Search Results
Results 451 - 500 of 835
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Camm A J - - 1996
Knowledge of normal adjustment of heart rate and its response to exercise is essential for understanding and management of chronotropic incompetence. The autonomic nervous system plays an important role in the modulation of normal heart rate. Chronotropic responses of a normal heart to exercise are associated with parallel hemodynamic changes ...
Andreas S - - 1996
OBJECTIVES: The aim of this study was to determine the impact of nasal nocturnal oxygen therapy on respiration, sleep, exercise capacity, cognitive function and daytime symptoms in patients with congestive heart failure and Cheyne-Stokes respiration. BACKGROUND: Cheyne-Stokes respiration is common in patients with congestive heart failure and is associated with ...
Xie G Y - - 1996
We analyzed the relation of Doppler transmitral flow patterns and New York Heart Association (NYHA) classification in 60 consecutive patients with heart failure (44 men and 16 women; mean age 58 +/- 13 years) with left ventricular ejection fraction of < 40 percent. Of the study population, 40 patients with ...
Ogino K - - 1996
OBJECTIVE: To assess energy depletion in skeletal muscle in patients with congestive heart failure by measuring blood purine metabolites during exercise and, at the same time, determine the implications of the ammonia response to exercise in these patients. SETTING: Tottori University Hospital, Yonago, Japan. PATIENTS: 49 heart failure patients (New ...
Kavanagh T - - 1996
Cardiac transplantation is now an accepted treatment for end-stage heart disease, relieving symptoms, increasing exercise tolerance, and improving survival. A number of studies have demonstrated that exercise training can further improve exercise capacity and quality of life. The atypical response of the denervated heart to exercise requires that training intensity ...
Chua T P - - 1996
OBJECTIVES: This study sought to establish the chemosensitivity of patients with chronic heart failure. BACKGROUND: The ventilatory response to exercise is often increased in patients with chronic heart failure, as characterized by the steeper regression slope relating minute ventilation to carbon dioxide output. We hypothesized that the sensitivity of chemoreceptors ...
Bell J M - - 1996
OBJECTIVE: To establish the accuracy of the traditional method of measuring the intensity of exercise in aerobic dance classes, that is, intermittent pulse palpation performed during a brief cessation of activity. METHODS: A short wave telemetry system was used to record heart rates during a class in a group of ...
Gabbay M - - 1996
It has been suggested that using additional spermicide with condoms provides added contraceptive effect and protection from infection, and that water-based lubricants may lower condom breakage rates. This questionnaire-based study investigated the use of additional lubrication with condoms amongst 525 female students presenting for post-coital contraception, and the current and ...
Munger M A - - 1996
Heart failure is a severe, disabling disease that portends a short life expectancy. This grave prognosis may be explained by growth-promoting effects of angiotensin II implicated in heart failure that mediate a genetic response called programmed cell death. The effects of angiotensin II are inhibited by angiotensin-converting enzyme (ACE) inhibitors, ...
Casadei B - - 1996
OBJECTIVE: To study the effect of transdermal scopolamine on heart rate variability, baroreflex sensitivity, and exercise performance in patients with heart failure and age matched healthy volunteers. DESIGN: Double blind, randomised, placebo controlled, crossover study. PATIENTS: 16 patients with chronic, stable heart failure due to ischaemic cardiomyopathy (mean (SEM) age ...
MacGowan G A - - 1996
Maximal treadmill exercise responses were compared with light forearm isometric exercise responses in patients with chronic, stable heart failure (n = 14), and normal sedentary controls (n = 11). Isometric exercise was performed to exhaustion with 25% of maximal voluntary contraction. Gas-exchange analysis was used to determine oxygen consumption (VO2), ...
Oka R K - - 1996
The physiologic changes that accompany heart failure are complex and evolve over time. Adaptations to an initial insult include both central (myocardial) and peripheral mechanisms that attempt to maintain adequate cardiac output at rest, as well as during increased metabolic demands such as exercise. Physiologic models provide insight into these ...
Narang R - - 1996
There is a wealth of evidence that angiotensin converting enzyme (ACE) inhibitors improve symptoms, morbidity and mortality in patients with heart failure. In this context the use of ACE inhibitors could be considered a tool with which to assess the effect of trial design and methodology on the ability to ...
