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1.
Objective: Evidence for links between anger inhibition or suppression and chronic pain severity is based mostly on studies with correlation designs. Following from ironic process theory, we proposed that attempts to suppress angry thoughts during provocation would increase subsequent pain intensity among chronic low back pain (CLBP) patients, and do so through paradoxically enhanced accessibility of anger. Design: CLBP patients (N = 58) were assigned to suppression and nonsuppression conditions while performing a computer maze task with a harassing confederate. A structured pain behavior task (SPBT) followed. Main outcome measures: Self-reported anger, anxiety, and sadness following maze task. Self-reported pain severity and number of observed pain behaviors during SPBT. Results: Patients told to suppress during provocation: (a) reported greater anger following the maze task, reported greater pain intensity during the SPBT, and exhibited more pain behaviors than patients not suppressing; (b) postmaze anger levels significantly mediated group differences on pain behaviors. Conclusion: Attempts by CLBP patients to suppress anger may aggravate pain related to their clinical condition through ironically increased feelings of anger. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

2.
Depression was examined in 45 patients evaluated within 2 months of diagnosis of MS. At the time of testing, 40% of the MS sample met the diagnostic criteria for major depression, 22% had adjustment disorder with depressed mood and 37% showed no evidence of mood disorder. Personal and family history of depression in patients with MS was also examined and compared with a sample of patients with chronic low back pain (CLBP) who were matched for age, gender, marital and employment status and current level of depression. Fifty-two per cent of patients with MS reported experiencing a depressive episode before the onset of MS compared with 17% of patients with CLBP (P < 0.001). Sixteen patients with MS (35%) reported family history (parent or sibling) of treatment for depression compared with seven (15%) of patients with CLBP (P < 0.05). MS patients with a history of depression reported more initial symptoms than MS patients without a history of depression. Clinical and theoretical implications of the findings are discussed.  相似文献   

3.
In our previous study, we demonstrated that chronic ethanol (EtOH) exposure down-regulated the cannabinoid receptors (CB1) in mouse brain synaptic plasma membrane (SPM) (Basavarajappa et al., Brain Res. 793 (1998) 212-218). In the present study, we investigated the effect of chronic EtOH (4-day inhalation) on the CB1 agonist stimulated guanosine-5'-O-(3-[35S]thio)-triphosphate ([35S]GTP gamma S) binding in SPM from mouse. Our results indicate that the net CP55,940 stimulated [35S]GTP gamma S binding was increased with increasing concentrations of CP55,940 and GDP. This net CP55,940 (1.5 microM) stimulated [35S]GTP gamma S binding was reduced significantly (-25%) in SPM from chronic EtOH group (175 +/- 5.25%, control; 150 +/- 8.14%, EtOH; P < 0.05). This effect occurs without any significant changes on basal [35S]GTP gamma S binding (152.1 +/- 10.7 for control, 147.4 +/- 5.0 fmol/mg protein for chronic EtOH group, P > 0.05). Non-linear regression analysis of net CP55,940 stimulated [35S]GTP gamma S binding in SPM showed that the Bmax of cannabinoid stimulated binding was significantly reduced in chronic EtOH exposed mouse (Bmax = 7.58 +/- 0.22 for control; 6.42 +/- 0.20 pmol/mg protein for EtOH group; P < 0.05) without any significant changes in the G-protein affinity (Kd = 2.68 +/- 0.24 for control; 3.42 +/- 0.31 nM for EtOH group; P > 0.05). The pharmacological specificity of CP55,940 stimulated [35S]GTP gamma S binding in SPM was examined with CB1 receptor antagonist, SR141716A and these studies indicated that CP55,940 stimulated [35S]GTP gamma S binding was blocked by SR141716A with a decrease (P < 0.05) in the IC50 values in the SPM from chronic EtOH group. These results suggest that the observed down-regulation of CB1 receptors by chronic EtOH has a profound effect on desensitization of cannabinoid-activated signal transduction and possible involvement of CB1 receptors in EtOH tolerance and dependence.  相似文献   

