Search Results
Results 301 - 350 of 833
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Kobayashi K - - 2000
Exertional dyspnea, a major symptom of patients with chronic heart failure, mainly stems from an abnormally high ventilatory response to exercise. However, there has been considerable controversy surrounding the mechanisms of respiratory control during exercise, especially regarding the role of serum potassium. We investigated the relation between serum potassium concentration ...
Carraro U - - 2000
BACKGROUND: In dynamic cardiomyoplasty, standard stimulation produces high fatigue resistance but also undesirable dynamic characteristics of the latissimus dorsi (LD). Based on results of intermittent stimulation in animals we introduced demand stimulation, a lighter regimen of LD activity-rest stimulation, and the mechanogram, a noninvasive method to determine the contractile characteristics ...
Chauhan A - - 2000
OBJECTIVE: To test the hypothesis that respiratory function contributes to limit maximal exercise performance in patients with chronic heart failure by using the technique of dead space loading during exercise. DESIGN: Blinded subjects underwent two maximal incremental exercise tests in random order on an upright bicycle ergometer: one with and ...
Harrington D - - 2000
We performed a randomised placebo-controlled trial to investigate the effects of the anabolic drug salbutamol on skeletal muscle and exercise capacity in chronic heart failure. Twelve patients received salbutamol slow-release 8 mg twice daily or placebo for 3 weeks. We assessed the effect of treatment on exercise capacity, quadriceps muscle ...
Khatta M - - 2000
BACKGROUND: Coenzyme Q10 is commonly used to treat congestive heart failure on the basis of data from several unblinded, subjective studies. Few randomized, blinded, controlled studies have evaluated objective measures of cardiac performance. OBJECTIVE: To determine the effect of coenzyme Q10 on peak oxygen consumption, exercise duration, and ejection fraction. ...
Dine T - - 2000
The degree of exposure to DEHP was assessed in 11 patients with chronic renal failure undergoing maintenance haemodialysis. The amount of DEHP leached from the dialyser during a 4-h dialysis session was estimated by monitoring the DEHP blood concentration using a HPLC method. When a patient undergoes a dialysis treatment, ...
Yousufuddin M - - 2000
This study is aimed at examining the relative importance of norepinephrine and endothelin-1 in treadmill exercise-induced changes in brachial arterial tone of the non-exercised arm in patients with chronic heart failure (CHF). Brachial artery diameter and blood flow were measured before and after exercise in eight healthy volunteers and 18 ...
Clark A L - - 2000
BACKGROUND: Peak oxygen consumption (V(O(2))) is a powerful predictor of outcome in patients with chronic heart failure. This is not a test that is readily clinically available. We therefore sought to establish a method of assessing peak V(O(2)) from non-invasively acquired data. METHODS: We analysed the results from incremental treadmill ...
Guazzi M - - 2000
One of the consequences of an elevation of the pulmonary capillary pressure in chronic heart failure is the occurrence of structural and functional changes at the level of the alveolar-capillary interface. These changes are called "stress failure" of the membrane, and consist of thickening of the interstitium, increase in capillary ...
Udelson J E - - 2000
BACKGROUND: A preliminary study suggested that the long-acting late-generation calcium-channel blocker amlodipine has favorable effects on exercise tolerance and is safe to use in heart failure, in contrast to earlier generation agents. The goal of 2 multicenter studies was to assess the effect of adjunctive therapy with amlodipine in addition ...
Owen A - - 2000
Benefit from exercise training programmes for patients with chronic heart failure has been demonstrated in relatively young (mean age 60 years) and predominantly male subjects. This study was undertaken to assess the effect of an exercise programme for older subjects more representative of the general heart failure population. Twenty-two patients ...
Guazzi M - - 2000
In patients with heart failure, carvedilol ameliorated cardiac function, but it did not affect oxygen uptake, kinetics, and ventilatory efficiency during 6-minute exercise at a constant 50-W workload. Persistence of respiratory incompetence may prevent improvement in submaximal oxygen uptake kinetics.
Adams Cynthia D. - - 2000
Exercise intolerance, as a hallmark symptom in patients with heart failure, has been the focus of numerous research initiatives in recent years. The purpose of this review is to synthesize the current literature in order to provide the clinician with an understanding of the state of knowledge regarding the role ...
