Skeletal muscle effects of electrostimulation after COPD exacerbation: a pilot study.

Muscle dysfunction is a major problem in chronic obstructive pulmonary disease (COPD), particularly after exacerbations. We thus asked whether neuromuscular electrostimulation (NMES) might be directly useful following an acute exacerbation and if such a therapy decreases muscular oxidative stress and/or alters muscle fibre distribution. A pilot randomised controlled study of NMES lasting 6 weeks was carried out in 15 in-patients (n=9 NMES; n=6 sham) following a COPD exacerbation. Stimulation was delivered to the quadriceps and hamstring muscles (35 Hz). Primary outcomes were quadriceps force and muscle oxidative stress. At the end of the study, quadriceps force improvement was statistically different between groups (p=0.02), with a significant increase only in the NMES group (median (interquartile range) 10 (4.7-11.5) kg; p=0.01). Changes in the 6-min walking distance were statistically different between groups (p=0.008), with a significant increase in the NMES group (165 (125-203) m; p=0.003). NMES did not lead to higher muscle oxidative stress, as indicated by the decrease in total protein carbonylation (p=0.02) and myosin heavy chain carbonylation (p=0.01) levels. Finally, we observed a significant increase in type I fibre proportion in the NMES group. Our study shows that following COPD exacerbation, NMES is effective in counteracting muscle dysfunction and decreases muscle oxidative stress.

[Pulmonary rehabilitation, a historical perspective from Hippocrates to tele-rehabilitation]. / La réadaptation respiratoire, une perspective historique: d'Hippocrate à la télé-réadaptation.

In ancient times Hippocrates described a disease, the 3rd phthisis, which seems to correspond to COPD and is mainly treated by walking, gradually increasing the number of steps until reaching 10,000 steps a day at the end of the initial period of treatment. The recent era began in the second half of the 20th century and ended in 2015, with an unusual Cochrane Library editorial in which it was stated that the accumulated evidence (statistically significant and clinically relevant improvements in clinical signs, tolerance to exercise, quality of life, days hospitalization…) on the effects of rehabilitation programs suffice to suspend research on the subject and to justify focus on new elements in the programs. It is essential, in fact, to establish uniform practical recommendations for the prescription of routine rehabilitation (number and duration of physical activity sessions, therapeutic education, re-training intensity…). In addition, studies should be carried out on new practices: community or home rehabilitation, long-term rehabilitation, tele-rehabilitation.

[Applicability of the Arabic version of the French quality of life' (QOL) questionnaire (VQ11) in Tunisian patients with chronic obstructive pulmonary disease]. / Évaluation de la version arabe du questionnaire français de qualité de vie « VQ11 ¼ chez des patients tunisiens atteints de bronchopneumopathie chronique obstructive.

BACKGROUND: There is no validated Arabic version of the French questionnaire of quality of life, the VQ11. This study aimed to test the applicability of the Arabic version of the VQ11 in Tunisian patients with chronic obstructive pulmonary disease (COPD). METHODS: It was a prospective and cross-sectional study, spread over seven months, that included 40 stable COPD male patients. The Arabic version of VQ11, translated by a bilingual expert, was used. The functional, psychological, relational and total scores were calculated. Patients were divided into two groups according to the GOLD classification: "A-B" (n=25) and "C-D" (n=15). A significant correlation-coefficient (r) of≥0.51, between the VQ11 total score and the ADO index (age, dyspnoea, obstruction), and higher quality of life scores in GOLD "C-D" when compared to GOLD "A-B" would be in favour of application of the Arabic version of the VQ11. RESULTS: The mean±standard deviation of age, post-bronchodilator FEV1/FVC, ADO index and VQ11 total score were 64±8 years, 0.55±0.08, 4.8±1.7 and 2±10, respectively. A significant "r" (0.56) was identified between the ADO index and the total score. Psychological, relational and total scores of GOLD "A-B" patients were significantly lower than those in GOLD "C-D" patients: 10±4 vs. 12±3, 11±4 vs. 13±3 and 30±11 vs. 36±7, respectively. CONCLUSION: The Arabic version of VQ11 is applicable in Tunisian COPD patients with reliable results.

