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PubMed2002

Epoetin alfa for protection of metabolic and exercise capacity in cancer patients.

A controlled clinical trial was conducted to evaluate the use of epoetin alfa in cachectic patients with solid tumors who were not receiving chemotherapy to determine if increasing hemoglobin (Hb) resulted in increased exercise capacity, metabolism, and energy efficiency during a maximum work load. The randomized, prospective study included 108 patients who received oral indomethacin 50 mg twice daily (n = 58; control group), or oral indomethacin 50 mg twice daily with epoetin alfa 4,000 to 10,000 IU by subcutaneous injection 3 times weekly (n = 50; study group). Patients randomized to the study group received epoetin alfa only when Hb decreased below 12.8 g/dL for men and 12.0 g/dL for women. Mean Hb levels in the study group were significantly (P <.0001) improved overall compared with the control group, with significant differences seen between groups after 2 to 4 months (P <.003), 6 to 8 months (P <.01), and 10 to 30 months (P <.01). Mean inflammatory variables including serum albumin, erythrocyte sedimentation rate, and C-reactive protein were significantly (P <.02) changed in the study group compared with the control group (ie, the control group had more inflammation). Significantly lower mean body weight (P <.05) and resting energy expenditure (P <.007) were recorded for patients in the control group versus the study group. The study group showed significantly greater mean exercise capacity (P <.0001), mean oxygen uptake (P <.01), mean CO(2) production (P <.009), and respiration (P <.03). These results demonstrate that early use of epoetin alfa prevents anemia in patients with progressive cancer who are not receiving chemotherapy. Normalization of Hb levels resulted in improved whole-body metabolism and energy efficiency, which is associated with greater exercise capacity and better daily quality of life.

Aged↗

PubMed1985

Exercise capacity in subjects with high oxygen affinity.

Exercise capacity and hemodynamic parameters were measured in ten patients with a previously unpublished variant of hemoglobin (Hb-Linköping) and in ten age- and sex-matched controls. Bicycle ergometer test was almost maximal and the indices of working capacity and cardiac tolerance were similar in patients and controls. The hemoglobin dissociation curve was shifted to the left at rest and after exercise the shift to right was half of the corresponding shift in controls. Lactate accumulation during exercise was similar in patients and controls, also the elimination rate seems identical, but requires further studies. Hydrogen ion production in the patients during exercise was more marked than in the controls. If this is a sign of altered energy metabolism remains to be ascertained in future studies. In acute short-term exercise the patients with abnormally high hemoglobin oxygen affinity seem to have similar tolerance and cardiovascular load. Aberrant metabolism and adaptation to relative hypoxia in spite of erythrocytosis may have long-term effects that require long-term follow-up of these patients.

Adult↗

PubMed2001

Preservation of exercise capacity and lack of peripheral changes in asymptomatic patients with severely impaired left ventricular function.

AIMS: To establish the extent, if any, of peripheral changes in asymptomatic patients with severe left ventricular dysfunction. METHODS ANS RESULTS: Nine asymptomatic and nine symptomatic patients with left ventricular ejection fraction, <25%, matched for age and left ventricular ejection fraction (asymptomatic vs symptomatic, age: 52+/-1.5 vs 55.9+/-2.5 years [Mean+/-SEM], left ventricular ejection fraction: 16+/-2 vs 19+/-2%P=0.23 and 0.48, respectively) were studied and compared with 26 age-matched normal controls. We assessed exercise capacity, leg blood flow (occlusion plethysmography), respiratory muscle strength, quadriceps maximal isometric strength, fatigue and CT cross-sectional muscle area at mid thigh. Fatigue was expressed as the percentage reduction in maximal strength following a 20 min fatiguing protocol. There was a graded increase in peak oxygen consumption comparing symptomatic, asymptomatic and control groups (16.6+/-1.3 vs 27.1+/-1.6 vs 32.8+/-1.3 ml x min(-1) x kg(-1)respectively, ANOVA P<0.0001). Between the three groups there was significant variation in muscle strength (P<0.0001), endurance (P=0.0002) and cross-sectional area (P=0.0003) and in peak blood flow (P=0.027) and respiratory muscle strength (P<0.05). When asymptomatic patients and controls were compared no significant differences existed. CONCLUSIONS: Patients with severe left ventricular dysfunction may have near normal exercise capacity and no peripheral changes. Exercise capacity may depend less upon left ventricular function than on the presence or absence of peripheral factors.