Uberfuhr P - - 2000
OBJECTIVE: Heart transplantation (HTx) is associated with autonomic denervation of the donor heart. Sympathetic reinnervation (RI) as defined by the presence of functional nerve terminals occurs only if sympathetic ganglia outside the heart are connected with nerve terminals in the transplanted heart. The purpose of this study was to define ...
Robbins M - - 1999
BACKGROUND: An abnormally low chronotropic response and an abnormally high ventilatory response (V(E)/V(CO2)) to exercise are common in patients with severe heart failure, but their relative prognostic impacts have not been well explored. METHODS AND RESULTS: Consecutive patients with heart failure referred for metabolic stress testing who were not taking ...
Houghton A R - - 1999
The AT1 receptor antagonists differ from the angiotensin converting enzyme inhibitors by achieving a more complete blockade of angiotensin II's actions and by not affecting bradykinin metabolism. There is little information on whether this causes clinically significant differences in haemodynamics, neurohormones and exercise tolerance in heart failure. To compare the ...
Quittan M - - 1999
The aim of this study was to evaluate the impact of a three-month exercise program on the perception of quality of life in patients with severe chronic heart failure. In a randomized controlled setting, 27 patients with a left ventricular ejection fraction of 18.1 +/- 8.0% were entered into the ...
Cole C R - - 1999
BACKGROUND: The increase in heart rate that accompanies exercise is due in part to a reduction in vagal tone. Recovery of the heart rate immediately after exercise is a function of vagal reactivation. Because a generalized decrease in vagal activity is known to be a risk factor for death, we ...
Guimarães G V - - 1999
OBJECTIVE - To identify, the anaerobic threshold and respiratory compensation point in patients with heart failure. METHODS - The study comprised 42 Men,divided according to the functional class (FC) as follows: group I (GI) - 15 patients in FC I; group II (GII) - 15 patients in FC II; and ...
Picozzi N M - - 1999
OBJECTIVE: To describe the kinetics of metabolic gas exchange at the onset and offset of low level, constant work exercise in patients with chronic heart failure. SETTING: Tertiary referral centre for cardiology. PATIENTS: 10 patients with chronic heart failure and 10 age matched controls. METHODS: Each subject undertook maximum incremental ...
Lachin J M - - 1999
Many randomized clinical trials schedule subjects to undergo some assessment at a fixed time (or times) after the initiation of treatment. Often, these follow-up measurements may be missing for some subjects because a disease-related event occurred prior to the time of the follow-up observation. For example, a study of congestive ...
Brunner-La Rocca H P - - 1999
Oxygen uptake kinetics during low-intensity exercise were investigated in 48 patients with congestive heart failure to assess their prognostic value compared with established predictors of prognosis including neurohumoral stimulation. Mean response time of oxygen uptake during low-intensity exercise, which does not require the patient's maximal effort, appears to be an ...
Gottlieb S S - - 1999
BACKGROUND: Exercise programs for patients with heart failure have often enrolled and evaluated relatively healthy, young patients. They also have not measured the impact of exercise performance on daily activities and quality of life. METHODS AND RESULTS: We investigated the impact of a 6-month supervised and graded exercise program in ...
Marlin D J - - 1999
Knowledge of the competitive demands of different sports or activities is important for designing appropriate training programmes to ensure that animals reach a sufficient level of fitness to reduce the risk of overexertion and injury or illness and to achieve the best possible performance in relation to an individual's genetic ...
Pavia L - - 1999
BACKGROUND: Patients with congestive heart failure exhibit a prolonged period of recovery to baseline levels of oxygen consumption, but the decline of heart rate during recovery from exercise has been shown to be similar to that in healthy subjects, and the results of studies on the response of ventilation in ...
Knapp J - - 1999
In human ventricular trabeculae carneae 100 microM AP4A (diadenosine tetraphosphate) increased force of contraction to 162.8+/-15.7% of predrug value (n=9). This positive inotropic effect was accompanied by a prolongation of time parameters: time to peak tension and time of relaxation were prolonged by 7.8+/-1.3% and 14.9+/-3.8%, respectively (P<0.05). In the ...
