Search

Background: Currently, excess ventilation has been grounded under the relationship between minute-ventilation/carbon dioxide output ( V ˙ E - V ˙ CO 2 ). Alternatively, a new approach for ventilatory efficiency ( η E V ˙ ) has been published., Objective: Our main hypothesis is that comparatively low levels of η E V ˙ between chronic heart failure (CHF) and chronic obstructive pulmonary disease (COPD) are attainable for a similar level of maximum and submaximal aerobic performance, conversely to long-established methods ( V ˙ E - V ˙ CO 2 slope and intercept)., Methods: Both groups performed lung function tests, echocardiography, and cardiopulmonary exercise testing. The significance level adopted in the statistical analysis was 5%. Thus, nineteen COPD and nineteen CHF-eligible subjects completed the study. With the aim of contrasting full values of V ˙ E - V ˙ CO 2 and η V ˙ E for the exercise period (100%), correlations were made with smaller fractions, such as 90% and 75% of the maximum values., Results: The two groups attained matched characteristics for age (62±6 vs. 59±9 yrs, p>.05), sex (10/9 vs. 14/5, p>0.05), BMI (26±4 vs. 27±3 Kg m2, p>0.05), and peak V ˙ O 2 (72±19 vs. 74±20 %pred, p>0.05), respectively. The V ˙ E - V ˙ CO 2 slope and intercept were significantly different for COPD and CHF (27.2±1.4 vs. 33.1±5.7 and 5.3±1.9 vs. 1.7±3.6, p<0.05 for both), but η V ˙ E average values were similar between-groups (10.2±3.4 vs. 10.9±2.3%, p=0.462). The correlations between 100% of the exercise period with 90% and 75% of it were stronger for η V ˙ E (r>0.850 for both)., Conclusion: The η V ˙ E is a valuable method for comparison between cardiopulmonary diseases, with so far distinct physiopathological mechanisms, including ventilatory constraints in COPD.

Objectives: This study primarily aimed to investigate the clinical determinants of the Modified Incremental Step Test (MIST) in adults with non-cystic fibrosis bronchiectasis (NCFB). A secondary objective was to compare the cardiopulmonary responses after the MIST and Incremental Shuttle Walk Test (ISWT), two commonly adopted symptom-limited maximum field tests in chronic respiratory diseases., Methods: Forty-six patients with clinically stable bronchiectasis participated in this cross-sectional study. MIST and ISWT were performed to determine exercise capacity, while disease severity, fatigue, and quality of life were assessed using the Bronchiectasis Severity Index (BSI), the Fatigue Severity Scale (FSS), and St. George's Respiratory Questionnaire (SGRQ), respectively. Quadriceps muscle strength was evaluated using a hand-held dynamometer, walking speed with a wireless inertial sensing device, and the level of physical activity (steps/day) with a pedometer., Results: The BSI score, quadriceps muscle strength, daily step count, and the SGRQ total score explained 61.9% of the variance in the MIST (p < 0.001, R2 = 0.67, AR2 = 0.619). The BSI score (r = -0.412, p = 0.004), quadriceps muscle strength (r = 0.574, p = 0.001), daily step count (r = 0.523, p < 0.001), walking speed (r = 0.402, p = 0.006), FSS score (r = -0.551, p < 0.001), and SGRQ total score (r = -0.570, p < 0.001) correlated with the MIST. The patients achieved higher heart rates (HR), HR%, desaturation, dyspnea, and leg fatigue in the MIST compared to the ISWT (p < 0.05)., Conclusions: Disease severity, quadriceps muscle strength, physical activity level, and quality of life were determinants of MIST. The advantages of the MIST, including higher cardiopulmonary response than ISWT and greater portability, which facilitates its use in various settings, make MIST the preferred choice for investigating symptom-limited exercise capacity in patients with NCFB.

Objective: One of the common limitations after COVID-19 pneumonia is the decrease in exercise capacity. The identification of the factors affecting exercise capacity and the assessment of patients at risk are important for determining treatment strategy. This study was conducted to determine the predictors of decreased exercise capacity in long post-COVID-19 patients., Methods: We investigated the association of exercise capacity as measured by the incremental shuttle walk test (ISWT) with age, sex, spirometric variables, respiratory and peripheral muscle strength, quality of life, fatigue, hospital anxiety depression scale, chest X-ray involvement, and hospitalization. The patients were divided into three groups: outpatients, inpatients, and ICU patients. Regression analysis was used to determine which parameters were significant predictors of exercise capacity., Results: Of the 181 patients included in the study, 56 (31%) were female. The mean ISWT in percentage of predicted values (ISWT%pred) was 43.20% in the whole sample, whereas that was 52.89%, 43.71%, and 32.21% in the outpatient, inpatient, and ICU patient groups, respectively. Linear regression analysis showed that predictors of decreased ISWT%pred were sex (b = 8.089; p = 0.002), mMRC scale score (b = -7.004; p ≤ 0.001), FVC%pred (b = 0.151; p = 0.003), and handgrip strength (b = 0.261; p = 0.030)., Conclusions: In long post-COVID-19 patients, sex, perception of dyspnea, restrictive pattern in respiratory function, and decrease in peripheral muscle strength are predictors of reduced exercise capacity that persists three months after COVID-19. In this context, we suggest that pulmonary rehabilitation might be an important therapy for patients after COVID-19.

Background: Post-COVID-19 exercise intolerance is poorly understood. Cardiopulmonary exercise testing (CPET) can identify the underlying exercise limitations., Objectives: To evaluate the source and magnitude of exercise intolerance in post-COVID-19 subjects., Methods: Cohort study assessing subjects with different COVID-19 illness severities and a control group selected by propensity score matching. In a selected sample with CPET prior to viral infection, before and after comparisons were performed. Level of significance was 5% in the entire analysis., Results: One hundred forty-four subjects with COVID-19 were assessed (median age: 43.0 years, 57% male), with different illness severities (60% mild, 21% moderate, 19% severe). CPET was performed 11.5 (7.0, 21.2) weeks after disease onset, with exercise limitations being attributed to the peripheral muscle (92%), and the pulmonary (6%), and cardiovascular (2%) systems. Lower median percent-predicted peak oxygen uptake was observed in the severe subgroup (72.2%) as compared to the controls (91.6%). Oxygen uptake differed among illness severities and controls at peak and ventilatory thresholds. Conversely, ventilatory equivalents, oxygen uptake efficiency slope, and peak oxygen pulse were similar. Subgroup analysis of 42 subjects with prior CPET revealed significant reduction in only peak treadmill speed in the mild subgroup and in oxygen uptake at peak and ventilatory thresholds in the moderate/severe subgroup. By contrast, ventilatory equivalents, oxygen uptake efficiency slope, and peak oxygen pulse did not change significantly., Conclusions: Peripheral muscle fatigue was the most common exercise limitation etiology in post-COVID-19 patients regardless of the illness severity. Data suggest that treatment should emphasize comprehensive rehabilitation programs, including aerobic and muscle strengthening components.

Objective: Patients with COPD are prone to cardiac remodeling; however, little is known about cardiac function in patients recovering from an acute exacerbation of COPD (AECOPD) and its association with exercise capacity. The aim of this study was to evaluate the cardiac function and structure and to compare their relationship with exercise capacity in patients with a recent AECOPD and patients with clinically stable COPD., Methods: This was a cross-sectional study including 40 COPD patients equally divided into two groups: recent AECOPD group (AEG) and clinically stable COPD group (STG). Echocardiography was performed to assess cardiac function and chamber structure. The six-minute walk distance (6MWD) and the Duke Activity Status Index (estimated Vo2) were used in order to assess exercise capacity., Results: No significant differences in cardiac function and structure were found between the groups. The 6MWD was associated with early/late diastolic mitral filling velocity ratio (r = 0.50; p < 0.01), left ventricular posterior wall thickness (r = -0.33; p = 0.03), and right atrium volume index (r = -0.34; p = 0.04), whereas Vo2 was associated with right atrium volume index (r = -0.40; p = 0.02)., Conclusions: Regardless of the clinical condition (recent AECOPD vs. stable COPD), the cardiac function and structure were similar between the groups, and exercise capacity (determined by the 6MWD and Vo2) was associated with cardiac features.