4.
The effects of exercise for isolated lumbar extensor muscles were examined in 54 chronic low-back pain patients. Subjects were randomly assigned to a 10-week exercise program (N = 31) or a wait-list control group (N = 23). Results indicated a significant increase in isometric lumbar extension strength for the treatment group and a significant reduction in reported pain compared with the control group (P 0.05). Treated subjects reported less physical and psychosocial dysfunction whereas the control group increased in pain, and physical and psychosocial dysfunction. There were no concomitant changes in reported daily activity levels. These results show that lumbar extension exercise is beneficial for strengthening the lumbar extensors and results in decreased pain and improved perceptions of physical and psychosocial functioning in chronic back pain patients. However, these improvements were not related to changes in activities or psychological distress.  相似文献   

5.
Vulnerability to stressors after pain may depend on the degree to which the strategy used to process information about pain perpetuates thoughts of suffering and distress. Patients with chronic low back pain (CLBP) may show susceptibility to stress after pain through symptom-specific (lower paraspinal [LP]) muscle reactivity. Patients with CLBP (n = 100) and healthy nonpatients (n = 105) underwent a cold pressor, under sensory focus, distraction, suppression, or control conditions, and then performed mental arithmetic. Only patients under the suppression condition revealed increased LP tension during pain that was sustained during mental arithmetic and sustained systolic blood pressure after mental arithmetic. Patients with CLBP who suppress pain may detrimentally affect responses to the next noxious event, particularly through prolonged LP muscle tension, that may contribute to a cycle of pain-stress-pain. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

6.
The purpose of this study was to determine changes in the amount of work performed and lifting speed, style, and coordination during a repetitive dynamic-lifting task for patients with chronic low back pain (CLBP) after an intensive 3 1/2-week pain rehabilitation program. Subjects included 57 CLBP patients and an age- and gender-matched control group (n = 57). Patients' work indices increased by 71%, but remained significantly less than those observed for controls. Similarly, their lifting speed also increased significantly after treatment, but remained slower than the lifting speed of controls. Patients' posttreatment coordination indices, however, were not significantly different from those of controls. This finding suggests that treatment effectively normalized the dynamic lifting motion used by the patients. These findings, along with the basic kinematic patterns developed in this study, have important implications for determining improvements in functional capacity in the treatment of patients with CLBP.  相似文献   

7.
Resistance exercise has been suggested to increase blood volume, increase the sensitivity of the carotid baroreceptor cardiac reflex response (BARO), and decrease leg compliance, all factors that are expected to improve orthostatic tolerance. To further test these hypotheses, cardiovascular responses to standing and to pre-syncopal limited lower body negative pressure (LBNP) were measured in two groups of sedentary men before and after a 12-week period of either exercise (n = 10) or no exercise (control, n = 9). Resistance exercise training consisted of nine isotonic exercises, four sets of each, 3 days per week, stressing all major muscle groups. After exercise training, leg muscle volumes increased (P < 0.05) by 4-14%, lean body mass increased (P = 0.00) by 2.0 (0.5) kg, leg compliance and BARO were not significantly altered, and the maximal LBNP tolerated without pre-syncope was not significantly different. Supine resting heart rate was reduced (P = 0.03) without attenuating the heart rate or blood pressure responses during the stand test or LBNP. Also, blood volume (125I and 51Cr) and red cell mass were increased (P < 0.02) by 2.8% and 3.9%, respectively. These findings indicate that intense resistance exercise increases blood volume but does not consistently improve orthostatic tolerance.  相似文献   