[Spirometric profile of narghile smokers]. / Profil spirométrique des fumeurs de narguilé

INTRODUCTION: Studies of the spirometric profile of narghile smokers are few, have some methodologic limits (ie. small sample size) and present contradictory conclusions. OBJECTIVE: (i) To determine the percentage of smokers having an obstructive ventilatory defect (OVD) and/or a restrictive ventilatory defect (RVD) or static hyperinflation (SHI). (ii) To compare the chronological and the estimated lung ages. INCLUSION CRITERIA: men aged 20-60 years smoking narghile (>1 narghile-year (NA). Non-inclusion criteria: cigar or cigarettes smoker and co-morbidity. Narghile consummation quantification: NA and kg of cumulated tobacco (1 NA=9.125 kg of cumulated tobacco). DEFINITIONS: large airway OVD: FEV1/FVCLLN and forced mid expiratory flowupper limit of normal. Spirometric measures (Vmax 22 Series/6200 Autobox, Yorba Linda, California, USA with measurement of functional residual capacity by nitrogen washout). Measurements were made according to international recommendations. RESULTS: 110 narghile smokers were included (34+/-10Yr; 1.76+/-0.07m; 84+/-14kg). 36% of subjects had SHI; 14% had small airway OVD; 14% had RVD and 6% had large airway OVD. (ii) Estimated lung age was higher than the chronological lung age (47+/-18Yr vs 34+/-10Yr, p<0.05). CONCLUSION: Narghile consumption accelerates ageing of the lung. This study provides the health authorities with valid arguments to fight this blight on society which increasingly involves children and pregnant women.

Cost-sparing effect of twice-weekly targeted endurance training in type 2 diabetics: a one-year controlled randomized trial.

OBJECTIVE: We evaluated the effects of targeted, moderate endurance training on healthcare cost, body composition and fitness in type 2 diabetes patients routinely followed within the French healthcare system. DESIGN AND METHODS: A total of 25 type 2 diabetic patients was randomly assigned to one of two groups: 13 underwent a training programme (eight sessions, followed by training twice a week for 30-45 minutes at home at the level of the ventilatory threshold [V(T)]); and 12 received their usual routine treatment. Both groups were followed for one year to evaluate healthcare costs, exercise effectiveness and a six-minute walking test. RESULTS: The training prevented loss of maximum aerobic capacity, which decreased slightly in the untrained group (P=0.014), and resulted in a higher maximum power output (P=0.041) and six-minute walking distance (P=0.020). The Voorrips activity score correlated with both V(O2max) (r=0.422, P<0.05) and six-minute walking distance (r=0.446, P<0.05). Changes in V(O2max) were negatively correlated with changes in body weight (r=0.608, P<0.01). Training decreased the insulin-resistance index (HOMA-IR) by 26% (P<0.05). Changes in percentages of fat were correlated to changes in waist circumference (r=0.436, P<0.05). The total healthcare cost was reduced by 50% in the trained group (euro 1.65+/-1 per day versus euro 3.00+/-1.47 per day in the untrained group; P<0.02) due to fewer hospitalizations (P=0.05) and less use of sulphonylureas (P<0.05). CONCLUSION: Endurance training at V(T) level prevented the decline in aerobic working capacity seen in untrained diabetics over the study period, and resulted in a marked reduction in healthcare costs due to less treatments and fewer hospitalizations.

An innovative maintenance follow-up program after a first inpatient pulmonary rehabilitation.

Although the benefits of pulmonary rehabilitation (PR) have been demonstrated in patients with COPD, most studies suggest that short-term programs are insufficient to maintain the benefits beyond a post-discharge period of 6 months to 1 year. We were interested to evaluate the effects of an innovative maintenance intervention compared with a usual after-care. Forty moderate to severe COPD patients, who had just completed their first inpatient PR, were consecutively included in either a maintenance group (MG) or a standard after-care group. The maintenance program was coordinated within a health-care network including self-help associations, and offered weekly activities. We measured the 6-min walk distance (6MWD), the quality of life using the St George Respiratory Questionnaire (SGRQ), the dyspnea, the maximal workload and the health-care utilization. Data were collected at respiratory clinic admission and discharge, and at 6- and 12-month visits after the PR. After 12 months, we found statistically and clinically significant differences in favor of the MG in 6MWD (74 m; p < or = 0.01) and in the three domains of SGRQ: symptom (19%; p < or = 0.01), activity (27%; p < or = 0.01) and impact (32%; p < or = 0.01). The results showed no difference between groups in dyspnea and maximal workload. We also found that the number of days spent in hospital for respiratory disorders was significantly lower in the MG after 12 months (p < or = 0.03). The multidisciplinary management of COPD patients in the post-rehabilitation period within a health-care network including self-help associations seems to be an effective strategy for maintaining, and even improving, the benefits of a first initial structured program.

