High Cardiorespiratory Optimal Point Values Are Related to Cardiovascular Mortality in Men Aged 46 to 70 Years: a Prospective Cohort Study

Abstract Background: Several hemodynamic and respiratory variables measured during cardiopulmonary exercise testing (CPX) have been shown to predict survival. One such measure is the cardiorespiratory optimal point (COP) that reflects the best possible circulation-respiration interaction, but there are still limited data on its relationship with adverse outcomes. Objective: To assess the association between COP and cardiovascular mortality in men aged 46 to 70 years. Methods: A sample of 2201 men who had anthropometric, clinical, and COP data obtained during cycling CPX between 1995 and 2022 was extracted from the CLINIMEX Exercise cohort. COP was identified as the minimal minute-to-minute VE/VO2 during CPX. Vital data were censored on October 31, 2022 for ICD-10-identified cardiovascular deaths. Cox proportional hazard models were used to estimate hazard ratios (HRs) with 95% confidence intervals (95% CIs). Results: The mean ± standard deviation age was 57 ± 6 years and the median COP value was 24 (interquartile range = 21.2 to 27.4). During a mean follow-up of 4688 ± 2416 days, 129 (5.6%) patients died from cardiovascular causes. The death rates for low (< 28), high (28 to 30), and very high (> 30) categories of COP were 3.2%, 9.6%, and 18.7%, respectively. Following adjustment for age, history of myocardial infarction, diagnosis of coronary artery disease, and diabetes mellitus, the HR (95% CI) for cardiovascular mortality comparing very high versus low COP was 2.76 (1.87 to 4.07; p < 0.001). Conclusions: Our data indicate that, for a general population-based sample of men, COP > 30 represents a considerably higher risk for cardiovascular death. Information on COP could assist cardiovascular risk assessment in men.

Early and mid-term results of Fontan operation versus anatomic correction for congenitally corrected transposition of the great arteries: A retrospective cohort study in a single center / 中国胸心血管外科临床杂志

@#Objective     To compare the early and mid-term results between Fontan operation and anatomic correction for congenitally corrected transposition of the great arteries (ccTGA). Methods     The clinical data of 53 patients with ccTGA who underwent anatomic correction and Fontan operation from January 2009 to September 2021 in our hospital were reviewed, including 41 males and 12 females with a mean age of 55.02 (3-168) months. They were divided into an anatomic correction group (16 patients) and a Fontan operation group (37 patients) according to the operation. The hospitalization mortality, survival rate, postoperative complications, and free rate from re-intervention between the two groups were compared. Another 180 healthy children were recruited as a control group, and 14 children were matched with the propensity score matching method as a Fontan control group. The results of cardiopulmonary exercise testing (CPET) between the Fontan operation group and the Fontan control group were compared. Results     There were 2 (12.5%) early deaths and 3 (18.8%) early re-intervention in the anatomic correction group, while 1 death and 2 re-intervention in the Fontan operation group. In addition, there were 9 patients (56.3%) in the anatomic correction group and 6 (16.2%) patients in the Fontan operation group suffering from arrhythmia after operation, respectively. Compared with the anatomic correction group, cardiopulmonary bypass time, aortic cross-clamping time, intubation time and ICU stay were significantly shortened in the Fontan operation group (P<0.05). CPET results showed that, percent predicted max VO2 in the Fontan operation group was lower than that in the Fontan control group (0.84±0.11 vs. 0.99±0.12, P<0.05). The patients were followed up for 0.5-126.0 months. Two patients were lost in the Fontan operation group. There was no death and 1 re-intervention in the anatomic correction group, while no death or re-intervention in the Fontan operation group. The 1-year, 5-year and 10-year transplant-free survival rate of the anatomic correction group and the Fontan operation group was 87.5%, 87.5%, 87.5% and 97.3%, 97.3%, 97.3%, respectively (P>0.05). The 48 patients were classified as grade Ⅰ-Ⅱ in cardiac function in the last follow-up. Conclusion     There is no statistical difference in the transplant-free survival rate between the anatomic correction and the Fontan operation group. The postoperative complications in the Fontan operation group are decreased than those in the anatomic correction group. The Fontan operation is also a good choice, even though the patients with ccTGA meet the condition of the procedure of anatomic correction.

Effects of individualized exercise on the cardiopulmonary functioning of senile persons with chronic obstructive pulmonary disease / 中华物理医学与康复杂志

Objective:To explore any effect of following an individualized exercise program on the cardio-pulmonary health of elderly persons with stable chronic obstructive pulmonary disease (COPD).Methods:A total of 120 elderly COPD patients were randomly divided into an experimental group and a control group, each of 60. Both groups were given medication and routine rehabilitation treatment for 3 months, but the experimental group also followed an individualized exercise program based on the cardiopulmonary exercise test. Before and after the treatment, Borg scoring was used to assess the subjects′ degree of dyspnea. Forced expiratory volume (FEV 1), forced vital capacity (FVC), maximum oxygen uptake (VO 2max), anaerobic threshold (AT), heart rate (HR) and a heart index (CI) were also recorded. The 6-minute walk test (6 MWD) was administered to evaluate the rehabilitation effect. Results:There were no significant differences in the average Borg scores, cardiopulmonary function indexes or 6MWD distances between the two groups before treatment. After the treatment significant improvement was observed in all of the measurements in both groups, but at that point all of the experimental group′s averages were better than those of the control group.Conclusion:Individualized exercise based on the cardiopulmonary exercise test can alleviate the symptoms of dyspnea in elderly COPD patients, improve their cardiopulmonary functioning and exercise endurance and improve the rehabilitation effect.

