Cardiopulmonary exercise testing in congenital heart disease: equipment and test protocols

Aerobic physical capacity and health-related quality of life in children with sickle cell disease

BACKGROUND

Aerobic fitness is a predictor of cardiovascular health which correlates with health-related quality of life in the general population. The aim is to evaluate the aerobic capacity by cardiopulmonary exercise test (CPET) in children with sickle cell disease in comparison with healthy matched controls.

METHODS

Controlled cross-sectional study.

RESULTS

A total of 72 children (24 with sickle cell disease and 48 healthy controls), aged 6-17 years old were enrolled. Children with sickle cell disease had a poor aerobic capacity, with median VO2max Z-score values significantly lower than matched controls (-3.55[-4.68; -2.02] vs. 0.25[-0.22; 0.66], P < 0.01, respectively), and a high proportion of 92% children affected by an impaired aerobic capacity (VO2max Z-score < -1.64). The VO2max decrease was associated with the level of anemia, the existence of a homozygote HbS/S mutation, restrictive lung disease and health-related quality of life.

CONCLUSION

Aerobic capacity is poor in children with sickle cell disease. VO2max decrease is associated with the level of anemia, the existence of a homozygote HbS/S mutation, lung function, and health-related quality of life. These results represent a signal in favor of early initiation of cardiac rehabilitation in patients with sickle cell disease.

CLINICAL TRIALS

NCT05995743.

IMPACT

Aerobic fitness is a predictor of cardiovascular health which correlates with health-related quality of life in the general population. Aerobic capacity (VO2max) is poor in children with sickle cell disease, despite the absence of any pattern of heart failure. VO2max decrease was associated with the level of anemia, the existence of a homozygote HbS/S mutation, restrictive lung disease, and health-related quality of life. These results are in favor of early initiation of cardiac rehabilitation in children with sickle cell disease.

Cardiopulmonary Fitness of Preschoolers with Congenital Heart Disease: An Observational Study

With advancements in cardiopulmonary rehabilitation over the past few decades, the survival rate of patients with congenital heart disease (CHD) has increased. However, the Cardiopulmonary fitness (CPF) of these patients is poor. Here, we aimed to investigate CPF in preschoolers with CHD (aged 4 to 6 years) using cardiopulmonary exercise testing. We retrospectively compared 102 healthy preschoolers with 80 preschoolers with CHD. The latter had lower peak oxygen consumption, oxygen consumption at anaerobic threshold and metabolic equivalent at anaerobic threshold. The same result was observed in boys with CHD, but not in girls, when sex was sub-analyzed. Considering the body composition, children with CHD had a lower fat-free mass index (FFMI) than their healthy peers. Healthy preschoolers with a normal body mass index (BMI) had higher anaerobic threshold and peak metabolic equivalent values than overweight or underweight children. This was categorized under the BMI reference of the Ministry of Health and Welfare in Taiwan. In conclusion, the CPF difference between the CHD and healthy groups was identified as early as in preschool age, and better CPF in healthy preschoolers within the normal BMI range suggests the importance of weight control in young children.

Practices and Procedures in Clinical Pediatric Exercise Laboratories in North America

Interinstitutional differences in clinical pediatric exercise laboratory (CPEL) practices may affect patient care and efficacy of multicenter research.

PURPOSE

To describe current practices/procedures in CPELs and explore differences in CPELs employing exercise physiologists to those that do not.

METHODS

A 40-item survey was distributed to CPELs in North America focusing on (1) staffing; (2) exercise stress testing (EST) volumes, reporting, and interpretation; and (3) EST procedures/protocols.

RESULTS

Of the 55 responses, 89% were in the United States, 85% were children's hospitals with university affiliation, and 58% were cardiology specific. Exercise physiologists were employed in 56% of CPELs, and 78% had master's degrees or higher. Certifications were required in most CPELs (92% emergency life-support, 27% professional, and 21% clinical). Median volume was 201 to 400 ESTs per year, 80% used treadmill, and 10% used cycle ergometer as primary modalities. Ninety-three percent of CPELs offered metabolic ESTs, 87% offered pulmonary function testing, 20% used institution-specific EST protocols, and 72% offered additional services such as cardiac/pulmonary rehabilitation. CPELS staffing exercise physiologists performed higher volumes of ESTs (P = .004), were more likely to perform metabolic ESTs (P = .028), participated in more research (P < .001), and provided services in addition to ESTs (P = .001).

CONCLUSIONS

Heterogeneity in CPELs staffing and operation indicates need for standardization.

Determinants of oxygen uptake and prognostic factors in cardiopulmonary exercise test in patients with Fontan surgery

INTRODUCTION

Cardiopulmonary exercise test (CPET) allows quantification of functional capacity of patients with Fontan. The objective of this study was to determine the role of CPET parameters in predicting a higher maximum oxygen consumption (VO2 max) and to analyse the role of CPET parameters in predicting an unfavourable outcome.

METHODS

A retrospective, cross-sectional, descriptive study was carried out on 57 patients with Fontan, who had undergone incremental CPET with cycloergometer between 2010 and 2020. Determinants of VO2 max and determinants of clinical deterioration were analysed.