Drexler H - - 1996
Fatigue is a prominent symptom in patients with chronic heart failure, limiting physical activity and impairing quality of life. Although the underlying mechanisms are not clearly identified, alterations associated with peripheral adaptation in heart failure appear to play an important role, including a variably impaired peripheral perfusion during exercise, reduced ...
Massie B M - - 1996
OBJECTIVES: The present study was undertaken to further characterize changes in skeletal muscle morphology and histochemistry in congestive heart failure and to determine the relation of these changes to abnormalities of systemic and local muscle exercise capacity. BACKGROUND: Abnormalities of skeletal muscle appear to play a role in the limitation ...
Metra M - - 1996
Patients with heart failure have, compared with normal subjects, an increased minute ventilation (VE) at matched workloads. This heightened ventilatory drive may contribute to their limitation of functional capacity through an increase in the work of breathing and further worsening in the lung ventilation-perfusion mismatch. To measure the ventilatory response ...
Banning A P - - 1996
OBJECTIVE: Diuretics, angiotensin converting enzyme inhibitors and digoxin have become "standard" triple therapy for many patients with chronic cardiac failure. Flosequinan increases exercise duration and improves symptoms when added to standard triple therapy. Despite intensive study, the clinical pharmacology of flosequinan remains uncertain. SETTING: The University Hospital of Wales, a ...
Lord S W - - 1996
OBJECTIVE: To investigate the relation between sympathetic efferent reinnervation and chronotropic competence during exercise testing after cardiac transplantation. PATIENTS: Twenty five long-term cardiac transplant recipients and 11 normal controls. SETTING: Regional cardiothoracic centre. METHODS: Intracoronary tyramine was given to the transplant recipients and the per cent heart rate change measured. ...
Reindl I - - 1996
BACKGROUND: Hyperpnea in chronic heart failure occurs even in the absence of considerable impairment of lung function. It is caused by altered respiratory pattern with rapid shallow breathing and ventilation-perfusion mismatch, so far thought to be irreversible. OBJECTIVES: To test the underlying pathophysiologic disorders and the reversibility of this hyperpnea, ...
Andreas S - - 1995
Patients with chronic heart failure have an increased ventilation/carbon dioxide production ratio (VE/VCO2) during exercise. Recently it was discussed whether the cause of this increase was a ventilatory stimulus driven other than by CO2. Dyspnoea during exercise is thought to be related to impaired respiratory function. However, clinical confirmation is ...
Al-Rawas O A - - 1995
The mechanism of breathlessness on exertion in patients with chronic heart failure are still not fully understood. We therefore investigated the effects of ventilatory and gas exchange abnormalities on exercise capacity in chronic heart failure. Exercise testing was performed in 30 patients with exertional breathlessness due to chronic heart failure ...
Hattler B G - - 1995
We and others have provided indirect evidence for the presence of a constitutive nitric oxide synthase (cNOS) in the mammalian heart. We now provide more direct evidence for the regulation of a myocardial cNOS in the hearts of patients undergoing elective cardiopulmonary bypass (CPB). cNOS enzyme activity was demonstrable in ...
Chelimsky-Fallick C - - 1995
Although peak oxygen consumption is reduced in patients with symptomatic heart failure, the degree of limitation during routine activity often appears greater or lesser than expected from peak capacity. This study was undertaken to determine whether abnormalities could be detected during the initiation of steady-state low-level exercise, approximating routine activity, ...
Walsh J T - - 1995
OBJECTIVES: To examine the effects of drug treatment on laboratory exercise tests in relation to measures of daily activity in patients with chronic heart failure. SETTING: University teaching hospital. SUBJECTS: 18 patients with mild to moderate chronic heart failure (New York Heart Association functional class II-III) and 10 age matched ...
Smith G D - - 1995
1. In autonomic failure, supine exercise lowers blood pressure and worsens postural hypotension. The somatostatin analogue, octreotide, reduces post-prandial and postural hypotension, but its effects on exercise-induced hypotension and on postural hypotension post-exercise are unknown. 2. Eighteen subjects with chronic sympathetic denervation were studied; 12 had pure autonomic failure and ...