Application of exercise testing in the diagnosis and evaluation of cardiovascular diseases in children / 国际儿科学杂志

In recent years, exercise testing has been increasingly used in pediatrics, especially in pediatric cardiovascular diseases.Its ability to monitor heart rate, blood pressure, electrocardiogram, oxygen saturation, and expiratory gas analysis is of great clinical value.In pediatric cardiovascular diseases, exercise testing can further evaluate arrhythmias, facilitate the differential diagnosis of syncope, and detect early myocardial perfusion defects in children with cardiomyopathy and Kawasaki disease; in addition, expiratory gas analysis of exercise testing can assess cardiorespiratory fitness in children and the operative results of congenital heart disease, etc.This article reviews the use of exercise testing in children with arrhythmias, cardiomyopathy, congenital heart disease, and Kawasaki disease.

Respiratory gas kinetics in patients with congestive heart failure during recovery from peak exercise

Abstract Background Cardiopulmonary Exercise Testing (CPX) is essential for the assessment of exercise capacity for patients with Chronic Heart Failure (CHF). Respiratory gas and hemodynamic parameters such as Ventilatory Efficiency (VE/VCO2 slope), peak oxygen uptake (peak VO2), and heart rate recovery are established diagnostic and prognostic markers for clinical populations. Previous studies have suggested the clinical value of metrics related to respiratory gas collected during recovery from peak exercise, particularly recovery time to 50% (T1/2) of peak VO2. The current study explores these metrics in detail during recovery from peak exercise in CHF. Methods Patients with CHF who were referred for CPX and healthy individuals without formal diagnoses were assessed for inclusion. All subjects performed CPX on cycle ergometers to volitional exhaustion and were monitored for at least five minutes of recovery. CPX data were analyzed for overshoot of respiratory exchange ratio (RER=VCO2/VO2), ventilatory equivalent for oxygen (VE/VO2), end-tidal partial pressure of oxygen (PETO2), and T1/2 of peak VO2 and VCO2. Results Thirty-two patients with CHF and 30 controls were included. Peak VO2 differed significantly between patients and controls (13.5 ± 3.8 vs. 32.5 ± 9.8 mL/Kg*min−1, p < 0.001). Mean Left Ventricular Ejection Fraction (LVEF) was 35.9 ± 9.8% for patients with CHF compared to 61.1 ± 8.2% in the control group. The T1/2 of VO2, VCO2 and VE was significantly higher in patients (111.3 ± 51.0, 132.0 ± 38.8 and 155.6 ± 45.5s) than in controls (58.08 ± 13.2, 74.3 ± 21.1, 96.7 ± 36.8s; p < 0.001) while the overshoot of PETO2, VE/VO2 and RER was significantly lower in patients (7.2 ± 3.3, 41.9 ± 29.1 and 25.0 ± 13.6%) than in controls (10.1 ± 4.6, 62.1 ± 17.7 and 38.7 ± 15.1%; all p < 0.01). Most of the recovery metrics were significantly correlated with peak VO2 in CHF patients, but not with LVEF. Conclusions Patients with CHF have a significantly blunted recovery from peak exercise. This is reflected in delays of VO2, VCO2, VE, PETO2, RER and VE/VO2, reflecting a greater energy required to return to baseline. Abnormal respiratory gas kinetics in CHF was negatively correlated with peak VO2 but not baseline LVEF.

Development of a reference equation for maximal exercise capacity in normal Indian subjects using cardiopulmonary exercise testing

Objectives: Cardiopulmonary exercise testing (CPET) is an integrative assessment of multiple interdependent variables contributing to exercise response. CPET parameters such as maximum or peak oxygen uptake (VO2max/peak) are used to estimate this response. VO2max/peak varies with physiological predictors such as age, sex, body mass index (BMI), and activity level. The existing normative values for Indian subjects have, thus, far been adapted from Western populations who have a different body habitus in terms of these physiological predictors. We aimed to determine the relation and a prediction equation of these variables with VO2peak. Materials and Method: One hundred and twenty-one healthy subjects underwent CPET on a treadmill (Cortex Metalyzer) in a tertiary care hospital and VO2peak was calculated through Metasoft software. Statistical analysis: Student’s t-test and one-way analysis of variance (ANOVA) were used for calculating the between-group difference. Logistic regression with univariate and multivariate ANOVA was used for computing the reference equation. Results: Mean VO2peak (ml/min/kg) was 29.9 ± 7.7. It was higher for males (32.81 ± 7.9 vs. 26.79 ± 6.1 [P < 0.001]) and active individuals (32.8 ± 7 vs. 26.1 ± 6.9 [P < 0.001]). Higher values were observed in younger and non-obese population (P < 0.001). Regression coefficient (r2) was 0.44 and 0.36 for male and female, respectively. Reference equation was then calculated for males and females using the r2 value. Conclusion: VO2peak was higher in males and active individuals, it declined with increasing age and BMI. The values obtained were much lower than the Western population, therefore stressing the need for the development of our own set of reference equations.

Spine curvature and the cardiopulmonary exercise endurance of adolescents with idiopathic scoliosis / 中华物理医学与康复杂志

Objective:To quantify any correlation between the severity of spinal curvature of an adolescent with idiopathic scoliosis and their cardiopulmonary exercise endurance.Methods:The cardiopulmonary exercise test (CPET) results and the full-length spinal X-rays in a standing position of 64 adolescents with idiopathic scoliosis were reviewed retrospectively. Independent t-tests were used to compare the two datasets obtained from those with left or right thoracic scoliosis. The correlation between the Cobb angle and cardiopulmonary exercise endurance was analyzed using Pearson correlation coefficients, multiple factor linear regression and two-stage linear regression.Results:After adjusting for gender, age, height and weight, the multiple linear regression analysis showed that the Cobb angle was significantly negatively correlated with maximum tidal volume (β=-0.013) and significantly positively correlated with the rate of respiration (β=0.421). The relationship between the Cobb angle and cardiopulmonary exercise endurance was non-linear. With a Cobb angle > 34°, a 1° increase reduces cardiopulmonary exercise endurance by a factor of 1.4 on average. At smaller Cobb angles the corresponding increase is about 0.87 times.Conclusions:The Cobb angle is a negative predictor of ventilation during exercise among adolescents with idiopathic scoliosis. The more severe a patient′s spinal curvature, the lower the cardiopulmonary exercise endurance is likely to be.