RESULTS

In the univariate analysis, the variables significantly related to VO2 max were: age, sex, body mass index (BMI), years of Fontan evolution, intracardiac Fontan, oxygen consumption at anaerobic threshold (VO2AT), CO2 equivalents at anaerobic threshold (VE/VCO2) and chronotropic insufficiency. The multiple linear regression model that best fitted the relationship between VO2 max and independent variables (correlation coefficient 0.73) included sex (correlation index 3.35; p = 0.02), BMI (-0.27; p = 0.02), chronotropic failure (-2.79; p = 0.01) and VO2AT (0.92; p < 0.0001). In the univariate analysis of the prognostic CPET variables related to an unfavourable clinical situation, significance was only obtained with chronotropic insufficiency (p = 0.003). In multivariate analysis, chronotropic insufficiency maintains its association [p= 0.017, OR = 4.65 (1.3-16.5)].

CONCLUSIONS

In conclusion, together with the anthropometric parameters universally related to VO2 max, chronotropic insufficiency and VO2AT are the main determinants of functional capacity in patients with Fontan. Moreover, chronotropic insufficiency is closely related to unfavourable clinical evolution. Our data would support the intensive treatment of chronotropic insufficiency in order to improve the quality of life and the clinical situation of patients with Fontan.

A Combined Analysis of Peak and Submaximal Exercise Parameters in Delineating Underlying Mechanisms of Sex Differences in Healthy Adolescents

Peak exercise parameters are considered the gold standard to quantify cardiac reserve in cardiopulmonary exercise testing (CPET). We studied whether submaximal parameters would add additional values in analyzing sex differences in CPET. We reviewed CPET of age-matched healthy male and female adolescents by cycle ergometer. Besides peak parameters, submaximal CPET parameters, including ventilatory anaerobic threshold (VAT), oxygen uptake efficiency slope (OUES), and submaximal slopes of Δoxygen consumption (ΔVO2)/Δwork rate (ΔWR), Δheart rate (ΔHR)/ΔWR, ΔVO2/ΔHR, and Δminute ventilation (ΔVE)/ΔCO2 production (ΔVCO2), were obtained. We studied 35 male and 40 female healthy adolescents. Peak VO2 (pVO2), peak oxygen pulse (pOP), and VAT were significantly lower in females than males (1.9 ± 0.4 vs. 2.5 ± 0.6 L/min; 10 ± 2.0 vs. 13.2 ± 3.5 ml/beat; 1.23 ± 0.3 vs. 1.52 ± 0.5 L/min, respectively, all p < 0.005). Females showed significantly lower pVO2, VAT, and OUES with the same body weight than males, implying higher skeletal muscle mass in males. When simultaneously examining ΔHR/ΔWR and pOP, females showed higher dependency on increases in HR than in stroke volume. Females demonstrated significantly lower pOP with the same levels of ΔVO2/ΔHR, suggesting more limited exercise persistence than males under an anaerobic condition at peak exercise. Oxygen uptake efficiency in relation to peak VE was significantly higher in males. There was no sex difference in either ΔVO2/ΔWR or ΔVE/ΔVCO2. Combinational assessment of peak and submaximal CPET parameters delineates the multiple mechanisms that contribute to the sex differences in exercise performance.

Oxygen uptake efficiency slope: a reliable surrogate parameter for exercise capacity in healthy and cardiac children?

OBJECTIVES

Cardiopulmonary exercise test (CPET) provides accurate evaluation of physical capacity and disease severity in children with congenital heart disease (CHD). However, full participation to obtain optimal measure of VO_2max may be difficult. As an alternative, the oxygen uptake efficiency slope (OUES) is a reproducible and reliable parameter measured during CPET, which does not require a maximal exercise to be interpretable. This study aimed to evaluate the OUES of a large cohort of children with CHD, in comparison with healthy controls. We also intended to identify, in this specific population, the clinical and CPET variables associated with the OUES.

METHODS

This cross-sectional study was carried out between November 2010 and September 2015 in two tertiary care paediatric and congenital cardiology centres.

RESULTS

709 children were included (407 CHD and 302 healthy controls). The association of clinical characteristics with weight-normalised OUES (OUES_kg) was studied using a multivariable analysis. The mean OUES_kg was significantly lower in CHD than in healthy controls (38.6±8.5 and 43.9±8.5; p<0.001, respectively), especially in the most severe CHD. The OUES_kg correlated with VO_2max (r=0.85, p<0.001), with cut-off values for normal exercise capacity of 38.4 in boys and 31.0 in girls. The decrease of OUES_kg was associated with increased age, increased Body Mass Index, number of cardiac catheter or surgical procedures, female gender and decreased forced vital capacity (Z-score).

CONCLUSION

The OUES is significantly impaired in children with CHD and strongly correlates with VO_2max. The OUES has the same clinical determinants as VO_2max and therefore may be of interest in submaximal exercise.

TRIAL REGISTRATION NUMBER

NCT01202916.