Exercise Test↗

PubMed2005

Physical exercise capacity is associated with coronary and peripheral vascular function in healthy young adults.

Short-term exercise training has been shown to improve cardiovascular function, whereas long-term effects of a physically active lifestyle, on coronary artery function in particular, are still not well studied. We explored possible relationships between physical exercise capacity and coronary and peripheral vascular function in healthy young adults. Twenty-nine healthy young male and female volunteers participated in the study. They underwent 1) basic clinical and echocardiographic characterization, 2) coronary flow velocity reserve (CFVR) measurement of the left anterior descending coronary artery (LAD), 3) common carotid artery (CCA) intima-media thickness (IMT) measurement, 4) assessment of CCA stiffness index (SI), 5) forearm flow-mediated vasodilation (FMD), and 6) submaximal exercise test. The calculated weight-adjusted maximal oxygen uptake capacity (Vo(2 max)(c)) was positively correlated to LAD CFVR and inversely correlated to IMT and SI. Also, subjects with high compared with moderate exercise capacity had higher FMD. In addition, subjects with LAD CFVR in the upper median had greater ratios between endothelium-dependent and -independent vasodilation in the forearm and lower SI in CCA. High exercise capacity due to a physically active lifestyle is associated with high coronary and peripheral artery function, indicating an early protective role of physical exercise for cardiovascular health.

Adult↗

PubMed1996

What is the ideal study design for evaluation of treatment for heart failure? Insights from trials assessing the effect of ACE inhibitors on exercise capacity.

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 detect improvement in symptoms and exercise performance. Thirty-five published, double-blind, randomized placebo-controlled trials, involving a total of 3411 patients, which compared the effect of ACE inhibitors and placebo on exercise capacity in patients with symptomatic chronic heart failure were identified. Studies were examined in relation to whether they used cross-over or parallel group study design, study size, use of treadmill vs bicycle exercise test, year of publication, patient entry criteria, duration of follow-up and the particular ACE inhibitor used. Exercise duration improved in 23 of the studies, while symptoms improved in 25 of the 33 studies which evaluated this. In the majority of the trials (27 of 33) there was concordance between the effect on symptoms and on exercise capacity. There were six trials which showed discrepant results. Study size, duration of follow-up and method of exercise testing used were found to be major factors affecting the outcome. Trials using treadmill exercise tests were more likely to be positive than those using bicycle ergometry. All nine trials with study size more than 50, follow-up of 3-6 months and using treadmill exercise tests showed improved exercise capacity as well as symptoms. These findings may be useful in designing future trials for evaluating treatment for heart failure.

Angiotensin-Converting Enzyme Inhibitors↗

PubMed2005

Adults with Ebstein's anomaly--Cardiopulmonary exercise testing and BNP levels exercise capacity and BNP in adults with Ebstein's anomaly.

