Six-Minute Walking Test to Assess Exercise Tolerance and Cardiorespiratory Responses During Training Program in Children With Congenital Heart Disease

Exercise training in paediatric congenital heart disease: fit for purpose?

Exercise and physical activity (PA) have been shown to be effective, safe and feasible in both healthy children and children with congenital heart disease (CHD). However, implementing exercise training as an intervention is still not routine in children with CHD despite considerable evidence of health benefits and well-being. Understanding how children with CHD can safely participate in exercise can boost participation in PA and subsequently reduce inactivity-related diseases. Home-based exercise intervention, with the use of personal wearable activity trackers, and high-intensity interval training have been beneficial in adults' cardiac rehabilitation programmes. However, these remain underutilised in paediatric care. Therefore, the aims of this narrative review were to synthesise prescribed exercise interventions in children with CHD, identify possible limitation to exercise training prescription and provide an overview on how to best integrate exercise intervention effectively for this population into daily practice.

Exercise Capacity in Children and Adolescents With Congenital Heart Disease: A Systematic Review and Meta-Analysis

Background

Congenital heart disease (CHD) entails structural defects in the morphogenesis of the heart or its main vessels. Analyzing exercise capacity of children and adolescents with CHD is important to improve their functional condition and quality of life, since it can allow timely intervention on poor prognostic factors associated with higher risk of morbidity and mortality.

Objective

To describe exercise capacity in children and adolescents with CHD compared with healthy controls.

Methods

A systematic review was carried out. Randomized clinical trials and observational studies were included assessing exercise capacity through direct and indirect methods in children and adolescents between 5 and 17 years-old. A sensitive analysis was performed including studies with CHD repaired participants. Additionally, it was sub-analyzed by age range (< and ≥ 12 years old). Two independent reviewers analyzed the studies, extracted the data, and assessed the quality of the evidence.

Results

5619 articles were found and 21 were considered for the review. Eighteen articles used the direct exercise capacity measurement method by cardiopulmonary exercise test (CPET). The CHD group showed significant differences in peak oxygen consumption (VO₂peak) with a value of −7.9 ml/Kg/min (95% CI: −9.9, −5.9, p = 0.00001), maximum workload (Wmax) −41.5 (95% CI: −57.9, −25.1 watts, p = 0.00001), ventilatory equivalent (VE/VCO₂) slope 2.6 (95% CI: 0.3, 4.8), oxygen pulse (O₂ pulse)−2.4 ml/beat (95% CI: −3.7, −1.1, p = 0.0003), and maximum heart rate (HRmax) −15 bpm (95% CI: −18, −12 bpm, p = 0.00001), compared with healthy controls. Adolescents (≥ 12 yrs) with CHD had a greater reduction in VO₂peak (−10.0 ml/Kg/min (95% CI: −12.0, −5.3), p < 0.00001), Wmax (−45.5 watts (95% CI: −54.4, −36.7), p < 0.00001) and HRmax (−21 bpm (95% CI: −28, −14), p<0.00001).

Conclusion

Suffering CHD in childhood and adolescence is associated with lower exercise capacity as shown by worse VO₂peak, Wmax, VE/VCO₂ slope, O₂ pulse, and HRmax compared with matched healthy controls. The reduction in exercise capacity was greater in adolescents.

Systematic Review Registration

www.crd.york.ac.uk/prospero/display_record.php?RecordID=208963, identifier: CRD42020208963.

Leveraging Walking Performance to Understand Work Fatigue Among Young Adults: Mixed-Methods Study

Background

Work fatigue negatively impacts personal health in the long term. Prior research has indicated the possibility of leveraging both walking parameters and perceptual measures to assess a person’s fatigue status. However, an effective and ubiquitous approach to assessing work fatigue in young adults remains unexplored.

Objective

The goals of this paper were to (1) explore how walking rhythms and multiple streams of data, including reaction time, self-reports, and an activity diary, reflect work-induced fatigue in the lab setting; (2) identify the relationship between objective performance and subjective perception in indicating fatigue status and fatigability; and (3) propose a mobile-based assessment for work-induced fatigue that uses multiple measurements.

Methods

We conducted a 2-day in-lab study to measure participants’ fatigue status using multiple measurements, including the stair climb test (SCT), the 6-minute walk test (6MWT), and the reaction time test. Both the SCT and the 6MWT were conducted at different points in time and under 2 conditions (measurement time, including prior to and after work, and pace, including normal and fast). Participants reported their fatigue perception through questionnaires completed before conducting walking tests and in an activity diary recorded over a week. Walking performance data were collected by a smartphone with a built-in 3-axis accelerometer. To examine the effect of fatigability on walking performance, we first clustered participants into 2 groups based on their reported mental fatigue level in the entry surveys and then compared their walking performance using a generalized linear model (GLM). The reaction time was examined using a 2-way repeated-measures GLM. We conducted semistructured interviews to understand participants’ fatigue perception after each day’s walking tests.