The V̇e/V̇co2 slope: a useful tool to evaluate the physiological status of children with congenital heart disease

Cardiopulmonary exercise test (CPET) is becoming a key examination to assess physical capacity and disease severity in pediatric cardiology. The V̇e/V̇co₂ slope has been increasingly used as a surrogate marker for morbidity and mortality in adult heart failure, pulmonary arterial hypertension, and for adult patients with congenital heart disease (CHD). Nevertheless, the use of the V̇e/V̇co₂ slope in children remains limited in the absence of reference values and clearly identified clinical determinants. This study aimed to compare the V̇e/V̇co₂ slope in a pediatric cohort with CHD to that of age- and gender-adjusted healthy controls. We also intended to identify the clinical and CPET variables associated with V̇e/V̇co₂ slope in this population. This cross-sectional study was carried out between November 2010 and September 2015 in two tertiary care pediatric cardiology reference centers. A total of 700 children were enrolled (399 CHD and 301 healthy controls). The mean V̇e/V̇co₂ slope was significantly higher in the CHD subjects than in healthy subjects (31.6 ± 4.8 vs. 29.3 ± 4.8; P < 0.001). The V̇e/V̇co₂ slope was higher in children with significant pulmonary regurgitation, tricuspid regurgitation, right ventricular hypertension, and right ventricle outflow tract (RVOT) obstacle. In the CHD group, V̇e/V̇co₂ slope increase was associated with body mass index, the presence of a RVOT obstacle, the number of cardiac catheter procedures, as well as low age, forced vital capacity, tidal volume, and [Formula: see text]. Increased V̇e/V̇co₂ slope was predominantly in children with single ventricle and/or residual right heart abnormalities, suggesting that maldistribution of pulmonary blood flow during exercise is an important CHD-unique determinant of V̇e/V̇co₂ slope.NEW & NOTEWORTHY Using V̇e/V̇co₂ slope is useful for children with congenital heart disease. V̇e/V̇co₂ slope is sensitive to pulmonary blood flow maldistribution during exercise, this concerns congenital heart disease with pulmonary regurgitation, tricuspid regurgitation, right ventricular hypertension, and right ventricle outflow tract obstacle. V̇e/V̇co₂ slope is a good parameter to follow single ventricles and right heart residual lesions (tetralogy of Fallot; pulmonary atresia; truncus arteriosus…).

Maximal cardiopulmonary exercise testing in childhood acute lymphoblastic leukemia survivors exposed to chemotherapy

PURPOSE

The purpose of this study was to demonstrate if childhood acute lymphoblastic leukemia (ALL) survivors exposed to chemotherapy (i.e., doxorubicin) are able to achieve a safe maximal cardiopulmonary exercise test (CPET).

METHODS

A total of 250 childhood ALL survivors were eligible to undergo a CPET on ergocycle. Analyses were performed in 216 survivors and stratified in regard to their prognostic risk groups: 99 survivors (55 males and 44 females) at standard risk and 117 survivors (56 males and 61 females) at high risk.

RESULTS

Results showed that 100% (n = 216) of survivors completed a maximal CPET confirmed by the achievement of two out of three of the following criteria: 197 survivors (91.2%) reached a peak RER value of ≥ 1.15, 197 survivors (91.2%) reached a RPE score > 7, and 210 survivors (97.2%) reached a maximal heart rate ≥ 85% of the predicted value. Linear regression analysis showed a significant association between the survivors' cumulative dose of doxorubicin and their VO₂ peak measured. Two non-fatal adverse events were observed and reported at the end of the maximal CPET, while non-fatal adverse events were reported in 5 survivors during the recovery period. None of these events resulted in a long-term complication.

CONCLUSION

Childhood ALL survivors with prior exposure to chemotherapy can achieve a safe maximal CPET. They were able of achieving a maximal exercise test without being limited by symptoms, potential overprotection, or musculoskeletal issues. Thus, it should be the norm to realize a CPET prior a physical activity program to propose an optimal prescription. This study provides important information regarding the maximal physiological parameters that childhood ALL survivors are able to reach and have important clinical implications in the exercise and oncology field for this population of survivors.

Plasma antioxidants and oxidative stress status in obese women: correlation with cardiopulmonary response

INTRODUCTION

A high body fat coupled with low cardiopulmonary fitness and an increase in oxidative stress has been connoted as contributing factors in developing cardiovascular comorbidities. This study aimed to investigate the correlation between antioxidants and oxidative stress status with cardiopulmonary responses in women of different body mass index (BMI).

SUBJECTS AND METHODS

Eighty female adults were recruited and divided into three groups; normal weight (n = 23), overweight (n = 28) and obese (n = 29), according to their BMI. Blood samples were obtained prior to cardiopulmonary exercise testing. Plasma samples were separated by centrifugation and analysed for enzymatic antioxidant activity including catalase, glutathione peroxidase and superoxide dismutase. Non-enzymatic antioxidant activities were assessed using 2, 2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical scavenging and ferric reducing ability of plasma (FRAP) assays. To evaluate the oxidative stress status of subjects, levels of reactive oxygen species and malondialdehyde, the by-product of lipid peroxidation, were measured. Cardiopulmonary responses were analysed using cardiopulmonary exercise testing (CPET) which involved 15 various parameters such as peak oxygen consumption, metabolic equivalents and respiratory exchange ratio.

RESULTS

The obese group had significantly lower ABTS radical scavenging and FRAP activities than the normal weight group. A higher catalase activity was observed in the obese group than the normal weight group. Spearman's correlation showed an inverse relationship between catalase and peak oxygen consumption, while partial correlation analysis showed inverse correlations between superoxide dismutase and respiratory frequency, ABTS activity and oxygen pulse, and between ABTS activity and cardiac output.