INTRODUCTION: Ebstein's anomaly is defined as the significant apical displacement of the part of the tricuspid valve causing significant tricuspid regurgitation and reduction of the functional right ventricle. The aim of the study was to evaluate exercise capacity with cardiopulmonary stress testing and to determine plasma BNP levels in adults with Ebstein's anomaly, and to establish their relation with echocardiogaphic grading of the lesion severity. MATERIALS AND METHODS: Study group consisted of 21 patients (16 males, aged 40.3+/-11.5 years). The control group: 19 healthy individuals (13 males, aged mean 39.9+/-9.3 years). On echocardiography the grade of the lesion severity was calculated (EGE) and used to define the following four groups: I < 0.5, II: 0.5-0.9, III: 1.0-1.49, IV > 1.5. The forced vital capacity (FVC), first second forced expiratory volume (FEV1), peak oxygen uptake (peak VO2), and VE/VCO2 slope were assessed with cardiopulmonary stress test and plasma BNP levels measured with radioimmunometric assay. RESULTS: In the studied group VO2 was lower than in control (21.9+/-5.4 vs. 33.6+/-8.3 mL/kg/min [p = 0.00001]), VE/VCO2 slope was higher in Ebstein's group (40.1+/-8.1, p = 0.00001). BNP levels were higher in the Ebstein group then in controls (35.9+/-25.0 vs. 17.2+/-9.9 pg/mL [p = 0.0002]) and did not differ significantly between EGE groups. PeakVO2 of 24.5+/-3.9 in patients from II EGE group were higher than in patients from EGE groups: III (17.2+/-5.2 p = 0.007) and IV (22.9+/-4.7 p = 0.05). CONCLUSIONS: Exercise capacity of adults with Ebstein's anomaly is significantly reduced and plasma BNP levels are higher compared to healthy individuals. Exercise capacity in patients with Ebstein's anomaly becomes gradually lower alongside the EGE severity; however, BNP levels do not correlate significantly with this parameter.

Adult↗

PubMed2001

The relationship between left ventricular filling shortly after an uncomplicated myocardial infarction and subsequent exercise capacity.

Resting measurement of only left ventricular systolic function, is not enough sufficient parameter that predicts exercise capacity in patients with cardiac disease. Therefore, left ventricular filling shortly after an acute myocardial infarction (AMI) was prospectively studied to determine whether it could predict subsequent exercise time. Consecutive AMI patients underwent Doppler and two-dimensional echocardiography within 48 hours of infarction. The study group consisted of 63 participants: 33 patients with an uncomplicated AMI who had undergone symptom-limited stress testing during recovery and 30 healthy subjects. Systolic function was evaluated by wall motion score index (WMSI), and diastolic one was assessed by the peak transmitral Doppler velocity in early diastole (E) and atrial systole (A), then by their ratio (E/A), normalized E/A ratio, and by diastolic filling period (DFP). Myocardial infarction (MI) size was measured electrocardiographically, using Selvester's QRS scoring system (QRSSI) and then expressed in percentages. Healthy participants and patients were compared, through common parameters. The patients receiving BB treatment at the time of exercise testing, had a lower resting pulse, and achieved a lower maximal pulse, yet their exercise time was similar incomparison to that of the group not receiving BB therapy. Our results have shown a strong positive correlation between exercise time and WMSI (r = 0.77, p < 0.001) DFP (r = 0.56, p < 0.001), respectively weak negative correlation with QRSSI (r = -0.17, p < 0.001) and better negative correlation with normalized E/A ratio (r = -0.56, p < 0.001). This correlation was not influenced by beta-blokers (BB) at the time of stress testing. Normalized E/A ratio and DFP are the only diastolic function parameters, which predict exercise capacity during recovery, measured soon after an uncomplicated AMI.

Adrenergic beta-Antagonists↗

PubMed2005

Close coupling of systolic and diastolic function: combined assessment provides superior prediction of exercise capacity.

BACKGROUND: Isolated diastolic dysfunction is thought to account for approximately 50% of cases of heart failure. We tested the hypotheses that (1) the use of different methods for assessing systolic and diastolic function may contribute to the apparent frequency with which they are dissociated and (2) that combined assessment of systolic and diastolic function is superior to either one alone. METHODS AND RESULTS: A total of 110 patients underwent echocardiography with tissue Doppler imaging (TDI) of the mitral annulus before maximal exercise testing. The correlation between left ventricular (LV) ejection fraction (EF) and exercise capacity was weak (r = 0.199). Among patients with EF greater than 55%, those with normal exercise capacity (>7 METs) had a higher systolic velocity of the mitral annulus than those achieving less than 7 METs (9.6 +/- 0.3 versus 7.5 +/- 0.4 cm/s, P = .001). The mitral annular systolic (Sa) and early diastolic (Ea) velocities each correlated moderately with exercise tolerance (r = 0.40 and 0.49, respectively). Sa and Ea correlated highly with each other (r = 0.79, P < .001). The sum of isovolumic contraction and relaxation times measured from TDI correlated moderately with exercise duration (r = -0.59). A combined index of systolic and diastolic function that includes isovolumic contraction and relaxation times and ejection time had the best correlation with achieved METs (r = -0.73, P < .001). A TDI index of cardiac performance higher than 0.52 had excellent sensitivity (86%) and specificity (100%) for predicting reduced exercise tolerance lower than 7 METs. CONCLUSION: When assessed with the same technique, LV systolic and diastolic function are tightly linked. A TDI-derived combined index of myocardial performance is the best predictor of exercise capacity.