Objective: To evaluate the construct validity and reproducibility of the six-minute step test (6MST) in individuals with obstructive sleep apnea (OSA) treated with continuous positive airway pressure (CPAP)., Methods: We evaluated 48 volunteers diagnosed with OSA and treated with CPAP for at least two months. The volunteers underwent the six-minute walk test (6MWT) and the 6MST, in random order and on different days, with an interval of, at most, seven days between the two tests., Results: A moderate positive correlation was found between the distance walked on the 6MWT and the number of steps climbed on the 6MST (r = 0.520; p < 0.001). There was no significant difference between the two 6MSTs in terms of the number of steps climbed (121.7 ± 27.1 vs. 123.6 ± 26.7). Reproducibility for performance on the 6MST and for cardiovascular variables was considered excellent (intraclass correlation coefficient > 0.8). Regarding cardiovascular responses, the 6MST produced higher values than did the 6MWT for HR at six minutes, percent predicted maximum HR, and leg fatigue at six minutes, as well as for systolic blood pressure at six minutes and at one minute of recovery., Conclusions: The 6MST is valid and reproducible, producing greater cardiovascular stress than does the 6MWT. However, the 6MST is also characterized as a submaximal test for the assessment of exercise tolerance in individuals with OSA treated with CPAP.

Objective To verify if there are differences in Chronic Obstructive Pulmonary Disease (COPD) patient exacerbator and non-exacerbator phenotypes undergoing a Pulmonary Rehabilitation Program (PRP). Methods A real life retrospective study included outpatients with COPD from public primary care who completed a 12-weeks PRP, three times a week. All were assessed before and after PRP using the six-minute walk test (6MWT), the modified Medical Research Council (mMRC) dyspnea index, quality of life and Body-mass Index, airflow Obstruction, Dyspnea and Exercise (BODE index). Results A total of 151 patients were analyzed and mean age was 65.0 ± 8.1 years and mean Forced Expiratory Volume (FEV) 1% of predicted was 39.8 ± 15.9. The predominant gender was male (66.9%). Of these patients 31 (20.5%) were exacerbator phenotype There was a significant improvement in the mean distance in the 6MWT in both groups, with the largest change observed in the exacerbator group [mΔ (95% CI): 84.9 (57.1-112.6) vs. 48.6 (37-60.2) p= 0.018]. Significant reduction in dyspnea on the mMRC scale occurred in both groups, with the highest intensity in the exacerbator group [mΔ (95% CI): - 0.8 (-1.11 to 0.51) vs. -1.6 (-2.20 to -1.13) p = 0.006]. Improvement in the BODE index occurred in both groups, but the mean variation was also significantly greater in the exacerbator group [mΔ (95% CI): -1.44 (-2.17 to -0.70) p= 0.045]. Conclusion Patients with COPD exacerbator phenotype had a greater magnitude of response to PRP (36 meters) when compared to non-exacerbator phenotype regardless the severity of airflow obstruction, also showing improvement in prognosis measured by the BODE index.

Objective To evaluate the effect of an interdisciplinary intervention with a motivational approach on exercise capacity and usual physical activity levels in overweight and obese adolescents. Methods This is a randomized, controlled clinical trial with single blinding of subjects. Adolescents aged 15 to 18 years with overweight and obesity (body mass index ≥ 85 percentile) were included. The adolescents were randomized into two groups: interdisciplinary intervention or control - traditional approach aiming at lifestyle modifications. The initial evaluations were carried out, including the cardiopulmonary exercise test and the physical activity level measurement by using the International Physical Activity Questionnaire and a pedometer. The evaluations were performed in two moments: time zero (time of inclusion in the study) and after 3 months (end of intervention). There were 12 sessions with weekly meetings. Results A total of 37 participants were included, 19 in the Intervention Group. There were no significant differences in the baseline demographic, anthropometric and physical activity characteristics between groups, with mean age of 17.3±1.0 years in the Control Group, and 16.8±0.9 years in the Intervention Group (p=0.14). The motivational intervention did not cause significant differences (p>0.05) in the comparison of the variables of exercise capacity and usual physical activity (questionnaire and pedometer) between groups. Conclusion The intervention with a motivational approach did not alter exercise capacity and levels of usual physical activity in overweight and obese adolescents. Clinical Trial Registry: NCT02455973 and REBEC: RBR-234nb5.

Objective To determine the discriminative capacity and cut-off point of different 4-metre gait speed test (4MGS) protocols in identifying preserved or reduced exercise capacity using the six-minute walk test (6MWT) in patients with Chronic Obstructive Pulmonary Disease (COPD); also, to compare 4MGS protocols and characteristics of individuals according to the best cut-off point. Methods We evaluated fifty-six patients with COPD, all of which were submitted to the assessment of anthropometric characteristics, pulmonary function (spirometry) and functional exercise capacity (6MWT and four protocols of the 4MGS). In the 4MGS test, patients were instructed to walk at normal pace and at maximum speed in a 4 meters course (4MGS 4m - usual pace and at maximum) and 8 meters course (4MGS 8m - usual pace and at maximum). Results Only the 4MGS 4m-maximum protocol was able to identify preserved exercise capacity in the 6MWT (AUC=0.70) with moderate correlation between them (r=0.52; P=0<0.0001). The cut-off point found in the 4MGS 4m-maximum was 1.27 m/s. Patients with preserved exercise capacity (4MGS 4m-maximum ≥1.27m/s) walker greater distances on the 6MWT in %pred (91±2 vs 76±3; P<0.0001). In the other comparisons involving gender, BMI, FEV1% pred and GOLD index there were no significant differences between the groups. In addition, the agreement of individuals classified as preserved and reduced exercise capacity in the 6MWT and 4MGS 4m-maximum was significant (P = 0.008). Conclusion The 4MGS 4m-maximum test can be used to discriminate preserved exercise capacity in patients with COPD and correlates with the 6MWT.

Introduction and Objectives: To describe the progression of aerobic exercise intensity in patients on a cardiac rehabilitation (CR) program., Methods: We conducted a retrospective analysis of a random sample of patients referred for CR after acute coronary syndrome between 2008 and 2016. The weekly peak exercise intensity achieved during aerobic exercise was estimated by treadmill speed and grade at peak effort and the corresponding perception of effort was assessed using the Borg scale. Initial exercise intensity was prescribed as 60-80% of reserve heart rate plus resting heart rate, and was modified according to perceived exertion. Peak heart rate/intensity and perceived exertion index were used as variables to characterize the response to the intensity achieved. Variables were compared at different time points: T1 (1st week), T2 (4th week) and T3 (8th week)., Results: Of the total of 868, 238 patients were randomly selected. At peak heart rate during the session, exercise intensity (in metabolic equivalents) was: T1: 7.2±2.0, T2: 9.0±2.2, and T3: 9.4±2.2 (p<0.01). The peak heart rate/intensity index was T1: 16.8±5.4, T2: 13.4±3.6 and T3: 13.1±3.8 (p<0.01) and the perceived exertion index was T1: 1.8±0.6; T2: 1.4±0.5; T3: 1.4±0.5 (p<0.01)., Conclusions: Increasing exercise intensity during CR, associated with lower perception of effort and lower heart rate necessary to achieve such intensity, leads to significant improvement in functional capacity., (Copyright © 2019 Sociedade Portuguesa de Cardiologia. Publicado por Elsevier España, S.L.U. All rights reserved.)

