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Diffee Gary M - - 2004
Recent work suggests that chronic exercise induces alterations in the contractile properties of cardiac myocytes. These alterations include increased sensitivity to activation by Ca, changes in the force-length relationship, and increased power output. A recently observed shift in expression of myosin light chain 1 subunit isoforms induced by training may ...
Pianosi Paul T - - 2004
The purpose of this study was to track changes in stroke volume during exercise by impedance cardiography in order to validate the method, and to obtain such data in a large number of healthy children for reference purposes. One hundred and fifteen healthy children (aged 7-19 years) performed progressive exercise ...
Michaud Katarzyna - - 2004
A case of sudden death following exercise testing in a 33-year-old man is reported. The forensic autopsy showed atherosclerotic stenosis of the left coronary artery, as well as some changes in the cardiac conduction system, including anomalies of the atrioventricular node and moderate fibrosis and fatty infiltration of the branching ...
Riedlbauchova Lucie - - 2004
Acute hemodynamic studies suggest that resynchronization therapy using single-site left ventricular pacing (LVP) is equivalent to biventricular pacing (BIVP). The aim of this study was to assess the performance of LVP versus BIVP during exercise by means of stress echocardiography. A total of 28 patients (25 men and 3 women, ...
Deligiannis A - - 2004
Patients with chronic renal failure (CRF) on hemodialysis (HD) are at increased risk of cardiovascular disease. This is due, mainly, to a higher prevalence of established arteriosclerotic risk factors, including diabetes mellitus, hypertension, dyslipidemia, physical inactivity, as well as to unique CRF-related risk factors. Accordingly, cardiorespiratory insufficiency, left ventricle dysfunction, ...
Tam Enrico - - 2004
The beat-by-beat non-invasive assessment of cardiac output (Q litre x min(-1)) based on the arterial pulse pressure analysis called Modelflow can be a very useful tool for quantifying the cardiovascular adjustments occurring in exercising humans. Q was measured in nine young subjects at rest and during steady-state cycling exercise performed ...
Pitt Marjorie S - - 2004
Portapres derives continuous estimates of cardiac output from the peripheral pulse and has the potential to be an extremely valuable physiological and clinical tool. We assessed Portapres estimates of cardiac output in healthy subjects at rest, during maximal treadmill exercise ( n = 8) and during decreases caused by orthostatic ...
Matsukawa K - - 2004
To investigate whether the Model-flow method, by simulating the aortic input impedance model from a noninvasive monitoring of arterial blood pressure, reflected a reliable measure of cardiac output (CO) during postural change and whole-body exercise occurring in daily life, we compared the Modelflow-estimated CO with a simultaneous reference determined by ...
Silber Jeffrey H - - 2004
PURPOSE: To determine whether an angiotensin-converting enzyme (ACE) inhibitor, enalapril, prevents cardiac function deterioration (defined using maximal cardiac index [MCI] on exercise testing or increase in left ventricular end-systolic wall stress [LVESWS]) in long-term survivors of pediatric cancer. PATIENTS AND METHODS: This was a randomized, double-blind, controlled clinical trial comparing ...
Ono Takashi - - 2004
The purpose of this study was to assess the validity of an adaptive filter, the scaled Fourier linear combiner (SFLC), in the impedance cardiography (ICG). Eight healthy males underwent constant-load bicycle exercise at different intensities from unloaded to near maximal intensity. The stroke volume (SV) and cardiac output (Q) measured ...
Tordi N - - 2004
We compared cardiac output (CO) determined simultaneously by electrical impedance cardiography method (CO (ICG)) and by the CO (2) rebreathing technique (CO (2REB)) during three different steady-state exercises (target heart rate of 120, 140, and 160 min (-1)) in 8 healthy fit young men. The mean difference correlation coefficient obtained ...
Shave R E - - 2004
BACKGROUND: Exercise induced cardiac fatigue has recently been observed after prolonged exercise. A moderate to high altitude has been suggested as a possible stimulus in the genesis of such cardiac fatigue. OBJECTIVE: To investigate if exercise induced cardiac fatigue and or cardiac damage occurs after prolonged exercise in a hypoxic ...
Sarzi Braga Simona - - 2004
Few data are available about the prognostic role of T wave alternans in patients with congestive heart failure. To assess the ability of T wave alternans, used alone or in combination with other risk markers, to predict cardiac death in decompensated patients, we enrolled 46 patients, mean age 59+/-9, males ...