Adult↗

PubMed1995

Effects of cardiac rehabilitation and exercise training on exercise capacity, coronary risk factors, behavioral characteristics, and quality of life in women.

Despite the known benefits of cardiac rehabilitation, limited data are available on the outcome of this treatment in women, and this secondary prevention strategy may be underutilized. To assess the gender differences in baseline exercise capacity, indexes of obesity, lipid profiles, behavior characteristics, and components of quality of life, as well as the improvements in these components after a secondary prevention program, we retrospectively reviewed data from 458 patients (83 women and 375 men) enrolled in a phase II cardiac rehabilitation and exercise program after a major cardiac event. At baseline (6 weeks after the cardiac event and before rehabilitation), exercise capacity (-9%, p = 0.08) and ratio of low-density lipoprotein cholesterol/high-density lipoprotein cholesterol (-14%, p < 0.01) were lower, but total cholesterol (+7%, p < 0.01), high-density lipoprotein cholesterol (+25%, p < 0.0001), low-density lipoprotein cholesterol (+8%, p < 0.01), and percent body fat (+15%, p < 0.0001) were higher in women than in men with coronary artery disease. In addition, with regard to quality of life, women had lower scores for energy (p = 0.06), function (p < 0.01), and total quality of life (p < 0.05) than men. After cardiac rehabilitation and exercise training, women had significant improvements in exercise capacity (+33%, p < 0.0001) and percent body fat (-7%, p < 0.001), which compared favorably with the improvements (+40% and -5%, respectively) seen in men, but improvements in body mass index and lipids were not statistically significant.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed2002

Partial normalization of the heart rate response to exercise after cardiac transplantation: frequency and relationship to exercise capacity.

OBJECTIVE: To determine the frequency of partial normalization of the heart rate response to graded exercise and its relationship to exercise capacity in cardiac transplant recipients. SUBJECTS AND METHODS: The study subjects were 95 adults (77 men, 18 women) who were available to perform a cardiopulmonary exercise test 1 year after orthotopic cardiac transplantation, which occurred between June 1988 and September 1998. All subjects received standard immunosuppressant medications. At the time of the exercise tests, the mean +/- SD age of the subjects was 49+/-14 years. The mean +/- SD resting left ventricular ejection fraction was 62%+/-8%. All subjects participated in a 6- to 8-week supervised exercise program, starting no later than 1 month after surgery. Subjects were given an exercise prescription for independent exercise training after finishing the supervised program. Self-reported weekly exercise training had a median value of 90 minutes (interquartile range, 0-210 minutes). Symptom-limited graded exercise was performed on a treadmill, with breath-by-breath analysis of expired air. RESULTS: For the entire cohort, peak exercise oxygen uptake was 19.9+/-4.8 mL x kg(-1) x min(-1) (61%+/-15% of age and sex predicted). Thirty-two subjects (34%) had a partially normalized heart rate response to graded exercise. The frequency was similar for men (25/77 [33%]) and for women (7/18 [39%]) and was independent of recipient or donor age. Peak exercise heart rate (147+/-18 vs 134+/-21 beats/min; P=.008) and heart rate reserve (46+/-15 vs 33+/-15 beats/min; P<.001) were greater for subjects with a partial normalization of heart rate response. Peak exercise oxygen uptake was similar for subjects with or without partial normalization of the heart rate response (20.9+/-5.8 vs 19.4+/-4.2 mL x kg(-1) x min(-1); P=.22). Submaximal exercise oxygen uptake during the first few minutes of exercise was also not affected by normalization of the heart rate response. CONCLUSION: At 1 year after cardiac transplantation, approximately one third of subjects had partial normalization of the heart rate response to graded exercise. However, a higher peak exercise heart rate and a larger heart rate reserve did not result in better aerobic exercise capacity.

