be useful in many clinical settings where invasive monitoring is not desired. Bioimpedance (intrabeat measurement of changes in transthoracic voltage amplitude in response to an injected high-frequency current) has been explored for this purpose but is limited in some clinical settings because of inherently ...
Scognamiglio R - - 2007
Sudden cardiac death (SCD) occurs in patients with Bartter/Gitelman syndromes. Hypokalemia and QTc prolongation are suggested mechanisms. SCD, however, has also been described at normal potassium concentration. This study reports the cases of one Bartter and one Gitelman patient, who experienced an aborted SCD, and evaluates the possible mechanisms of ...
Shepherd Albert P - - 2007
Measured oxygen consumption rates (VO2) are being used less frequently for direct Fick cardiac output determinations during cardiac catheterization because the instruments that measure VO2 are usually cumbersome, expensive and difficult to use. A small, inexpensive VO2 device recently became available. Therefore, the aims of this report are: (1) to ...
Riera Salvador Quintana - - 2007
OBJECTIVES: To analyse how rescuers tolerate the effort derived of giving uninterrupted chest compressions during 2min. MATERIALS AND METHODS: Twenty-three healthy volunteers, nurses and doctors of the Intensive Care Unit (ICU), members of the hospital cardiac arrest team, were enrolled in the study. Using a training manikin, participants were asked ...
McMullen Julie R - - 2007
Physical activity protects against cardiovascular disease, and physiological cardiac hypertrophy associated with regular exercise is usually beneficial, in marked contrast to pathological hypertrophy associated with disease. The p110alpha isoform of phosphoinositide 3-kinase (PI3K) plays a critical role in the induction of exercise-induced hypertrophy. Whether it or other genes activated in ...
Querido Jordan S - - 2007
Constant cerebral blood flow (CBF) is vital to human survival. Originally thought to receive steady blood flow, the brain has shown to experience increases in blood flow during exercise. Although increases have not consistently been documented, the overwhelming evidence supporting an increase may be a result of an increase in ...
Myers Jonathan - - 2007
The carbon dioxide (CO(2)) rebreathing method is a noninvasive technique to estimate cardiac output during exercise, but few data are available on the validity and reliability of this measure in individuals with spinal cord injury (SCI). Sixteen male subjects with SCI (mean age 45 +/- 9, seven paraplegic and nine ...
Lorsomradee Suraphong - - 2007
OBJECTIVE: The purpose of this study was to determine whether a relationship exists between the inferior vena cava diameter (IVCD) or the superior vena cava diameter (SVCD) measured at the point of entry into the right atrium using transesophageal echocardiography (TEE) and the central venous pressure (CVP) under different experimental ...
Sakamoto Masaya - - 2006
Exercise-induced cardiac hypertrophy has been reported to have better prognosis than pressure overload-induced cardiac hypertrophy. Cardiac hypertrophy induced by exercise was associated with less cardiac fibrosis and better systolic function, suggesting that the adaptive mechanisms may exist in exercise-induced hypertrophy. Here, we showed a critical role of heat shock transcription ...
Green Daniel J - - 2006
PURPOSE OF REVIEW: To briefly review some recent studies of cardiac and vascular adaptation to acute exercise and exercise training. RECENT FINDINGS: Recent studies have suggested that prolonged strenuous bouts of exercise may be associated with transient impairment in systolic and diastolic function, referred to as 'cardiac fatigue'. Furthermore, some ...
McGaw Iain J - - 2006
The osmoregulatory physiology of decapod crustaceans has received extensive attention. Within this field there is a growing body of literature on cardiovascular and respiratory responses to low salinity. Most species exhibit a tachycardia coupled with an increase in ventilation rate and oxygen uptake. However, these previous experiments were conducted on ...
Staib Jessica L - - 2007
The expression of myocardial heat shock protein 72 (HSP72) postexercise is initiated by the activation of heat shock transcription factor 1 (HSF1). However, it remains unknown which physiological stimuli govern myocardial HSF1 activation during exercise. These experiments tested the hypothesis that thermal stress and mechanical load, concomitant with simulated exercise, ...