Roul G - - 1995
Various parameters have been found useful for establishing the prognosis of patients with chronic heart failure, in particular haemodynamic parameters measured at rest. However, few studies deal with the prognostic value of invasive exercise haemodynamic parameters in such patients. Our aim was to test the value of such parameters to ...
Kao W - - 1995
These data confirm the presence of abnormal skeletal muscle metabolic function in patients with chronic heart failure. These changes are independent of patient compliance and central hemodynamic response to conventional exercise, and may explain, in part, the marked decrease in exercise tolerance often observed in patients with chronic severe heart ...
Persson H - - 1995
OBJECTIVE: To evaluate whether xamoterol, a partial agonist, would improve exercise time more than metoprolol in patients with mild to moderate heart failure after a myocardial infarction. DESIGN: Single-centre double blind randomised parallel group comparison of metoprolol 50-100 mg and xamoterol 100-200 mg twice daily. PATIENTS: 210 patients aged 40-80 ...
Sandvik L - - 1995
BACKGROUND: Resting heart rate is directly associated and maximal exercise-induced heart rate inversely associated with cardiovascular mortality, and therefore their difference might contain prognostic information from both variables. The comparative long-term prognostic values of maximal exercise-induced heart rate and of the difference between it and resting heart rate were studied ...
Delehanty J M - - 1995
The role of metabolic processes in the control of the normal circulation will be discussed with particular emphasis on how metabolic events, particularly those that occur with the performance of exercise, result in production of vasoactive substances and sympathetic activation. Heart failure patients will have altered metabolism, particularly in skeletal ...
Wilson J R - - 1995
BACKGROUND: Patients with heart failure frequently report exertional dyspnea and fatigue. These symptoms are usually attributed to circulatory dysfunction and therefore are typically treated with cardiovascular medications. Serial assessment of exertional symptoms has also become the principal method used to assess drug efficacy in heart failure. Nevertheless, the relation between ...
Krum H - - 1995
In conclusion, plasma levels of the endothelial-derived vasoconstrictor endothelin-1 (but not those of other neurohormonal vasoconstrictor factors), measured during exercise correlated closely with objective variables of exercise capacity in patients with heart failure. These findings suggest that endothelin-1 may contribute to exercise intolerance in patients with heart failure, perhaps by ...
Sanders L R - - 1995
Nonsteroidal anti-inflammatory drugs predispose to acute renal failure in conditions associated with decreased RBF. Such conditions include advanced age, hypertension, chronic renal insufficiency, diuretic use, and any condition decreasing effective circulating volume. Strenuous exercise also causes marked reductions in RBF. The patient discussed developed severe acute renal failure after strenuous ...
Clark A L - - 1995
BACKGROUND: The exercise limitation of patients with chronic heart failure may be due in part to an inability to increase heart rate as normal, a limitation sometimes referred to as chronotropic incompetence. This may be due to down regulation of beta receptors. METHODS: Fifty-seven patients with chronic heart failure and ...
Gottlieb S S - - 1995
The appreciation that congestive heart failure is not merely a disorder of myocardium has led to a substantial alteration in the treatment of this disease. The use of angiotensin-converting enzyme inhibitors is increasing as their well-demonstrated mortality and symptomatic benefits become better publicized and known. Although diuretics and digoxin continue ...
Yamani M H - - 1995
OBJECTIVES: This study investigated whether recovery of skeletal muscle function is impaired in patients with heart failure and whether impaired recovery is associated with abnormal submaximal systemic exercise tolerance during repeated testing. BACKGROUND: Patients with heart failure experience fatigue during daily activities. Because abnormalities of skeletal muscle play a role ...
Walsh S M - - 1995
OBJECTIVE: To describe the clinical and pathological features of a patient with probable cardiotoxicity related to a newer chemotherapeutic agent, DuP-941. PATIENT AND METHODS: A 42-year-old woman with metastatic breast carcinoma treated with only DuP-941 developed, and died of, heart failure for which no other explanation was apparent. RESULTS: Clinically ...