Bunt Christopher M - - 2004
Rock bass (Ambloplites rupestris) are a widespread centrarchid species with both riverine and lacustrine populations. After precipitation events, rivers often carry elevated silt loads, where as lakes generally remain free from suspended silt and sediment. To examine the physiological effects of silt on rock bass, we conducted a series of ...
Koike Akira - - 2004
BACKGROUND: Until recently, compensatory mechanisms have been believed to regulate adequately cerebral blood flow in humans. However, this has been called into question by a series of new investigations suggesting that patients with left ventricular dysfunction suffer from cerebral hypoperfusion. We compared cerebral oxygenation during incremental exercise between patients with ...
Rhodes Melissa C - - 2003
BACKGROUND: Beta(2)-Adrenoceptor (betaAR) agonists, such as terbutaline, are widely used to arrest preterm labor. They also cross the placenta where they stimulate receptors in fetal tissues, which in turn use betaAR input for trophic control of cell replication and differentiation. METHODS: As rats are altricial, we administered terbutaline in two ...
Konttinen Niilo - - 2003
This study investigated the timing of the trigger pull in relation to the cardiac cycle during air rifle shooting. Electrocardiogram) was recorded from 20 male nonelite rifle shooters in two separate testing sessions. The testing was conducted at an indoor shooting range using an optoelectronic shooting system. Each participant fired ...
Sugawara J - - 2003
AIMS: The Modelflow method can estimate cardiac output from arterial blood pressure waveforms using a three-element model of aortic input impedance (aortic characteristic impedance, arterial compliance, and systemic vascular resistance). We tested the reliability of a non-invasive cardiac output estimation during submaximal exercise using the Modelflow method from finger arterial ...
Weinberg Laurence - - 2003
Mortality rates of exercise testing are low and cardiac rupture and sudden death are rare. Three cases of fatal cardiac rupture that occurred during exercise stress testing are reported. Once thought to be a fatal complication, there are increasing reports of ante-mortem diagnosis and survival. Cardiac rupture is a stuttering ...
Marconi Claudio - - 2003
Exercise intolerance in heart transplant recipients (HTR) has a multifactorial origin, involving complex interactions among cardiac, neurohormonal, vascular, skeletal muscle and pulmonary abnormalities. However, the role of these abnormalities may differ as a function of time after transplantation and of many other variables. The present review is aimed at evaluating ...
Rowland T - - 2003
AIM: To examine relative contributions of factors responsible for cardiac diastolic filling during exercise by investigating changes in systemic venous return (as indicated by alterations in cardiac output) after abrupt cessation of skeletal muscle pump function. METHODS: Two cycle exercise studies differing in subject population (men, boys), intensity (submaximal, maximal), ...
Hart G - - 2003
Cardiac hypertrophy is a general term signifying an increase in cardiac mass in response to applied stress. In mild, early hypertrophy, cardiac myocyte contractile performance may be normal or enhanced, whereas in severe hypertrophy associated with cardiac failure, myocyte contraction is reduced in amplitude and increased in duration. In contrast ...
Han Shih-Tsung - - 2003
A 57-y-old man took over 1000 ml of a decoction made from Acyranthes aspera and was found unconscious in his bathroom. Hypotension and bradycardia were noted. The patient recovered 4 d later after dopamine and supportive care. There was no further cardiac abnormalities noted in serial cardiac examinations. We suggest ...
Song C G - - 2003
In this study, a new ensemble averaging technique was developed to measure cardiac output during treadmill exercise. Each dz/dt peak is used as a starting point for ensemble averaging, instead of the conventionally used R point of ECG, in order to prevent the peak dz/dt waveform (C point) to be ...
Wehrens Xander H T - - 2003
Arrhythmias, a common cause of sudden cardiac death, can occur in structurally normal hearts, although the mechanism is not known. In cardiac muscle, the ryanodine receptor (RyR2) on the sarcoplasmic reticulum releases the calcium required for muscle contraction. The FK506 binding protein (FKBP12.6) stabilizes RyR2, preventing aberrant activation of the ...