Is impairment similar between arm and leg cranking exercise in COPD patients?

UNLABELLED: Impaired skeletal muscle function has been reported in patients with chronic obstructive disease (COPD), but such impairment is not homogenous and its distribution between the upper and the lower limbs is still unclear. The present study was designed to assess and compare upper and lower limb capacities in patients with moderate to severe COPD during incremental and constant-load exercises. Thirteen COPD patients of similar age with moderate to severe air flow limitation (FEV(1): 35%+/-5% predicted) and 19 healthy subjects were studied. Four sessions were organized: two incremental and two constant-load cycling exercises with arm or leg in randomized order. As observed in a previous study involving incremental and constant tests, power, VO(2), RER, VE, and HR were all significantly lower in the upper and lower limbs of patients with COPD than in healthy controls. In the healthy population, aerobic capacity and mechanical efficiency (ME) were lower in the course of arm exercises than in leg exercises. For the same relative workload, dyspnea and blood lactate production were higher during arm exercise. In contrast, no significant difference was observed between arm and leg capacities for any of these parameters in COPD patients. CONCLUSION: Although aerobic capacity is impaired in COPD patients, arm aerobic capacity is relatively preserved. Given the lack of significant difference between arm and leg capacities in COPD, we hypothesize that upper limb muscles are less compromised than lower limb muscles in this patient population.

[What are the post-rehabilitation options for patients with COPD?]. / Quelles solutions pour l'après-réhabilitation des patients BPCO?

INTRODUCTION: The efficacy of pulmonary rehabilitation in the short term for patients with Chronic Obstructive Pulmonary Disease (COPD) is now clearly established. However, several studies have shown that these benefits last only for between 6 months to one year. On the basis of the current literature, the authors believe that a follow-up of rehabilitation "post-rehabilitation" is necessary not only to maintain benefits but also to reinforce them. STATE OF THE ART: We review studies that have focused specifically on post-rehabilitation and found a heterogeneity of tested solutions. As with conventional pulmonary rehabilitation, a multidisciplinary approach including physical activity, health education and psychosocial supports seem to be the key to successfully maintain rehabilitation's gains. PERSPECTIVES: Further randomised and controlled research will be needed to confirm the medical and economic effectiveness of this combination of intervention in patients with different severities of COPD. CONCLUSION: Individualised, objective and coordinated follow-up activities allow COPD patients to cope with the chronicity of their disease and the unpredictability of symptoms in the context of daily life.

[Incidence of individualized training on exercise-induced desaturation in COPD patients]. / Effets d'un réentraînement individualisé sur la désaturation à l'exercice des sujets atteints de BPCO.

BACKGROUND: Exercise-induced desaturation is a well-described phenomenon in COPD patients during exercise assessments such as the six minute walk test (6MWT). Some of the pathophysiological mechanisms involved in this O2 desaturation could be modified by individualized exercise training as part of a pulmonary rehabilitation programme. The aim of this study was to determine the effect of pulmonary rehabilitation on O2 desaturation exhibited by COPD patients during a 6MWT. METHODS: Twenty COPD patients (FEV1=61.1 +/- 3.2% predicted) who exhibited O2 desaturation before rehabilitation (mean 7.3 +/- 0.7% with a mean duration of 5.3 +/- 0.1 min) participated. They performed four weeks of RP including individualized whole-body exercise training achieving a mean 9.3 +/- 0.27 hours per week of exercise tailored to their ventilatory threshold. RESULTS: Dyspnoea at the end of the test, ventilatory threshold and FEV1 were retained as correlates of desaturation before rehabilitation. After rehabilitation, 6MWT distance increased (p<0.01) with reduced dyspnoea (p<0.05). Two sub-groups were identified: persistent desaturaters (DS, n=13) and non-desaturaters group (NDS, n=7). There were no baseline differences between the two groups. After rehabilitation only the persistent desaturaters showed a significant increase in distance achieved during 6MWT associated with a reduced dyspnea (p<0.05). This group showed a mean O2 desaturation equal to 8.1 +/- 0.9% which persisted to 5 +/- 0.3 min. A tendency to a lower dyspnoea at the end of 6MWT performed before rehabilitation was observed in NDS compared with DS (p<0.058). CONCLUSION: It seems that responses to a pulmonary rehabilitation programme including individualized exercise training could act on O2 desaturation. Indeed 7 of 20 (35%) COPD patients exhibiting O2 desaturation during a 6MWT showed no O2 desaturation after rehabilitation programme while 13 on 20 (65%) do it.

