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PubMed1983

Effect of attitudes and beliefs on exercise tolerance in chronic bronchitis.

In 50 patients with chronic bronchitis the relation was assessed between exercise tolerance and pulmonary function and psychological factors, including subjective perception of exertion, mood, general psychiatric disturbance, and the attitudes and beliefs held by patients concerning themselves, their illness, and its treatment. Ventilatory capacity was significantly correlated with but a poor predictor of exercise tolerance. Subjective perception of exertion was most closely correlated with exercise tolerance. The distance walked in a 12-minute exercise test was significantly correlated with measurements of mood and with several attitudes and beliefs. Attitudes and beliefs greatly outweighed measurements of mood and ventilatory capacity as components in a multiple regression predicting distance walked in 12 minutes. This method of psychological assessment emphasises the importance of attitudes and beliefs in respiratory disability and may have useful applications in rehabilitation in other chronic diseases.

Adult↗

PubMed1979

Persistence of improved exercise tolerance and degree of revascularization after coronary bypass surgery. A prospective randomized study.

Exercise tolerance was repeatedly determined over a 2-year period in a series of 100 patients with coronary heart disease randomly allocated for medical therapy and coronary bypass surgery. The surgical group had a consistently better exercise tolerance than the medical group during the whole follow-up. Completeness of the revascularization, assessed by repeated graft and native vessel angiography, resulted in a marked improvement whereas incompletely revascularized patients exhibited only a marginal improvement which, nevertheless, to some degree exceeded the result of medical management alone. It is concluded that coronary bypass surgery and medical therapy, when indicated, result in markedly better exercise tolerance than medical management alone. This improvement persists up two years after the operation and is largely dependent on the completeness of the revascularization.

Adrenergic beta-Antagonists↗

PubMed1994

Maximal exercise tolerance in chronic congestive heart failure. Relationship to resting left ventricular function.

The relationship between maximal exercise tolerance and resting radionuclide indexes of left ventricular systolic and diastolic function were evaluated in 20 ischemic and 44 idiopathic cardiomyopathy patients with New York Heart Association class 2-4 chronic congestive heart failure. Left ventricular ejection fraction, peak systolic ejection rate, peak diastolic filling rate, time to peak filling from end-systolic volume, and fractional filling in early diastole were measured from the radionuclide ventriculogram. All patients underwent symptom-limited exercise testing with on-line measurement of oxygen consumption. In the ischemic group, all of the radionuclide indexes correlated poorly with maximal exercise oxygen consumption (VO2max) except the peak systolic ejection rate which correlated modestly (r = 0.58, p < 0.05). Peak systolic ejection rate was significantly lower (p < 0.01) as were the peak diastolic filling rate and fractional filling in the first third of diastole (p < 0.05) in ischemic patients with marked exercise intolerance (VO2max < or = 14 mL/kg/min) compared with those with preserved exercise tolerance (VO2max > 14 mL/kg/min). In the idiopathic group, none of the radionuclide indexes correlated well with VO2max; and all indexes were similar in patients with and without marked exercise intolerance. These data suggest that (1) resting left ventricular ejection fraction poorly predicts maximal exercise capacity in both ischemic and idiopathic cardiomyopathy and (2) resting peak systolic ejection rate, peak diastolic filling rate, and fractional filling in early diastole may predict exercise tolerance in ischemic but not idiopathic cardiomyopathy.

Adult↗

PubMed1994

Effects of breathing a normoxic helium mixture on exercise tolerance of patients with cystic fibrosis.