Combining ventilation efficiency and peak systolic blood pressure in prognostic assessment of patients with chronic heart failure / 中华全科医师杂志

Objective:To analyze the value of minute ventilation to carbon dioxide production slope (VE/VCO 2 slope) combined with peak systolic blood pressure (SBP) in predicting prognosis for patients with chronic heart failure (CHF). Methods:A total of 170 patients with CHF who visited the Cardiac Rehabilitation Center of Tongji Hospital Affiliated to Tongji University and completed cardiopulmonary exercise test from March 2007 to December 2018 were enrolled in the study. The clinical data, cardiopulmonary exercise testing results and follow-up information of patients were collected to explore the predictors of all-cause mortality in patients with CHF.Results:The median follow-up time was 647 (182-1 764) days. All-cause death occurred in 34 patients. Compared with surviving patients, the proportion of diabetes and angiotensin-converting enzyme inhibitor/angiotensin Ⅱ receptor blocker (ACEI/ARB) use in fatal patients was significantly higher ( P<0.01). The VE/VCO 2 slope and peak SBP*VE/VCO 2 in the fatal patients were significantly higher, and the peak oxygen consumption (peak VO 2) was lower than those in the surviving patients ( P<0.01). The areas under the receiver operating characteristic curve (AUC) of VE/VCO 2 slope and peak SBP*VE/VCO 2 in predicting all-cause mortality in patients with CHF were 0.648 ( P=0.008) and 0.681 ( P=0.001), respectively; the optimal thresholds were >40.95 ( P=0.008) and > 5 423.50 mmHg (1 mmHg=0.133 kPa, P=0.006), the sensitivity was 0.559 and 0.588, and the specificity was 0.728 and 0.735, respectively. Multivariate Cox regression analysis showed that after adjusting for age, gender, diabetes and ACEI/ARB use, VE/VCO 2 slope ( HR=2.12, P=0.036) and peak SBP*VE/VCO 2 ( HR=2.42, P=0.016) were independent risk factors for all-cause mortality in patients with CHF. Conclusion:Compared to the traditional index VE/VCO 2 slope, a novel index peak SBP* VE/VCO 2 provides a relatively better predictive value for all-cause death of CHF patients.

The exercise tolerance and ventilatory efficiency of lung cancer patients with type 2 diabetes / 中华物理医学与康复杂志

Objective:To explore the aerobic exercise tolerance and ventilatory efficiency during cardiopulmonary exercise testing (CPET) of persons with non-small cell lung cancer (NSCLC) complicated by type 2 diabetes mellitus (T2DM).Methods:Forty-eight persons with NSCLC and T2DM formed an NSCLC-T2DM group while another 48 persons with NSCLC but not T2DM formed an NSCLC-non T2DM group. Another 24 healthy counterparts were enrolled into the control group. All completed CPET before pneumonectomies were performed on those with NSCLC. Indexes of static pulmonary function, exercise tolerance, heart rate recovery, ventilation efficiency and gas exchange were computed.Results:Compared with the control group, both NSCLC groups had, on average, lower peak oxygen uptake (VO 2peak), lower anaerobic thresholds (ATs) and lower peak O 2 pulse rates. They also had higher average VE/VCO 2 slopes and VE/VCO 2 nadirs. Compared with the NSCLC-non T2DM group, those with T2DM had a significantly lower average VO 2peak and WRpeak, as well as significantly higher average VE/VCO 2 slope and VE/VCO 2 nadir. Compared with the control group, the average VO 2 and VCO 2 of both NSCLC groups was lower at the AT and during peak exercise, with the NSCLC-T2DM group′s averages significantly lower than those of the NSCLC-non T2DM group during peak exercise. During warm-up and at the AT, the NSCLC groups had a significantly higher average heart rate than the control group. Then, compared with the control group and the NSCLC-non T2DM group, the average heart rate in the NSCLC-T2DM group decreased significantly more slowly during the first three minutes of the recovery period. Compared with the control group, the VE/VCO 2 values of the NSCLC groups were significantly higher at the AT and during peak exercise. During the warm-up and at the AT, the average partial pressures of end-tidal carbon dioxide in the NSCLC groups were significantly lower than among control group, and during peak exercise the NSCLC-T2DM group′s average value was significantly lower than the control group′s. Compared with the control group and the NSCLC-non T2DM group, the NSCLC-T2DM group′s average forced expiratory volume in one second, forced vital capacity, peak expiratory flow rate and maximum voluntary ventilation were all significantly lower. Conclusions:Diabetes impairs the exercise tolerance and ventilation efficiency of persons with NSCLC. Without diabetes their exercise tolerance and ventilation efficiency would be impaired only slightly. CPET can provide a basis for risk assessment before pneumonectomy.