Postoperative exercise tolerance after aortic valve replacement by small-size prosthesis: functional consequence of small-size aortic prosthesis.

OBJECTIVES: The objective of this study was to determine whether a small-size valve prosthesis contributes to exercise intolerance, as assessed by VO2 measurement during an exhaustive cycle ergometer exercise. BACKGROUND: The determinants of exercise capacity after mechanical aortic replacement are not well known. The selection of small valve sizes has, however, been described as an independent predictor of exercise intolerance as assessed by exercise duration. Maximal oxygen uptake (VO2max) is a good index of exercise tolerance. METHODS: Fourteen patients were eligible, with a mean age of 62 +/- 6 years. Before surgery, the mean left ventricular ejection fraction (LVEF) was 73 +/- 8%. Two valve types with small diameter (19 to 21 mm) were used: Medtronic Hall and St Jude Medical. A healthy sedentary control group (n = 14) paired for age, weight and size was constituted. After one year of follow-up, cardiorespiratory tests were performed. In addition, the gradients through the prostheses were determined by continuous pulse Doppler at rest and immediately after the cardiorespiratory test. RESULTS The exercise tolerance was not significantly different between the control group and patient group: VO2 peak (21.7 vs. 20.4 ml/kg/min; p = 0.42), workloads (115 vs. 93 W; p = 0.13) and ventilatory parameters were similar. The mean and peak gradients at rest and during exercise were not correlated with VO2max. CONCLUSIONS: Valve replacement by small aortic prosthesis does not seem to be a factor of exercise intolerance as assessed by VO2max in patients without LVEF dysfunction before surgery.

Effect of endurance training on lung function: a one year study.

OBJECTIVE: To identify in a follow up study airway changes occurring during the course of a sport season in healthy endurance athletes training in a Mediterranean region. METHODS: Respiratory pattern and function were analysed in 13 healthy endurance trained athletes, either during a maximal exercise test, or at rest and during recovery through respiratory manoeuvres (spirometry and closing volume tests). The exercise test was conducted on three different occasions: during basic endurance training and then during the precompetition and competitive periods. RESULTS: During the competitive period, a slight but non-clinically significant decrease was found in forced vital capacity (-3.5%, p = 0.0001) and an increase in slope of phase III (+25%, p = 0.0029), both at rest and after exercise. No concomitant reduction in expiratory flow rates was noticed. During maximal exercise there was a tachypnoeic shift over the course of the year (mean (SEM) breathing frequency and tidal volume were respectively 50 (2) cycles/min and 3.13 (0.09) litres during basic endurance training v 55 (3) cycles/min and 2.98 (0.10) litres during the competitive period; p < 0.05). CONCLUSIONS: This study does not provide significant evidence of lung function impairment in healthy Mediterranean athletes after one year of endurance training.

[Home-based exercise training and physical activity level over one year in COPD patients]. / Réentraînement à l'effort à domicile et niveau d'activité physique à un an chez les patients BPCO.

INTRODUCTION: The aim of our study was to investigate whether exclusive home-based training was feasible and effective in COPD patients and if patients have a persistent improvement in their level of physical activity after this intervention. METHODS: One hundred COPD patients (FEV1=42.6% predicted) first underwent 25 weekly sessions of supervised cycle ergometry training, followed by one year of monthly supervised follow-up. Six minutes walking test, endurance test, BODE index and activity monitoring were performed before, after and one year after inclusion. RESULTS: About 80% of the patients completed the program. They improved their exercise tolerance and their daily physical activity level, even one year after inclusion. However, more severe patients did not maintain these benefits. Daily physical activity quantity was also decreased in these patients one year after inclusion. CONCLUSION: This home-based exercise training program is feasible and effective. Improvements are sustainable for the majority of patients. However, severe patients were not able to maintain these benefits. Other exercise training strategies may have to be considered in these patients.