Adult↗

PubMed1997

Exercise capacity and mid-term survival in patients with tricuspid atresia and complex congenital cardiac malformations after modified Fontan-operation.

OBJECTIVE: Continued follow-up of the Fontan population group is mandatory in order to evaluate the best approach for long term treatment. We studied exercise capacity and survival in patients with either right atrial to right ventricular (Fontan-Bjoerk, RA-RV) anastomosis or right atrial to pulmonary artery (RA-PA) connection. METHODS: Between January 1980 and December 1995 Fontan-Bjoerk modifications were performed in 73 patients with tricuspid atresia. A RA-PA anastomosis (performed either with direct atrio-pulmonary connection or with a lateral tunnel of autologous atrial tissue) was used in 118 patients with single ventricle or complex cardiac malformations. Using bicycle ergospirometry and impedance cardiography standard variables of exercise testing were measured in 15 patients with RA-RV and in 18 patients with RA-PA connection. A group of 23 healthy pupils served as controls. RESULTS: Follow-up was complete for 97.9% (n = 187) of all operated patients. Survival (% mean +/- SEM) at 5, 10 and 15 years was 89.3 +/- 3.6, 76.8 +/- 0.6 and 63.6 +/- 10.5 for RA-RV connection and 80.2 +/- 4.0, 75.3 +/- 4.5 and 64.6 +/- 10.7 for RA-PA connection (P = 0.12) respectively. Exercise capacity was tested after a median time of 6.0 (0.8-19.8) years after Fontan operation in RA-RV and of 7.8 (4.3-18.2) years in RA-PA patients. Total work load was equal in the two Fontan groups, but it was below normal. Heart rate, respiratory rate, oxygen uptake and ventilatory equivalent for oxygen were not different between the two Fontan groups. Cardiac index and stroke volume index were consistently lower at anaerobic threshold and at maximal exercise in RA-PA patients compared with controls. CONCLUSION: Survival analysis between RA-RV and RA-PA Fontan connection failed to demonstrate a better outcome for patients with either Fontan modification. Although there was a tendency for RA-RV connection to adapt cardiac output more efficient to exercise compared with RA-PA patients, total work load and ventilatory equivalent was not significantly different between the two Fontan modifications. We conclude, that by incorporation of a residual subpulmonary ventricular chamber within the Fontan circulation no additional benefit for exercise capacity could be observed.

Adolescent↗

PubMed2006

Effect of physical training on exercise capacity, gas exchange and N-terminal pro-brain natriuretic peptide levels in patients with chronic heart failure.

BACKGROUND: Decreased exercise capacity is the main factor restricting the daily life of patients with chronic heart failure. N-terminal pro-brain natriuretic peptide (NT pro-BNP) is strongly related to the severity of and is an independent predictor of outcome in chronic heart failure. DESIGN: The study aimed to evaluate the effect of exercise training on functional capacity and on changes in NT pro-BNP levels and to assess the effect of exercise training on quality of life. MATERIALS AND METHODS: Sixty patients (45 men/15 women, mean age 52.7 years; +/-5.3 SD), with stable heart failure (45 ischaemic/hypertensive and 15 idiopathic patients), in New York Heart Association (NYHA) functional class II (n=35) to III (n=25), with an ejection fraction less than 40%, were randomly assigned to a training (n=30) and a control group (n=30). The training group (30 patients) performed 3 months of supervised physical training programme using a bicycle ergometer for 30 min three times a week at a load corresponding to 60-70% of their oxygen consumption (VO2) peak. The control group did not change their previous physical activity. A graded maximal exercise test with respiratory gas analysis and an endurance test with constant workload corresponding to 85% of the peak oxygen load at the baseline and after 3 months were performed, and at the same times NT pro-BNP levels were measured. RESULTS: The exercise capacity increased from 15.8 (+/-2.3 SD) to 29.9 (+/-2.1 SD) min (P<0.0001) and the peak VO2 tended to improve from 14.5 (+/-1.4 SD) to 17.7 (+/-2.6 SD) ml/kg per min (P<0.0001) during the supervised training period. VO2 at the anaerobic threshold increased from 12.9 (+/-1.0 SD) to 15.5 (+/-1.7 SD) ml/kg per min (P<0.0001). NT pro-BNP levels decreased from 3376 (+/-3133 SD) to 1434 (+/-1673 SD) pg/ml (P=0.043). The positive training effects were associated with an improvement in the NYHA functional class. CONCLUSION: Physical training of moderate intensity significantly improves the exercise capacity and neurohormonal modulation in patients with chronic heart failure. This is associated with an alleviation of symptoms and improvement in quality of life.