8.
Anger may have greater effects on chronic pain severity than other negative emotions and may do so by increasing muscle tension near the site of injury (symptom-specific reactivity). For patients with chronic low back pain (CLBP), relevant muscles are lower paraspinals (LP). Ninety-four CLBP patients and 79 controls underwent anger and sadness recall interviews. EMG and cardiovascular activity were recorded. Patients exhibited greater LP tension increases during anger and slower recovery than controls. Only patients showed greater LP reactivity during anger than sadness. For both groups, trapezius reactivity during anger and sadness did not differ. LP reactivity to anger correlated with everyday pain severity for patients. Anger-induced symptom-specific LP reactivity may be linked to chronic pain aggravation among CLBP patients. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

9.
BACKGROUND: Elevated serum uric acid concentrations have been observed in clinical conditions associated with hypoxia. Since chronic heart failure is a state of impaired oxidative metabolism, we sought to determine whether serum uric acid concentrations correlate with measures of functional capacity and disease severity. METHODS: Fifty nine patients with a diagnosis of chronic heart failure due to coronary heart disease (n = 34) or idiopathic dilated cardiomyopathy (n = 25) and 20 healthy controls underwent assessment of functional capacity. Maximal oxygen uptake (MVO2) and regression slope relating to minute ventilation to carbon dioxide output (VE-VCO2) were measured during a maximal treadmill exercise test. Metabolic assessment consisted of measuring serum uric acid and fasting lipids, and insulin sensitivity, obtained by minimal modelling analysis of glucose and insulin responses during an intravenous glucose tolerance test. Clustering of indices of functional disease capacity and metabolic factors was explored using factor analysis and multivariate regression analysis. RESULTS: Compared to 20 healthy controls, patients with chronic heart failure had a 52% lower MVO2 (P < 0.001), 56.8% higher serum uric acid concentrations (P < 0.001) as well as a 60.5% lower insulin sensitivity (P < 0.001). Salient univariate correlations in the chronic heart failure group included serum uric acid concentrations with exercise time during the exercise test (r = -0.53), MVO2 (r = -0.50) (both P < 0.001), VE-VCO2 slope (r = 0.45), and NYHA functional class (r = 0.36) (both P < 0.01). In factor analysis of the chronic heart failure group, serum uric acid formed part of a principal cluster of metabolic variables which included MVO2 and VE-VCO2 slope. In multivariate regression analysis, serum uric acid concentrations emerged as a significant predictor of MVO2, exercise time (both P < 0.001,) VE-VCO2 slope and NYHA functional class (both P < 0.02), independent of diuretic dose, age, body mass index, serum creatinine, alcohol intake, plasma insulin levels, and insulin sensitivity index. CONCLUSIONS: There is an inverse relationship between serum uric acid concentrations and measures of functional capacity in patients with cardiac failure. The strong correlation between serum uric acid and MVO2 suggests that in chronic heart failure, serum uric acid concentrations reflect an impairment of oxidative metabolism.  相似文献   

10.
Certain types of jaw-muscle pain may be managed with pharmacologic treatment. This study evaluated the effect of topical and systemic nonsteroidal anti-inflammatory drugs on acute postexercise jaw-muscle soreness. Ten men without temporomandibular disorders performed six 5-minute bouts of submaximal eccentric jaw exercise. The outcome variables were pressure pain thresholds and pain tolerance thresholds at the masseter muscles, and maximum voluntary occlusal force. Surface electromyography from the masseter muscles was used to assess the development of muscle fatigue during the exercise period. Three treatment modalities were tested in a placebo-controlled, double-blind approach: (A) placebo gel and placebo tablets; (B) nonsteroidal anti-inflammatory drug gel (2 g, 5% ibuprofen) and placebo tablets; and (C) placebo gel and nonsteroidal anti-inflammatory drug tablets (400 mg ibuprofen). The subjects used their medication 3 times a day for 3 days in the postexercise period. In the exercise period, the mean power frequency of the electromyography signal, pressure pain threshold, pain tolerance threshold, and maximum voluntary occlusal force decreased significantly (analysis of variance, P < .01). In the postexercise period, the effect of treatment on pressure pain thresholds was significant (F[2,9] = 4.41, P = .02). On day 3, treatment with topical nonsteroidal anti-inflammatory drugs was associated with significantly higher pressure pain thresholds as compared to treatment with systemic nonsteroidal anti-inflammatory drugs (P < .05) and placebo (P < .05). Treatment effects on pain tolerance thresholds and on maximum voluntary occlusal force were nonsignificant. The results demonstrated that repeated eccentric jaw exercise caused muscle fatigue and low levels of postexercise pain and soreness. Topical nonsteroidal anti-inflammatory drugs seem to have some advantages over systemic nonsteroidal anti-inflammatory drugs for management of exercise-induced jaw-muscle pain.  相似文献   