Antioxidants and mitochondrial respiration in lung, diaphragm, and locomotor muscles: effect of exercise.

Previous studies have shown that exhaustive exercise may increase reactive oxygen species (ROS) generation in oxidative muscles that may in turn impair mitochondrial respiration. Locomotor muscles have been extensively examined, but there is few report about diaphragm or lung. The later is a privileged site for oxygen transit. To compare the antioxidant defense system and mitochondrial function in lung, diaphragm and locomotor muscles after exercise, 24 young adult male rats were randomly assigned to a control (C) or exercise (E) group. E group rats performed an exhaustive running test on a motorized treadmill at 80-85% VO2max Mean exercise duration was 66+/-2.7 min. Lung, costal diaphragm, mixed gastrocnemius, and oxidative muscles (red gastrocnemius and soleus: RG/SOL homogenate) were sampled. Mitochondrial respiration was assessed in tissue homogenates by respiratory control index (RCI: rate of uncoupled respiration/rate of basal respiration) measurement. Lipid peroxidation was evaluated by malondialdehyde concentration (MDA) and we determined the activity of two antioxidant enzymes: superoxide dismutase (SOD) and glutathione peroxidase (GPX). We found elevated basal (C group data) SOD and GPX activities in both lung and diaphragm compared to locomotor muscles (p<.001). Exercise led to a rise in GPX activity in red locomotor muscles homogenate (GR/SOL; C = 10.3+/-0.29 and E = 14.4+/-1.51 micromol x min(-1) x gww(-1); p<.05), whereas there was no significant change in lung and diaphragm. MDA concentration and mitochondrial RCI values were not significantly changed after exercise. We conclude that lung and diaphragm had higher antioxidant protection than locomotor muscles. The exercise test did not lead to significant oxidative stress or alteration in mitochondrial respiration, suggesting that antioxidant function was adequate in both lung and diaphragm in the experimental condition.

A standardized method for the evaluation of respiratory muscle endurance in patients with Duchenne muscular dystrophy.

The aim of the study was to develop a standardized method using controlled breathing to quantify respiratory muscle endurance in children with Duchenne muscular dystrophy (DMD) and to test its reproducibility. In 10 DMD patients, all between 10 and 14 years (mean age, 11.5 +/- 1.5 years), except for two patients of 20 and 22 years, and 10 healthy children (mean age, 12 +/- 1 years), we measured the maximal time (Tlim) that a threshold load fixed at 35% of the individual maximal inspiratory pressure (Pimax) could be tolerated. We asked the children to maintain their rest breathing pattern until exhaustion using visual feedback and an auditory signal. The mean Tlim in the DMD children was 4.45 +/- 1.45 min and values were reproducible. All healthy children were able to obtain Tlim values greater than 30 min. The respiratory muscles of DMD children are more susceptible to fatigue than those of healthy subjects. This method should be satisfactory for estimating the effect of treatment and for the specific training of respiratory muscles in DMD patients without significant learning disability.

Diaphragm kinetics during pneumatic belt respiratory assistance: a sonographic study in Duchenne muscular dystrophy.

The principal aim of this study was to demonstrate the usefulness of M-mode sonography as a noninvasive technique to evaluate diaphragm excursion. The secondary aim was to assess the efficacy of pneumatic abdomino-diaphragmatic belt ventilation in patients with Duchenne muscular dystrophy. Using M-mode sonography, we measured the amplitude of diaphragm excursion in seven patients with Duchenne muscular dystrophy in various positions (0 degrees, 45 degrees, 75 degrees ) with and without pneumatic abdomino-diaphragmatic belt respiratory assistance. The belt significantly increased mean amplitude of diaphragm excursion by 62% at 45 degrees and by 55% at 75 degrees, and increased mean tidal volume by 43.5% at 45 degrees and by 49% at 75 degrees. Two patients were unable to tolerate the horizontal position (0 degrees ) During quiet breathing without the belt, amplitude of diaphragm excursion and tidal volume were positively correlated at 45 degrees (r=0.81; P=0.027) and 75 degrees (r=0.75; P=0.05). There was a significant intra-individual correlation between these two parameters during belt use but no inter-individual correlation. Without the belt, thoracic posture had no significant effect on amplitude of diaphragm excursion, either in quiet or deep breathing. After overnight respiratory assistance, arterial oxygen pressure and arterial oxygen saturation increased significantly, and arterial carbon dioxide pressure decreased from 52+/-6.4 to 46.4+/-4 mmHg. The pneumatic abdomino-diaphragmatic belt significantly improved gas exchanges and ventilation by increasing diaphragm excursion, as was clearly shown by noninvasive M-mode sonography. Indeed, M-mode sonography may be helpful in pneumatic abdomino-diaphragmatic belt pressure adjustment.