Dysfunctional breathing (DB) is a respiratory condition characterized by irregular breathing patterns that occur either in the absence of concurrent diseases or secondary to cardiopulmonary diseases. Although the primary symptom is often dyspnea or "air hunger", DB is also associated with nonrespiratory symptoms such as dizziness and palpitations. DB has been identified across all ages. Its prevalence among adults in primary care in the United Kingdom is approximately 9.5%. In addition, among individuals with asthma, a positive diagnosis of DB is found in a third of women and a fifth of men. Although DB has been investigated for decades, it remains poorly understood because of a paucity of high-quality clinical trials and validated outcome measures specific to this population. Accordingly, DB is often underdiagnosed or misdiagnosed, given the similarity of its associated symptoms (dyspnea, tachycardia, and dizziness) to those of other common cardiopulmonary diseases such as COPD and asthma. The high rates of misdiagnosis of DB suggest that health care professionals do not fully understand this condition and may therefore fail to provide patients with an appropriate treatment. Given the multifarious, psychophysiological nature of DB, a holistic, multidimensional assessment would seem the most appropriate way to enhance understanding and diagnostic accuracy. The present narrative review was developed as a means of summarizing the available evidence about DB, as well as improving understanding of the condition by researchers and practitioners.

Introduction: Left atrial (LA) size and function are associated with outcome after myocardial infarction (MI). In this study we aimed to assess the impact of LA function as a predictor of exercise capacity through speckle tracking echocardiography., Methods: A total of 94 patients (mean age 54.8±11.0 years; 82% male) were enrolled one month after MI. Echocardiography was used to assess LA volumes and various indices of LA conduit, contraction and reservoir function. LA deformation was assessed by two-dimensional speckle tracking to calculate strain and strain rate at different phases of the cardiac cycle. Exercise capacity was assessed by oxygen uptake (VO 2 ) on cardiopulmonary exercise testing., Results: Increased LA volumes, especially LA volume before atrial contraction, were correlated with reduced peak VO 2 and reduced VO 2 at anaerobic threshold. Decreased peak VO 2 was associated with reduced LA conduit function (ρ=0.24; p=0.02), but not with LA booster function (ρ=-0.07; p=0.53). Lower peak atrial longitudinal strain was associated with worse exercise capacity (ρ=0.24; p=0.02)., Conclusions: After MI, increased LA volumes were markers of decreased functional capacity that was associated with decreased LA conduit function, but not with LA contractile function. In these patients, LA longitudinal strain analysis may be useful to predict reduced exercise capacity., (Copyright © 2018 Sociedade Portuguesa de Cardiologia. Publicado por Elsevier España, S.L.U. All rights reserved.)

Background: Despite significant advances in understanding the pathophysiology and management of asthma, some of systemic effects of asthma are still not well defined., Objectives: To compare heart function, baseline physical activity level, and functional exercise capacity in young patients with mild-to-moderate asthma and healthy controls., Methods: Eighteen healthy (12.67 ± 0.39 years) and 20 asthmatics (12.0 ± 0.38 years) patients were enrolled in the study. Echocardiography parameters were evaluated using conventional and tissue Doppler imaging (TDI)., Results: Although pulmonary acceleration time (PAT) and pulmonary artery systolic pressure (PASP) were within normal limits, these parameters differed significantly between the control and asthmatic groups. PAT was lower (p < 0.0001) and PASP (p < 0.0002) was higher in the asthma group (114.3 ± 3.70 ms and 25.40 ± 0.54 mmHg) than the control group (135.30 ± 2.28 ms and 22.22 ± 0.40 mmHg). The asthmatic group had significantly lower early diastolic myocardial velocity (E', p = 0.0047) and lower E' to late (E'/A', p = 0.0017) (13.75 ± 0.53 cm/s and 1.70 ± 0.09, respectively) compared with control group (15.71 ± 0.34 cm/s and 2.12 ± 0.08, respectively) at tricuspid valve. In the lateral mitral valve tissue Doppler, the asthmatic group had lower E' compared with control group (p = 0.0466; 13.27 ± 0.43 cm/s and 14.32 ± 0.25 cm/s, respectively), but there was no statistic difference in the E'/A' ratio (p = 0.1161). Right isovolumetric relaxation time was higher (p = 0.0007) in asthmatic (57.15 ± 0.97 ms) than the control group (52.28 ± 0.87 ms), reflecting global myocardial dysfunction. The right and left myocardial performance indexes were significantly higher in the asthmatic (0.43 ± 0.01 and 0.37 ± 0.01, respectively) compared with control group (0.40 ± 0.01 and 0.34 ± 0.01, respectively) (p = 0.0383 and p = 0.0059, respectively). Physical activity level, and distance travelled on the six-minute walk test were similar in both groups., Conclusion: Changes in echocardiographic parameters, evaluated by conventional and TDI, were observed in mild-to-moderate asthma patients even with normal functional exercise capacity and baseline physical activity level. Our results suggest that the echocardiogram may be useful for the early detection and evoluation of asthma-induced cardiac changes.

Objective: To evaluate a 24-month supervised, community-based maintenance exercise program after 3 months of pulmonary rehabilitation (PR) in comparison with a 27-month physical activity counseling program, in terms of the effects on maximal muscle strength, muscle power output, and exercise capacity, in individuals with COPD., Methods: Sixty-three men with moderate-to-severe COPD were recruited from two previous studies. Of those 63 participants, 31 were offered 3 months of PR followed by a 24-month supervised maintenance exercise program (24MME group) and 32 were offered a 27-month physical activity counseling program (27MPAC group). Measurements at 3 months and at the end of the study period included maximal strength of the upper and lower limbs, power output of the lower limbs, six-minute walk distance (6MWD), and quality of life., Results: At 27 months, the improvements in maximal strength of the upper and lower limbs were greater in the 24MME group than in the 27MPAC group (37.6 ± 28.3% and 28.4 ± 13.3%, respectively, vs. 8.8 ± 16% and 13.6 ± 16.4%, respectively; p < 0.05), as was the improvement in power output of the lower limbs (24.6 ± 18.4% vs. -2.3 ± 28.5%; p < 0.01). The increase in the 6MWD after 3 months was also greater in the 24MME group than in the 27MPAC group (33.2 ± 36.6 m vs. 2.9 ± 34.7 m; p < 0.05), although there were no differences between the two groups in terms of the Δ6MWD at 27 months (vs. baseline)., Conclusions: A supervised, community-based maintenance program is a successful long-term strategy to preserve the benefits of PR on peripheral muscle function and exercise capacity in individuals with COPD. However, physical activity counseling can maintain maximal muscle strength and exercise capacity in such individuals.

Background: Children and adolescents with congenital heart disease often have alterations in their exercise capacity that can be evaluated by various functional testing., Objective: To evaluate the functional capacity of children and adolescents with congenital heart disease (CHD) with systematic review and meta-analyses., Methods: The review included observational studies, data from the first evaluation of randomized clinical trials or observational follow-up periods after clinical trials which evaluated functional capacity by cardiopulmonary exercise test, stress testing, six-minute walk test or step test, in children and adolescents with CHD, aged between six and 18 years, and comparisons with healthy controls in the same age group. The quantitative assessment was performed by meta-analysis, by comparing the maximal oxygen consumption (VO2max) of children and adolescents with CHD and respective control groups., Results: Twenty-five of 2.683 studies identified in the search met the inclusion criteria. The VO2max measurement showed that patients with CHD have a decrease of 9.31 ml/Kg/min (95% CI. -12.48 to -6.13; I2, 94.3%, P for heterogeneity < 0.001) compared with the control group. The meta-analysis of the data of maximum heart rate (HR) reached during cardiopulmonary test and stress testing, retrieved from 18 studies, showed a HR value of -15.14 bpm (95% CI. -20.97 to -9.31; I2, 94.3%, P for heterogeneity < 0.001) compared with the control group., Conclusion: Children and adolescents with CHD have lower VO2max and HR compared to controls.