Breathing helium-oxygen (He-O2) mixtures of 20.9% O2/79.1% He has been shown to increase exercise ventilation and peak oxygen uptake in healthy subjects. The improved exercise performance is thought to be due to the reduced density of He-O2 compared to air and the resulting increases in ventilation. Patients with cystic fibrosis (CF) frequently have abnormal pulmonary function test results, low exercise ventilations and diminished exercise tolerance. This led to the hypothesis that in CF the exercise tolerance of patients might improve when breathing He-O2. To test this hypothesis, 11 patients with CF or mild to severe airway obstruction performed spirometry and progressive maximal exercise tests while breathing air or He-O2. The He-O2 mixture significantly increased (P < 0.05) forced expiratory volume in 1 sec (FEV1) by 8.2%, peak expired flow by 39%, and maximal voluntary ventilation (MVV) by 17.9% compared to air, while forced vital capacity (FVC) and forced mid-expiratory flow rate (FEF25-75%) were unchanged by breathing He-O2. Ventilation and oxygen uptake at matched submaximal power outputs were not increased while breathing He-O2, nor were peak exercise ventilation (VEpeak) or peak exercise oxygen uptake (VO2peak). Estimated hemoglobin saturation and total exercise time were also unchanged during He-O2 breathing. However, there was a trend for the subjects with the better FEV1 to increase VO2peak. Increases in VO2peak when breathing He-O2 and air were correlated (r = 0.67, P < 0.05) with the percent of predicted FEV1 values. Still, in the 11 patients as a group, breathing He-O2 did not significantly improve VO2peak, VEpeak, or exercise tolerance.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1989

[Factors influencing exercise tolerance in patients with myocardial infarction as elucidated by Tl-201 myocardial scintigraphy].

Measurements of O2 consumption during treadmill exercise tests and Tl-201 myocardial scintigraphy were performed in 17 cases of myocardial infarction to elucidate O2 consumption at an anaerobic threshold ATVO2 as an adequate index of exercise tolerance, and the scintigraphic indices influencing the exercise tolerance. ATVO2 was obtained using the method of Wasserman and Davisand corrected by body weight. The scintigraphic indices such as the location, extent (residual myocardium), and severity (% uptake) of myocardial infarction were obtained from SPECT and bull's eye displays on Tl-201 myocardial scintigraphy. ATVO2 was correlated with theoretical VO2max as obtained by the predicted maximal heart rate (r = 0.56, p less than 0.01) and with left ventricular ejection fraction as obtained by radionuclide left ventriculography (r = 0.59, p less than 0.01). There was no significant difference between ATVO2 in cases of anterior wall infarction and those of inferior (and/or lateral wall) infarction. There was no significant correlation between % uptake and ATVO2. However, the residual myocardium showed a significant correlation with ATVO2 (r = 0.61, p less than 0.01). In conclusion, 1) ATVO2 is an adequate index of exercise tolerance and reflects cardiac function. 2) The extent of the residual myocardium is most strongly influenced by ATVO2 among the indices of myocardial damage as obtained by Tl-201 myocardial scintigraphy.

Adaptation, Physiological↗

PubMed1983

Breathlessness and exercise tolerance in chronic airflow obstruction: 2-hourly versus 4-hourly salbutamol by inhalation.

Breathlessness, exercise tolerance, and spirometry were measured in 12 patients whose major symptom was breathlessness, secondary to severe chronic airflow limitation, during a double-blind crossover comparison of inhaled salbutamol in two dosages (200 micrograms 4-hourly and 200 micrograms 2-hourly) with placebo. Daily visual analogue scores of breathlessness, exercise tolerance and spirometry were all significantly improved with salbutamol in both dosages compared to placebo. The 2-hourly regimen was superior to the 4-hourly regimen only in terms of exercise tolerance. Walking distance had deteriorated significantly 2 hours after salbutamol on the 4-hourly regimen and was usefully increased by an extra dose of salbutamol on the 2-hourly regimen at the equivalent time, without side-effects. Salbutamol provided considerable symptomatic relief in addition to spirometric improvement in patients with chronic airflow limitation.

Aged↗

PubMed1996

Ineffectiveness of intravenous beta 2-agonists on improving exercise tolerance in patients with reversible chronic airway obstruction.