11.
BACKGROUND: Patients with univentricular hearts have decreased exercise tolerance and may demonstrate exertional dyspnoea. It is not known if chronic hypoxaemia exacerbates exercise intolerance and contributes to symptomatic limitation. The extent to which surgical correction of a right-to-left shunt by a Fontan-type procedure can increase exercise tolerance by reducing arterial deoxygenation is not well documented. The cardiopulmonary exercise responses and the symptomatic status in two groups of univentricular patients, those who are cyanotic and those who are acyanotic with Fontan-type circulation, were compared. METHODS AND FINDINGS: Cardiopulmonary exercise testing was performed in 10 univentricular patients with rest or stress-induced cyanosis (age 30.5 +/- 2.3 [SE] years; 5 men) who had palliative or no surgery and eight patients (age 29.4 +/- 1.5 years; 4 men) with Fontan-type circulation. Peak oxygen consumption was comparable in both groups of univentricular patients (21.7 +/- 2.5 vs 21.0 +/- 1.9 ml.kg-1.min-1, P = 0.85) but was less than an age-matched group of 10 healthy subjects (34.7 +/- 1.9 ml.kg-1.min-1, P < 0.001 for both). Arterial oxygen saturation was 90.6% at rest in the cyanotic patients compared with 95.1% in the Fontan patients (P < 0.001) and at peak exercise, 66.2% compared with 90.5% (P < 0.001). Using a modified Borg scale (0-10), the symptoms of dyspnoea and fatigue were also assessed during exercise in the patient groups. The Borg scores for dyspnoea in the cyanotic and the corrected univentricular patients were, respectively, as follows: Stage 1: 0.5 vs 1.7; P= 0.04; Stage 2: 1.8 vs 2.3, P = 0.5; Stage 3: 3.0 vs 3.5, P = 0.7; Peak Exercise: 4.9 vs 4.8, P = 0.9. In addition, the Borg scores for fatigue were: Stage 1: 0.4 vs 1.6, P = 0.08; Stage 2: 2.0 vs 2.2, P = 0.9; Stage 3: 3.0 vs 4.3, P = 0.5; Peak Exercise: 4.9 vs 5.4, P = 0.5. The major limiting symptom at peak exercise was dyspnoea in four cyanotic patients compared with one in the Fontan group (Chi-square 0.982, P > 0.10). The arterial oxygen desaturation at peak exercise in the cyanotic patients limited by dyspnoea was not different from those limited by fatigue (67.5 +/- 10.1% vs 66.7 +/- 13.7%, P = 0.92). Exercise tolerance was also not related to the arterial oxygen saturation at peak exercise (r = 0.47, P = 0.17) in these patients. CONCLUSIONS: Despite correction with Fontan-type surgery, the exercise tolerance and symptoms of these univentricular patients remained similar to those who were cyanosed. Cyanotic patients have adjusted to chronic hypoxaemia and it does not appear to determine the exercise tolerance or the genesis of dyspnoea in these patients. Further randomized prospective studies are required to investigate the long-term benefits of Fontan-type procedures in these patients on exercise tolerance, symptoms and prognosis.  相似文献   