Objective: To evaluate the prevalence of sarcopenia in COPD patients, as well as to determine whether sarcopenia correlates with the severity and prognosis of COPD., Methods: A cross-sectional study with COPD patients followed at the pulmonary outpatient clinic of our institution. The patients underwent dual-energy X-ray absorptiometry. The diagnosis of sarcopenia was made on the basis of the skeletal muscle index, defined as appendicular lean mass/height2 only for low-weight subjects and adjusted for fat mass in normal/overweight subjects. Disease severity (COPD stage) was evaluated with the Global Initiative for Chronic Obstructive Lung Disease (GOLD) criteria. The degree of obstruction and prognosis were determined by the Body mass index, airflow Obstruction, Dyspnea, and Exercise capacity (BODE) index., Results: We recruited 91 patients (50 females), with a mean age of 67.4 ± 8.7 years and a mean BMI of 25.8 ± 6.1 kg/m2. Sarcopenia was observed in 36 (39.6%) of the patients, with no differences related to gender, age, or smoking status. Sarcopenia was not associated with the GOLD stage or with FEV1 (used as an indicator of the degree of obstruction). The BMI, percentage of body fat, and total lean mass were lower in the patients with sarcopenia than in those without (p < 0.001). Sarcopenia was more prevalent among the patients in BODE quartile 3 or 4 than among those in BODE quartile 1 or 2 (p = 0.009). The multivariate analysis showed that the BODE quartile was significantly associated with sarcopenia, regardless of age, gender, smoking status, and GOLD stage., Conclusions: In COPD patients, sarcopenia appears to be associated with unfavorable changes in body composition and with a poor prognosis.

Background: Hypertension is a public health problem and increases the incidence of cardiovascular diseases., Objective: To evaluate the effects of a resistance exercise session on the contractile and relaxing mechanisms of vascular smooth muscle in mesenteric arteries of NG-nitro L-arginine methyl ester (L-NAME)-induced hypertensive rats., Methods: Wistar rats were divided into three groups: control (C), hypertensive (H), and exercised hypertensive (EH). Hypertension was induced by administration of 20 mg/kg of L-NAME for 7 days prior to experimental protocols. The resistance exercise protocol consisted of 10 sets of 10 repetitions and intensity of 40% of one repetition maximum. The reactivity of vascular smooth muscle was evaluated by concentration‑response curves to phenylephrine (PHEN), potassium chloride (KCl) and sodium nitroprusside (SNP)., Results: Rats treated with L-NAME showed an increase (p < 0.001) in systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean arterial pressure (MAP) compared to the initial period of induction. No difference in PHEN sensitivity was observed between groups H and EH. Acute resistance exercise reduced (p < 0.001) the contractile response induced by KCl at concentrations of 40 and 60 mM in group EH. Greater (p < 0.01) smooth muscle sensitivity to NPS was observed in group EH as compared to group H., Conclusion: One resistance exercise session reduces the contractile response induced by KCl in addition to increasing the sensitivity of smooth muscle to NO in mesenteric arteries of hypertensive rats.

Background: Circulatory power (CP) and ventilatory power (VP) are indices that have been used for the clinical evaluation of patients with heart failure; however, no study has evaluated these indices in patients with coronary artery disease (CAD) without heart failure., Objective: To characterize both indices in patients with CAD compared with healthy controls., Methods: Eighty-seven men [CAD group = 42 subjects and healthy control group (CG) = 45 subjects] aged 40-65 years were included. Cardiopulmonary exercise testing was performed on a treadmill and the following parameters were measured: 1) peak oxygen consumption (VO2), 2) peak heart rate (HR), 3) peak blood pressure (BP), 4) peak rate-pressure product (peak systolic HR x peak BP), 5) peak oxygen pulse (peak VO2/peak HR), 6) oxygen uptake efficiency (OUES), 7) carbon dioxide production efficiency (minute ventilation/carbon dioxide production slope), 8) CP (peak VO2 x peak systolic BP) and 9) VP (peak systolic BP/carbon dioxide production efficiency)., Results: The CAD group had significantly lower values for peak VO2 (p < 0.001), peak HR (p < 0.001), peak systolic BP (p < 0.001), peak rate-pressure product (p < 0.001), peak oxygen pulse (p = 0.008), OUES (p < 0.001), CP (p < 0.001), and VP (p < 0.001) and significantly higher values for peak diastolic BP (p = 0.004) and carbon dioxide production efficiency (p < 0.001) compared with CG. Stepwise regression analysis showed that CP was influenced by group (R2 = 0.44, p < 0.001) and VP was influenced by both group and number of vessels with stenosis after treatment (interaction effects: R2 = 0.46, p < 0.001)., Conclusion: The indices CP and VP were lower in men with CAD than healthy controls.

Objective: To evaluate respiratory muscle strength and six-minute walk test (6MWT) variables in patients with uncontrolled severe asthma (UCSA)., Methods: This was a cross-sectional study involving UCSA patients followed at a university hospital. The patients underwent 6MWT, spirometry, and measurements of respiratory muscle strength, as well as completing the Asthma Control Test (ACT). The Mann-Whitney test was used in order to analyze 6MWT variables, whereas the Kruskal-Wallis test was used to determine whether there was an association between the use of oral corticosteroids and respiratory muscle strength., Results: We included 25 patients. Mean FEV1 was 58.8 ± 21.8% of predicted, and mean ACT score was 14.0 ± 3.9 points. No significant difference was found between the median six-minute walk distance recorded for the UCSA patients and that predicted for healthy Brazilians (512 m and 534 m, respectively; p = 0.14). During the 6MWT, there was no significant drop in SpO2. Mean MIP and MEP were normal (72.9 ± 15.2% and 67.6 ± 22.2%, respectively). Comparing the patients treated with at least four courses of oral corticosteroids per year and those treated with three or fewer, we found no significant differences in MIP (p = 0.15) or MEP (p = 0.45)., Conclusions: Our findings suggest that UCSA patients are similar to normal subjects in terms of 6MWT variables and respiratory muscle strength. The use of oral corticosteroids has no apparent impact on respiratory muscle strength.

Background: No studies have described and evaluated the association between hemodynamics, physical limitations and quality of life in patients with pulmonary hypertension (PH) without concomitant cardiovascular or respiratory disease., Objective: To describe the hemodynamic profile, quality of life and physical capacity of patients with PH from groups I and IV and to study the association between these outcomes., Methods: Cross-sectional study of patients with PH from clinical groups I and IV and functional classes II and III undergoing the following assessments: hemodynamics, exercise tolerance and quality of life., Results: This study assessed 20 patients with a mean age of 46.8 ± 14.3 years. They had pulmonary capillary wedge pressure of 10.5 ± 3.7 mm Hg, 6-minute walk distance test (6MWDT) of 463 ± 78 m, oxygen consumption at peak exercise of 12.9 ± 4.3 mLO2.kg-1.min-1 and scores of quality of life domains < 60%. There were associations between cardiac index (CI) and ventilatory equivalent for CO2 (r=-0.59, p <0.01), IC and ventilatory equivalent for oxygen (r=-0.49, p<0.05), right atrial pressure (RAP) and 'general health perception' domain (r=-0.61, p<0.01), RAP and 6MWTD (r=-0.49, p<0.05), pulmonary vascular resistance (PVR) and 'physical functioning' domain (r=-0.56, p<0.01), PVR and 6MWTD (r=-0.49, p<0.05) and PVR index and physical capacity (r=-0.51, p<0.01)., Conclusion: Patients with PH from groups I and IV and functional classes II and III exhibit a reduction in physical capacity and in the physical and mental components of quality of life. The hemodynamic variables CI, diastolic pulmonary arterial pressure, RAP, PVR and PVR index are associated with exercise tolerance and quality of life domains.

Objective: To evaluate the ability of COPD patients to perform activities of daily living (ADL); to identify barriers that prevent these individuals from performing ADL; and to correlate those barriers with dyspnea severity, six-minute walk test (6MWT), and an ADL limitation score., Methods: In COPD patients and healthy, age-matched controls, the number of steps, the distance walked, and walking time were recorded with a triaxial accelerometer, for seven consecutive days. A questionnaire regarding perceived barriers and the London Chest Activity of Daily Living (LCADL) scale were used in order to identify the factors that prevent the performance of ADL. The severity of dyspnea was assessed with two scales, whereas submaximal exercise capacity was determined on the basis of the 6MWT., Results: We evaluated 40 COPD patients and 40 controls. In comparison with the control values, the mean walk time was significantly shorter for COPD patients (68.5 ± 25.8 min/day vs. 105.2 ± 49.4 min/day; p < 0.001), as was the distance walked (3.9 ± 1.9 km/day vs. 6.4 ± 3.2 km/day; p < 0.001). The COPD patients also walked fewer steps/day. The most common self-reported barriers to performing ADL were lack of infrastructure, social influences, and lack of willpower. The 6MWT distance correlated with the results obtained with the accelerometer but not with the LCADL scale results., Conclusions: Patients with COPD are less active than are healthy adults of a comparable age. Physical inactivity and the barriers to performing ADL have immediate implications for clinical practice, calling for early intervention measures.