CONCLUSION

Our results demonstrate a lower cardiovascular fitness and antioxidant capacity in obese women; the higher catalase activity may be a compensatory mechanism. The negative correlations found between these two parameters may indicate the potential effect of antioxidants on the cardiopulmonary system and deserve further analysis in a larger population. Nevertheless, this study provides the basis for future studies to further explore the relationships between redox status and cardiopulmonary responses. This can potentially be used to predict future risk of developing diseases associated with oxidative stress, especially pulmonary and cardiovascular diseases.

Fitkids Treadmill Test: Clinical Utility and Factors Associated With Its Use Among Physical Therapists

BACKGROUND

Although the Fitkids Treadmill Test (FTT) has been validated and normative values are available for healthy 6- to 18-year-old children and adolescents, these facts do not automatically imply uptake of the test in routine practice of physical therapists.

OBJECTIVE

The objectives of this study were to evaluate the utility of the FTT in different diagnostic groups and to explore potential factors affecting the use of the FTT in clinical practice.

DESIGN

Mixed methods with both quantitative and qualitative data were used in this study.

METHODS

Outcome parameters from the FTT were retrieved from the Fitkids database. For evaluation of the utility of the FTT, 2 indicators, exercise duration and maximal effort, were used. An online survey was sent to physical therapists in Fitkids practices to identify factors affecting the use of the FTT in clinical practice.

RESULTS

The proportion of children and adolescents in each of the diagnostic groups who reached the minimal duration of a maximal exercise test ranged from 94% to 100%. The proportion of participants who reached a peak heart rate ≥180 beats/min ranged from 46% for participants with cognitive, psychological, or sensory disorders to 92% for participants with metabolic diseases. The most important facilitator for use of the FTT was the fact that most physical therapists were convinced of the additional value of the FTT. The main barriers were therapists' attitudes (resistance to change/lack of experience) and, on the environmental level, the absence of a treadmill ergometer in physical therapist practice.

LIMITATIONS

Structured interviews would have provided more information on potential factors affecting the use of the FTT in clinical practice.

CONCLUSIONS

This study has shown the clinical utility of the FTT in different diagnostic groups in pediatric physical therapist practice. Responding to the factors identified in this study should enable improved uptake of the FTT in clinical practice.

Diastolic dysfunction is associated with exercise impairment in patients with sickle cell anemia

BACKGROUND

Left ventricular diastolic dysfunction (DD) is an independent risk factor for mortality in sickle cell anemia (SCA) and is associated with increased extracellular volume (ECV) on cardiac MRI (CMR). Exercise impairment is common in SCA, but its causes and prognostic value are not well understood.

OBJECTIVE

To study the effects of DD and ECV on cardiopulmonary exercise test (CPET) in patients with SCA.

METHODS AND RESULTS

As part of a prospective study to characterize the cardiomyopathy of SCA (NCT02410811), 20 children and adults with SCA underwent CMR, echocardiography, and cycle ergometer CPET (age range 8-43 years). Maximum exercise was reached in 18 patients and 17 (94%) had reduced exercise capacity (%predicted VO₂ less than 80%). Six patients had DD and none had systolic dysfunction. Patients with DD had lower exercise capacity compared to patients with normal diastolic function (%predicted VO₂ 48.2 ± 9.1% vs. 61.2 ± 11.7%; P = 0.01). The z-score of left ventricular lateral E/e' ratio, which is a marker of DD, was negatively associated with %predicted VO₂ (r = -0.61, P = 0.01). All patients with moderate-to-severe exercise impairment (%predicted VO₂  < 60%) had lateral E/e' z-score > 2. In a multivariate analysis, lateral E/e' z-score was independently associated with %predicted VO₂ (P = 0.02). All participants had elevated ECV but the degree of elevation was not associated with exercise parameters.

CONCLUSION

Left ventricular DD is associated with decreased exercise capacity in SCA. Interventions to prevent or delay DD could improve exercise capacity, quality of life, and long-term outcomes in SCA.

Cardiopulmonary fitness in children with congenital heart diseases versus healthy children

Objective

We aimed to compare the cardiopulmonary fitness of children with congenital heart diseases (CHD) with that of age-adjusted and gender-adjusted controls. We also intended to identify clinical characteristics associated with maximum oxygen uptake (VO2max) in this population.

Methods and results

We included in a cross-sectional multicentre study a total of 798 children (496 CHD and 302 controls) who underwent a complete cardiopulmonary exercise test (CPET). The association of clinical characteristics with VO2max was studied using a multivariate analysis. Mean VO2max in the CHD group and control represented 93%±20% and 107%±17% of predicted values, respectively. VO2max was significantly lower in the CHD group, overall (37.8±0.3vs 42.6±0.4 mL/kg/min, P<0.0001) and for each group (P<0.05). The mean VO2max decline per year was significantly higher in CHD than in the controls overall (−0.84±0.10 vs −0.19±0.14 mL/kg/min/year, P<0.01), for boys (−0.72±0.14vs 0.11±0.19 mL/kg/min/year, P<0.01) and for girls (−1.00±0.13 vs −0.55±0.21 mL/kg/min/year, P=0.05). VO2max was associated with body mass index, ventilatory anaerobic threshold, female gender, restrictive ventilatory disorder, right ventricle systolic hypertension, tricuspid regurgitation, the number of cardiac catheter or surgery procedures, and the presence of a genetic anomaly.