Keteyian S J - - 1999
OBJECTIVE: To describe the effects of exercise training on chronotropic incompetence in patients with stable heart failure, as measured by their inability to achieve a peak exercise heart rate greater than 85% of maximum. BACKGROUND: Exercise intolerance and chronotropic incompetence are characteristic of patients with heart failure. Exercise training improves ...
Schwaiblmair M - - 1999
STUDY OBJECTIVE: The reduced exercise capacity observed in most patients after heart transplantation may be due to treatment with immunosuppressive drugs, deconditioning, cardiac denervation, and graft rejection. Cardiac allograft vasculopathy (CAV) is presently the major factor limiting long-term survival after transplantation. Little information is available with regard to the relationship ...
Wright D J - - 1999
The clinical syndrome of heart failure has been investigated so extensively that it may now almost be regarded as a metabolic disorder. Although an initial insult reduces cardiac pump efficacy, the resultant physiological response culminates in complex neurohormonal dysfunction. This has created confusion and prevented the acceptance of a universal ...
Symons J D - - 1999
We hypothesized that nitric oxide (NO) opposes ANG II-induced increases in arterial pressure and reductions in renal, splanchnic, and skeletal muscle vascular conductance during dynamic exercise in normal and heart failure rats. Regional blood flow and vascular conductance were measured during treadmill running before (unblocked exercise) and after 1) ANG ...
Sturm B - - 1999
OBJECTIVE: To evaluate whether a specific program of moderate-intensity step aerobics training may be sufficient to improve the exercise tolerance of patients with severe chronic heart failure. PATIENTS: Twenty-six patients (22 men, 4 women; mean +/- SD age, 54 +/- 9yrs) with a history of severe chronic heart failure (left ...
Notarius C F - - 1999
AIMS: Exercise intolerance and increased efferent vasoconstrictor traffic to muscle are two characteristics of heart failure that have not been explicitly linked. We tested the hypothesis that peak oxygen consumption is inversely related to resting muscle sympathetic nerve activity in heart failure. METHODS AND RESULTS: We recorded peroneal muscle sympathetic ...
Wilson J R - - 1999
OBJECTIVES: The present study was undertaken to investigate the relationship over time between exertional symptoms in heart failure and functional capacity. BACKGROUND: Most clinicians rely on exertional symptoms rather than on exercise testing to assess functional capacity in heart failure. However, it remains uncertain whether the subjective symptoms reported by ...
Wielenga R P - - 1999
AIMS: Physical training is considered to be safe and beneficial as part of the treatment in heart failure patients. Prospective, sufficiently large studies are still needed to confirm this hypothesis. METHODS: In a prospective study, 80 patients with chronic heart failure class II and III (age, 56.6+/-8.3 years; left ventricular ...
Piepoli M - - 1999
BACKGROUND: In chronic heart failure the cause of exercise limitation is still unclear: ergoreceptors, muscle afferents sensitive to exercise metabolites, are proposed as a neural link between muscular abnormalities and the limited exercise responses in this syndrome. METHODS: In 92 stable patients with heart failure (34 in New York Heart ...
MacKinnon S N - - 1999
The purpose of this study was to examine the relationship between ratings of perceived exertion (RPE) and activity intensity, as determined by heart rate. Fifteen participants completed a standardized treadmill protocol in order to establish a heart rate--RPE calibration profile. These participants then completed two simulated occupational tasks--box carrying and ...
Sami M - - 1999
Angiotensin-converting enzyme (ACE) inhibitors play an important role in protecting various organs in patients with congestive heart failure. The mechanisms of action of ACE inhibitors in congestive heart failure are multiple and may involve important effects on endothelial function in addition to the well known hemodynamic and neurohormonal effects. Skeletal ...
Katz S D - - 1999
BACKGROUND: Impaired endothelium-dependent, nitric oxide (NO)-mediated vasodilation may contribute to increased vasomotor tone in patients with heart failure. Whether decreased endothelium-dependent, NO-mediated vasodilation in patients with heart failure is due to decreased synthesis or increased degradation of NO is unknown. METHODS AND RESULTS: To specifically assess the synthetic activity of ...