Background: Heart rate recovery at one minute of rest (HRR1) is a predictor of mortality in heart failure (HF), but its prognosis has not been assessed at six-minute walk test (6MWT) in these patients., Objective: This study aimed to determine the HRR1 at 6MWT in patients with HF and its correlation with six-minute walk distance (6MWD)., Methods: Cross-sectional, controlled protocol with 161 individuals, 126 patients with stable systolic HF, allocated into 2 groups (G1 and G2) receiving or not β-blocker and 35 volunteers in control group (G3) had HRR1 recorded at the 6MWT., Results: HRR1 and 6MWD were significantly different in the 3 groups. Mean values of HRR1 and 6MWD were: HRR1 = 12 ± 14 beat/min G1; 18 ± 16 beat/min G2 and 21 ± 13 beat/min G3; 6MWD = 423 ± 102 m G1; 396 ± 101 m G2 and 484 ± 96 m G3 (p < 0.05). Results showed a correlation between HRR1 and 6MWD in G1(r = 0.3; p = 0.04) and in G3(r = 0.4; p= 0.03), but not in G2 (r= 0.12; p= 0.48)., Conclusion: HRR1 response was attenuated in patients using βB and showed correlation with 6MWD, reflecting better exercise tolerance. HRR1 after 6MWT seems to represent an alternative when treadmill tests could not be tolerated.

Background: Characterized as a sudden and temporary loss of consciousness and postural tone, with quick and spontaneous recovery, syncope is caused by an acute reduction of systemic arterial pressure and, therefore, of cerebral blood flow. Unsatisfactory results with the use of drugs allowed the nonpharmacological treatment of neurocardiogenic syncope was contemplated as the first therapeutic option., Objectives: To compare, in patients with neurocardiogenic syncope, the impact of a moderate intensity aerobic physical training (AFT) and a control intervention on the positivity of head-up tilting test (HUT) and orthostatic tolerance time., Methods: Were studied 21 patients with a history of recurrent neurocardiogenic syncope and HUT. The patients were randomized into: trained group (TG), n = 11, and control group (CG), n = 10. The TG was submitted to 12 weeks of AFT supervised, in cycle ergometer, and the CG to a control procedure that consisted in 15 minutes of stretching and 15 minutes of light walk., Results: The TG had a positive effect to physical training, with a significant increase in peak oxygen consumption. The CG did not show any statistically significant change before and after the intervention. After the intervention period, 72.7% of the TG sample had negative results to the HUT, not having syncope in the revaluation., Conclusion: The program of supervised aerobic physical training for 12 weeks was able to reduce the number of positive HUT, as it was able to increase tolerance time in orthostatic position during the HUT after the intervention period.

Background: Physical stress tolerance (ST) is a measurement of cardiorespiratory fitness. Aerobic capacity is reduced in heart failure (HF) although there is no data available on this parameter in animals with ventricular dysfunction and no signs of HF., Objective: Evaluate ST in rats with ventricular diastolic dysfunction isolated or associated with systolic dysfunction induced by ascending aortic stenosis (AoS)., Methods: Young male Wistar rats (20-30 days old), divided in: control group (CG, n=11) and AoSG group, (n=12). Animals were assessed at 6 and 18 weeks after AoS surgery. Treadmill exercise test was until exhaustion and evaluated treadmill speed and lactate concentration [LAC] at lactate threshold, treadmill speed and [LAC] at exhaustion, and total testing time., Results: Echocardiography data revealed remodeling of the left atrium and left ventricular concentric hypertrophy at 6 and 18 weeks. Endocardial fractional shortening was greater in AoSG than CG at 6 and 18 weeks. Midwall fractional shortening was greater in AoSG than in CG only 6 week. Cardiac index was similar in CG and AoSG at 6 and 18 weeks and decreased between from 6 to 18 weeks in both groups. The E wave to A wave ratio was greater in CG than in AoSG at both periods and did not change in both groups between week 6 and 18. Treadmill stress testing parameters were similar in both groups at 6 or 18 weeks., Conclusion: Although AoS promotes isolated diastolic dysfunction or associated with systolic dysfunction at 6 or 18 weeks, it is not sufficient to modify physical stress tolerance.

Background: In pulmonary arterial hypertension (PAH) health-related quality of life (HRQOL) has been investigated over the short-term (weeks) but little is known about patient's perspective over the medium and long term., Objective: To analyze how patients on specific PAH therapies do over one year of observation in terms of HRQOL, and to investigate if possible associations between the exercise capacity (EC) and HRQOL persist over the medium term., Methods: Thirty-four patients on PAH therapies (bosentan and/or sildenafil) were enrolled (age 14 to 58 years, median 35.5 years, functional class II or III), and evaluated at baseline, and 3, 6, 9 and 12 months subsequently using the six-minute walk test and the SF-36 HRQOL questionnaire., Results: The six minute walked distance did not change over the follow-up (387-432 meters, median values, p=0.2775), the same for the functional class and peripheral oxygen saturation. The SF-36 scores also remained stable, with physical health always worse than mental health. Of 40 possible associations between EC and HRQOL, only 12 were significant (30%, p<0.05). Prediction of severely depressed HRQOL based on a walked distance of <235 meters was >90% specific but <43% sensitive., Conclusion: Patients with PAH who remain stable in terms of EC also seem to do so in terms of HRQOL. However, EC and HRQOL are not consistently tied over time, and should be analyzed as different perspectives in the individual patient.

Objective: To compare the behavior of the oxygen uptake efficiency slope (OUES) with that of oxygen uptake at peak exertion (VO₂peak)., Methods: This was a prospective cross-sectional study involving 21 patients (15 men) with mild-to-moderate COPD undergoing spirometry, handgrip strength (HGS) testing, cardiopulmonary exercise testing, and determination of lactate at peak exertion (LACpeak)., Results: Mean weight was 66.7 ± 13.6 kg, and mean age was 60.7 ± 7.8 years. With the exception of FEV₁ and FEV1/FVC ratio (75.8 ± 18.6 of predicted and 56.6 ± 8.8, respectively), all spirometric variables were normal, as was HGS. The patients exhibited significant metabolic and hemodynamic stress, as evidenced by the means (% of predicted) for VO₂peak (93.1 ± 15.4), maximum HR (92.5 ± 10.4), and OUES (99.4 ± 24.4), as well as for the gas exchange rate (1.2 ± 0.1). The correlation between VO₂peak and OUES was significant (r = 0.747; p < 0.0001). The correlation between HGS and VO₂peak (r = 0.734; p < 0.0001) was more significant than was that between HGS and OUES (r = 0.453; p < 0.05). Similar results were found regarding the correlations of VO₂peak and OUES with MIP. Although LACpeak correlated significantly with VO₂peak (r = -0.731; p < 0.0001), only LACpeak/maximum power correlated significantly with OUES (r = -0.605; p = 0.004)., Conclusions: Our findings suggest that, in mild-to-moderate COPD, VO2 determinants other than overall muscle strength have a greater impact on OUES than on VO₂peak.