Impaired skeletal muscle endurance related to physical inactivity and altered lung function in COPD patients.

STUDY OBJECTIVE: The aims of this work were to determine (1) whether patients with COPD have impaired skeletal muscle performance (ie, maximal strength and endurance) compared with healthy subjects, and (2) whether the level of physical activity, body composition, and lung function are related to skeletal muscle performance in COPD patients. METHODS: Seventeen COPD patients and eight healthy age-matched control subjects performed maximum voluntary contraction (MVC) of the quadriceps and an endurance test consisting of dynamic contractions of the quadriceps against 20% of MVC at an imposed regular pace until exhaustion. The endurance test duration determined the muscle "limit time" (Tlim). A score of physical activity (PA score) was obtained using an adapted physical activity questionnaire for the elderly, and body composition was measured by the bioelectrical impedance method. Symptom-limited oxygen uptake (VO2 sl) was also assessed in COPD patients using a maximal incremental exercise test. RESULTS: The results showed that Tlim and PA score were significantly decreased in COPD patients (p<0.05). Significant positive correlations were found in the COPD group between Tlim and the PA score (r=0.60; p<0.05), FEV1 (r=0.52; p<0.05), and PaO2 (r=0.63; p<0.05). The same results were found between the PA score and VO2 sl (r=0.57; p<0.05) and FEV1 (r=0.63; p<0.05). CONCLUSION: These findings indicate impaired skeletal muscle endurance in COPD patients related to altered lung function and associated physical inactivity.

Cardiorespiratory fitness evaluation by the shuttle test in asthmatic subjects during aerobic training.

PURPOSE: The purpose of this study was to assess the validity of the 20-m shuttle test with 1-min stages (20-MST) to estimate maximal oxygen uptake (VO2 max) and its ability to register cardiorespiratory modifications over the course of an individualized aerobic training program for mild to moderately asthmatic children acclimatized to moderate altitude. METHODS: Forty-eight asthmatic subjects aged 12 to 17 years performed both a maximal incremental exercise test on a cycle ergometer and the 20-MST. Ten of the subjects were then randomly chosen and trained three times per week at their ventilatory threshold (Vth) intensity level for three months. Another group of ten asthmatic subjects served as control subjects. Training intensity was adjusted monthly; heart rate values at Vth were increased by the same proportion as the increase in Vo2 max as measured by the 20-MST. At the end of training, both groups were again evaluated with the two tests. The Vo2 max values by direct measurement and by the 20-MST were not significantly different for the entire population (46.5 +/- 1.6 vs 47.2 +/- 2.1 ml.min-1.kg-1). In addition, the two test results were in close agreement (r = 0.84; p < 0.01). After training, a sharp improvement in the direct Vo2 max (44.1 +/- 2.4 to 51.2 +/- 1.9 ml.min-1.kg-1) was noted in the training group as well as an increase in the Vth (25.6 +/- 1.9 to 32.1 +/- 3.4 ml.min-1.kg-1), the maximal power (152 +/- 7.1 to 185 +/- 3.8 W), and the maximal oxygen pulse (0.24 +/- 0.007 to 0.27 +/- 0.008 ml.beat-1.kg-1). CONCLUSION: The indirect measure confirmed these results: a simultaneous increase in VO2 max (43.7 +/- 2.5 to 53.8 +/- 2.1 ml.min-1.kg-1), maximal oxygen pulse (0.22 +/- 0.004 to 0.27 +/- 0.006 ml.beat-1.kg-1), and the number of stages completed (7 +/- 1.4 to 10.1 +/- 1.3) was observed. It was concluded that the 20-MST has sufficient validity to assess VO2 max and to register cardiorespiratory modifications over the course of individualized aerobic training programs in mild and moderately asthmatic children. It thus may be used to adjust training intensities during these programs.

Cardiopulmonary exercise testing. Determinants of dyspnea due to cardiac or pulmonary limitation.