The effects on exercise tolerance after acute administration of beta 2-agonists were investigated in 11 patients with partly reversible chronic airway obstruction after 400 micrograms of salbutamol (S) given intravenously (i.v.) and after 400 micrograms i.v. of a new selective beta 2-agonist, broxaterol (B), by a cardiopulmonary incremental exercise test. At rest, while VE increased in respect to basal conditions (C) after S (from 13.3 +/- 2.2 to 14.4 +/- 2.8 l/min; p < 0.05) and after B (from 13.6 +/- 3.1 to 15.5 +/- 3.6 l/min; p < 0.05), VO2, VCO2 and VO2/HR showed no substantial variations. A small, not significant reduction of PaO2 was observed both after S (from 82.7 +/- 11.7 to 79.1 +/- 16.7 mm Hg) and B (from 81.6 +/- 10.5 to 78.0 +/- 11.0 mm Hg). The maximum workload increased neither after S (from 67.5 +/- 39.1 to 66.6 +/- 37.0 W) nor after B (from 65.7 +/- 39.3 to 60.0 +/- 35.8 W). At peak of exercise, VO2, VCO2 and VO2/HR did not change after S and B as compared with C, whereas VE remained higher after both beta 2-agonists throughout the effort. VO2 at ventilatory anaerobic threshold (AT) was significantly greater either after S (from 744 +/- 378 to 815 +/- 302 ml/min; p < 0.05) and after B (from 756 +/- 290 to 842 +/- 292 ml/min; p < 0.05). The PaO2 increase shown by these patients during effort was greater after beta 2-agonists administration, delta PaO2 from rest to peak of exercise amounting to 14.9 +/- 14.3 vs. 7.8 +/- 8.2 mm Hg after S and to 17.8 +/- 15.1 vs. 8.8 +/- 10.9 mm Hg after B, in respect to relative baseline (p < 0.05). We conclude that beta 2-agonists, when given acutely, do not improve exercise tolerance in patients with reversible chronic airflow obstruction, although these drugs can induce a small increment of ventilatory AT. In addition, arterial blood gases do not deteriorate at rest and are better preserved during exercise after beta 2-agonists.

Adrenergic beta-Agonists↗

PubMed1982

[Exercise tolerance for indicating of aortocoronary bypass surgery (author's transl)].

In order to evaluate effects of aortocoronary bypass grafting on exercise tolerance, we analyzed the data of 109 patients who performed exercise tests before and one month or one year after surgery. Subgroups of patients were formed on the basis of preoperative exercise tolerance. Previously severely impaired patients benefited from surgery by an improvement of exercise capacity, whether preoperative left ventricular enddiastolic pressure at rest exceeded 16 mm Hg and left ventricular ejection fraction was below 50% or not. On the other hand, exercise capacity of patients who were comparable in respect to the numbers of coronary lesions and bypass grafts but whose exercise tolerance was less impaired preoperatively did not improve after surgery. Because in such patients, independent of coronary anatomy, surgery has been reported to be ineffective for prolongation of life, indication for aortocoronary bypass grafting in the presence of "good" exercise capacity must be questioned for symptomatic as well as for prognostic reasons.

Aged↗

PubMed1978

Comparative effects of placebo and plain and slow-release tablets of xanthinol nicotinate on exercise tolerance in normal human subjects.

The effects of placebo and plain and slow-release xanthinol nicotinate on exercise tolerance were studied in 6 normal human subjects. Placebo administration had no significant effect on exercise tolerance. Administration of plain and slow-release xanthinol nicotinate significantly increased exercise tolerance at 1 hour and 1--9 hours respectively from ingestion of the drug. The intensity and duration of action correlated well with the blood levels of nicotinic acid reported earlier. Four subjects experienced moderate to severe side-effects with plain xanthinol nicotinate. Only 1 subject experienced mild side-effects with slow-release xanthinol nicotinate. Slow-release tablets of xanthinol nicotinate may prove useful in the treatment of angina pectoris.

Adolescent↗

PubMed1992

Regional blood flow in chronic heart failure: the reason for the lack of correlation between patients' exercise tolerance and cardiac output?