Objective: To assess children and adolescents diagnosed with mild intermittent or mild persistent asthma, in terms of their aerobic capacity between attacks., Methods: We included 33 children and adolescents recently diagnosed with asthma (mild intermittent or mild persistent) and 36 healthy children and adolescents. Those with asthma were evaluated between attacks. All participants underwent clinical evaluation; assessment of baseline physical activity level; pre- and post-bronchodilator spirometry; and a maximal exercise test, including determination of maximal voluntary ventilation, maximal oxygen uptake, respiratory quotient, maximal minute ventilation, ventilatory equivalent, ventilatory reserve, maximal HR, SpO2, and serum lactate., Results: No significant differences were found among the groups (intermittent asthma, persistent asthma, and control) regarding anthropometric or spirometric variables. There were no significant differences among the groups regarding the variables studied during the maximal exercise test., Conclusions: A diagnosis of mild intermittent/persistent asthma has no effect on the aerobic capacity of children and adolescents between asthma attacks.

Step tests are typically used to assess exercise capacity. Given the diversity of step tests, the aim of this review was to describe the protocols that have been used in healthy subjects and in patients with chronic lung disease. Step tests for use in healthy subjects have undergone a number of modifications over the years. In most step tests, the duration is variable (90 s-10 min), but the step height (23.0-50.8 cm) and stepping rate (22.5-35.0 steps/min) remain constant throughout the test. However, the use of a fixed step height and constant stepping rate might not provide adequate work intensity for subjects with different levels of fitness, the workload therefore being above or below individual capacity. Consequently, step test protocols have been modified by introducing changes in step heights and stepping rates during the test. Step tests have been used in patients with chronic lung diseases since the late 1970s. The protocols are quite varied, with adjustments in step height (15-30 cm), pacing (self-paced or externally paced), and test duration (90 s-10 min). However, the diversity of step test protocols and the variety of outcomes studied preclude the determination of the best protocol for use in individuals with chronic lung disease. Shorter protocols with a high stepping rate would seem to be more appropriate for assessing exercise-related oxygen desaturation in chronic lung disease. Symptom-limited testing would be more appropriate for evaluating exercise tolerance. There is a need for studies comparing different step test protocols, in terms of their reliability, validity, and ability to quantify responses to interventions, especially in individuals with lung disease.

Unlabelled: Chronic and persistent mouth or oral breathing (OB) has been associated with postural changes. Although posture changes in OB causes decreased respiratory muscle strength, reduced chest expansion and impaired pulmonary ventilation with consequences in the exercise capacity, few studies have verified all these assumptions., Objective: To evaluate exercise tolerance, respiratory muscle strength and body posture in oral breathing (OB) compared with nasal breathing (NB) children., Material and Method: A cross-sectional contemporary cohort study that included OB and NB children aged 8-11 years old. Children with obesity, asthma, chronic respiratory diseases, neurological and orthopedic disorders, and cardiac conditions were excluded. All participants underwent a postural assessment, maximal inspiratory pressure (MIP), maximal expiratory pressure (MEP), the six-minute walk test (6MWT), and otorhinolaryngologic evaluation., Results: There were 107 children (45 OB and 62 NB). There was an association between abnormal cervical posture and breathing pattern: 36 (80.0%) OB and 30 (48.4%) NB presented abnormal head posture (OR=4.27 [95% CI: 1.63-11,42], p<0.001). The mean MIP and MEP were lower in OB (p=0.003 and p=0.004)., Conclusion: OB children had cervical spine postural changes and decreased respiratory muscle strength compared with NB.

A large body of evidence has suggested the existence of a reflex network that becomes hyperactive secondary to musculoskeletal alterations that occur in heart failure (HF) syndrome. Together with sympathoinhibitory cardiovascular reflexes, suppressed in the presence of the syndrome, heart failure can contribute to physical exercise intolerance. The hyperactivation of signals originated from receptors located in skeletal muscles (mechanoreceptors - metaboreceptors) is a recently proposed hypothesis to explain the origin of fatigue and dyspnea symptoms in HF. In HF, other alterations in the reflex control system, which are not mutually exclusive, contribute to dyspnea. The inappropriate stimulation of the arterial baroreceptors, with the consequent lack of inhibition of the muscle metaboreflex and carotid chemoreflex unloading and the increase in the renal vasoconstriction with angiotensin II release can also be considered. Although the functional alterations of the reflexes were used independently to illustrate the sympathetic excitation observed in HF, the interaction between these reflexes under normal and pathological conditions, especially its contribution to the sympathoexcitatory state found in HF, has not been broadly investigated. Therefore, questions about a possible association between the muscle receptors (mechano and metaboreceptors) in the genesis of the ergoreflex exacerbation, observed in HF, remain. Thus, the objective of this review was to integrate the knowledge on the mechano and metaboreflex (ergoreflex) in HF syndrome, as well as to clarify the influence of HF drug therapy on the ergoreflex.

Objective: To evaluate submaximal exercise tolerance and respiratory muscle strength in relation to forward head posture (FHP) and respiratory mode in children, comparing mouth-breathing (MB) children with nasal-breathing (NB) children., Methods: This was a controlled, analytical cross-sectional study involving children in the 8-12 year age bracket with a clinical otorhinolaryngology diagnosis of MB, recruited between October of 2010 and January of 2011 from the Mouth Breather Clinic at the State University of Campinas Hospital de Clínicas, located in the city of Campinas, Brazil. The exclusion criteria were obesity, asthma, chronic respiratory diseases, heart disease, and neurological or orthopedic disorders. All of the participants underwent postural assessment and the six-minute walk test (6MWT), together with determination of MIP and MEP., Results: Of the 92 children in the study, 30 presented with MB and 62 presented with NB. In the MB group, the differences between those with moderate or severe FHP and those with normal head posture, in terms of the mean MIP, MEP and six-minute walk distance (6MWD), were not significant (p = 0.079, p = 0.622, and p = 0.957, respectively). In the NB group, the mean values of MIP and MEP were higher in the children with moderate FHP than in those with normal head posture (p = 0.003 and p = 0.004, respectively). The mean MIP, MEP, and 6MWD were lower in the MB group than in the NB group. Values of MIP and MEP were highest in the children with moderate FHP., Conclusions: Respiratory biomechanics and exercise capacity were negatively affected by MB. The presence of moderate FHP acted as a compensatory mechanism in order to improve respiratory muscle function.

Background: Chronic heart failure (HF) is a syndrome characterized by reduced cardiac output in relation to the metabolic needs of the organism, as well as metabolic and neurohormonal axis abnormalities. Symptoms such as fatigue and dyspnoea are notorious and stress tests are widely used to assess functional capacity, prognosis and effectiveness of therapeutic interventions in this syndrome., Objective: To evaluate the reproducibility of the six-minute walk test (6MW) in patients with HF and correlate the magnitude of the variables reached at peak exercise of the 6MWT with a cardiopulmonary exercise test (CPET)., Methods: We studied 16 patients (12 men and 4 women) diagnosed with HF FC I-II (NYHA). The volunteers underwent two 6MWT (6MWT'1 and 6MWT'2) with 30-minute interval between them; then, they underwent a maximum CPET., Results: All variables obtained in the two 6MWT' proved to be significant with high correlations: distance walked (DW) (r = 0.93, p < 0.0001), heart rate (HR) (r = 0.89, p < 0.0001), oxygen consumption (VO2) (r = 0.93, p < 0.0001) and scale of perceived exertion (r = 0.85, p < 0.0001). In turn, all variables analyzed in the 6MWT' showed significant and moderate correlations with the variables obtained from the CPET, namely: peak HR (r = 0.66; p = 0.005); VO2 (r = 0.57; p = 0.02) and VO2 in the CPET and DT in the 6MWT'2 (r = 0.70; p = 0.002)., Conclusion: The 6MWT was reproducible in this group of patients with HF (NYHA - I-II) and correlated with the CPET. Therefore, it is a tool for reliable evaluation, and a suitable, safe and low-cost alternative for the prescription of aerobic exercise in patients with HF.