Conclusions

Although the magnitude of the difference was not large, VO2max among children with CHD was significantly lower than in normal children. We suggest performing CPET in routine follow-up of these patients.

Trial registration number

ClinicalTrials.gov NCT01202916; Post-results.

Cardiopulmonary Exercise Test: Background, Applicability and Interpretation

Cardiopulmonary exercise test (CPET) has been gaining importance as a method of functional assessment in Brazil and worldwide. In its most frequent applications, CPET consists in applying a gradually increasing intensity exercise until exhaustion or until the appearance of limiting symptoms and/or signs. The following parameters are measured: ventilation; oxygen consumption (VO₂); carbon dioxide production (VCO₂); and the other variables of conventional exercise testing. In addition, in specific situations, pulse oximetry and flow-volume loops during and after exertion are measured. The CPET provides joint data analysis that allows complete assessment of the cardiovascular, respiratory, muscular and metabolic systems during exertion, being considered gold standard for cardiorespiratory functional assessment.^1-6

The CPET allows defining mechanisms related to low functional capacity that can cause symptoms, such as dyspnea, and correlate them with changes in the cardiovascular, pulmonary and skeletal muscle systems. Furthermore, it can be used to provide the prognostic assessment of patients with heart or lung diseases, and in the preoperative period, in addition to aiding in a more careful exercise prescription to healthy subjects, athletes and patients with heart or lung diseases.

Similarly to CPET clinical use, its research also increases, with the publication of several scientific contributions from Brazilian researchers in high-impact journals.

Therefore, this study aimed at providing a comprehensive review on the applicability of CPET to different clinical situations, in addition to serving as a practical guide for the interpretation of that test.

Physical activity evaluation in children with congenital heart disease

Significant advances in the management of children with congenital heart disease (CHD) have resulted in marked improvements in survival and life expectancy. Thus, there is an increased emphasis on promoting physical activity to optimise healthy development and long-term cardiovascular health. Evaluation of physical activity levels as part of ongoing clinical care is recommended to facilitate physical activity counselling and/or exercise prescription. Physical activity is a complex health behaviour that is challenging to evaluate. We provide an overview of techniques for measuring physical activity in children with CHD with a focus on how to do this in the clinical context. Accelerometers are devices that objectively assess intensity and duration of physical activity under free living conditions. They enable evaluation against physical activity guidelines, but are costly and require advanced technical expertise. Pedometers are a simple-to-use and cost-effective alternative, but an outcome metric of daily step count limits classification against guidelines. Commercial wearable activity trackers offer an appealing user experience and can provide valid estimates in children. Furthermore, activity trackers enable remote monitoring of physical activity levels, which may facilitate exercise prescription and activity counselling. Questionnaires are the most cost-effective and time-effective method, but recall error in younger children is a consideration. Routine exercise testing in children with CHD provides important insight into functional status but should not be viewed as a proxy measure of habitual physical activity. Understanding the spectrum and role of physical activity measurement tools is important for clinicians focused on optimising cardiovascular health in children with CHD.

Relationship of aerobic fitness with cardiovascular risk factors in firefighters

BACKGROUND

Epidemiological studies on the general population have shown that increased physical activity and aerobic fitness (AF) significantly decrease the risk of coronary artery disease. Finding ways to decrease such risk factors can promote the health of firefighters.

METHODS

This study was conducted in a large industrial facility in Tehran. AF assessment and submaximal aerobic fitness testing of participants were performed according to the guidelines of the American College of Sports Medicine (ACSM). AF was determined using a bicycle ergometer. Other information was collected using a specifically designed questionnaire, physical examination and blood test. Data were analyzed using SPSS. Level of significance was set at P < 0.05.

RESULTS

A total of 157 male firefighters were evaluated in an industrial facility. The results of logistic regression analysis revealed that AF was significantly correlated with age, body mass index (BMI), cigarette smoking, physical activity, hemoglobin level, low-density lipoprotein (LDL) level, high-density lipoprotein (HDL) level, resting systolic blood pressure (RSBP), diastolic blood pressure (RDBP) and heart rate (RHR) (P < 0.05).

CONCLUSIONS

Firefighters with greater AF had lower cardiovascular disease (CVD) risk factors. Longitudinal studies are required to further confirm this finding. Increasing the AF may decrease CVD risk factors in firefighters.

Prediction of peak oxygen uptake in children using submaximal ratings of perceived exertion during treadmill exercise

Purpose

This study assessed the utility of the Children’s Effort Rating Table (CERT) and the Eston–Parfitt (EP) Scale in estimating peak oxygen uptake (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot{V}{\text{O}}_{{2{\text{peak}}}}$$\end{document}V˙O2peak) in children, during cardiopulmonary exercise testing (CPET) on a treadmill.

Methods

Fifty healthy children (n = 21 boys; 9.4 ± 0.9 years) completed a continuous, incremental protocol until the attainment of \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot{V}{\text{O}}_{{2{\text{peak}}}}$$\end{document}V˙O2peak. Oxygen uptake (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot{V}{\text{O}}_{2}$$\end{document}V˙O2) was measured continuously, and ratings of perceived exertion (RPE) were estimated at the end of each exercise stage using the CERT and the EP Scale. Ratings up to- and including RPE 5 and 7, from both the CERT (CERT 5, CERT 7) and EP Scale (EP 5, EP 7), were linearly regressed against the corresponding \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot{V}{\text{O}}_{2}$$\end{document}V˙O2, to both maximal RPE (CERT 10, EP 10) and terminal RPE (CERT 9, EP 9).

