Respiratory Muscular Strength Research Articles

Respiratory muscular strength in children with mucopolysacaridosis: comparison with predictive equations.

Mucopolysaccharidoses (MPS) are rare metabolic diseases that impair respiratory function leading to respiratory failure. This study aimed to compare maximal inspiratory and expiratory pressures (MIP and MEP) obtained in children with MPS and compare with predicted values from previous studies involving healthy children. This is a cross-sectional study, in which the chest deformity was evaluated; MIP, MEP through digital manometer, and lung function through spirometry. MIP and MEP were compared with five different predict equations and with a control group of healthy children. Agreement between respiratory muscle weakness regarding absolute values of MIP and MEP in relation to predictive values by the equations included in the study were assessed by Kappa coefficient. MPS group was composed of 22 subjects. 45.5% had pectus carinatum, 36.4% pectus excavatum, and presented lower MIP (37.14±36.23 cmH<inf>2</inf>O) and MEP (60.09±22.3 cmH<inf>2</inf>O) compared with control group (22 healthy subjects) (MIP: 91.45±35.60; MEP: 95.73±22.38). Only the MEP equations proposed by Tomalak et al. were close to those found in our MPS children (P=0.09). In the MPS group it was observed a weak agreement between inspiratory weakness through absolute and predicted values in only two equations: Tomalak et al. and Domenèch-Clar et al. (for both: k=0.35, P value =0.03); and for MEP a moderate agreement was found using all predictive equations. In MPS children MRP data should not be normalized using the reference equations for healthy ones, is more coherent to longitudinally follow absolute pressures and lung volumes in this group.

Respiratory muscular strength in children with mucopolysacaridosis: comparison with predictive equations.

Mucopolysaccharidoses (MPS) are rare metabolic diseases that impair respiratory function leading to respiratory failure. This study aimed to compare maximal inspiratory and expiratory pressures (MIP and MEP) obtained in children with MPS and compare with predicted values from previous studies involving healthy children. This is a cross-sectional study, in which the chest deformity was evaluated; MIP, MEP through digital manometer, and lung function through spirometry. MIP and MEP were compared with five different predict equations and with a control group of healthy children. Agreement between respiratory muscle weakness regarding absolute values of MIP and MEP in relation to predictive values by the equations included in the study were assessed by Kappa coefficient. MPS group was composed of 22 subjects. 45.5% had pectus carinatum, 36.4% pectus excavatum, and presented lower MIP (37.14±36.23 cmH<inf>2</inf>O) and MEP (60.09±22.3 cmH<inf>2</inf>O) compared with control group (22 healthy subjects) (MIP: 91.45±35.60; MEP: 95.73±22.38). Only the MEP equations proposed by Tomalak et al. were close to those found in our MPS children (P=0.09). In the MPS group it was observed a weak agreement between inspiratory weakness through absolute and predicted values in only two equations: Tomalak et al. and Domenèch-Clar et al. (for both: k=0.35, P value =0.03); and for MEP a moderate agreement was found using all predictive equations. In MPS children MRP data should not be normalized using the reference equations for healthy ones, is more coherent to longitudinally follow absolute pressures and lung volumes in this group.

Accuracy of handgrip and respiratory muscle strength in identifying sarcopenia in older, community-dwelling, Brazilian women

Certain cut-off points for sarcopenia screening and diagnosis are arbitrary and based on European populations, with normative references often obtained from healthy young adults. Although respiratory skeletal muscle strength tests represent low-cost clinical measures commonly performed in clinical practice by health professionals, a gap remains regarding whether respiratory skeletal muscle strength tests are adequate and sensitive measures for sarcopenia screening. This study aimed to verify the value of handgrip and respiratory muscle strength as possible discriminators to identify sarcopenia and to establish cut-off points for sarcopenia screening in community-dwelling, Brazilian women. In a cross-sectional study, 154 community-dwelling, Brazilian women (65–96 years) were assessed for appendicular skeletal muscle mass, handgrip (HGS), and respiratory muscular strength, including maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP). The data were analyzed using the ROC curve and the Youden Index determined cut-off points. Statistical significance was set at 5%. 88 participants (57%) were sarcopenic. MEP (OR 0.98 [95%CI 0.97, 1.00], p = 0.023) and HGS (OR 0.82 [95% CI 0.75, 0.90], p < 0.001) were independent factors for sarcopenia in older. The optimal cut-off points for identifying sarcopenia were ≤ 77 cmH2O for MEP (AUC = 0.72), and ≤ 20 kg for HGS (AUC = 0.80). Simple muscular strength tests, including HGS and MEP, may be considered in the identification of sarcopenia in older, community-dwelling, Brazilian women. Future work is still needed to assess external validation of the proposed cut-offs before the clinical application.