Schmidt T A - - 1995
OBJECTIVE: The aim was to evaluate whether digitalisation of heart failure patients affects extrarenal potassium handling during and following exercise, and to assess digoxin receptor occupancy in human skeletal muscle in vivo. METHODS: In a paired study of before versus after digitalisation, 10 patients with congestive heart failure underwent identical ...
Marcelino J - - 1995
OBJECTIVE: A circuit of seven exercises was designed for a cardiac population. This study evaluated whether the patients achieved their training heart rate during the circuit, recommended to be 70-85% of the maximum heart rate achieved during an exercise test. DESIGN: Patients were randomly allocated to a starting exercise to ...
Clark A L - - 1995
The mechanisms underlying the increased ventilatory response to exercise seen in patients with chronic heart failure are not clearly understood. Arterial potassium has been suggested as an important ventilatory stimulant. The authors have investigated the arterial potassium response in patients with heart failure. Although arterial potassium rises during exercise, no ...
Hofman-Bang C - - 1995
Seventy-nine patients with stable chronic congestive heart failure were randomized into a double-blind, crossover placebo controlled study with 3-month treatment periods, where either 100 mg coenzyme Q10 (CoQ10) or placebo was added to conventional therapy. Mean patient age was 61 +/- 10 years, ejection fraction at rest was 22% +/- ...
McKelvie R S - - 1995
Congestive heart failure is a potentially debilitating disorder that affects a significant number of patients. The age-adjusted death rate has doubled over the past decade. Patients live an average of 4 to 5 years, and nearly all suffer from fatigue and breathlessness, which limits exercise capacity and produces a poor ...
Adamopoulos S - - 1995
In animals, intermittent sympathomimetic stimulation with dobutamine produces benefits analogous to those of physical conditioning. Longer intermittent or continuous beta-stimulant therapies have not, however, been successful in managing patients with chronic heart failure. We have investigated the role of beta-receptor stimulants in patients with severe chronic heart failure by changing ...
Dékány M - - 1995
The prognostic value of maximal exercise capacity as well as that of the simple exercise systolic blood pressure and heart rate variables were evaluated in 50 patients with dilated cardiomyopathy. Patients were treated beside digitalis and/or diuretics with vasodilators aggressively. Exercise was performed on an upright bicycle ergometer. Continuous, multistage, ...
Clark A L - - 1995
The pathogenesis of the limiting symptoms in patients with chronic heart failure, shortness of breath and fatigue on exercise, are poorly understood. We analysed data from 222 incremental symptom limited exercise tests to determine whether there were differences between patients stopped by breathlessness or fatigue. One hundred and sixty patients ...
- - 1995
In order to compare directly the efficacy of two different angiotensin-converting enzyme (ACE) inhibitors in terms of clinical status and exercise capacity, 443 patients with chronic heart failure (New York Heart Association classes II-IV) were randomized into a 24-week double-blind study to receive cilazapril (CLZ) 1-2.5 mg once daily (n ...
Linden R J - - 1995
So now we have a view of the circulation in exercise in the upright posture. The output of the heart depends on the input which is driven by the muscle pumps mainly from the lower limbs but augmented by the upper limbs, and the thoracic and abdominal muscles. The heart ...
Chen Y - - 1994
We wanted a new and innovative method of engaging students in interactive learning. To this end, we developed an educational tool that compares and contracts the cardiopulmonary responses to exercise in an individual with heart failure with an individual with normal cardiac function. This exercise provides a unique opportunity to ...
Imai K - - 1994
OBJECTIVES: Vagally mediated heart rate recovery after exercise was assessed in patients with chronic heart failure and in well trained athletes by analyzing the postexercise heart rate decay. BACKGROUND: Vagal reactivation is an important cardiac deceleration mechanism after exercise. However, alterations of this mechanism under pathologic conditions have not been ...
Rouse W - - 1994
1. ZENECA ZD7288 (4-(N-ethyl-N-phenylamino)-1,2-dimethyl-6-(methylamino) pyrimidinium chloride, formerly ICI D7288) is a novel sino-atrial node function modulator which selectively slows heart rate. 2. The haemodynamic effects of ZD7288 (0.1, 0.3 and 1.0 mg kg-1, i.v.) have been evaluated and compared with those of placebo (physiological saline), zatebradine (ULFS 49, 0.1, 0.3 ...
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