Cardiopulmonary exercise test in patients with refractory angina: functional and ischemic evaluation

Abstract Objectives Refractory angina (RA) is a chronic condition clinically characterized by low effort tolerance; therefore, physical stress testing is not usually requested for these patients. Cardiopulmonary exercise testing (CPET) is considered a gold standard examination for functional capacity evaluation, even in submaximal tests, and it has gained great prominence in detecting ischemia. The authors aimed to determine cardiorespiratory capacity by using the oxygen consumption efficiency slope (OUES) in patients with refractory angina. The authors also studied the O2 pulse response by CPET and the association of ischemic changes with contractile modifications by exercise stress echocardiography (ESE). Methods Thirty-one patients of both sexes, aged 45 to 75 years, with symptomatic (Canadian Cardiovascular Society class II to IV) angina who underwent CPET on a treadmill and exercise stress echocardiography on a lower limb cycle ergometer were studied. ClinicalTrials.gov: NCT03218891. Results The patients had low cardiorespiratory capacity (OUES of 1.74 ± 0.4 L/min; 63.9±14.7% of predicted), and 77% of patients had a flattening or drop in O2 pulse response. There was a direct association between Heart Rate (HR) at the onset of myocardial ischemia detected by ESE and HR at the onset of flattening or drop in oxygen pulse response detected by CPET (R = 0.48; p = 0.019). Conclusion Patients with refractory angina demonstrate low cardiorespiratory capacity. CPET shows good sensitivity for detecting abnormal cardiovascular response in these patients with a significant relationship between flattening O2 pulse response during CEPT and contractile alterations detected by exercise stress echocardiography. Highlights OUES analysis is useful for assessing functional capacity in refractory angina. O2 pulse curve is correlated with contractile alterations in exercise echocardiogram. Cardiopulmonary exercise test is useful toll in patients with refractory angina.

Tolerancia a la prueba ergométrica graduada al utilizar barbijo o tapaboca / Exercise Testing Tolerance when Using Face Mask

RESUMEN Introducción: es poco conocida la tolerancia al ejercicio con el uso de barbijo. Objetivo: investigar tolerancia al barbijo en ergometrías (PEG). Material y métodos: estudio multicéntrico con PEG con barbijo. Resultados: 118 PEG (62 cinta, 56 cicloergómetro), 68 hombres, edad 46,74 ± 16,7 años. Setenta (59,3%) completaron PEG con barbijo, 48 (40,7%) debieron retirarlo: 17 en cinta (27,4%), 31 (55,4%) en bicicleta (p = 0,002). Porcentaje de frecuencia cardíaca al retirar barbijo con respecto a máxima alcanzada: 94,5±5,35%. Edad de quienes retiraron barbijo: 42,69±17,35 años y de quienes toleraron: 49,51 ± 15,88 (p = 0,003). Saturación basal: 97,46 ± 1,01%; en esfuerzo máximo con barbijo: 96,58 ± 1,37% (p <0,0001). Al retirar barbijo, saturación de 97,06 ± 1,35% (p < 0.0001). Edad menor y uso de cicloergómetro fueron predictores de no tolerar el barbijo. Conclusiones: la mayoría completó el ejercicio máximo con barbijo. La intensidad de ejercicio al retirar el barbijo fue alta. La saturación cayó en ejercicio con barbijo, aunque sin repercusión clínica.

ABSTRACT Background: Tolerance to exercise with the use of face mask is not well known. Objective: The aim of this study was to investigate the tolerance of exercise parameters during exercise stress testing (EST) while wearing a face mask. Methods: Multicenter study of EST while wearing face mask. Results: 118 ESTs (62 on treadmill, 56 on cycle ergometer), 68 men, age 46.74 ± 16.7 years. Seventy patients (59.3%) completed the EST wearing a face mask, and 48 (40.7%) removed it; 17 patients (27.4%) were on treadmill and 31 (55.4%) on cycle ergometer (p = 0.002). Percentage of maximum predicted heart rate attained when the patients removed their face mask: 94.5 ± 5.35%. Age of those who removed the face mask: 42.69 ± 17.35 years and of those who tolerated the face mask: 49.51 ± 15.88 years (p = 0.003). Baseline SpO2 was 97.46 ± 1.01% and 96.58 ± 1.37% on peak exercise wearing face mask (p < 0.0001). SpO2 when the face mask was removed: 97.06 ± 1.35% (p <0.0001). Younger age and use of cycle ergometer were predictors of intolerance to face mask. Conclusion: Most patients completed peak exercise with face mask. Exercise intensity was high when the face mask was removed. Oxygen saturation dropped during exercise with face mask without clinical impact.

Effect of Exercise-based Cardiac Rehabilitation on Patients with Acute Coronary Syndrome after Percutaneous Coronary Intervention / 中国康复理论与实践

Objective:To analyze the effects of exercise-based cardiac rehabilitation (ER) on patients with acute coronary syndrome (ACS) after percutaneous coronary intervention (PCI), and to identify which type of ACS patients would benefit most in terms of cardiovascular functional capacity after ER. Methods:From December, 2017 to July, 2019, 31 ACS patients who discharged in a stable situation after PCI were studied. All patients were referred to a three-month ER program after discharge. They were divided into normal wall motion group (normal group, n = 14) and abnormal regional wall motion group (abnormal group, n = 17) according to baseline myocardial wall motion reported by echocardiography. The degree of wall motion abnormalities was quantified by the wall motion score index (WMSI). Echocardiography and cardiopulmonary exercise testing (CPET) were performed before and after ER. Results:Eight patients were dropped, and 23 patients completed the trial. WMSI decreased in the abnormal group (Z = -2.852, P = 0.004), and the left ventricular ejection fraction (LVEF) didn't change in both groups (P > 0.05) after ER. CPET showed that the heart rate at rest decreased in the normal group after ER (t = -2.268, P = 0.047); and the peak work rate, peak oxygen uptake, percentage of predicted value of peak oxygen uptake, peak minute ventilation and the third minute heart rate recovery increased in the abnormal group after ER (t > 2.739, P < 0.05). Conclusion:ER during recovery period could help more improve the cardiac function and exercise tolerance of ACS patients with abnormal WMSI after PCI. WMSI is an important indicator of cardiac function in ACS patients with preserved ejection fraction.