BACKGROUND: In patients with chronic heart failure there is no relation between cardiac output and symptom limited exercise tolerance measured on a bicycle or treadmill. Furthermore, the increase in cardiac output in response to treatment may not be matched by a similar increase in exercise tolerance. More important in determining exercise capability is blood flow to skeletal muscle. This implies that the reduction in skeletal muscle blood flow is not directly proportional to the reduction in cardiac output and that there are regional differences in blood flow in patients with heart failure. METHODS: Cardiac output and regional blood flow measured in 30 patients with chronic heart failure were compared with values obtained from 10 healthy controls. Measurements were made at rest and in response to treadmill exercise and were all made non-invasively. RESULTS: Cardiac output was lower in the patients at rest and during exercise. Blood flow in the superior mesenteric and renal arteries was also lower in the patients and represented a different proportion of cardiac output than in the controls. In response to exercise the increase in blood flow to the calf and therefore to skeletal muscle, was reduced in the patients. In the patients there was no correlation between resting cardiac output and blood flow in the superior mesenteric artery, renal artery, or calf. CONCLUSIONS: Because blood flow to skeletal muscle and to the kidneys is likely to be important in determining patients' symptoms this factor may explain why central haemodynamic variables do not correlate with the exercise tolerance in patients with chronic heart failure.

Aged↗

PubMed1995

Cardiopulmonary evaluation of exercise tolerance after chest irradiation and anticancer chemotherapy in children and adolescents.

OBJECTIVE: The aim of the study was to evaluate the cardiopulmonary exercise tolerance in children and adolescents after chest irradiation and anticancer chemotherapy. METHODS: We studied 30 subjectively asymptomatic patients aged 8 to 25 years treated for pediatric malignancies with chest irradiation (XRT) +/- chemotherapy. The median interval since XRT was 7 (range, 2 to 13) years. The median XRT dose for mediastinum and/or lungs was 2550 (range, 1000 to 5100) cGy. The median cumulative dose of anthracyclines was 250 (range, 0 to 480) mg/m2. Cardiac function and exercise tolerance were evaluated by electrocardiography, echocardiography, radionuclide cineangiography, and exercise test with gas exchange analysis. RESULTS: The patients differed from normal controls in systolic indices of myocardial function. In echocardiography, the left ventricular contractility was abnormal in 14/30 patients. In radionuclide cineangiography, the left ventricular ejection fraction was subnormal in 6/30 patients, and in 9/30 patients the rise in ejection fraction during exercise was inadequate (< 5%). In exercise testing, the mean (+/- SD) maximum workload attained was 2.7 (+/- 0.7) watts/kg, and the mean (+/- SD) maximum oxygen consumption was 35.4 (+/- 9.7) mL/min/kg. Both variables were < 80% of predicted values in 11 patients. CONCLUSIONS: XRT and anticancer chemotherapy very often lead to late cardiopulmonary toxicity and impaired exercise tolerance. Although in most cases this toxicity seemed to be mild and subclinical, the long-term clinical sequels merit further evaluation.

Adolescent↗

PubMed1983

Improved exercise tolerance of the polycythemic lung patient following phlebotomy.

The present study evaluated the effects of therapeutic phlebotomy on the exercise tolerance and the maximal carbon dioxide output of polycythemic patients with chronic obstructive pulmonary disease. Fifteen maximal exercise studies were performed before and after phlebotomy in patients with moderate to severe chronic obstructive pulmonary disease (mean forced expiratory volume in one second [FEV1]= 970 ml). After phlebotomy there were no significant differences in pulmonary function, blood gases, oxygen consumption, or carbon dioxide production at rest. However, after phlebotomy there was a significant increase in the exercise tolerance of the patients. The mean workload, the duration of exercise, the maximal oxygen consumption, the maximal carbon dioxide production, and the ventilation at maximal exercise all increased significantly. The improved exercise tolerance after phlebotomy appeared due to an increased cardiac output generated mainly through an increased stroke volume. We hypothesize that the increased stroke volume was due to a higher ejection fraction of the right ventricle secondary to a lower pulmonary artery pressure. This study provides further evidence that patients with chronic obstructive pulmonary disease who have polycythemia benefit by therapeutic interventions that maintain their hematocrits below 55 percent.