Results

There were no differences between measured- and predicted \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot{V}{\text{O}}_{{2{\text{peak}}}}$$\end{document}V˙O2peak from CERT 5, CERT 7, EP 5 and EP 7 when extrapolated to either CERT 9 or EP 9 (P > 0.05). Pearson’s correlations of r = 0.64–0.86 were observed between measured- and predicted \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot{V}{\text{O}}_{{2{\text{peak}}}}$$\end{document}V˙O2peak, for all perceptual ranges investigated. However, only EP 7 provided a small difference when considering the standard error of estimate, suggesting that the prediction of \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot{V}{\text{O}}_{{2{\text{peak}}}}$$\end{document}V˙O2peak from EP 7 would be within 10 % of measured \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot{V}{\text{O}}_{{2{\text{peak}}}}$$\end{document}V˙O2peak.

Conclusions

Although robust estimates of \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot{V}{\text{O}}_{{2{\text{peak}}}}$$\end{document}V˙O2peak may be elicited using both the CERT and EP Scale during a single CPET with children, the most accurate estimates of \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot{V}{\text{O}}_{{2{\text{peak}}}}$$\end{document}V˙O2peak occur when extrapolating from EP 7.

Exercise Capacity Long-Term after Arterial Switch Operation for Transposition of the Great Arteries

Transposition of the great arteries (TGA) is a congenital heart defect successfully corrected through arterial switch operation (ASO). Although this technique had significant impact in improving survival, little is known about the functional capacity of the operated patients long-term after surgery.

OBJECTIVE

The aim of this study was to compare the functional capacity of children with TGA long-term after ASO with that of healthy children.

DESIGN

Retrospective study.

PATIENTS

All patients that performed cardiopulmonary exercise test (CPET) were included in the study. As a control group, healthy children in evaluation for physical activity that performed CPET during the same period were also enrolled.

RESULTS

Thirty-one TGA patients (19 male) were compared with 29 age-matched controls (21 male). Maximum oxygen consumption was higher in the control group (45.47 ± 8.05 vs. 40.52 ± 7.19, P = .017), although within normal limits in both groups (above 90% of predicted value). The heart rate behavior during exercise was different in both groups, with a mean chronotropic index significantly lower in the TGA group (63% ± 14 vs. 81% ± 12, P < .001).

CONCLUSIONS

Our results showed that exercise capacity long-term after ASO in TGA is well preserved although lower than in healthy children what might be explained by the presence of chronotropic incompetence in the TGA group.

Relationships between physical activity and muscular strength among healthy adults across the lifespan

The purpose of this study was to examine relationships between objective and self-report measures of physical activity and muscle strength among healthy adults ranging in age from 20 to 91 years. Participants (n = 412) were mostly Caucasian men (48 %) and women (52 %) 43.9 ± 16.1 year of age with a body mass index (BMI) of 26.4 ± 4.8 kg/m(2). Physical activity was measured objectively with an accelerometer and by self-report with the Paffenbarger Physical Activity Questionnaire. Upper and lower body muscle strength were measured with an isokinetic dynamometer and handgrip strength with a static dynamometer. Multivariate regression assessed relationships between physical activity and muscle strength. The strongest correlates of upper body strength including handgrip strength were gender (r = -0.861 to -0.716), age (r = -0.445 to -0.241), BMI (r = 0.134-0.397), and physical activity (r = 0.093-0.186). The strongest correlates of lower body strength were gender (r = -0.772 to -0.634), age (r = -0.663 to -0.445), BMI (r = 0.160-0.266), and physical activity (r = -0.139 to 0.151). The strongest correlates of muscle strength were gender (explaining 40-74 % of the variance), age (6-44 %), and BMI (2-16 %), while physical activity correlations were weaker (1-3 %). Conflict surrounding the influence of a physically active lifestyle on muscle strength with age may be due to the stronger influences of other factors that supersede those of physical activity whether measured objectively or by self-report methods.

Health-related fitness profiles in adolescents with complex congenital heart disease

PURPOSE

This study investigates whether subgroups of different health-related fitness (HrF) profiles exist among girls and boys with complex congenital heart disease (ConHD) and how these are associated with lifestyle behaviors.

METHODS

We measured the cardiorespiratory fitness, muscle strength, and body composition of 158 adolescents aged 13-16 years with previous surgery for a complex ConHD. Data on lifestyle behaviors were collected concomitantly between October 2010 and April 2013. A cluster analysis was conducted to identify profiles with similar HrF. For comparisons between clusters, multivariate analyses of covariance were used to test the differences in lifestyle behaviors.

RESULTS

Three distinct profiles were formed: (1) Robust (43, 27%; 20 girls and 23 boys); (2) Moderately Robust (85, 54%; 37 girls and 48 boys); and (3) Less robust (30, 19%; 9 girls and 21 boys). The participants in the Robust clusters reported leading a physically active lifestyle and participants in the Less robust cluster reported leading a sedentary lifestyle. Diagnoses were evenly distributed between clusters.