The aim of this study was to bring to light new and simple criteria, obtained during cardiopulmonary exercise testing, in order to demonstrate in patients the cardiac or the pulmonary origin of a comparable exertional dyspnea. Forty male subjects were compared, who exercised with a 30-W/3-min protocol and were divided into three groups: the cardiac heart failure (CHF) group (n = 15), the chronic obstructive lung disease (COLD) group (n = 15), and the control group (n = 10). The two groups of patients differed totally from the control group concerning their spirometric values at rest and a clear inability during effort which was confirmed by all the studied cardiopulmonary parameters at maximal exercise. The CHF and COLD groups differed slightly concerning their maximum symptom-limited oxygen uptake, only when related to body mass (13.26 +/- 0.69 ml/kg/min in CHF group, 17.05 +/- 1.59 ml/kg/min in COLD group; p < 0.05), and concerning their maximum ventilatory equivalent for oxygen which tended to be higher in the CHF group in comparison with the COLD group (p = 0.082). Furthermore, and as foreseen, the two groups of patients clearly differed at maximum exercise concerning the ventilatory reserve respiratory parameter (49.73 +/- 3.18 percent in CHF group, 8.38 +/- 5.85 percent in COLD group; p < 0.01). On the other hand, they did not differ concerning cardiac parameters or those considered as such (maximum heart rate [HR], HR reserve, HR response, maximum O2 pulse measurement). While their maximum ventilation was similar in the CHF and COLD groups, a difference in adaptation during exercise was found by observing their breathing pattern. In the CHF group, this was demonstrated by a significantly lower breathing frequency at maximum exercise (31.24 +/- 1.53 beats/min vs 37.75 +/- 2.24 beats/min; p < 0.05) and a tidal volume that tended to be higher at maximum exercise (p = 0.077) and significantly higher at 60-W work load (p < 0.05). This work shows that the study of ventilatory reserve and breathing pattern during exercise testing allows one to discriminate if dyspnea on exertion in patients is due to cardiac or respiratory disease.

Individualized aerobic and high intensity training for asthmatic children in an exercise readaptation program. Is training always helpful for better adaptation to exercise?

In order to define the role of individualized training intensity in a conditioning program for asthmatic children, we have trained seven asthmatics (age = 11.4 +/- 1.8 years) at their ventilatory threshold (VTh) intensity level for a three-month period (aerobic training) and at maximal intensity also for three months (high intensity training). VTh is the point at which a nonlinear increase of VE occurs. Another group of seven asthmatics (age = 11.4 +/- 1.5) served as control subjects. Cardiopulmonary fitness was determined on a cycle ergometer before and after each training session. This study demonstrated that aerobic training, correctly adapted to the child's physical ability, induces the following: (1) a rapid and marked cardiovascular fitness increase; and (2) a decrease in VE over a given work range so that VTh is increased. This is of great importance because hyperventilation is a major determinant of exercise-induced bronchospasm. In contrast, even if high intensity training is well tolerated in an indoor swimming pool, the long-term effects are unsuitable for asthmatic children because the decrease of VTh will involve an increase of hyperventilation, even when exercise is performed at submaximal intensity.

High-resolution CT scan in the evaluation of exercise-induced interstitial pulmonary edema in cardiac patients.

OBJECTIVE: To evaluate the onset of exercise-induced interstitial pulmonary edema in cardiac patients by high-resolution CT (HRCT). DESIGN: Prospective, normal controlled. PARTICIPANTS: Thirty subjects divided into three groups: group 1--10 outpatients with chronic congestive heart failure (CCHF), New York Heart Association (NYHA) class I; group 2--10 outpatients with CCHF, NYHA class II/III; and group 3 (control)--10 normal subjects. METHOD: HRCT scans were obtained at rest and 4, 8, 12, 16, and 20 min after progressive treadmill exercise test. RESULTS: The following HRCT findings consistent with interstitial edema were significantly different (p<0.05) in group 2 when compared with groups 1 and 3: artery/bronchus ratio > 1 in the upper lobes, peripheral increase in the vascular markings, interlobular septal thickening, and peribronchial "cuffing." These differences were maximal at 12 min after exercise and returned to normal values after 20 min. CONCLUSION: Interstitial pulmonary edema was present immediately after exercise in CCHF patients. It may be important in the genesis of dyspnea of these patients.