Relationship of Ventilatory Efficiency to Cardiac Function after Exercise in Patients with Chronic Obstructive Pulmonary Disease / 中国康复理论与实践

Objective:To observe the relationship of ventilatory efficiency to cardiac function, especially heart rate recovery after exercise for patients with chronic obstructive pulmonary disease (COPD). Methods:From January, 2019 to December, 2020, 190 patients with COPD were recruited for Cardiopulmonary Exercise Testing. The general condition, medical history and medication history, lung function test and parameters of Cardiopulmonary Exercise Testing were recorded. They were divided into normal group and delay group according to whether the heart rate decline more than twelve beats within a minute after Cardiopulmonary Exercise Testing. Results:There were 89 patients (46.84%) in the delay group. Compared with the normal group, the delay group were older (Z = 2.282, P < 0.05), with less ratio of force exiratory volume in the first second in prediction (FEV1.0%) (Z = 3.626, P < 0.001), maximum power (t = 5.547, P < 0.001), breath reserve (BR) (t = 2.122, P < 0.05) and higher minimum ventilation equivalent of carbon dioxide (VE/VCO2nadir) (Z = 3.296, P = 0.001). Logistic regression showed that the COPD severity, VE/VCO2nadir and BR correlated with heart rate recovery. After adjusting for gender, age, body mass index and COPD severity, VE/VCO2nadir was an independent risk factor for delayed heart rate recovery (OR = 1.203, 95%CI 1.032 to 1.873, P = 0.004), and the best cut-off point was 33.15 (AUC = 0.6387, 95%CI 0.5595 to 0.7178, P = 0.001). Conclusion:The ventilatory inefficiency may increase the risk of abnormal heart rate recovery after exercise in COPD patients.

Reliability and validity of six-minute step test in patients with heart failure

Exercise intolerance is the hallmark consequence of advanced chronic heart failure (HF). The six-minute step test (6MST) has been considered an option for the six-minute walk test because it is safe, inexpensive, and can be applied in small places. However, its reliability and concurrent validity has still not been investigated in participants with HF with reduced ejection fraction (HFrEF). Clinically stable HFrEF participants were included. Reliability and error measurement were calculated by comparing the first with the second 6MST result. Forty-eight hours after participants underwent the 6MST, they were invited to perform a cardiopulmonary exercise test (CPET) on a cycle ergometer. Concurrent validity was assessed by correlation between number of steps and peak oxygen uptake (V̇O2 peak) at CPET. Twenty-seven participants with HFrEF (60±8 years old and left ventricle ejection fraction of 41±6%) undertook a mean of 94±30 steps in the 6MST. Intra-rater reliability was excellent for 6MST (ICC=0.9), with mean error of 4.85 steps and superior and inferior limits of agreement of 30.6 and -20.9 steps, respectively. In addition, strong correlations between number of steps and CPET workload (r=0.76, P<0.01) and peak V̇O2 (r=0.71, P<0.01) were observed. From simple linear regression the following predictive equations were obtained with 6MST results: V̇O2 peak (mL/min) = 350.22 + (7.333 × number of steps), with R2=0.51, and peak workload (W) = 4.044 + (0.772 × number of steps), with R2=0.58. The 6MST was a reliable and valid tool to assess functional capacity in HFrEF participants and may moderately predict peak workload and oxygen uptake of a CPET.

Study protocol of a single-arm pre-post study to assess the preliminary effectiveness and feasibility of a home-based bimodal prehabilitation program on preoperative aerobic fitness in high-risk patients scheduled for liver or pancreatic resection

Background:Controversial evidence currently exists regarding the feasibility and effectiveness to improve preoperative aerobic fitness during home-based prehabilitation in patients scheduled for liver or pancreatic resection, whereas morbidity rates are high following these resections. The primary aim of this study is to evaluate the preoperative oxygen uptake (VO2) at the ventilatory anaerobic threshold before and after a four-week home-based preoperative training program with nutritional supplementation in high-riskpatients scheduled for elective liver or pancreatic resection. Secondary aims are to evaluate program feasibility, immune system function, cardiopulmonary exercise test responses, individual progression profiles on training responses, quality of life, andpostoperative course.Methods:In this multicenter study with a pretest-posttest design, patients with a liver or pancreatic tumor scheduled for elective resection will be recruited. To select the high-risk fraction of this surgical population, their VO2at the ventilatory anaerobic threshold should be <11 ml/kg/min for final inclusion. A planned total of 24 high-risk patients will participate in a four-week (three sessions per week) home-based bimodal prehabilitation program. The partly supervised home-based preoperative training program consists of individualized goal setting followed by titration of interval and endurance training on an advanced cycle ergometer, combined with functional task exercises. Additionally, patients will be given protein and vitamin/mineral supplementation.Discussion: Effects of a partly supervised home-based bimodal prehabilitation regimen are unknown in high-risk patients opting for liver or pancreatic resection. Improved preoperative aerobic fitness might translate into improved postoperative outcomes and a reduced demand on care resources.Trial Registration:The study is registered in the Netherlands Trial Registry (NL6151) and was approved by the Institutional Ethics Committee, Twente, Enschede, the Netherlands (P17-08)

Effect of Individualized Moderate-intensity Exercise Prescription on Cardiopulmonary Function for Patients with Pulmonary Arterial Hypertension / 中国康复理论与实践