CONCLUSIONS

The cluster analysis attributed some of the variability in cardiorespiratory fitness among adolescents with complex ConHD to lifestyle behaviors and physical activity. Profiling of HrF offers a valuable new option in the management of person-centered health promotion.

The prevalence of arrhythmias, predictors for arrhythmias, and safety of exercise stress testing in children

Exercise testing is commonly performed in children for evaluation of cardiac disease. Few data exist, however, on the prevalence, types of arrhythmias, predictors for arrhythmias, and safety of exercise testing in children. A retrospective review of all patients ≤21 years undergoing exercise testing at our center from 2008 to 2012 was performed. Patients with clinically relevant arrhythmias were compared to those not experiencing a significant arrhythmia. 1,037 tests were performed in 916 patients. The mean age was 14 ± 4 years, 537 (55 %) were male, 281 (27 %) had congenital heart disease, 178 (17 %) had a history of a prior arrhythmia, and 17 (2 %) had a pacemaker or ICD. 291 (28 %) patients had a rhythm disturbance during the procedure. Clinically important arrhythmias were noted in 34 (3 %) patients and included: 19 (1.8 %) increasing ectopy with exercise, 5 (0.5 %) VT, 5 (0.5 %) second degree AV block, 3 (0.3 %) SVT, and 2 (0.2 %) AFIB. On multivariate logistic regression, variables associated with the development of clinically relevant arrhythmias included severe left ventricular (LV) dysfunction on echo (OR 1.99, CI 1.20-3.30) and prior history of a documented arrhythmia (OR 2.94, CI 1.25-6.88). There were no adverse events related to testing with no patient requiring cardioversion, defibrillation, or acute anti-arrhythmic therapy. A total of 28 % of children developed a rhythm disturbance during exercise testing and 3 % were clinically important. Severe LV dysfunction and a history of documented arrhythmia were associated with the development of a clinically important arrhythmia.

Cardiopulmonary exercise testing in healthy children and adolescents at moderately high altitude

OBJECTIVE

Cardiopulmonary exercise testing is a tool that helps clinicians to establish diagnosis and calculate risk stratification in adults. However, the utility of this test among children with congenital heart disease has not been fully explored. The goal of this study was to describe reference values for cardiopulmonary performance of healthy children.

METHODS

This study included 103 apparently healthy children (aged from 4 to 18 years; 61 boys), who underwent cardiopulmonary test using a treadmill protocol. All tests took place at 2240m above sea level (Mexico City).

RESULTS

Exercise time was 11±4min. There were no complications. Peak oxygen uptake correlated closely with height in both genders (girls r=0.84; boys r=0.84, p<0.001). A multivariable linear regression model showed that body surface area, exercise time, gender and heart rate reserve were significant predictors of peak oxygen uptake (R(2)=0.815, p<0.001). Peak oxygen uptake was strongly associated with age even among children younger than thirteen years (r=0.74, p<0.001).

CONCLUSION

This study provides physiological values for the major cardiopulmonary variables obtained from exercise testing using a treadmill among healthy children. Cardiopulmonary exercise test can be safely and effectively performed in young children even as young as 4 years old. Variables including age, gender and height are strongly associated with exercise time, peak heart rate and peak oxygen uptake. Regression equations for predicting peak heart rate and peak oxygen uptake are presented as reference values that allow researchers to compare children with heart disease versus those who are healthy.

The results of cardiopulmonary exercise test in healthy Korean children and adolescents: single center study

PURPOSE

The cardiopulmonary exercise test (CPET) is an important clinical tool for evaluating exercise capacity and is frequently used to evaluate chronic conditions including congenital heart disease. However, data on the normal CPET values for Korean children and adolescents are lacking. The aim of this study was to provide reference data for CPET variables in children and adolescents.

METHODS

From August 2006 to April 2009, 76 healthy children and adolescents underwent the CPET performed using the modified Bruce protocol. Here, we performed a medical record review to obtain data regarding patient' demographics, medical history, and clinical status.

RESULTS

The peak oxygen uptake (VO2Peak) and metabolic equivalent (METMax) were higher in boys than girls. The respiratory minute volume (VE)/CO2 production (VCO2) slope did not significantly differ between boys and girls. The cardiopulmonary exercise test data did not significantly differ between the boys and girls in younger age group (age, 10 to 14 years). However, in older age group (age, 15 to 19 years), the boys had higher VO2Peak and METMax values and lower VE/VCO2 values than the girls.

CONCLUSION

This study provides reference data for CPET variables in case of children and adolescents and will make it easier to use the CPET for clinical decision-making.

Cardiopulmonary assessment in primary ciliary dyskinesia

BACKGROUND

Primary ciliary dyskinesia (PCD) is a rare, usually autosomal recessive disorder of ciliary dysfunction associated with lung involvement, which has a great impact on health. There is limited information concerning the aerobic fitness of children and adolescents with PCD. The aim of this study was to assess cardiopulmonary functional capacity and its relationship with pulmonary function and physical activity (PA) levels in patients with PCD.

DESIGN

Ten patients with PCD (age 13·2 ± 2·8 years) underwent spirometry and cardiopulmonary exercise testing. PA was investigated through a questionnaire. Eight age- and body mass index-matched healthy children were enrolled as controls. Main variables were forced expiratory volume at 1 s, peak oxygen uptake (VO(2peak) ) and time spent in PA.