Achan Vinod - - 2003
OBJECTIVE: Plasma levels of an endogenous nitric oxide (NO) synthase inhibitor, asymmetric dimethylarginine (ADMA), are elevated in chronic renal failure, hypertension, and chronic heart failure. In patients with renal failure, plasma ADMA levels are an independent correlate of left ventricular ejection fraction. However, the cardiovascular effects of a systemic increase ...
Rowland Thomas - - 2003
PURPOSE: To assess cardiac responses to exercise and cardiac functional capacity in moderately obese adolescent females. METHODS: Thirteen healthy females (mean age 13.6 +/- 1.5 years) with a body mass index from 30 to 43 kg per m(2) underwent maximal cycle testing. Cardiac responses were measured by Doppler echocardiogram, and ...
Giordano Ugo - - 2003
BACKGROUND: The aim of this study was to assess blood pressure at rest, the response to exercise and the 24-hour ambulatory blood pressure monitoring (ABPM) profile in children operated for aortic coarctation. METHODS: Twenty children were operated upon for aortic coarctation. The patients' data were compared with those obtained from ...
Loor J J - - 2003
Diet digestibility and outputs of biohydrogenation intermediates were assessed in a continuous culture of ruminal microorganisms. Orchardgrass or red clover harvested and frozen during spring or fall served as the primary substrates for fermentation. During 10-d incubations, fermenters were fed thawed forage (50 g of DM/d), forage (42 g/d) plus ...
Kaplan Vladimir - - 2003
INTRODUCTION/PURPOSE: Inductance cardiography is a noninvasive technique that monitors changes in cardiac output from an inductance plethysmographic transducer encircling the chest at the level of the heart. The method has been previously validated in supine patients at rest by comparisons to thermodilution. Our purpose was to investigate whether the technique ...
Strömvall Larsson Eva - - 2003
OBJECTIVE: To assess the haemodynamic regulation at rest and during exercise in Fontan patients at a long-term follow-up. DESIGN: Cardiac output was measured with the dye-dilution technique. We examined 15 out of the surviving 20 patients operated upon in Göteborg between 1980 and 1991. Their mean age was 26.4 years. ...
Convertino Victor A - - 2003
Patients who have been restricted to bed rest following myocardial infarction or cardiac artery bypass grafting routinely develop orthostatic hypotension or frank syncope during their initial attempt at ambulation. Orthostatic intolerance and reduced exercise capacity secondary to bed rest is accompanied by reduced circulating blood volume, lower cardiac output, attenuated ...
Takai Shinji - - 2003
Previously, we reported that levels of chymase activity and its mRNA in cardiac tissues were significantly increased along with progression of cardiac fibrosis in cardiomyopathic hamsters, but the involvement of chymase in the progression of fibrosis has been unclear. In cultured human fibroblasts, the concentration of transforming growth factor-beta in ...
Convertino Victor A - - 2003
INTRODUCTION: We hypothesized that repeated respiratory straining maneuvers (repeated SM) designed to elevate arterial BPs (arterial baroreceptor loading) would acutely increase baroreflex responses. METHODS: We tested this hypothesis by measuring cardiac baroreflex responses to carotid baroreceptor stimulation (neck pressures), and changes in heart rate and diastolic BP after reductions in ...
Crisafulli Antonio - - 2003
PURPOSE: Accumulation of by-products of metabolism within skeletal muscle may stimulate sensory nerves, thus evoking a pressor response named muscle metaboreflex. The aim of this study was to evaluate changes in central hemodynamics occurring during the metaboreflex activation. METHODS: In seven healthy subjects, the metaboreflex was studied by postexercise regional ...
Pittrow D - - 2003
Local anaesthetics have been shown to exert pronounced cardiodepressant effects after intravenous administration in high doses. Thus, we compared the cardiovascular effects of articaine with those of lidocaine and placebo after submucous administration in healthy volunteers during bicycle exercise ergometry. A single-blind, randomised, placebo-controlled, crossover study design with washout periods ...
Cooke Steven J - - 2003
We examined the cardiac responses of different fish species to anaerobic exercise at low temperatures (3 degrees C). Three species of sympatric warmwater fish with perceived differences in winter activity were used for this comparative study: the winter-quiescent largemouth bass (Micropterus salmoides); the winter-active white bass (Morone chrysops); and the ...