Background: The exercise treadmill test can be used in ventricular dysfunction patients for functional capacity or predicting prognosis. The cardiac image with 123I MIBG shows cardiac sympathetic activation., Objective: To evaluate the relationship between exercise treadmill test variables and cardiac image changes in 123I MIBG., Methods: 23 patients with LVEF ≤ 45% performed scintigraphy cardiac with 123I MIBG and divided into two groups. G1: Washout rate < 27%; G2: ≥ 27%. Systolic blood pressure (SBP), heart rate (HR) and functional capacity were evaluated. It was performed Student t test or Mann-Whitney U test, Spearman coefficient and linear regression., Results: SBP at exercise peak (G1: 181.00 ± 28.01; G2: 153.27 ± 27.71 mmHg, p = 0.027), SBP variation [G1: 64(47.5-80.5); G2: 36(25-47) mmHg, p = 0.015], the HR at exercise peak (G1: 136.91 ± 19.66; G2: 118.45 ± 13.98 bpm, p = 0.018) and chronotropic response (G1: 70.42 ± 17.94; G2: 49.47 ± 14.89%, p = 0.006), and functional capacity [G1: 8.37(6.47-10.27); G2: 4.42(2.46-6.38) METs, p = 0.003] were smaller in G2 group. There was negative correlation between Washout rate and SBP at exercise peak (r = -0.505, p = 0.014), variation in SBP (r = -0.493, p = 0.017) and functional capacity (r = -0.646, p = 0.001). Nevertheless, SBP at exercise peak (r = -0.422, p = 0.016) and functional capacity (r = -0.804, p = 0.004) were the only variables associated with Washout rate, after linear regression., Conclusion: In heart failure patients, the SBP at exercise peak and functional capacity were the variables associated with Washout rate.

Background: Increased pulmonary capillary pressure (PCP) is one of the mechanisms of exercise intolerance. Assessment of the diastolic function by echocardiography (ECHO) enables estimation of PCP., Objective: To identify variables that determine the exercise capacity in patients undergoing routine exercise test (ET), conventional ECHO, and tissue Doppler imaging (TD)., Methods: A total of 640 patients undergoing ET, ECHO, and TD were retrospectively studied. Patients with ejection fraction < 55% were excluded. Mitral annulus velocities by conventional Doppler imaging were obtained in early diastole (E) and late diastole (A), and TD of the mitral annulus measured early diastole (e') and late diastole (a') velocities. E/e'> 10 was considered an estimate of increased PCP. Maximal exercise capacity was analyzed by the number of metabolic equivalents (MET). The patients were divided into two groups for analysis: MET<7 (n=48) and MET>7 (n=572). Morise score showed a population at low risk (60%) for coronary artery disease (CAD)., Results: The number of patients with E/e' > 10 was significantly higher in the MET < 7 group in relation to the MET > 7 group (41.7% vs 9.4%, p=0.001), and so was the presence of any degree of diastolic dysfunction (76.6% vs 34.1% p=0.001). Using logistic regression analysis, age, female gender and A velocity (late diastole) were the independent variables related to a low exercise capacity (MET < 7)., Conclusion: Diastolic dysfunction as determined by ECHO, female gender, and age are associated with a lower exercise capacity in a population at low risk for CAD.

Over the last few years, the use of exercise tests has come to be recognized as a convenient method of evaluating respiratory function, because the reserves of the various systems in the human body should be known in order to provide a more complete portrayal of the functional capacities of the patient. Because walking is one of the main activities of daily living, walk tests have been proposed in order to measure the state or the functional capacity of patients. The six-minute walk test has proven to be reproducible and is well tolerated by patients. It evaluates the distance a person can walk on a flat, rigid surface in six minutes. Its main objective is to determine exercise tolerance and oxygen saturation during submaximal exercise. In this review, we present various clinical areas in which the test can provide useful data.

Objective: To determine the correlations among various dyspnea scales, spirometric data, exercise tolerance data, and the Body mass index, airway Obstruction, Dyspnea, and Exercise capacity (BODE) index in patients with COPD., Methods: Between March of 2008 and July of 2009, 79 patients with COPD were recruited, and 50 of those patients were included in the study. After being regularly treated with formoterol for one month, the patients completed the modified Medical Research Council (mMRC, dyspnea scale), Baseline Dyspnea Index (BDI), Oxygen Cost Diagram (OCD), and Shortness Of Breath Questionnaire (SOBQ). Subsequently, the patients underwent spirometry and six-minute walk tests (6MWTs), with determination of the six-minute walk distance (6MWD), as well as initial and final SpO2. All patients also completed the Visual Analogue Scale (VAS) and the Borg scale., Results: The best correlations were between the Borg scale and the VAS (r s = 0.79) and between the BDI and the SOBQ (r s = -0.73). Among the one-dimensional scales (the VAS, mMRC, OCD, and Borg scale), only the VAS correlated with the spirometric parameters, whereas the multidimensional scales BDI and SOBQ did correlate, but poorly. The MRC, BDI, and SOBQ correlated well with 6MWD. Among the spirometric data, inspiratory capacity (IC) and FVC had the strongest correlations with 6MWD. In the multivariate analysis, BDI and IC were selected as the best predictors of 6MWD., Conclusions: Multidimensional dyspnea scales should be applied in the evaluation of COPD patients.

Objective: To evaluate the effect of chemotherapy on the physical condition of patients with advanced lung cancer., Methods: We evaluated 50 patients with non-small cell lung cancer (in stages IIIB and IV) and Eastern Cooperative Oncology Group (ECOG) performance status scale scores between zero and two. All patients underwent chemotherapy using paclitaxel and platinum derivatives and were evaluated at three time points (prechemotherapy, postchemotherapy and six months after starting the treatment), at which the ECOG scale, the body mass index (BMI) and the six-minute walk distance (6MWD) were assessed., Results: Of the 50 patients included in the study, 14 died, 5 were excluded due to the worsening of their performance status, and 31 completed the six-month follow-up. There was no statistically significant difference between the time points of assessment for BMI (prechemotherapy vs. postchemotherapy, p = 1.00; and prechemotherapy vs. six months later, p = 0.218) or for 6MWD. Performance status improved, and this was especially due to the increase in the number of asymptomatic patients after the six-month follow-up (p = 0.031)., Conclusions: Chemotherapy had a beneficial effect on the performance status of the patients. No significant changes in BMI or 6MWD were found during the study period, which might suggest the maintenance of the physical condition of the patients.

Congestive heart failure is a pathology that limits the patient's physical function. This study analyzed one patient who was submitted to a cardiac rehabilitation program associated to Continuous Positive Airway Pressure (CPAP), by assessing the results of the six-minute walk test (6MWT) and a questionnaire on the quality of life and performing an echocardiographic assessment before the study and after six weeks. The distance walked by the patient increased from 152.5 m to 520.44 m at the 6MWT. The Minnesota questionnaire score decreased from 62 to 18. Ejection fraction increased from 33% to 36%. Therefore, the management chosen for this case improved the patient's physical performance and quality of life.

Objective: To determine whether the Body mass index, airway Obstruction, Dyspnea, and Exercise capacity (BODE) index correlates with health-related quality of life in patients with COPD., Methods: We evaluated 42 patients with COPD, quantifying the following: lung function parameters; anthropometric variables; exercise capacity, with the six-minute walk test; dyspnea, with the modified Medical Research Council (MRC) scale; the BODE index; and quality of life, with the modified Saint George's Respiratory Questionnaire (mSGRQ). Patients were divided into two groups by disease severity: FEV1 >or= 50% and FEV1 < 50%., Results: The mean BODE index was 2.58 ± 1.17 and 4.15 ± 1.81, respectively, for the FEV1 >or= 50% and FEV1 < 50% groups. There was a significant difference between the groups in terms of FEV1 and the FEV1/FVC ratio. There were moderate to significant correlations between the BODE index scores and all of the mSGRQ domains in the group of patients with FEV1 <50%., Conclusions: The BODE index score correlated with the scores of all of the mSGRQ domains in COPD patients with FEV1 < 50%. Therefore, COPD patients with FEV1 < 50% die sooner and have a poorer quality of life.