Nassis George P - - 2006
PURPOSE OF REVIEW: To critically evaluate the most recent literature on the methods used to assess body composition, cardiovascular and metabolic function in children and adolescents. RECENT FINDINGS: Although regional body composition can be fairly accurately calculated by dual-energy X-ray absorptiometry, the accuracy of noninvasive estimations of visceral adipose tissue ...
Hanson Linda M - - 2006
As rainbow trout approach exhaustion during prolonged exercise, they maintain maximum cardiac output despite the fact their venous blood, which bathes the heart, becomes hypoxic, acidotic and hyperkalemic. Because these factors are individually recognized to have detrimental inotropic and chronotropic effects on cardiac performance, we hypothesized that adrenergic stimulation is ...
Scharhag Jürgen - - 2006
BACKGROUND: Cardiac troponins I and T and brain natriuretic peptide are the accepted standards to serologically identify myocardial necrosis and elevated wall stress. In addition, they allow risk stratification in cardiovascular patients. The clinical significance of increases in cardiac markers after strenuous endurance exercise in obviously healthy athletes is unclear. ...
Balouch Jamal - - 2007
The open circuit acetylene uptake method is a useful non-invasive means of measuring cardiac output. However, because of accumulation of inhaled acetylene in tissues, the cardiac output uptake is underestimated, if residual acetylene is not allowed to wash out completely in between measurements. We determined the effect of applying a ...
Hsueh Chia-Hsiang - - 2006
An 18-year-old woman presented with exercise induced sudden collapse. Series of cardiac work up revealed no structural cardiac abnormalities. Bidirectional ventricular tachycardia occurred during a treadmill exercise test. Under the impression of catecholaminergic polymorphic ventricular tachycardia, we screened the cardiac ryanodine receptor gene for mutation. We identified a novel heterozygous ...
Kasikcioglu Erdem - - 2006
BACKGROUND: Although the underlying mechanisms responsible for cardiac dysfunction after prolonged exercise remains to be elucidated, it has reported cardiac deterioration following exhaustive exercise in the absence of underlying cardiovascular diseases, which has been attributed to cardiac fatigue. The study was designed to investigate the effects of after fatiguing exercise ...
Hinken Aaron C - - 2006
Chronic exercise training increases the functional capacity of the heart, perhaps by increased myocyte contractile function, as has been observed in rodent exercise models. We examined whether cardiac myocyte function is enhanced after chronic exercise training in Yucatan miniature swine, whose heart characteristics are similar to humans. Animals were designated ...
Lindholm P - - 2006
Blood gas changes occurring in the lung undergo delay and damping on their way to a peripheral artery sampling site. Knowledge of the time components of circulatory transfer is important for the understanding of respiratory control and cardiovascular reflexes in response to blood gas transients. Providing steady state with regard ...
Chicco Adam J - - 2006
The use of doxorubicin, a highly effective antitumor antibiotic, is limited by a dose-dependent cardiotoxicity. The purpose of this study was to determine whether chronic exercise training (ET) prior to doxorubicin treatment would preserve cardiac function and reduce myocardial oxidative stress following treatment. Rats were exercise trained on a motorized ...
Dujić Zeljko - - 2006
PURPOSE: A similar postexercise hypotension (PEH) has been reported in sedentary and mildly endurance-trained individuals of both sexes after a single dynamic submaximal exercise. In endurance-trained men, the hypotension was associated with a reduction of cardiac output, whereas the peripheral vasodilatation was the main mechanism of this fall in other ...
Haga, Shukoh
HAGA, S., ESAKI, K., TOSHINAI, K., KINUGASA, T., TAKEMASA, T., UEYA, E., HAMAOKA, T., KATSUMURA, T., KIZAKI, t. and OHNO, H., Cardiac Output and Stroke Volume at Anaerobic Threshold During Walking Exercise in Healthy Aged Subjects. Abv. Exerc. Sports Physiol., Vol.9, No.1 pp.37-43, 2003. There have been few previous studies ...
