Search Results
Results 351 - 400 of 833
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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 ...
Billman George E - - 2002
Sudden, unexpected cardiac death due to ventricular fibrillation is the leading cause of death in most industrially developed countries. Yet, despite the enormity of this problem, the development of safe and effective antiarrhythmic therapies has proven to be an elusive goal. In fact, many initially promising antiarrhythmic medications were subsequently ...
Rowland Thomas - - 2002
Insights into both normal and pathological cardiac responses to exercise have been hampered by lack of a safe, accurate, feasible means of estimating cardiac output (Q) during high-intensity and maximal exercise. Doppler ultrasound noninvasively measures blood velocity as it exits the heart and can be performed during exhaustive exercise without ...
Takayanagi K - - 2001
We investigated the neural regulation of the cardiac interval to an exercise demand signal and to a repeated exercise in 20 healthy human subjects. Electrocardiogram (ECG), muscle torque, and electromyogram (EMG) were simultaneously measured and their time relationships compared before and during the exercise. The R-R interval of ECG was ...
Zöllner C - - 2001
PURPOSE: To evaluate the performance of two different continuous cardiac output monitoring systems based on the thermodilution principle in critically ill patients. METHODS: Nineteen cardiac surgical patients were randomly assigned to continuous cardiac output monitoring using one of the two systems under study (group I, IntelliCath(TM) catheter, n=9; group II, ...
Marshall P - - 2001
There is evidence that multiple benefits can be obtained through exercise training that leads to increases in peak oxygen consumption (V(O(2))). It is unclear whether significant improvements can also be achieved through unsupervised low-budget home-based training regimes, especially in terms of cardiac functional gains. A randomized cross-over trial was conducted ...
Rowland T W - - 2001
The circulation of blood during upright exercise involves a two-pump system, a central cardiac pump and a peripheral pump responsible for systemic venous return. Axiomatically, the function of the two pumps must be equal, and certain evidence suggests that the peripheral pump may "drive" the circulation during exercise. Despite its ...
Oliver D - - 2001
BACKGROUND: Reduced skeletal muscle strength is characteristic of individuals following heart transplantation. Weight lifting exercise has been demonstrated as an effective means by which to increase muscular strength in other cardiac patients but the appropriateness of this form of exercise in heart transplant patients has not been investigated. The purpose ...
Kennedy R R - - 2001
Cardiac output is a major determinant of the rate of uptake of volatile anaesthetic agents. Theoretical work suggests a 30% change in cardiac output will produce a measurable change in end-tidal volatile agent. We present three patients in whom significant changes in haemodynamic parameters, consistent with a large fall in ...
Bengel F M - - 2001
BACKGROUND: Late after cardiac transplantation, limited reinnervation of the transplanted heart may occur, but little is known about the effect of reinnervation on cardiac function and exercise performance. METHODS: We quantified the extent of myocardial reinnervation noninvasively in 29 cardiac-transplant recipients, using positron-emission tomography and the catecholamine analogue [11C]hydroxyephedrine. Global ...
Türkmen A - - 2001
In this study, a minimal mathematical model of the cardiovascular system is used to study the effects of changes in arterial compliance and cardiac contractility on the onset time of Korotkoff sounds during an auscultatory procedure. The model provides blood pressure waveforms in the ventricle, the aorta and the brachial ...
Williams S G - - 2001
OBJECTIVES: This study assessed the prognostic value of peak cardiac power output, measured non-invasively during maximal cardiopulmonary exercise testing, against other exercise-derived haemodynamic variables in patients with chronic congestive heart failure. METHOD AND RESULTS: Two hundred and nineteen unselected, consecutive patients with congestive heart failure (166 men, mean (+/-SD) age ...
Richard R - - 2001
One of the greatest challenges in exercise physiology is to develop a valid, reliable, non-invasive and affordable measurement of cardiac output (CO). The purpose of this study was to evaluate the reproducibility and accuracy of a new impedance cardiograph device, the Physio Flow, during a 1-min step incremental exercise test ...
Moser D J DJ Department of Psychiatry, University of Iowa, Iowa City, IA 52240, USA. - - 2001
We used bilateral transcranial Doppler to monitor the number of microembolic events (ME) in the left and right middle cerebral arteries of 29 patients during cardiac surgery that required extracorporeal circulation. Based on a previously published study, we hypothesized that the commonly used method of doubling unilateral ME counts to ...
Adachi H - - 2001
The issue of whether exercise training improves exercise hyperpnea in patients after coronary arterial bypass graft (CABG) surgery has not been fully explored. Effects of short-term physical training on ventilatory response and cardiac output during exercise in patients following coronary arterial bypass grafting surgery is studied. Thirty-four patients underwent exercise ...
Yasui K - - 2001
Stroke volume (SV), cardiac output (CO) and systolic blood pressure (SBP) were measured during maximal symptom-limited bicycle exercise testing in 13 young patients (age, 11-26 years) with nonobstructive hypertrophic cardiomyopathy (HCM). SV was measured by impedance plethysmocardiography; %SVend, %COend, and %SBPend represent the ratio of the value at termination of ...
Freeman K - - 2001
The medical treatment of chronic heart failure has undergone a dramatic transition in the past decade. Short-term approaches for altering hemodynamics have given way to long-term, reparative strategies, including beta-adrenergic receptor (betaAR) blockade. This was once viewed as counterintuitive, because acute administration causes myocardial depression. Cardiac myocytes from failing hearts ...
Arruda A M - - 2001
OBJECTIVES: We sought to determine the prognostic value of exercise echocardiography in the elderly. BACKGROUND: Limited data exist regarding the prognostic value of exercise testing in the elderly, a population which may be less able to exercise and is at increased risk of cardiac death. METHODS: Follow-up (2.9 +/- 1.7 ...
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