Background: VO2 may be predicted with base on anthropometric and physiological parameters for determined populations., Objective: To propose models for submaximal and maximal VO2 prediction in young Brazilian adults., Methods: A total of 137 volunteers (92 men) underwent graded maximal exercise test (GXT) in a cycle ergometer (MonarkTM, Br). Gas exchange and respiratory measurements were performed in an open circuit (AerosportTM TEEM 100, USA). In another group, 13 volunteers underwent GXT and a square wave test (SWT) in order to evaluate the external validity of Neder et al's formula, ACSM's formula, and of Astrand-Ryhming nomogram. The study design chosen was a cross-validation and the significance level was set at p < 0.05., Results: For men during submaximal exercises, a mathematical model was deduced with base on workload, body mass, and age, which explained 89% of the VO2 variation, with SEE (standard error of the estimate) = 0.33 l.min-1. For the maximum load in the male group, another model with the same variables explained 71% of VO2 variation, with SEE = 0.40 l.min-1. For women, 93% of VO2 variation could be explained, with SEE = 0.17 l.min-1, both in submaximal and maximal exercise, with only one equation by use e of the same independent variables., Conclusion: The models derived in the present study proved to be accurate to predict submaximal and maximal VO2 in young Brazilian adults. (Arq Bras Cardiol. 2010; [online]. ahead print, PP.0-0).

Background: Obesity can affect the cardiac autonomic modulation, blood lipid levels and the physical capacity., Objective: To study the effect of obesity on the heart rate variability (HRV), blood lipid levels and physical capacity of obese children., Methods: Thirty children aged 9 to 11 years were studied, divided in two groups: a) 15 obese children (O) aged 10.2 +/- 0.7 years and body mass index (BMI) between the 95th and the 97th percentiles; b) 15 non-obese children (NO) aged 9.8 +/- 0.7 years and BMI between the 5th and 85th percentiles. All children were submitted to an anthropometric and clinical assessment, analysis of the HRV at rest and a physical exercise protocol (PEP). Non-parametric tests were used to compare the variables between the groups. The level of significance was set at p < 0.05., Results: The waist circumference and levels of triglycerides were higher in O. The cardiac sympathetic activity in the standing position in normalized units (LF n.u.) was higher in O, 71.4%, when compared to NO, 56.3%. The low frequency/high frequency ratio (LF/HF) was 3.8 in O and 1.7 in NO. The PEP showed differences between the groups, with higher values observed in NO children regarding the total distance, time of exposure to PEP, peak oxygen consumption (VO2 peak) and metabolic equivalent (MET)., Conclusion: Obesity in children resulted in alterations in cardiac autonomic control in the standing position and decreased the physical capacity.

Background: Lack of a standardized and monitored technique to start rehabilitation of patients with acute coronary syndrome (ACS) in the coronary care unit., Objective: To describe the technique of and circulatory response to a 50-m walk (W50m)., Methods: Experimental cross-sectional study of 65 patients with ACS; of these, 36 (54%) with acute myocardial infarction (AMI), Killip I, 29 (45.2%) with unstable angina (UA), 61.5% males with age of 62.8 +/- 12.7 years. Walk was started 45+/-23 h after hospitalization. Parameters measured: systolic blood pressure (SBP mmHg), diastolic blood pressure (DBP mmHg), heart rate (HR bpm), double product (SBP mmHg X HR bpm), peripheral oxygen saturation (SpO2%), walking time, and exercise tolerance by Borg scale (BS). Measurements were taken while supine, sitting, in orthostasis (phase 1 [gravitational stress]), end of the walk, and after a 5-minute rest (phase 2 [exercise stress])., Results: Increased HR in response to the sitting gravitational stress (Delta=4.18) and with orthostasis (Delta=2.69) (p<0.001) was observed. At the end of walk, there was an elevation in SBP (Delta=4.84), (p<0.001), HR (Delta=4.68), (p<0.001) and DP (Delta=344.97), (p=0.004), and a reduction in SpO2 (Delta=-1.42), (p<0.001), with return to baseline values after 5 minutes. Walking time was 2'36''+/-1'17'', and exercise tolerance by BS was good. SBP response >or= 142 mmHg when sitting was associated with a significant increase (p=0.031) of 11 mmHg at exercise in 13 patients with overweight/obesity and 85% with hypertension. Adverse effects occurred in 19 (29.2%) patients and dizziness in 23.1%, which impaired the walk in three of them., Conclusion: In this sample, patients did not present severe collateral effects to W50m. 24 hours after a coronary event.

Background: Chronic heart failure is a major cardiovascular disorder., Objective: The aim of this study was to prospectively examine whether a 6-min walk test (6-MWT) result correlates with echocardiographic variables in patients with left ventricular systolic dysfunction and stable chronic heart failure., Methods: We prospectively studied 52 patients (65% male; mean age 60+/-11 years) who had chronic heart failure secondary to ischemic heart disease or idiopathic cardiomyopathy. All patients had left ventricular systolic dysfunction (ejection fraction

Objective: Although lean body mass (LBM) has been associated with mortality in patients with COPD, its influence on functional limitation is not clear. The objective of this study was to analyze the cardiopulmonary variables in COPD patients with or without LBM depletion, prior to and after the six-minute walk test (6MWT)., Methods: We evaluated COPD patients, 32 with LBM depletion and 36 without. All patients underwent clinical evaluation, spirometry, evaluation of body mass composition and 6MWT, as well as completing questionnaires related to quality of life and perception of dyspnea., Results: No significant differences in the severity of airway obstruction, perception of dyspnea and quality of life scores were found between the groups. The distance covered on the 6MWT was similar in COPD patients with and without LBM depletion (470.3 +/- 68.5 m vs. 448.2 +/- 89.2 m). However, patients with LBM depletion presented significantly greater differences between baseline and final values in terms of heart rate and Borg scale index for lower limb fatigue. There was a significant positive correlation between distance covered on the 6MWT and FEV1 (r = 0.381, p = 0.01)., Conclusions: In the patients studied, functional exercise tolerance and quality of life were unaffected by LBM depletion. However, the patients with LBM depletion presented more pronounced lower limb fatigue during the 6MWT, which underscores the importance of the evaluation and treatment of systemic manifestations in COPD patients.

This study aimed at establishing the cross-cultural equivalence of scales used to evaluate physical activity level and measure cardiorespiratory fitness, for further application in elderly subjects. Three scales were identified after systematic review: Veterans Physical Activity Questionnaire (VSAQ), Rating of Perceived Capacity (RPC), and Physical Activity Rating (PA-R). The model proposed by Herdman et al. was applied to analyze equivalence. Test-retest reliability was calculated in a sample of 12 elderly subjects (74.5 +/- 3.5 years) using Lin's concordance coefficient and intraclass correlation coefficient. Good reproducibility was detected in all scales except RPC. Due to the small sample size, hardly any conclusions can de drawn, but the results point to the need for changes in the original scale's structures. The findings also suggest the adequacy of the scale's Portuguese-language version, although further validity studies appear to be necessary.

Objective: To translate the London Chest Activity of Daily Living (LCADL) scale into Portuguese and to determine whether this version is reproducible in Brazilian patients with severe chronic obstructive pulmonary disease (COPD)., Methods: The LCADL scale was translated into Portuguese and then back-translated into English. This pilot Brazilian Portuguese version was administered to 8 patients with COPD, and possible text-related problems were investigated. The principal problems were discussed with the authors of the original scale, and a final translated version was arrived at. At the study outset, two observers administered this final version (twice in one day) to 31 patients with COPD. One of those observers again administered the scale to the same patients 15-20 days later. At baseline, the patients were submitted to pulmonary function testing and to the six-minute walk test (6MWT)., Results: The Brazilian Portuguese version of the LCADL scale demonstrated excellent reproducibility in the total score and in most of the questions, with an inter-rater Cronbach's alpha coefficient of 0.97 (95% CI: 0.89-0.97; p < 0.01) and an intra-rater Cronbach's alpha coefficient of 0.96 (95% CI: 0.83-0.96; p < 0.01). The total score presented a negative correlation with forced expiratory volume in one second in liters (r = -0.49; p < 0.05) and with distance covered on the 6MWT (r = -0.56; p < 0.05)., Conclusion: The Brazilian Portuguese version of the LCADL scale is a reliable, reproducible, and valid instrument for evaluating dyspnea during activities of daily living in patients with severe COPD.