12.
AIMS: To assess whether a domiciliary programme of specific inspiratory muscle training in stable chronic heart failure results in improvements in exercise tolerance or quality of life. METHODS AND RESULTS: We conducted a randomized controlled trial of 8 weeks of inspiratory muscle training in 18 patients with stable chronic heart failure, using the Threshold trainer. Patients were randomized either to a training group inspiring for 30 min daily at 30% of maximum inspiratory mouth pressure, or to a control group of 'sham' training at 15% of maximum inspiratory mouth pressure. Sixteen of the 18 patients completed the study. Maximum inspiratory mouth pressure improved significantly in the training group compared with controls, by a mean (SD) of 25.4 (11.2) cmH2O (P=0.04). There were, however, no significant improvements in treadmill exercise time, corridor walk test time or quality of life scores in the trained group compared with controls. CONCLUSION: Despite achieving a significant increase in inspiratory muscle strength, this trial of simple domiciliary inspiratory muscle training using threshold loading at 30% of maximum inspiratory mouth pressure did not result in significant improvements in exercise tolerance or quality of life in patients with chronic heart failure.  相似文献   

13.
Deciding whether a patient with sub-optimal mitral valve anatomy will benefit from percutaneous mitral valvotomy remains a demanding clinical problem. We assessed the ability of an established echo score applied to transoesophageal images to predict absolute increases in mitral valve area and improvement in exercise capacity. Twenty five consecutive patients undergoing routine percutaneous mitral valvotomy were studied. Changes in exercise tolerance were measured by serial cardiorespiratory treadmill exercise testing. Before the procedure, exercise duration was directly related to mitral valve area (rs = 0.44, P < 0.05). Following percutaneous mitral valvotomy there was an increase in valve area (0.9 +/- 0.2 to 1.4 +/- 0.3 cm2, P < 0.0001) and repeat exercise testing demonstrated increases in exercise duration (470 +/- 220 to 610 +/- 240 s, P < 0.001) and peak VO2 (12.6 +/- 4.2 to 15.1 +/- 4.5 ml/kg/min, P < 0.01). There was an inverse correlation between the echo score and the increase in valve area (rs = -0.52, P < 0.05) but no relationship between the echo score and the increase in exercise duration or peak minute oxygen consumption (VO2). These data demonstrate that a score applied to transoesophageal images echocardiographic images can predict changes in mitral valve area but that the score fails to predict functional improvement for an individual patient. This suggests, therefore, that patients without contraindications to valvotomy whose valves have a high echo score should still be considered for valvotomy as they may benefit considerably from the procedure.  相似文献   

14.
Simultaneous activity of agonist and antagonistic muscles during a task is known as cocontraction. The primary aim of the present study was to use a cocontraction index (CI) to quantify differences in EMG activity between a group of CP and control children at two different walking speeds. The secondary aim was to compare the amount of time the muscles were activated ("on" thresholds) between the groups. Seventeen subjects volunteered for the study. One group consisted of 9 (7M, 2F) children with CP (age 12.7 +/- 2.8 years, mean +/- SD). The second group consisted of 8 able-bodied controls (7M, 1F). The discontinuous submaximal treadmill walking protocol had two 4min stages at 0% gradient. Speeds selected were 3 km.h-1 and 90% of the pre-determined fastest walking speed (FWS). Two sites of CI were measured from the EMGs of tibialis anterior and soleus (leg) and vastus lateralis and hamstrings (thigh). Significantly (p < 0.05) higher CI values were noted for the CP subjects compared to the controls, irrespective of speed or cocontraction site and there was a significant (p < 0.05) increase in CI values with increased walking speed for both CP and control subjects. Phasic analyses for 5% max EMG and 10% max EMG "on" thresholds demonstrated significant (p < 0.05) main effects for group (CP subjects had a longer time period of muscle activation than controls) and speed (muscles were active longer at 90% FWS than 3 km.h-1). The precise mechanisms by which cocontraction contributes toward abnormal gait and wasted mechanical energy require further research incorporating both electromyographic and kinematic analysis.  相似文献   