A Systematic Review investigating the Effectiveness of Exercise training in Glycogen Storage Diseases.

Glycogen storage diseases (GSDs) are rare inborn errors of carbohydrate metabolism typically with skeletal muscle and liver involvement. In those with skeletal muscle involvement, the majority display symptoms of exercise intolerance which can cause profound exercise limitation and impair everyday living and quality of life (QoL). There are no curative treatments for GSDs, thus therapeutic options, such as exercise training, are aimed at improving QoL by alleviating signs and symptoms. In order to investigate the effectiveness of exercise training in adults with GSDs, we systematically reviewed the literature. In this review we conducted searches within SCOPUS and MEDLINE to identify potential papers for inclusion. These papers were independently assessed for inclusion and quality by two authors. We identified 23 studies which included aerobic training, strength training or respiratory muscle training in patients with McArdles (n = 41) and Pompe disease (n = 139). In McArdle disease, aerobic exercise training improved aerobic capacity (VO2 peak) by 14-111% with further benefits to functional capacity and well-being. Meanwhile, strength training increased muscle peak power by 100-151% and reduced disease severity. In Pompe disease, a combination of aerobic and strength training improved VO2 peak by 9-10%, muscle peak power by 64%, functional capacity and well-being. Furthermore, respiratory muscle training (RMT) improved respiratory muscular strength [maximum inspiratory pressure (MIP) increased by up to 65% and maximum expiratory pressure (MEP) by up to 70%], with additional benefits shown in aerobic capacity, functional capacity and well-being. This adds to the growing body of evidence which suggests that supervised exercise training is safe and effective in improving aerobic capacity and muscle function in adults with McArdle or Pompe disease. However, the literature base is limited in quality and quantity with a dearth of literature regarding exercise training in other GSD subtypes.

Functional tests associated with sarcopenia in moderate chronic obstructive pulmonary disease

ABSTRACT Objectives: To evaluate the association of physical and functional measures with sarcopenia in moderate chronic obstructive pulmonary disease (COPD) and to establish cutoff points for sarcopenia screening. Methods: The study included COPD with and without sarcopenia, of both sexes who were over 50 years old. Participants were assessed for lung function, body composition, grip strength, Short Physical Performance Battery (SPPB), 5-repetition, 10-repetition and 30-s sit-to-stand tests (5STS, 10STS, and 30STS, respectively). In addition, 6-min walking test, respiratory muscular strength, and physical activity level were tested. Results: The study had 35 participants, 24 men (68.6%) and moderate COPD (51.4%). COPD-sarcopenia showed lower values in lean mass, body fat and body mass alongside lower performance in 10 and 30 STS tests, SPPB and gait speed compared to non-sarcopenic group. The cutoff points with better sensitivity and specificity to identify sarcopenia were 10.88 and 34.14 s, 15 repetitions, and 10 points in the 5STS, 10STS, 30STS, and SPPB, respectively. The comparison of the receiver operating curves evidenced no differences between the functional tests. Only 30STS and SPPB showed acceptable discriminatory power. Conclusion: Functional tests, especially 30STS and SPPB, are simple and affordable tools for screening sarcopenia in COPD with moderate obstruction.

Evaluation of Respiratory Muscular Strength Compared to Predicted Values in Patients with Stroke

The purpose of this study was to evaluate the inspiratory and expiratory muscle strength of individuals affected by stroke and to compare it with the predicted values in the literature considering their corresponding age. Respiratory muscle strength was evaluated in 22 elderly people who had sequels of stroke, four with right hemiparesis, 16 with left hemiparesis and two with bilateral, of ages ranging from 34 to 82 years. The collected data were submitted to statistical analysis using a Mann–Whitney test to evaluate if there was a significant difference in the average data collected when compared with a mean of the predicted data in the literature. Fourteen men and eight women were evaluated, who obtained mean values of 71.85 cmH2O and 57.75 cmH2O, respectively, for a maximal inspiratory pressure (MIP), and when compared to the predicted values for men and women, 105.41 cmH2O (p-value 0.0019) and 80.57 cmH2O (p-value 0.00464) were significantly lower. For a maximal expiratory pressure (MEP), the mean value obtained for men was 62.28 cmH2O and 49.5 cmH2O for women, whereas the predicted values in the literature were 114.79 cmH2O (p-value < 0.0001) and 78, 46 cmH2O (p-value 0.0059), respectively. In the statistical analysis, it was possible to notice that the studied population did not reach the predicted age indexes and that there was a significant difference between the median columns. In conclusion, there is a weakness in the respiratory muscles of hemiparetic men and women due to stroke.