Exercise↗

PubMed2003

Novel actions of thiazolidinediones on vascular function and exercise capacity.

The endothelium is the first line of defense for maintaining normal vascular function in the vessel wall; however, the endothelium is sensitive to metabolic stress. In patients with insulin resistance or type 2 diabetes mellitus, a set of metabolic insults--namely high plasma levels of glucose and free fatty acids, increased inflammation, dyslipidemia, and hypertension--cause endothelial dysfunction and a transition from an antiatherogenic endothelium to a proatherogenic endothelium. Disruption of endothelial function leads to activation of platelets and macrophages, increased thrombotic potential, transition of macrophages to foam cells, stimulation of cytokine secretion, and proliferation of vascular smooth muscle cells. Insulin-sensitizing agents, such as the thiazolidinediones (TZDs), improve flow-mediated vasodilation, decrease macrophage and smooth muscle cell activation, proliferation, and migration, and decrease plaque formation. The TZDs exert multifaceted effects on the vasculature by regulating the expression of transcription factors and orchestrating whole-gene programs that restore vascular physiology to the healthy state. Exercise training and increased levels of habitual physical activity have therapeutic benefit in terms of both preventing and treating insulin resistance and diabetes. However, this benefit of exercise training and increased physical activity is complicated by the fact that individuals with insulin resistance or type 2 diabetes have decreased maximal exercise capacity or maximal oxygen consumption and have slower oxygen uptake kinetics at the beginning of exercise. Both of these abnormalities contribute to the decreased levels of habitual physical activity observed in patients with diabetes. Preliminary data suggest that TZDs improve measures of cardiac function and exercise capacity, and investigators are assessing the impact of treatment with rosiglitazone on exercise capacity in an ongoing clinical trial.

Blood Glucose↗

PubMed1989

[Effects of isosorbide-5-mononitrate on exercise capacity, prostacyclin synthesis, the renin-aldosterone axis and catecholamines in patients with cardiac insufficiency].

Isosorbide-5-mononitrate (IS-5-MN) is an active metabolite of isosorbide dinitrate with a longer plasma half life. Aim of the study was the evaluation of the effects of 40 mg/day of IS-5-MN on exercise capacity in patients with heart failure NYHA class II. After 1 week of wash-out, 10 patients with heart failure NYHA Class II, assumed 20 mg bid for 3 weeks. Bicycle ergometer tests were performed before (A), at the end of therapy (B), and 1 week later (C); in phase B the stress test was performed after 6 hours from the last assumption of IS-5-MN. We measured 24 hour urinary 6K-PGF1 alpha, the stable metabolite of prostacyclin, basal plasma renin activity (PRA) and plasma aldosterone, exercise-release of epinephrine and norepinephrine at the end of each phase of the study. The treatment with IS-5-MN improved the exercise capacity sigma (Watt.min), A less than (B = C), (p less than 0.01), while delta of heart rate (HR) during exercise (basal HR - maximal exercise HR)/(Watt.min), decreased, A greater than (B = C), (p less than 0.008). Basal BP and HR did not change. This fact seems consistent with the hypothesis of a combined effect of nitrates on both the venular and the arteriolar districts. Basal PRA and aldosterone, and catecholamine release during exercise after IS-5-MN did not change, while only norepinephrine increased 1 week after the end of the therapy, (A = B) less than C, (p less than 0.05): 24 hour urinary 6-K-PGF1 alpha increased after IS-5-MN A less than (B = C), (p less than 0.05). The results indicate that medium-term IS-5-MN treatment increases exercise capacity in patients with heart failure NYHA class II and that the effect lasts for 1 week after nitrate withdrawal at least. Prostacyclin is probably involved in medium-term clinical effect of IS-5-MN.