Aged↗

PubMed1987

A comparison of nine calcium ion antagonists and propranolol: exercise tolerance, heart rate and ST-segment changes in patients with chronic stable angina pectoris.

The effects of nine calcium ion antagonists on exercise tolerance, heart rate and ST-segment changes were compared with those of propranolol in two hundred and eighty patients with established chronic stable angina pectoris. These patients participated in clinical trials for anti-anginal efficacy against placebo, using identical methods and similar protocols, but the comparison reported here was retrospective. The trials were all fixed dose, and the dose was determined by previous upward titration to arrive at an average maximal tolerance level. All the drugs except prenylamine increased the exercise tolerance significantly when compared with placebo. Maximal ST-segment depression on exercise was reduced during treatment with propranolol while treatment with the calcium ion antagonists had no significant effect. The time to the development of 1 mm ST-segment depression was prolonged by all the drugs. Nifedipine, PY-108-068 and nicardipine increased the resting heart rate whereas verapamil, diltiazem, gallopamil, KB-944, prenylamine and tiapamil produced a slight reduction. Propranolol produced a highly significant reduction in the resting and maximal heart rates and the rate-pressure product, whereas gallopamil increased the rate-pressure product by +8% and prenylamine reduced it by -10%. At the doses used, diltiazem, gallopamil and verapamil produced a greater increase in exercise tolerance than did propranolol, while the other drugs were inferior. None of the calcium ion antagonists matched the increase in the time taken to develop 1 mm ST-segment depression with propranolol, although the results with verapamil and gallopamil were close. The calcium ion antagonists are effective antianginal agents which produce their effects by mechanisms which are very different to the beta-adrenoreceptor blocking agents.

Adult↗

PubMed1991

Effects of atenolol, slow-release nifedipine, and their combination on respiratory gas exchange and exercise tolerance in stable effort angina.

The effects of atenolol, nifedipine, and their combination on gas exchange and exercise tolerance were studied in 27 patients with effort angina and normal global ventricular function in an open-label and randomized cross-over trial. Symptom-limited semi-supine exercise tests using a ramp protocol (20 W/min) with simultaneous breath-by-breath analysis of gas exchange were carried out after a 4-day wash-out period and after consecutive 2-week treatment periods with atenolol (50 mg b.i.d.), slow-release nifedipine (20 mg b.i.d.), and their combination (b.i.d.). Exercise tolerance was not significantly higher with atenolol than with nifedipine [118(24) vs 113(23) W]. Combination therapy [120(23) W] was more effective than monotherapy with nifedipine (p less than 0.05) but produced no further increase in exercise tolerance over atenolol monotherapy. Maximum oxygen uptake was not significantly different among the treatments. In the range of light to moderate exercise, the slope of the VO2-workload regression line expressed as ml.min-1.W-1 was lower with atenolol than with nifedipine [8.64(1.59) vs 10.28(1.74), p less than 0.005] and intermediate with combination therapy [9.99(1.83)]. The intercept on the VO2 axis was higher with atenolol than with nifedipine [366(111) vs 299(113) ml.min-1, p less than 0.05]. A similar pattern of results was seen when the drug effects on the slope of the VCO2-workload relation were analyzed. VE was higher with nifedipine than with atenolol at all points of the regression analysis [greater than 30 W].(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1995

Thyroid status and exercise tolerance. Cardiovascular and metabolic considerations.