Dosseville Fabrice - - 2002
To identify whether spontaneous motor rhythm is influenced by external or internal events and whether this rhythm fluctuates across the day in parallel with heart rate diurnal variations, we simultaneously recorded heart rate and spontaneous motor rate before and after a pedaling task performed five times a day by 10 ...
Magder S - - 2002
When right atrial pressure (Pra) is greater than zero (atmospheric pressure), cardiac output is determined by the intersection of two functions, cardiac function and return function, which is used here to mean the determinants of venous return. When Pra < or = 0, flow is only determined by circuit function. ...
Lyngsø Dorthe - - 2002
The interleukin-6 (IL-6) output from subcutaneous, abdominal adipose tissue was studied in nine healthy subjects before, during and for 3 h after 1 h two-legged bicycle exercise at 60 % maximal oxygen consumption. Seven subjects were studied in control experiments without exercise. The adipose tissue IL-6 output was measured by ...
Luckstead Eugene F EF - - 2002
Accurate assessment of the cardiac system in pediatric and adolescent youth is important. The hemodynamic demands associated with exercise, training, and sport participation are usually positive and beneficial; however, when an underlying cardiac problem exists, it is imperative that such cardiac problems be identified. Safe sport-related cardiac participation guidelines should ...
Boyle Andrew J - - 2002
Prompt and effective cardiopulmonary resuscitation (CPR) is the first link in the chain of survival following cardiac arrest. We assessed a new device, the CPR-Ezy (Medteq Innovations Pty Ltd., Brisbane, Australia), to aid timing and effectiveness of external cardiac compressions (ECC), by 32 subjects who had prior community-based training in ...
Oliveira N S - - 2002
Some reports have demonstrated that the vasoconstrictor effect of catecholamines may be amplified by felypressin. Thus, the association of felypressin and epinephrine with local anesthetics may be indicated to achieve more effective vasoconstrictor actions with fewer collateral effects from both the anesthetic and the vasoconstrictor. This study aimed to characterize ...
Buch Ashesh N - - 2002
There is little doubt that regular exercise results in increases in life expectancy and protects against adverse cardiac events in both healthy subjects and patients with cardiovascular disease. The mechanism of action of physical training remains unclear but a variety of evidence points towards an enhancement in cardiac vagal activity ...
Kahaly George J - - 2002
The heart is an organ sensitive to the action of thyroid hormone, and measurable changes in cardiovascular performance are detected with small variations in thyroid hormone serum concentrations. Most patients with thyroid disease experience cardiovascular manifestations, and the most serious complications of thyroid dysfunction occur as a result of cardiac ...
Krismer Anette C - - 2002
HMR 1883 (the free acid form of HMR 1098) selectively inactivates myocardial ATP sensitive potassium channels, which may be a potential important therapeutic approach to prevent life-threatening arrhythmias. This study was designed to assess the effects of HMR 1883 combined with adrenaline on haemodynamic variables, blood gases, and cardiac arrhythmias ...
Nakamura Yukio - - 2002
Endoscopic transthoracic sympathicotomy (ETS) is a minimal invasive procedure of thoracic sympathetic block and has been used successfully in the treatment of primary palmar hyperhidrosis. To examine the effect of Th 2-3 ETS on hemodynamic responses to submaximal upright treadmill exercise in humans, cardiac output, plasma noradrenaline and adrenaline at ...
Magosso Elisa - - 2002
The objective of this study was to determine the impact of a total cavopulmonary connection on the main hemodynamic quantities, both at rest and during exercise, when compared with normal biventricular circulation. The analysis was performed by means of a mathematical model of the cardiovascular system. The model incorporates the ...
Hagberg James M - - 2002
We sought to determine whether the angiotensin-converting enzyme (ACE) insertion (I)/deletion (D) polymorphism is associated with submaximal exercise cardiovascular hemodynamics. Postmenopausal healthy women (20 sedentary, 20 physically active, 22 endurance athletes) had cardiac output (acetylene rebreathing) measured during 40, 60, and 80% VO(2 max) exercise. The interaction of ACE genotype ...
Crisafulli A - - 2002
The case is reported of an athlete who, during an exercise test, had a complete atrioventricular block without symptoms of cardiac output failure. Heart rate, stroke index, cardiac index, and myocardial contractility were monitored during the episode by an impedance cardiograph. The most important findings of this report are the ...
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