Aged↗

PubMed1997

Importance of left ventricular diastolic function on maintenance of exercise capacity in patients with systolic dysfunction after anterior myocardial infarction.

To investigate the role of left ventricular (LV) diastolic function in the maintenance of exercise capacity in patients with systolic dysfunction, symptom-limited cardiopulmonary exercise testing combined with radionuclide ventriculography was performed in 24 patients with an LV ejection fraction < 35% after anterior myocardial infarction. The ratio of pulmonary artery wedge pressure (PAWP) to LV end-diastolic volume (EDV), an index of global diastolic function, correlated significantly with peak oxygen consumption at peak exercise (r = -0.55; p = 0.006), whereas ejection fraction at peak exercise did not. The change in PAWP/EDV ratio from rest to peak exercise was related to the increases in stroke volume (r = -0.54; p = 0.006) and cardiac output (r = -0.51; p = 0.01) during exercise, but the change in ejection fraction was not. Resting hemodynamics did not differ between patients with preserved exercise capacity (group 1, n = 8) and those with exercise impairment (group 2, n = 16). At peak exercise, stroke volume, cardiac output, and EDV were significantly higher, and PAWP and PAWP/EDV ratio were significantly lower in group 1 than in group 2, but ejection fraction and end-systolic volume were similar in both groups. Although the incidences of hypertension, LV hypertrophy, and infarct-related coronary artery lesions did not differ between the two groups, group 2 had a significantly higher incidence of non-infarct-related coronary artery lesions than group 1 (p < 0.05). Thus in patients with LV systolic dysfunction after anterior myocardial infarction, the major cause of exercise impairment and failure to increase LV performance during exercise was diastolic dysfunction associated with the presence of non-infarct-related coronary artery lesions with the potential for exercise-induced ischemia of the noninfarcted areas.

Adult↗

PubMed2005

The 1-year impact of severe acute respiratory syndrome on pulmonary function, exercise capacity, and quality of life in a cohort of survivors.

OBJECTIVE: To examine pulmonary function, exercise capacity, and health-related quality of life (HRQoL) among severe acute respiratory syndrome (SARS) survivors. METHODS: We evaluated survivors with confirmed SARS at the Prince of Wales Hospital, Hong Kong, at 3, 6, and 12 months after symptom onset. Our assessment included: lung volume (total lung capacity [TLC], vital capacity, residual volume, functional residual capacity), spirometry (FVC, FEV1), diffusing capacity of the lung for carbon monoxide (D(LCO)), inspiratory and expiratory respiratory muscle strength, 6-min walk distance (6MWD), chest radiographs (CXRs), and HRQoL by Medical Outcomes Study 36-Item Short-Form General Health Survey questionnaire. RESULTS: Ninety-seven patients completed the serial assessments. There were 39 male and 58 female patients, and 63 patients (70%) were health-care workers (mean age, 36.9 years [SD, 9.5 years]; body mass index, 23.7 kg/m2 [SD, 4.0 kg/m2]). At 1 year, 27 patients (27.8%) had abnormal CXR findings. Four patients (4.1%), 5 patients (5.2%), and 23 patients (23.7%) had FVC, TLC, and D(LCO) values < 80% of predicted values, respectively. The 6MWD at 12 months was 511.0 m (SD, 89.8 m), which was higher than at 3 months (mean difference, 47.0 m; 95% confidence interval [CI], 31.8 to 62.1 m; p < 0.01) but not different from 6 months (mean difference, 9.7 m; 95% CI, - 4.4 to 23.8 m; p = 0.18). The 6MWD was lower than that for normal control subjects of the same age groups, and there was impairment of HRQoL at 12 months. Patients who required ICU admission (n = 31) showed higher CXR scores (1.6 [SD, 3.1]; vs 0.4 [SD, 1.1]; p = 0.04) and lower percentage of predicted FVC, TLC, and Dlco than those who did not, but there were no differences in 6MWD and health status. CONCLUSION: Significant impairment in Dlco was noted in 23.7% of survivors 1 year after illness onset. Exercise capacity and health status of SARS survivors were remarkably lower than those of a normal population.