Objective:To analyze the cardiopulmonary function of stable patients with pulmonary arterial hypertension (PAH), and to explore effects of the cardiopulmonary exercise testing (CPET)-based individualized moderate-intensity exercise prescription on cardiopulmonary functional reserve and exercise capacity in patients with PAH. Methods:From April, 2018 to July, 2019, 31 stable patients with PAH (PAH group) and 32 healthy counterparts (normal group) were enrolled. All subjects underwent CPET. PAH group was assessed with 6-Minute Walking Test (6MWT), and then was divided into exercise group (n = 16) and control group (n = 15). Both groups were treated with ordinary targeted drugs, while the exercise group was additionally provided with an individualized moderate-intensity exercise prescription of △50% power treadmill training, five days a week for eight weeks. CPET and 6MWT were conducted again after intervention. Results:Before intervention, body mass, body mass index (BMI), force vital capacity (FVC), forced expiratory volume in one second (FEV1), maximum voluntary ventilation (MVV), anaerobic threshold (AT), peak heart rate (HRpeak), peak systolic blood pressure (SBPpeak), peak load power (WRpeak), peak oxygen uptake (VO2peak), peak oxygen pulse (VO2/HRpeak), peak cardiac output (COpeak), peak minute ventilation (VEpeak), peak end-tidal carbon dioxide (PETCO2peak), peak pulse oxygen saturation (SpO2peak) and oxygen uptake efficiency plateau (OUEP) were significantly lower (t > 2.419, P < 0.05), and the rest heart rate (HRrest), peak dead space to tidal volume ratio (VD/VTpeak), minimum ventilatory equivalent for carbon dioxide (Lowest VE/VCO2) and slope of ventilatory equivalent for carbon dioxide (VE/VCO2 slope) were higher (|t| > 2.615, P < 0.05) in PAH group than in the normal group. After intervention, FEV1, MVV, VO2peak (ml/min/kg) and VO2/HRpeak decreased in the control group (t > 2.272, P < 0.05); FVC, FEV1, MVV, AT, SBPpeak, WRpeak, VO2peak, VO2/HRpeak, COpeak, VEpeak, PETCO2peak, SpO2peak and 6-Minute Walking Distance (6MWD) increased (|t| > 2.167, P < 0.05), while the average Lowest VE/VCO2 and VE/VCO2 slope decreased (t > 2.264, P < 0.05) in the exercise group. Compared with the control group, the FEV1/FVC, AT, WRpeak, VO2peak, VO2/HRpeak, COpeak and 6MWD increased in the exercise group (|t| > 2.168, P < 0.05). Conclusion:The holistic cardiopulmonary function of stable patients with PAH decreases. CPET-based individualized moderate-intensity exercise could enhance the cardiopulmonary functional reserve and exercise capacity of patients with PAH.

Determinants of Work in the Six-Minute Walk Test in School-Age Children / Determinantes do trabalho no Teste de Caminhada de Seis Minutos em escolares

Abstract Introduction: The Six-Minute Walk Test (6MWT) is widely used to assess functional capacity in children. The measure of work during 6MWT can add important information to the 6MWT assessment in this population as it relates to walking efficiency. Objective: To verify the determinants of work during the Six-Minute Walk Test (6MWTwork) in school-aged children. Method: This is a cross-sectional and exploratory study that included healthy children recruited from the public and private schools of the cities of Belo Horizonte and Uberlândia, Brazil. The inclusion criteria were: children aged 7 to 12 years without diagnosis of chronic cardiorespiratory disease, cognitive, behavioral disorder or physical function impairment (information obtained through self-report of those responsible for children). Exclusion criteria were children who refused to perform the 6MWT; who did not understand the 6MWT or who did not answer the test commands. Three hundred and nineteen school-aged children were included in the study. Correlation analyses and multiple linear regression analysis were used to identify the variables associated with the 6MWTwork. Results: Age, height, nutritional status, physical activity and heart rate showed significant correlation with 6MWTwork (p <0.001) and explained 87% of its variation (p = 0.0001). Conclusion: Age, height, nutritional status and heart rate variation are determinants of 6MWTwork that is able to evaluate functional capacity of school-aged children.

Resumo Introdução: O teste de caminhada de seis minutos (TC6min) é amplamente utilizado para avaliar a capacidade funcional em crianças. A medida do trabalho durante o TC6 poderia adicionar informações importantes à avaliação do TC6 nessa população, no que se refere à eficiência da marcha. Objetivo: Verificar os determinantes do trabalho durante o Teste de Caminhada (TC6min) em crianças em idade escolar. Método: Trata-se de um estudo transversal e exploratório que incluiu crianças saudáveis recrutadas nas escolas públicas e privadas das cidades de Belo Horizonte e Uberlândia, Brasil. Os critérios de inclusão foram: crianças de 7 a 12 anos sem diagnóstico de doença cardiorrespiratória crônica, distúrbio cognitivo, comportamental ou comprometimento da função física (informações obtidas por auto-relato dos responsáveis pelas crianças). Os critérios de exclusão foram: crianças que se recusaram a realizar o TC6; que não entenderam o TC6 ou que não responderam aos comandos de teste. Trezentos e dezenove crianças em idade escolar foram incluídas no estudo. Análises de correlação e análise de regressão linear múltipla foram utilizadas para identificar as variáveis associadas ao trabalho com TC6. Resultados: Idade, altura, estado nutricional, atividade física e frequência cardíaca apresentaram correlação significativa com o trabalho durante o TC6min (p <0,001) e explicaram 87% de sua variação (p = 0,0001). Conclusão: Idade, altura, estado nutricional e variação da frequência cardíaca são determinantes do trabalho no TC6, e portanto, devem ser considerados na avaliação da capacidade funcional de crianças em idade escolar.