RESULTS

Forty per cent of patients with PCD had impaired lung function as expressed by FEV(1) < 85% predicted. Only patients with impaired lung function exhibited reduced VO(2peak) (18·1 ± 7·9 mL/kg/min). Time spent in total daily PA was slightly lower in patients than controls, with no difference between patients with normal or reduced lung function. In multiple regression models, male gender (β = 0·518, P = 0·018), age (β = 0·752, P = 0·035) and time spent in vigorous PA (β = 0·353, P = 0·049) were independent predictors of aerobic fitness.

CONCLUSIONS

Assessment of resting pulmonary function and cardiopulmonary functional capacity could contribute to the evaluation of pulmonary impairment in PCD. Given the benefit of physical exercise on airway clearance and on general health and quality of life, patients with PCD should be encouraged to adopt an active lifestyle.

Design and rationale for the PREVAIL study: effect of e-Health individually tailored encouragements to physical exercise on aerobic fitness among adolescents with congenital heart disease--a randomized clinical trial

Intensive exercise may be an important part of rehabilitation in patients with congenital heart disease (CHD). However, performing regular physical exercise is challenging for many adolescent patients. Consequently, effective exercise encouragements may be needed. Little is known on the effect of e-Health encouragements on physical fitness, physical activity, and health-related quality of life in adolescents. This trial is a nationwide interactive e-Health rehabilitation study lasting 1 year, centered on interactive use of mobile phone and Internet technology. We hypothesize that e-Health encouragements and interactive monitoring of intensive exercise for 1 year can improve physical fitness, physical activity, and health-related quality of life. Two hundred sixteen adolescents (age, 13-16 years) with surgically corrected complex CHD but without significant hemodynamic residual defects and no restrictions to participate in physical activity are in the process of being enrolled by invitation after informed consent. Physical fitness is measured as the maximal oxygen uptake (Vo(2)) at baseline and after 12 months by an assessor blinded to the randomization group. After baseline testing, the patients are 1:1 randomized to an intervention group or a control group. Individually fully automated tailored e-Health encouragements--SMS, Internet, and mobile applications--aimed at increasing physical activity are delivered to the participants in the intervention group once a week. The Bandura's Social Cognitive Theory inspires the behavioral theoretical background. The e-Health intervention and the Godfrey cycle ergometer protocol have been feasibility tested and seem applicable to adolescents with CHD. The trial is expected to contribute with new knowledge regarding how physical activity in adolescents with CHD can be increased and, possibly, comorbidity be reduced.

Exercise capacity in children with isolated congenital complete atrioventricular block: does pacing make a difference?

The management of patients with isolated congenital complete atrioventricular block (CCAVB) has changed during the last decades. The current policy is to pace the majority of patients based on a variety of criteria, among which is limited exercise capacity. Data regarding exercise capacity in this population stems from previous publications reporting small case series of unpaced patients. Therefore, we have investigated the exercise capacity of a group of contemporary children with CCAVB. Sixteen children (mean age 11.5 ± 4; seven boys, nine girls) with CCAVB were tested. In 13 patients, a median number of three pacemakers were implanted, whereas in three patients no pacemaker was given. All patients had an echocardiogram and completed a cardiopulmonary cycle exercise test. Exercise parameters were determined and compared with reference values obtained from healthy Dutch peers. The peak oxygen uptake/body mass was reduced to 34.4 ± 9.5 ml kg(-1) min(-1) (79 ± 24% of predicted) and the ventilatory threshold was reduced to 52 ± 17% of peak oxygen uptake (78 ± 21% of predicted), whereas the peak work load/body mass was 2.8 ± 0.6 W/kg (91 ± 24% of predicted), which was similar to controls. Importantly, 25% of the paced patients showed upper rate restriction by the pacemaker. In conclusion, children with CCAVB show a reduced peak oxygen uptake and ventilatory threshold, whereas they show normal peak work rates. This indicates that they generate more energy during exercise from anaerobic energy sources. Paced children with CCAVB do not perform better than unpaced children.

Cardiopulmonary exercise testing in congenital heart disease: equipment and test protocols

Cardiopulmonary exercise testing (CPET) in paediatric cardiology differs in many aspects from the tests as performed in adult cardiology. Children's cardiovascular responses during exercise testing present different characteristics, particularly oxygen uptake, heart rate and blood pressure response, which are essential in interpreting haemodynamic data. Diseases that are associated with myocardial ischaemia are very rare in children. The main indications for CPET in children are evaluation of exercise capacity and the identification of exercise-induced arrhythmias. In this article we will review exercise equipment and test protocols for CPET in children with congenital heart disease. (Neth Heart J 2009;17:339-44.).

Exercise testing and prescription in patients with congenital heart disease

The present paper provides a review of the literature regarding exercise testing, exercise capacity, and the role of exercise training in patients with congenital heart disease (CHD). Different measures of exercise capacity are discussed, including both simple and more advanced exercise parameters. Different groups of patients, including shunt lesions, pulmonary valvar stenosis, patients after completion of Fontan circulation, and patients with pulmonary arterial hypertension are discussed separately in more detail. It has been underscored that an active lifestyle, taking exercise limitations and potential risks of exercise into account is of utmost importance. Increased exercise capacity in these patients is furthermore correlated with an improvement of objective and subjective quality of life.