Adult↗

PubMedDate not supplied

Exercise capacity in pediatric patients with end-stage renal disease.

OBJECTIVE: To evaluate the correlation between exercise capacity and hemoglobin in pediatric patients with end-stage renal disease (ESRD) treated with automated peritoneal dialysis (APD) and hemodialysis. DESIGN: Prospective case-control study and retrospective review. SETTING: Dialysis summer camp and Children's Mercy Hospital exercise laboratory. PARTICIPANTS: Prospective evaluation conducted with 14 patients (9 males, mean age 14.5 +/- 2.5 years) who received either home APD (5 patients) or in-center hemodialysis (9 patients), and 8 healthy age-matched controls. Retrospective data derived from 10 children (7 males, mean age 12.3 +/- 3.3 years), all of whom received APD. INTERVENTION: Maximal treadmill evaluation conducted with each patient and control. The hemoglobin value of each patient was also assessed. MAIN OUTCOME MEASURES: Comparison of the following data generated during treadmill protocol: peak heart rate, blood pressure, oxygen saturation, treadmill time, oxygen consumption (VO2), ventilation (Ve), oxygen consumption at anaerobic threshold (VO2AT), and respiratory exchange ratio. RESULTS: The hemoglobin value of the current patient group (12.8 +/- 1.6 g/dL) was significantly greater than the previously studied patients (10.5 +/- 1.1 g/dL) (p = 0.001). Treadmill time, VO2, and VO2AT were significantly lower in both groups of dialysis patients compared to the control subjects (p < 0.05). No differences were noted in any of these variables when comparing these two groups of dialysis patients only. CONCLUSION: The exercise capacity of pediatric dialysis patients is significantly poorer than that of healthy children, an outcome apparently related to factors other than normalization of the hemoglobin value.

Adolescent↗

PubMedDate not supplied

Exercise capacity recovers slowly but fully in patients with a left ventricular assist device.

Left ventricular assist devices (LVAD) are used increasingly as bridges to cardiac transplantation. The typical LVAD candidate is a bedridden, critically ill, New York Heart Association (NYHA) Class IV patient with congestive heart failure (CHF) who is dependent upon intravenous, inotropic, and, in many cases, intra-aortic balloon support. The LVAD provides the potential for pre transplant rehabilitation by allowing the patient to become ambulatory, and by improving muscle tone, muscle mass, and nutritional status before transplantation. However, whether the abnormal exercise capacity of these patients improves after implantation has not been elucidated. The purpose of the present study was to evaluate the exercise capacity of patients with CHF after LVAD implantation (n = 10) using peak oxygen consumption during maximal exercise (MVO2), and comparing the results with those of a group of NYHA Class III patients with CHF (n = 14). After 2 months of implantation, MVO2 of the patients with LVAD was 12.8 +/- 0.3 ml/kg/min, which was comparable to that of the NYHA Class III patients with CHF (12.5 +/- 0.5 ml/kg/min). Four of 10 patients with LVAD were monitored for more than 5 months when MVO2 rose to 15.4 +/- 1.0 ml/kg/min (p < 0.05 vs NYHA Class III). In conclusion, the exercise capacity of patients with LVAD recovers slowly but significantly after 5 months of implantation, promising the potential for complete recovery from heart failure in patients supported with an LVAD.

Adult↗