Middleton Natalie - - 2006
The present study employed novel echocardiographic tools and cardiac markers to obtain a greater understanding of the aetiology and time course of altered cardiac function and cardiac damage following prolonged exercise and, in particular, the possible role of transient ischaemia within these phenomena. Fourteen runners in the 2004 London Marathon ...
Hydock D S - - 2006
PURPOSE: This study examined the effects of an 8-week androgen deprivation therapy treatment using Zoladex and an endurance training regimen on cardiac function. METHODS: Male Sprague-Dawley rats received either Zoladex or placebo. Animals remained sedentary or endurance trained during the drug treatment period. On day 57, ex vivo cardiac function ...
Atkinson Greg - - 2006
Although regular physical activity is beneficial for many clinical conditions, an acute bout of exercise might increase the risk of an adverse clinical event, such as sudden cardiac death or myocardial infarction, particularly in vulnerable individuals. Since it is also known that the incidence of these events peaks in the ...
Baum M M - - 2006
The mass spectrometer (MS) traditionally has been the instrument of choice for measuring cardiac output (Q (T)) non-invasively using the foreign gas uptake method. However, the size and cost of the MS has hampered widespread adoption of this technique outside of the laboratory. Here, we present results, from six normal ...
Vella C A - - 2005
AIM: The purpose of this study was to examine the relationships between the central cardiovascular variables (cardiac output, stroke volume and heart rate) and oxygen uptake (VO2) during continuous, incremental cycle exercise to maximal aerobic capacity (VO2max). METHODS: Twenty-one moderately to highly trained males (n=19) and females (n=2) participated in ...
Alonso-Fernández Alberto - - 2006
AIMS: To evaluate cardiac response to exercise in middle-aged normotensive obstructive sleep apnoea-hypoapnoea syndrome (OSAHS) adults with normal resting left ventricular systolic function and to test the hypothesis that nasal continuous positive airway pressure (CPAP) therapy might improve cardiac performance during exercise. METHODS AND RESULTS: We performed a prospective, randomized, ...
Rowland Thomas - - 2005
OBJECTIVE: To determine the magnitude of the effects of pectus excavatum deformity on endurance fitness and cardiorespiratory functional reserve in adolescent boys. DESIGN: Cross-sectional comparison of cardiac and ventilatory variables at rest and during a maximal cycle exercise test. SETTING: Pediatric exercise-testing laboratory. PARTICIPANTS: Twelve boys (mean +/- SD age, ...
Williams Simon G - - 2005
Cardiac power output (CPO), the product of cardiac output (CO) and mean arterial pressure (MAP), is a direct measure of cardiac pumping capability and is strongly indicative of prognosis and exercise ability in patients with chronic heart failure (CHF). However, it is not as easily measured as indirect indicators of ...
Snyder Eric M - - 2005
To avoid limitations associated with the use of single-breath and rebreathe methods for assessing the lung diffusing capacity for carbon monoxide (D(L)CO) during exercise, we developed an open-circuit technique. This method does not require rebreathing or alterations in breathing pattern and can be performed with little cognition on the part ...
Lindenfeld JoAnn - - 2005
Previous studies have concluded that polycythemia decreases oxygen delivery primarily because of a large fall in cardiac output associated with a rise in systemic vascular resistance that has been attributed to increased blood viscosity. However, because other studies have shown that polycythemia may not reduce oxygen delivery, an alternative hypothesis ...
Cooke Steven J - - 2005
In this study, the cardiovascular response to exhaustive exercise among differentiated stocks of largemouth bass Micropterus salmoides was compared at 10 degrees C and 20 degrees C to assess the level of their local adaptation. In addition, the impact that interstock hybridization had on adaptive differences was assessed using F1 ...
Dibski D W - - 2005
Comparison and reliability of two non-invasive acetylene uptake techniques for the measurement of cardiac output. Thirteen trained male cyclists performed CO2 rebreathing (CO2RB) at intensities from rest to 200 W, and open-circuit acetylene uptake (OpCirc) and single-breath acetylene uptake (SB) at intensities from rest to 300 W, with all procedures ...