Tanehata M - - 1999
The significance of the time from anaerobic threshold to respiratory compensation point (RCP-AT time) in patients with chronic heart failure was investigated. Thirty-seven patients with chronic heart failure (New York Heart Association class II or III) were enrolled into the study. Cardiopulmonary exercise testing was performed using breath-by-breath gas sampling. ...
Northridge D B - - 1999
To compare the effects on exercise capacity of the neutral endopeptidase inhibitor candoxatril, and the angiotensin converting enzyme inhibitor captopril, in patients with mild to moderate heart failure. In this multi-centre double-blind placebo controlled study, 60 patients with NYHA Class I-III heart failure were randomised to candoxatril 200 mg b.d. ...
Keteyian Steven J. - - 1999
Heart failure is a common health problem among persons at or above 65 years of age. To date, no data exist describing to what extent, if any, cardiac rehabilitation or exercise training might be useful in this population. Fourteen randomized trials involving mostly heart failure patients less than 65 years ...
Guazzi M - - 1999
OBJECTIVE: The backward effects of left ventricular dysfunction include alterations in alveolar-capillary gas transfer and ventilation-perfusion coupling. Because the angiotensin-converting enzyme (ACE) is highly concentrated in the vascular endothelium of the lungs, we examined whether ACE inhibitors may influence the pulmonary function in patients with congestive heart failure. METHODS: In ...
Cohen-Solal A - - 1999
OBJECTIVES: This prospective study was undertaken to correlate early and late metaiodobenzylguanidine (MIBG) cardiac uptake with cardiac hemodynamics and exercise capacity in patients with heart failure and to compare their prognostic values with that of peak oxygen uptake (VO2). BACKGROUND: The cardiac fixation of MIBG reflects presynaptic uptake and is ...
Beniaminovitz A - - 1999
The selection of patients for heart transplantation involves the use of multiple prognostic variables. Because of the complexity of the clinical syndrome of heart failure, central cardiac and peripheral maladaptations occur. Exercise capacity simultaneously assesses cardiovascular reserve and evaluates the peripheral maladaptations; accordingly, exercise testing has become an increasingly important ...
Agostoni P - - 1999
Exercise-induced hemoconcentration is a useful mechanism, particularly in heart failure, because it increases oxygen content of blood, perfusing the working muscles; in 50 normal subjects and 50 patients with congestive heart failure, hemoglobin at peak exercise increased by 7 +/- 3% and 5 +/- 3%, respectively. Hemoconcentration was due to ...
Davey P - - 1999
We investigated whether correction for body mass is appropriate when using variables derived from gas exchange measurements in the assessment of chronic heart failure. Patients with heart failure were studied either on a bicycle ergometer (22 subjects) or on a treadmill (28 subjects). For bicycle exercise testing either peak V(O2) ...
- - 1999
AIMS: In patients with chronic heart failure, fatigue is independent of haemodynamic and neuroendocrine changes and possibly may be due to impaired muscle metabolism. Propionyl-L-carnitine, a carnitine derivative, was shown in previous studies to improve muscle metabolism. The objective of this study was to evaluate the effect of propionyl-L-carnitine on ...
Richard R - - 1999
OBJECTIVES: The purpose of this study was to show that the chronotropic potential of the well trained heart transplant recipient (HTR) does not limit exercise capacity. BACKGROUND: Chronotropic incompetence is considered to be the main limiting factor of the functional capacity of heart transplant recipients. However, no systematic study had ...
Lewis B S - - 1999
BACKGROUND AND AIMS: Nitrate therapy improves hemodynamics in patients with heart failure, but the chronic effects of oral nitrates on exercise performance and clinical status have not been well studied. METHODS: Oral isosorbide-5-mononitrate (ISMN) (50 mg once daily) or placebo was administered to 136 patients (NYHA Class 2-3) treated for ...
Asakuma S - - 1999
OBJECTIVE: The accurate determination of limitations in physical activity is important in evaluating patients with heart failure and in assessing the efficacy of treatment. However, the conventional measures used to evaluate hemodynamics, functional class, and exercise capacity all have limitations. Our objective was to develop a simple method (The Master-Borg ...
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