Effect of resistance exercises applying maximum expiration on the respiratory muscle strength of elderly women.

Respiratory-muscle weakness is an important clinical problem. The respiratory system's health is a decisive factor in the physical and social life of the elderly. Changes in respiratory muscular strength and function activate the torso's adjustment ability, which affects daily activities. This study aimed to investigate the effects of resistance exercises combined with breathing exercises on the respiratory-muscle strength of elderly women. This study included 26 elderly woman, who were randomly divided into two sub-groups of 13 participants each. The experimental group performed breathing exercises and dynamic upper- and lower-extremity exercises, and the control group practiced only dynamic upper- and lower-extremity exercises. The maximum expiratory pressure (MEP) and maximum inspiratory pressure (MIP) were measured both before and at the end of the six-week study. In both groups, both the post-test MIPs and MEPs were significantly higher than the pre-intervention ones (p< 0.05). For MIPs, the between-group difference was not statistically significant, either before the intervention or post-test (p> 0.05). For MEPs, the between-group difference was statistically significant at post-intervention points (p< 0.05). The results showed that resistance exercises applying maximum expiration improved the respiratory-muscle strength of elderly women. These findings indicate that resistance exercises applying maximum expiration as described here in should be considered in patients who require breathing therapy, because the combination seems to significantly increase the strength of the respiratory muscles.

Respiratory muscle training with enzyme replacement therapy improves muscle strength in late - onset Pompe disease

BackgroundPompe disease is an autosomal recessive metabolic disorder caused by the deficiency of the lysosomal enzyme acid α-glucosidase. This deficiency leads to glycogen accumulation in the lysosomes of muscle tissue causing progressive muscular weakness particularly of the respiratory system. Enzyme replacement therapy (ERT) has demonstrated efficacy in slowing down disease progression in infants. Despite the large number of studies describing the effects of physical training in juvenile and adult late onset Pompe disease (LOPD). There are very few reports that analyze the benefits of respiratory muscle rehabilitation or training. MethodsThe effectiveness of respiratory muscle training was investigated using a specific appliance with adjustable resistance (Threshold). The primary endpoint was effect on respiratory muscular strength by measurements of MIP and MEP. Eight late-onset Pompe patients (aged 13 to 58years; 4 female, 4 male) with respiratory muscle deficiency on functional respiratory tests were studied. All patients received ERT at the dosage of 20mg/kg/every 2weeks and underwent training with Threshold at specified pressures for 24months. ResultsA significant increase in MIP was observed during the follow-up of 24month: 39.6cm H2O (+25.0%) at month 3; 39.5cm H2O (+24.9%) at month 6; 39.1cm H2O (+23.7%) at month 9; 37.3cm H2O (+18.2%) at month 12; and 37.3cm H2O (+17.8%) at month 24. Median MEP values also showed a significant increase during the first 9months: 29.8cm H2O, (+14.3%) at month 3; 31.0cm H2O (+18.6) at month 6; and 29.5cm H2O (+12.9) at month 9. MEP was then shown to be decreased at months 12 and 24; median MEP was 27.2cm H2O (+4.3%) at 12months and 26.6cm H2O (+1.9%) at 24months. The FVC remain stable throughout the study. ConclusionAn increase in respiratory muscular strength was demonstrated with Threshold training when used in combination with ERT.

Respiratory training as strategy to prevent cognitive decline in aging: a randomized controlled trial.