Results

All participants (N=26; mean age 24.68 years) were divided into 2 groups—the fatigue-sensitive group (11/26, 42%) and the fatigue-nonsensitive group (15/26, 58%)—based on their mental subscores from 3 entry surveys: Fatigue Scale-14, Three-Dimensional Work Fatigue Inventory, and Fatigue Self-Assessment Scale (FSAS). The fatigue-sensitive group reported a significantly higher FSAS score in the before-work setting (t₅₀=–3.361; P=.001). The fatigue-sensitive group covered fewer steps than the fatigue-nonsensitive group (β₁=–0.099; SE 0.019; t₁=–5.323; P<.001) and had a higher step-to-step time variability in the 6MWT (β₁=9.61 × 10^–4; t₁=2.329; P=.02). No strong correlation between subjective and objective measurements was observed in the study.

Conclusions

Walking parameters, including step counts and step-to-step time variability, and some selected scales (eg, FSAS) were found to reflect participants’ work-induced fatigue. Overall, our work suggests the opportunity of employing mobile-based walking measurements to indicate work fatigue among young adults.

Physical activity interventions for people with congenital heart disease

BACKGROUND

Congenital heart disease (ConHD) affects approximately 1% of all live births. People with ConHD are living longer due to improved medical intervention and are at risk of developing non-communicable diseases. Cardiorespiratory fitness (CRF) is reduced in people with ConHD, who deteriorate faster compared to healthy people. CRF is known to be prognostic of future mortality and morbidity: it is therefore important to assess the evidence base on physical activity interventions in this population to inform decision making.

OBJECTIVES

To assess the effectiveness and safety of all types of physical activity interventions versus standard care in individuals with congenital heart disease.

SEARCH METHODS

We undertook a systematic search on 23 September 2019 of the following databases: CENTRAL, MEDLINE, Embase, CINAHL, AMED, BIOSIS Citation Index, Web of Science Core Collection, LILACS and DARE. We also searched ClinicalTrials.gov and we reviewed the reference lists of relevant systematic reviews.

SELECTION CRITERIA

We included randomised controlled trials (RCT) that compared any type of physical activity intervention against a 'no physical activity' (usual care) control. We included all individuals with a diagnosis of congenital heart disease, regardless of age or previous medical interventions.  DATA COLLECTION AND ANALYSIS: Two review authors (CAW and CW) independently screened all the identified references for inclusion. We retrieved and read all full papers; and we contacted study authors if we needed any further information. The same two independent reviewers who extracted the data then processed the included papers, assessed their risk of bias using RoB 2 and assessed the certainty of the evidence using the GRADE approach. The primary outcomes were: maximal cardiorespiratory fitness (CRF) assessed by peak oxygen consumption; health-related quality of life (HRQoL) determined by a validated questionnaire; and device-worn 'objective' measures of physical activity.

MAIN RESULTS

We included 15 RCTs with 924 participants in the review. The median intervention length/follow-up length was 12 weeks (12 to 26 interquartile range (IQR)). There were five RCTs of children and adolescents (n = 500) and 10 adult RCTs (n = 424). We identified three types of intervention: physical activity promotion; exercise training; and inspiratory muscle training. We assessed the risk of bias of results for CRF as either being of some concern (n = 12) or at a high risk of bias (n = 2), due to a failure to blind intervention staff. One study did not report this outcome. Using the GRADE method, we assessed the certainty of evidence as moderate to very low across measured outcomes. When we pooled all types of interventions (physical activity promotion, exercise training and inspiratory muscle training), compared to a 'no exercise' control CRF may slightly increase, with a mean difference (MD) of 1.89 mL/kg^-1/min^-1 (95% CI -0.22 to 3.99; n = 732; moderate-certainty evidence). The evidence is very uncertain about the effect of physical activity and exercise interventions on HRQoL. There was a standardised mean difference (SMD) of 0.76 (95% CI -0.13 to 1.65; n = 163; very low certainty evidence) in HRQoL. However, we could pool only three studies in a meta-analysis, due to different ways of reporting. Only one study out of eight showed a positive effect on HRQoL. There may be a small improvement in mean daily physical activity (PA) (SMD 0.38, 95% CI -0.15 to 0.92; n = 328; low-certainty evidence), which equates to approximately an additional 10 minutes of physical activity daily (95% CI -2.50 to 22.20). Physical activity and exercise interventions likely result in an increase in submaximal cardiorespiratory fitness (MD 2.05, 95% CI 0.05 to 4.05; n = 179; moderate-certainty evidence). Physical activity and exercise interventions likely increase muscular strength (MD 17.13, 95% CI 3.45 to 30.81; n = 18; moderate-certainty evidence). Eleven studies (n = 501) reported on the outcome of adverse events (73% of total studies). Of the 11 studies, six studies reported zero adverse events. Five studies reported a total of 11 adverse events; 36% of adverse events were cardiac related (n = 4); there were, however, no serious adverse events related to the interventions or reported fatalities (moderate-certainty evidence). No studies reported hospital admissions.