Both hypo- and hyperthyroidism are characterised by exercise intolerance. In hypothyroidism, inadequate cardiovascular support appears to be the principal factor involved. Insufficient skeletal muscle blood flow compromises exercise capacity via reduced oxygen delivery, and endurance through decreased delivery of blood-borne substrates. The latter effect results in increased dependence on intramuscular glycogen. Additionally, decreased mobilisation of free fatty acids from adipose tissue and, consequently, lower plasma free fatty acid levels compound the problem of reduced lipid delivery to active skeletal muscle in the hypothyroid state. In contrast, cardiovascular support is enhanced in hyperthyroidism, implicating other factors in exercise tolerance. Greater reliance on muscle glycogen appears to be the primary reason for decreased endurance. Biochemical changes with hyperthyroidism that would favour enhanced flux through glycolysis may account for this dependence on glycogen. Deviations from normal thyroid function, and the ensuing exercise tolerance, require appropriate medical therapy to attain euthyroid status.

Cardiovascular Physiological Phenomena↗

PubMed1988

The effect of three test meals on exercise tolerance of an individual with McArdle's disease.

This study examined the effect of three test meals on exercise tolerance of an individual with McArdle's disease, a myopathy characterized by phosphorylase b deficiency. The subject's exercise tolerance and ability to achieve the second wind, in response to each test meal, was evaluated over a 16-week period using a bicycle ergometer in a double-blind situation. Data were analyzed using one-way analysis of variance. No significant differences were found. It was concluded that a high protein meal, a high polyunsaturated fat meal, and a meal containing MCT oil did not affect the exercise tolerance of this individual compared to the control meal.

Adult↗

PubMed1982

Exercise tolerance and cardiorespiratory adjustments at peak work capacity in cystic fibrosis.

Exercise tolerance and cardiorespiratory adjustments at peak work capacity (PWC) were determined in 20 patients with cystic fibrosis (CF) during progressive cycle ergometry. The results were related to resting lung function tests, expressed by a pulmonary function score (PFS) that ranged from 0 (no pulmonary dysfunction) to 18 (extreme dysfunction). Patients with CF with no (PFS less than 3), mild (PFS 3-7), or moderate (PFS 8-12) pulmonary dysfunction exercised as well as normal subjects. When the PFS exceeded 12, PWC was reduced on the average by 51%, peak heart rate (PHR) was reduced by 15%, and peak ventilation (PVE) was reduced by 39%. Severely affected patients developed arterial desaturation at PWC (-7.3%), CO2 retention (end-tidal PCO2 + 5 mmHg), and an increase in the PHR/PWC ratio. In most patients with CF the PVE/PWC ratio was elevated, suggestion wasted VE and a probable increase in dead space ventilation. The results indicate that whenever pulmonary disease in CF is advanced, there are decreases in exercise tolerance and cardiorespiratory reserves, exercise-induced ventilation-perfusion abnormalities, arterial desaturation, and alveolar hypoventilation. In view of the abnormal physiological adaptations to exercise in patients with CF with advanced lung disease (PFS greater than 12), they should engage in exercise training programs and strenuous physical activity with caution and only after their cardiorespiratory reserves and adjustments to exercise have been objectively evaluated.

Adolescent↗

PubMedDate not supplied

Cardiac neurosis: exercise tolerance and the role of sympathetic activity.

To evaluate the cardiovascular and plasma catecholamine responses to dynamic exercise in patients with cardiac neurosis (CN), treadmill testing was performed. Thirty-four patients with CN were chosen for this study based on exercise tolerance and the results were compared with those in 31 patients with organic heart disease and 12 normal subjects. Patients with CN showed an augmentation of cardiovascular and plasma catecholamine responses. The augmentation of the norepinephrine response in patients with CN was not as remarkable as that in patients with organic heart disease. On the other hand, the augmentation of the epinephrine response was greater in patients with CN than in those with organic heart disease. Administration of metoprolol (40 mg/day) for two weeks improved exercise tolerance in patients with CN. We suggest that anxiety augments both sympatho-neural and sympatho-adrenal activity and that it is the symptoms induced by the augmented cardiovascular response which reduce exercise tolerance in patients with CN.

Adult↗