BackgroundInadequate oxygenation may cause lesions and brain atrophy during aging. Studies show a positive association between pulmonary function and the cognitive performance of individuals from middle age on.ObjectiveTo investigate the effect of aerobic physical exercises and respiratory training on the blood oxygenation, pulmonary functions, and cognition of the elderly.DesignThis was a randomized and controlled trial with three parallel groups. A total of 195 community-dwelling elderly were assessed for eligibility; only n=102 were included and allocated into the three groups, but after 6 months, n=68 were analyzed in the final sample. Participants were randomized into a social interaction group (the control group), an aerobic exercise group (the “walking” group), or a respiratory training group (the “breathing” group). The main outcome measures were the Wechsler Adult Intelligence Scale, Wechsler Memory Scale, Wisconsin Card Sorting Test, respiratory muscular strength, cirtometry (thoracic–abdominal circumference); oxygen saturation in arterial blood (SpO2), and hemogram.ResultsNo differences were observed for any of the blood parameters. Aerobic exercise and respiratory training were effective in improving the pulmonary parameters. Better cognitive performance was observed for the breathing group as regards abstraction and mental flexibility. The walking group remained stable in the cognitive performance of most of the tests, except attention. The control group presented worst performance in mental manipulation of information, abstraction, mental flexibility, and attention.ConclusionOur results showed that both the walking and breathing groups presented improvement of pulmonary function. However, only the breathing group showed improved cognitive function (abstraction, mental flexibility). The improvement in cognitive functions cannot be explained by blood parameters, such as SpO2, erythrocytes, hemoglobin, and hematocrit.

Effects of nephrectomy on respiratory function and quality of life of living donors: a longitudinal study.

BACKGROUND: A living donor transplant improves the survival and quality of life of a transplant patient. However, the impact of transplantation on postoperative lung function and respiratory muscular strength in kidney donors remains unknown. OBJECTIVE: To evaluate pulmonary function, respiratory muscle strength, quality of life and the incidence of postoperative pulmonary complications (PPCs) in kidney donors undergoing nephrectomy. METHOD: This prospective cohort enrolled 110 consecutive kidney donors undergoing nephrectomy. Subjects underwent pulmonary function (using spirometry) and respiratory muscular strength (using manovacuometry) assessments on the day prior to surgery and 1, 2, 3 and 5 days postoperatively. Quality of life (measured by the SF-36) was evaluated preoperatively and 30 days postoperatively. PPCs were assessed daily by a blinded assessor. RESULTS: Donors exhibited a decrease of 27% in forced vital capacity, 58% in maximum inspiratory capacity and 51% in maximum expiratory pressure on the 1stpostoperative day (p<0.001) but this improved over days 2, 3 and 5 but had not returned to preoperative levels. Patient quality of life was still impaired at 30 days with regards to functional capacity, physical role, pain, vitality and social functioning (p<0.05) but these parameters improved slowly. None of the patients developed PPCs. CONCLUSION: Kidney donors submitted to nephrectomy exhibited a reduction in pulmonary function, respiratory muscular strength and quality of life, most of which were improving toward pre-surgical levels.

Subjective sleep quality in stable neuromuscular patients under non-invasive ventilation

ObjectivesPatients with neuromuscular diseases improve their sleep when treated with noninvasive ventilation (NIV), but their sleep architecture during NIV may still be disturbed by side effects of NIV or inadequacy of the ventilator setting. Little is known about subjective sleep quality during NIV. The aims of this study were to evaluate subjective sleep quality of stable neuromuscular patients under long-term NIV by using Pittsburgh questionnaire (PSQI), and to assess its possible determinants. MethodsFifty stable neuromuscular patients under long-term NIV were administered PSQI and underwent polysomnography. Arterial blood gases, forced vital capacity, and respiratory muscular strength were measured. ResultsThirty-three patients had global PSQI ≥ 5 and were classified as bad sleepers. Good and poor sleepers differed in age (P = 0.005), base excess (BE) (P = 0.02), NIV inspiratory pressure (P = 0.04), %N1 (P = 0.0006), and %N3 sleep stage (P = 0.02). Percent N3 duration and Arousal/Awakening Index were correlated with rate of patient–ventilator asynchronies (r = −0.41 and 0.37, respectively, P < 0.05) and with NIV inspiratory pressure (r = −0.44 and 0.36, P < 0.01 and <0.05, respectively). At the final multivariate regression model, only BE and %N3 independently predicted global PSQI (r2 = 0.326, P < 0.001). ConclusionsSubjective sleep quality is often poor in neuromuscular patients under long-term NIV. Amount of slow wave sleep and chronic hypoventilation resulting in increased BE are independent predictors of subjective sleep quality. Since inadequate NIV setting or application can influence sleep structure and alveolar ventilation, great care should be paid to the setting and the correct application of NIV to ensure a better subjective sleep quality.