15.
The purposes of this study were 1) to investigate glucose tolerance and insulin action immediately after exercise and 2) to determine how long the improved glucose homeostatic mechanisms observed 12-16 h after exercise persist. Nine (seven men, two women) moderately trained middle-aged (51 +/- 3 yr) subjects performed 45 min of exercise at 73 +/- 2% of peak O2 uptake for 5 days, followed by 7 days of inactivity. Oral glucose tolerance tests (OGTT; 75 g) were performed immediately postexercise (IPE; approximately 30 min) after the final exercise bout and 1, 3, 5, and 7 days after exercise. The incremental area under the plasma glucose curve was markedly higher IPE (355 +/- 82 mM.min) compared with those on days 1 (136 +/- 57 mM.min; P < 0.05) and 3 (173 +/- 62 mM.min; P < 0.05). The glucose area was significantly higher on days 5 (213 +/- 80 mM.min) and 7 (225 +/- 84 mM.min) compared with those on days 1 and 3 (P < 0.05). The incremental insulin area IPE (3,729 +/- 1,104 microU.ml-1.min) was 43% higher compared with that on day 1 (2,603 +/- 635 microU.ml-1.min; P < 0.05) and 66% higher compared with that on day 3 (2,240 +/- 517 microU.ml-1.min; P < 0.05). The insulin area increased to 3,616 +/- 617 microU.ml-1.min after 5 days of inactivity (P < 0.05). An additional 48 h of inactivity did not result in any further increase in the plasma insulin response.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

16.
beta-blocker therapy for mitral stenosis is controversial. This study compares right and left heart hemodynamics at rest and supine submaximal exercise in patients (n = 7) receiving chronic beta-antagonists with untreated patients (n = 17) matched for age (mean +/- SD = 51 +/- 12 years) and valve area (0.7 +/- 0.2 cm2/m2). Little benefit was observed with treatment at rest. Although pulmonary capillary wedge pressures (PCWP) were lower during exercise in the beta-blocker group (22 +/- 4 vs. 31 +/- 9 mmHg; P < 0.05), exercise performance was not enhanced and cardiac output response during exercise was reduced (control = 41% increase vs. 12% for beta-blockade). PCWP rose rapidly when diastolic filling periods were < 300 msec in both groups. Pulmonary capillary wedge pressure was found to be a nonlinear functions (P < 0.001) of diastolic filling period (PCWP = 15.9 + 5.84 x 10(5)/dfp2). These data suggest that there is a critical heart rate in patients with mitral stenosis above which hemodynamic compromise rapidly occurs.  相似文献   

17.
STUDY DESIGN: Eighteen-month, randomized controlled trial with partial crossover. OBJECTIVES: To test the hypothesis that the control of lumbar flexion in the early morning will significantly reduce chronic, nonspecific low back pain. SUMMARY OF BACKGROUND DATA: Previous studies have indicated an increased risk of low back pain with bending forward in the early morning, primarily because of increased fluid content in the intervertebral discs at that time. METHODS: After 6 months of recording baseline data, 85 subjects with persistent or recurring low back pain were randomly assigned to treatment and control groups. The treatment group received instruction in the control of early morning lumbar flexion. The control group received a sham treatment of six exercises shown to be ineffective in reducing low back pain. Six months later, the control group received the experimental treatment, Diaries were used to record daily levels of pain intensity, disability, impairment, and medication usage. RESULTS: Significant reductions in pain intensity (P < 0.01) were recorded for the treatment group, but not for the control group (point estimate, 33%; 95% confidence interval, 11-55%). After receiving the experimental treatment, the control group responded with similar reductions (P < 0.05). Significant reductions also were observed in total days in pain, disability, impairment, and medication usage. CONCLUSIONS: Controlling lumbar flexion in the early morning is a form of self-care with potential for reducing pain and costs associated with chronic, nonspecific low back pain.  相似文献   