Physiological demands of archery: effect of experience level / Demandas fisiológicas do tiro com arco: efeito do nível de experiência

Abstract The understanding of fatigue development during Archery competition would guide sports scientists, coaches and athletes on how to optimize the training routines of athletes from different competitive levels. This study investigated the effect of expertise level on physiological responses, during simulated archery competition (double-round 70m, 12 series, 6 arrows for an elite Brazilian Archer (EA) and a Novice Archer (NA). Ratings of perceived exertion, blood lactate and glucose, handgrip strength and electromyography were registered at the beginning, after each set from the 2nd to the 12tharrow and, 30-min after the competition simulation. The EA showed a greater handgrip strength for both arms, a constant lower mean RMS value (Baseline 0.279V and 12th set 0.221V, -20.7%), and a stable MF value throughout the competition (Baseline 146Hz to 12th set 140Hz). The NA showed a smaller handgrip strength, an increase in RMS after the 6th set towards the end of the competition (Baseline 0.387V, 6th 0.576V, and 12th set 0.720V, +46.2%) and a minor decrease in MF from the 6th to the end of 12th set (2nd set 122Hz, 4th set 127Hz, 6th set 112Hz and 12th set 117Hz, - 4.1%). In summary, all the fatigue-related markers showed a mild response to the Archery competition simulation, although a greater magnitude was observed in the NA, compared to the EA. This study reported the physiologic demands of an Archery simulated competition, in an official format, allowing coaches and sport scientists to draw more confident decisions on competition strategy and training design.

Resumo O entendimento da fadiga durante a competição de Tiro com Arco pode auxiliar na otimização da rotina de treinamento de atletas em diferentes níveis competitivos. Este estudo investigou o efeito do nível de experiência do atleta sobre as respostas fisiológicas, durante competição simulada de Tiro com Arco para um atleta de elite (EA) e um arqueiro iniciante (NA). Esforço percebido, concentração de lactato e glicose sanguínea, força de preensão manual e eletromiografia foram registrados no início, após cada série e, 30-min após a simulação. O EA apresentou maior força de preensão manual para ambos braços, valor de média RMS constantemente mais baixo (Baseline 0,279V e 12ª série 0,221V, -20,7%), e valor de MF estável no decorrer da competição (Baseline 146Hz a 12a série 140Hz). O NA demonstrou menor força de preensão manual, aumento na RMS após a 6a série até o final da competição (Baseline 0,387V, 6a 0,576V, and 12a série 0,720V, +46,2%) e pequena diminuição na MF da 6ª até o final da 12ª série (2a série 122Hz, 4a série 127Hz, 6a série 112Hz e 12a série 117Hz, - 4,1%). Assim, todos os marcadores relacionados a fadiga apresentaram resposta discreta na simulação de competição de Tiro com Arco, com maior magnitude no NA, em comparação com EA. Este estudo apresentou as demandas fisiológicas da competição simulada de Tiro com Arco, no formato oficial, permitindo que treinadores e cientistas do esporte possam tomar decisões com maior confiança sobre estratégias de competição e treinamento.

Functional capacity in adolescent idiopathic scoliosis during the postoperative period / Capacidade funcional na escoliose idiopática do adolescente no período pós-operatório / Capacidad funcional en la escoliosis idiopática del adolescente en el período postoperatorio

ABSTRACT Introduction: Patients with Adolescent Idiopathic Scoliosis (AIS) show reduced exercise capacity during the Incremental Shuttle Walk Test (ISWT). However, we not know how patients behave in the late postoperative (LPO) period. Objective: The aim of this study was to evaluate the ISWT distance (ISWTD) and physiological responses during ISWT in AIS patients during the LPO period. Methods: We included 22 patients with AIS in the LPO period (SG) and 21 adolescents in the Control Group (CG). We assessed pulmonary function (FVC and FEV1). During ISWT, a gas analyzer was used to assess peak oxygen (VO2) and submaximal relations: Oxygen Uptake Efficiency Slope (OUES) and the breathing pattern (ΔVT/ΔlnVE). Results: Significantly lower values were observed in SG: VO2 (22 ± 5 vs. 27 ± 4), ISWTD (567 ± 94 vs.604 ± 86), FVC (2.70 ± 0.47 vs. 3.33 ± 0.52) and FEV1 (2.41 ± 0.46 vs. 2.84 ± 0.52). There were significant correlations between ISWTD and VO2/Kg (r = 0.80); between OUES and ΔVT/ΔlnVE (r = 0.65); and between the main thoracic curve with VO2/Kg (r= −0.61). Conclusion: AIS patients in the LPO period have significantly reduced exercise capacity associated with reduced lung function, residual spinal curve and cardiovascular deconditioning. Level of Evidence III; Prognostic Studies - Investigation of the effect of characteristic of a patient on the outcome of the disease.

RESUMO Introdução: Pacientes com escoliose idiopática do adolescente (EIA) têm capacidade de exercício reduzida durante o Incremental Shuttle Walk Test (ISWT). No entanto, não sabemos como os pacientes se comportam no período pós-operatório tardio (POT). Objetivo: O objetivo deste estudo foi avaliar a distância do ISWT (ISWTD) e as respostas fisiológicas durante o teste em pacientes com EIA no período POT. Métodos: Foram incluídos 22 pacientes com EIA no período POT (GCi) e 21 adolescentes no Grupo Controle (GCo). Avaliamos a função pulmonar (CVF e VEF1). Durante o ISWT, foi utilizado um analisador de gases para avaliar o pico de oxigênio (VO2) e as relações submáximas: eficiência da captação de oxigênio (OUES) e o padrão de respiração (ΔVC/ΔlnVE). Resultados: Valores significativos mais baixos foram observados no GCi: VO2 (22 ± 5 vs. 27 ± 4), ISWTD (567 ± 94 vs. 604 ± 86), CVF (2,70 ± 0,47 vs. 3,33 ± 0,52) e VEF1 (2,41 ± 0,46 vs. 2,84 ± 0,52). Houve correlações significativas entre ISWTD e VO2/Kg (r = 0,80); entre OUES e ΔVC/ΔlnVE (r = 0,65) e entre a curva torácica principal com VO2/Kg (r = −0,61). Conclusão: Os pacientes com EIA no período POT tiveram redução significante da capacidade de exercício associada à função pulmonar reduzida, curva residual na coluna vertebral e descondicionamento cardiovascular. Nível de Evidência III; Estudos Prognósticos - Investigação do efeito de característica de um paciente sobre o desfecho da doença.