Sláma Karel - - 2005
Pulsations of the dorsal vessel were recorded in vivo during the whole postembryonic development of D. melanogaster, by means of a newly invented, pulse-light opto-cardiographic method. The young larvae of the 1st and 2nd instars submerged in the feeding medium exhibited extremely high rates of heartbeat, 7Hz at room temperature. ...
Mayosi B M - - 2006
To verify whether a deficiency in the cardiac sarcoplasmic reticulum pump SERCA2a causes cardiac dysfunction in humans. Cardiac performance was measured in a serendipitous human model of primary SERCA2a deficiency, Darier's disease, an autosomal dominant skin disorder caused by mutations inactivating one copy of the ATP2A2 gene, which encodes SERCA2a. ...
Measday Megan A - - 2005
Accurate anticoagulation monitoring, critical during cardiac surgery (CS), is especially important for novel therapeutics such as hirudins, for which there are no known antidotes. The activated clotting time (ACT), which is standard for heparin monitoring, has been reported to be insufficiently sensitive to high levels of hirudins. A simple, accurate, ...
Scherhag A - - 2005
BACKGROUND: Non-invasive evaluation of haemodynamic variables remains a preferable and attractive option in both pharmacologic research and clinical cardiology. OBJECTIVES: The objective of this study was to evaluate the correlation, feasibility and diagnostic value of haemodynamic measurements by ICG with the thermodilution (TD) method at rest and during exercise testing. ...
Krediet C T Paul - - 2005
A 27-year old female had one episode of transient loss of consciousness and several of near-unconsciousness during strenuous exercise and sexual activity. Episodes started with abdominal discomfort or nausea and light headedness. Unconsciousness never exceeded one minute. When trying to stand up, she felt she would lose consciousness again. We ...
Wolff Chris B - - 2005
Circulation time (Ct) between lung and periphery may be a surrogate for cardiac output, estimated here, for the most part, as the time between taking a breath of nitrogen and peripheral detection of a desaturation pulse. Use of pulse oximetry involves an internal, instrument delay; however, using the ear, we ...
Bassez G - - 2004
Cardiac tachyarrhythmias have rarely been studied in young patients with myotonic dystrophy type 1 (DM1). The authors observed major cardiac rhythm disturbances in 11 patients aged 10 to 18 years. Tachyarrhythmic events were more frequent than impulse conduction disorders. Wide variations in CTG expansion were observed among the population. Since ...
Spaak Jonas - - 2005
Long-term head-down-tilt bed rest (HDT) causes cardiovascular deconditioning, attributed to reflex dysfunctions, plasma volume reduction, or cardiac impairments. Our objective with the present study was to evaluate the functional importance and relative contribution of these during rest and exercise in supine and upright postures. We studied six subjects before (baseline), ...
Cava Joseph R - - 2004
This article reviews the risk factors that are associated with exercise that can lead to sudden cardiac death and what can be done to identify those who are at risk. Additionally, exercise recommendations to reduce the chance of sudden cardiac death and comments about restrictions and quality of life issues ...
Krep Henning - - 2004
OBJECTIVE: To evaluate the effects of hypertonic, isooncotic, and isotonic infusion therapy on cerebral blood flow (CBF) during and after cardiopulmonary resuscitation (CPR) from experimental cardiac arrest (CA). METHODS: In 32 domestic swine (13-23 kg) open chest CPR was initiated after 8 min of ventricular fibrillation. With the onset of ...
Cybulski Gerard - - 2004
Impedance cardiography (ICG) enables the non-invasive, reproducible, beat-to-beat estimation of stroke volume (SV) changes, and the measurement of the absolute values of the ejection time (ET) and pre-ejection period (PEP), which allows the indirect evaluation of cardiac contractility. The miniaturised, Holter-type impedance cardiography device with built-in one channel of ECG ...
Plachky Jens - - 2004
Neurological complications contribute significantly to morbidity and mortality of patients after orthotopic liver transplantation (OLT). One possible cause of postoperative neurological complications is cerebral ischemia during the surgical procedure. In this study, we investigated the relationship between intraoperative changes in regional cerebral oxygen saturation (rSo(2)) and postoperative values of neuron-specific ...
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