18.
The effect of gender on left ventricular systolic function and exercise haemodynamics in healthy young subjects was studied during 30-s all-out sudden strenuous dynamic exercise. A group of 22 men [19.3 (SD 1) years] 20 women [19.1 (SD 1) years] volunteered to participate in this study. Two-dimensional direct M-mode and Doppler echocardiograph studies were performed with the subject in the sitting position. The Doppler examination of flow was located with continuous-wave, interrogating ascending aorta measurements. The subjects completed the study without showing any electrocardiograph abnormalities. An interaction effect with stroke volume (P < 0.05) was characterized by a decrease in the men and an increase of stroke volume in the women. Cardiac output rose significantly (P < 0.05) up to 14.5 (SD 6) 1.min-1) for the men and 12.1 (SD 4) 1.min-1 for the women compared to the rest values [5.8 (SD 0.4) and 4.7 (SD 0.5) 1.min-1, respectively]. Flow velocity integral and acceleration time differed significantly between the two groups at rest (P < 0.05). During exercise these differences showed an interaction effect (P < 0.05). These results would indicate that normal men and women respond to sudden strenuous exercise by reducing their left ventricular systolic function, with a significantly greater decrease in women (P < 0.05). The gender differences in the haemodynamic responses during the present study, may, as suggested by others, be attributable to differences in energy metabolism. In addition, changes in Doppler parameters of aortic flow, haemodynamics and blood pressure responses during sudden strenuous exercise differed markedly from those seen before with endurance exercise.  相似文献   

19.
1. We investigated the effect of exercise on plasma adrenomedullin, atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) concentrations and studied the relationship between these peptides and haemodynamic parameters in nine patients with old myocardial infarction (MI) and in eight normal subjects. 2. The exercise protocol consisted of two fixed work loads (40 and 80 W) for 4 min each and venous blood samples were taken at rest, during each exercise stage and after exercise while monitoring the mean arterial pressure (MAP) and heart rate (HR). In MI, pulmonary arterial pressure (PAP), pulmonary capillary wedge pressure (PCWP), left ventricular end-diastolic pressure (LVEDP) and cardiac output (CO) were measured throughout exercise. 3. Adrenomedullin levels did not significantly increase with exercise. Adrenomedullin levels correlated with PAP and PCWP at rest (P < 0.05). Atrial natriuretic peptide levels correlated with PAP, PCWP and LVEDP throughout exercise (P < 0.05) but, on multiple regression analysis, PCWP correlated only with ANP (P < 0.01). Brain natriuretic peptide levels correlated with LVEDP throughout exercise (P < 0.01) and its increment correlated closely with basal BNP levels at rest (P < 0.01). 4. These results suggest that adrenomedullin does not respond to the acute haemodynamic changes of exercise, whereas ANP responds to it and PCWP is the major stimulus factor. Brain natriuretic peptide responds to exercise in proportion to the basal synthesis of BNP in patients with left ventricular dysfunction and LVEDP may play a role in increasing BNP during exercise.  相似文献   

20.
We examined the ability of patients with spinal cord injury to undergo adaptations to chronic exercise training (cycle ergometry) invoked by functional electrical stimulation (FES) of the legs. Nine such patients performed incremental and constant work rate exercise before and after exercise training. Exercise sessions averaged 2.1 +/- 0.4/wk, and consisted of 30 min/session of continuous FES recumbent cycling with increasing work rate as tolerated. Peak VO2 and peak work rate significantly improved with training. Peak VO2 was significantly correlated with peak heart rate both before and after training (r = 0.97 pre and 0.85 post, P < 0.01 for both). The time course of the VO2, VCO2 and VE responses to constant-load exercise (unloaded cycling) and in recovery (mean response time MRT) were very long prior to training, and became significantly faster following training. However, there was no correlation between percentage improvement in either MRTon or MRToff for VO2 and the percentage increase in peak VO2. Exercise tolerance in these patients with spinal cord injury appears to be a direct function of the ability to increase heart rate. Further, exercise training can elicit significant improvements in both exercise tolerance and in gas exchange kinetics, even when performed only twice per week. However, these improvements may be accomplished by different mechanisms.  相似文献   

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