RESUMEN Introducción: Pacientes con escoliosis idiopática del adolescente (EIA) tienen capacidad de ejercicio reducida durante el Incremental Shuttle Walk Test (ISWT). Sin embargo, no sabemos cómo los pacientes se comportan en el período postoperatorio tardío (POT). Objetivo: El objetivo de este estudio fue evaluar la distancia del ISWT (ISWTD) y las respuestas fisiológicas durante la prueba en pacientes con EIA en el período POT. Métodos: Se incluyeron 22 pacientes con EIA en el período POT (GQ) y 21 adolescentes en el grupo control (GC). Se evaluó la función pulmonar (CVF y VEF1). Durante el ISWT, se utilizó un analizador de gases para evaluar el pico de oxígeno (VO2) y las relaciones submáximas: eficiencia de la captación de oxígeno (OUES) y el patrón respiratorio (ΔVC/ΔlnVE). Resultados: Se observaron valores significativos más bajos en el GQ: VO2 (22 ± 5 vs. 27 ± 4), ISWTD (567 ± 94 vs. 604 ± 86), CVF (2,70 ± 0,47 vs. 3,33 ± 0,52) y VEF1 (2,41 ± 0,46 vs. 2,84 ± 0,52). Hubo correlaciones significativas entre ISWTD y VO2/Kg (r = 0,80) entre OUES y ΔVC/ΔlnVE (r = 0,65) y entre la curva torácica principal con VO2/Kg (r = −0,61). Conclusión: los pacientes con EIA en el período POT tuvieron reducción significativa de la capacidad de ejercicio asociada a la función pulmonar reducida, la curva residual de la columna vertebral y la falta de condicionamiento cardiovascular. Nivel de evidencia III; Estudios pronósticos - Investigación del efecto de característica de un paciente sobre el desenlace de la enfermedad.

Oxygen consumption and heart rate obtained in a ramp protocol are equivalent during exercise session of rectangular loading at ventilatory thresholds for athletes / Consumo de oxigênio e frequência cardíaca obtidos em um protocolo de rampa são equivalentes durante sessão de exercícios de carga retangular nos limiares ventilatórios para atletas

Abstract Training near or at ventilatory threshold (VT) is an adequate stimulus to improve the thresholds for sedentary subjects, but a higher intensity is necessary for conditioned subjects. The choice of cardiopulmonary exercise testing (CPx) protocol has an influence on VTs identification and can reduce their reliability for exercise prescription. This study tested if VO2 and heart rate (HR) corresponding to first (VT1) and second ventilatory threshold (VT2) determined during a ramp protocol were equivalent to those observed in rectangular load exercises at the same intensity in runners elite athletes (EA) and non-athletes (NA). Eighteen health subjects were divided into two groups: EA (n = 9, VO2max 68.6 mL·kg-1·min-1) and NA (n = 9, VO2max 47.2 mL·kg-1·min-1). They performed CPx and 48h and 96h later, a continuous running lasting 1 h for VT1 and until exhaustion for VT2. The results showed that EA at VT1 session, presented delta differences for VO2 (+9.1%, p = 0.125) vs. NA (+20.5%, p = 0.012). The Bland-Altman plots for VT1 presented biases of (4.4 ± 6.9) and (5.5 ± 5.6 mLO2·kg-1·min-1) for AE and NA, respectively. In VT2, the VO2 and HR of the NA showed biases of (0.4 ± 2.9 mLO2·kg-1·min-1) and (4.9 ± 4.2 bpm). The ramp protocol used in this study was inappropriate for NA because it underestimates the values of VO2 and HR at VT1 found in the rectangular load exercise. The HR showed good agreement at VT2 with CPx and may be a good parameter for controlling exercise intensity.

Resumo O treinamento no limiar ventilatório (LV) é um estímulo adequado para melhorar os limiares em indivíduos sedentários, entretanto uma maior intensidade é necessária para indivíduos condicionados. A escolha do protocolo de teste de exercício cardiopulmonar (CPx) tem influência na identificação dos LV e pode reduzir sua confiabilidade na prescrição do exercício. Este estudo testouse o VO2 e a frequência cardíaca (FC) correspondentes ao primeiro (LV1) e segundo limiar ventilatório (LV2) determinados durante um protocolo de rampa foram equivalentes àqueles observados em exercícios de carga retangular nas mesmas intensidades em atletas corredores de elite (AE) e não atletas (NA). Dezoito homens saudáveis foram divididos em dois grupos: AE (n = 9, VOmax 68,6 mL·kg-1·min-1) e NA (n = 9, VO2max 47,2 mL·kg-1·min-1). Eles realizaram CPx e 48h e 96h depois, uma corrida contínua com duração de 1 h para o LV1 e até a exaustão para o LV2. O grupo AE na sessão LV1, apresentou diferenças de delta para VO2(+ 9,1%, p = 0,125) vs. NA (+ 20,5%, p = 0,012). Bland-Altman para LV1 apresentaram vieses de (4,4 ± 6,9) e (5,5 ± 5,6 mLO2·kg-1·min-1) para AE e NA, respectivamente. No LV2, o VO2 e a FC do NA apresentaram vieses de (0,4 ± 2,9) mLO2·kg-1·min-1 e (4,9 ± 4,2) bpm. O protocolo de rampa utilizado foi inadequado para NA pois subestima os valores de VO2 e FC em LV1 encontrados no exercício de carga retangular. A FC exibiu boa concordância no LV2 e pode ser um bom parâmetro para controlar a intensidade do exercício.