Correlation between trunk control, respiratory muscle strength and spirometry in patients with stroke: An observational study

Stroke is the main cause of chronic disability in adults, and the effect of a stroke on the respiratory system depends on the structures affected by the lesion. To evaluate the correlation between trunk control, respiratory muscle strength and pulmonary function in individuals who suffered stroke. Observational, quantitative and descriptive study. Twenty-three patients who had a clinical diagnosis of ischaemic or haemorrhagic stroke. The trunk control was assessed through the Trunk Impairment Scale (TIS), and the respiratory muscle strength was assessed by manovacuometry by measuring the maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP). For pulmonary function analysis, we measured forced vital capacity (FVC), forced expiratory volume in one second (FEV₁), peak expiratory flow (PEF) and the Tiffeneau index (TIFF) through spirometry. A consistent and statistically significant correlation was found between TIS and PEF (r = 0.489, p = 0.024) and between TIS and EPmax (r = 0.517, p = 0.016). No relation was found between the other variables of pulmonary function and TIS. This study demonstrated that there is a relation between trunk control and respiratory muscular strength, especially concerning the expiratory muscles. However, there seems to be no relation between trunk control and pulmonary function in this series of individuals who suffered stroke.

Força muscular respiratória, postura corporal, intensidade vocal e tempos máximos de fonação na Doença de Parkinson

TEMA: Verificar os achados de força muscular respiratória (FMR), postura corporal (PC), intensidade vocal (IV) e tempos máximos de fonação (TMF), em indivíduos com Doença de Parkinson (DP) e casos de controle, conforme o sexo, o estágio da DP e o nível de atividade física (AF). PROCEDIMENTOS: três homens e duas mulheres com DP, entre 36 e 63 anos (casos de estudo - CE), e cinco indivíduos sem doenças neurológicas, pareados em idade, sexo e nível de AF (casos de controle - CC). Avaliadas a FMR, PC, IV e TMF. RESULTADOS: homens: diminuição mais acentuada dos TMF, IV e FMR nos parkinsonianos, mais alterações posturais nos idosos; mulheres com e sem DP: alterações posturais similares, relação positiva entre estágio, nível de AF e as demais medidas. CONCLUSÕES: Verificou-se nas parkinsonianas, prejuízo na IV e nos parkinsonianos déficits nos TMF, IV e FMR. Sugerem-se novos estudos sob um viés interdisciplinar.

Adenotonsillectomy improves the strength of respiratory muscles in children with upper airway obstruction

Objective The aim of this paper is to study the respiratory muscle strength by evaluating the maximal inspiratory pressure (MIP), maximal expiratory pressure (MEP) and lung volume before and 3 and 6 months after adenotonsillectomy. This is an interventional, before and after trial. It was set at the Department of Otolaryngology, University of São Paulo, School of Medicine. We included 29 children (6–13 years old), both genders, consecutively recruited from the waiting list for adenotonsillectomy. Children were submitted to maximal inspiratory pressures (MIP), maximal expiratory pressure (MEP) evaluation using an analog manovacuometer, lung volume, using incentive expirotometer and thoracic and abdominal perimeter using a centimeter tape. Children were evaluated in 3 different moments: 1 week before and 3 and 6 months after surgery. Results MIP improved significantly 3 months ( p < 0.001) after adenotonsillectomy and MEP did not change ( p = 1). There were increases in lung volume ( p = 000), chest ( p = 0.017) and abdominal perimeter ( p = 0.05). Six months after surgery, all parameters improved. MIP ( p = 0), MEP ( p = 0), lung volume ( p = 0.02), chest ( p = 0.034) and abdominal perimeter ( p = 0.23). Conclusion This study suggests that there was an improvement in respiratory muscular strength, once there was a significant improvement in maximal inspiratory pressure, lung volume and other parameters after adenotonsillectomy.

Correlação entre pressão inspiratória máxima, ventilação pulmonar e tempo de ventilação em pacientes ventilados no modo pressão de suporte

Neste estudo, avalia-se a influência do tempo de permanência em ventilação mecânica sobre a pressão inspiratória máxima e o volume pulmonar de pacientes ventilados no modo pressão de suporte. Foram incluídos 12 pacientes adultos, 4 do sexo feminino e 8 do masculino, em desmame da ventilação mecânica no modo pressão de suporte. Para cada paciente foi aferida a pressão inspiratória máxima, volume minuto e corrente, e tempo de ventilação mecânica. A análise estatística foi feita por meio do coeficiente de correlação linear de Pearson, com nível de significância p0,05. Observou-se correlação negativa entre o tempo de ventilação mecânica, a pressão inspiratória máxima (r = -0,7142; p = 0,009), tempo de ventilação mecânica e volume corrente (r = -0,601; p = 0,0387. O tempo de permanência em ventilação mecânica tem influência negativa sobre a força muscular respiratória e o volume corrente em pacientes ventilados no modo pressão de suporte.

Functional respiratory effects of noninvasive ventilation in acute hypercapnic patients with chronic obstructive pulmonary disease

Noninvasive ventilation (NIV) is useful for improving oxygenation, decreasing hypercapnia, and avoiding invasive S4 mechanical ventilation in patients with chronic obstructive pulmonary disease (COPD) exacerbations and acute respiratory failure [1,2]. During the hospitalization, the treatment intensity is quite variable on the basis of the patient's clinical condition. Often, after the acute phase, patients need only periods of NIV followed by oxygenotherapy. NIV reduces the work of breathing and probably improves the respiratory muscular strength even when the ventilation is ended [3]. The aim of this study is to evaluate this effect in COPD submitted to NIV.

Respiratory Muscular Strength Decrease in Children With Mylomeningocele

Case-control study. To evaluate respiratory muscle force in children with myelomeningocele. Myelomeningocele is a common spinal cord malformation with limitations linked to central nervous system lesions and abnormalities in respiratory movements. Despite this, little attention has been given to evaluating respiratory muscle force in these patients. Children with myelomeningocele aged between 4 and 14 years (myelomeningocele group; MG, n = 20) were studied and compared with healthy children (control group; CG, n = 20) matched for age and gender. Respiratory muscular force was evaluated by maximum inspiratory (Pimax) and expiratory (Pemax) pressures. Groups were similar for age [CG = 8 (6-13) x MG = 8 (4-14), P > 0.05]; gender, and body mass index [CG = 17.4 (14.1-24.7) x MG = 19.2 (12.6-31.9), P > 0.05]. The lumbosacral region was predominantly affected (45%). Maximum respiratory pressures were significantly higher in CG than MG (Pimax = CG: -83 +/- 21.75 > MG: -54.1 +/- 23.66; P < 0.001 and Pemax = CG: +87.4 +/- 26.28 > MG: +64.6 +/- 26.97; P = 0.01). Patients with upper spinal lesion (UL) had lower maximum respiratory pressure values than those with lower spinal lesion (LL), [Pimax (UL = -38.33 +/- 11.20 cm H2O x LL = -60.85 +/- 24.62 cm H2O), P < 0.041 and Pemax (UL = +48 +/- 20.82 cm H2O x LL + 71.71 +/- 26.73 cm H2O), P = 0.067]). Children with myelomeningocele at the ages studied presented reduced respiratory muscle force with more compromise in upper spinal lesion.

Relationship between Exercise Tolerance and Respiratory Pattern and Muscular Strength of Legs in Patients with Chronic Heart Failure.

The main symptom of chronic heart failure (CHF) is dyspnea and leg fatigue on exercise, demonstrating a decrease in exercise capacity. However, the precise mechanisms of these symptoms are not fully understood. The existence of a relationship between exercise tolerance and respiratory pattern and muscular strength of legs in patients with CHF has not been demonstrated. In this study, therefore, we measured these parameters to clarify the factors which relate to exercise tolerance in CHF patients. Subjects were fifty-four consecutive patients (37 men and 17 women, mean age 53 years) with CHF who underwent cardiopulmonary exercise testing at our hospital from February 1999 to September 2000. Peak oxygen uptake (peak VO2) and respiratory pattern (TV/RR; tidal volume/respiratory rate) were evaluated. The strength of quadriceps was also measured. The respiratory pattern was weak but significantly correlated with peak VO2 (r=0.27, p<0.05). Maximal isometric strength of quadriceps showed a tendency to correlate with peak VO2 (r=0.25, p=0.06). These findings suggest that exercise intolerance, seen in these CHF patients, is related to both respiratory pattern and the maximal muscular strength of legs.