AUTHORS' CONCLUSIONS

This review summarises the latest evidence on CRF, HRQoL and PA. Although there were only small improvements in CRF and PA, and small to no improvements in HRQoL, there were no reported serious adverse events related to the interventions. Although these data are promising, there is currently insufficient evidence to definitively determine the impact of physical activity interventions in ConHD. Further high-quality randomised controlled trials are therefore needed, utilising a longer duration of follow-up.

Cardiopulmonary Rehabilitation Improves Respiratory Muscle Function and Functional Capacity in Children with Congenital Heart Disease. A Prospective Cohort Study

Critical surgical and medical advances have shifted the focus of congenital heart disease (CHD) patients from survival to achievement of a greater health-related quality of life (HRQoL). HRQoL is influenced, amongst other factors, by aerobic capacity and respiratory muscle strength, both of which are reduced in CHD patients. This study evaluates the influence of a cardiopulmonary rehabilitation program (CPRP) on respiratory muscle strength and functional capacity. Fifteen CHD patients, ages 12 to 16, with reduced aerobic capacity in cardiopulmonary exercise testing (CPET) were enrolled in a CPRP involving strength and aerobic training for three months. Measurements for comparison were obtained at the start, end, and six months after the CPRP. A significant improvement of inspiratory muscle strength was evidenced (maximum inspiratory pressure 21 cm H₂O, 23%, p < 0.01). The six-minute walking test showed a statistically and clinically significant rise in walked distance (48 m, p < 0.01) and a reduction in muscle fatigue (1.7 out of 10 points, p = 0.017). These results suggest CPRP could potentially improve respiratory muscle function and functional capacity, with lasting results, in children with congenital heart disease, but additional clinical trials must be conducted to confirm this finding.

Valores médios percorridos no teste de caminhada de seis minutos em crianças saudáveis de Coari (AM)

RESUMO O objetivo desta pesquisa foi estabelecer valores médios percorridos para o teste de caminhada de seis minutos em crianças saudáveis no Norte do Brasil. Este foi um estudo experimental, randomizado, cego e transversal que avaliou 63 crianças saudáveis do sexo masculino e feminino, de 10 a 12 anos, que após terem seus dados antropométricos registrados foram treinadas e instruídas para a realização do teste conforme recomendações da American Thoracic Society, após avaliação-padrão. O teste foi realizado numa pista reta de 30 metros, com marcações a cada 3 metros e cones indicando onde o retorno deveria ser feito para a continuidade do teste. Ao final, foi refeita a avaliação pré-teste. Foi observado índice de massa corporal muito baixo nos meninos de 11 anos, e normal nas outras faixas. A frequência cardíaca imediata pós-teste apresentou-se significativamente elevada em todos os grupos (p<0,001), enquanto todos os outros dados cardiovasculares colhidos não apresentaram alterações. As distâncias percorridas foram significativamente inferiores às previstas por equação-padrão para todos os grupos e sexos (p<0,0001). O valor médio percorrido encontrado em meninas foi de 436,30±56,74m e 460,80±63,90m em meninos, enquanto a média geral foi de 445,70±54,10m, abaixo dos valores esperados para a amostra. O resultado obtido pelo grupo estudado, menor que a média esperada, pode ser creditado ao fenótipo regional, mas o Índice de Desenvolvimento muito mais baixo que a média brasileira deve ter sua influência mais bem estudada. Espera-se que os achados contribuam no apontamento de valores de referência do teste em crianças do Norte brasileiro.

Quantitative Assessment of Muscular Stiffness in Children With Chronic Kidney Disease Using Acoustic Radiation Force Impulse Ultrasound Elastography

ABSTRACT

The aim of this study was to evaluate the feasibility of quantitative analysis of muscle stiffness in the rectus femoris muscle (RFM) by acoustic radiation force impulse (ARFI) ultrasound elastography in children with chronic kidney disease (CKD). Twenty-three children with CKD and 22 healthy children participated in the study in our radiology department. The strength of each CKD group and healthy group participants' tight extensors was assessed by a physiatrist using a handheld dynamometer. Acoustic radiation force impulse was used to measure the shear wave velocities (SWVs) of the RFM. The mean SWV value of the RFM correlated with the strengths of the tight extensors in the CKD and healthy groups. The mean ± SD SWV values of the RFM in the CKD group for the right (n = 23) and left sides (n = 21) were 1.23 ± 0.25 and 1.26 ± 0.30 m/s, respectively. The mean ± SD SWV values of the RFM in the healthy group for the right (n = 23) and left sides (n = 21) were 1.62 ± 0.33 and 1.65 ± 0.35 m/s, respectively. The SWV of the RFM significantly decreased in the patients with CKD when compared with controls (P < 0.001). The SWV values were not correlated to the handheld dynamometry. The interobserver agreement expressed as the interclass correlation coefficient was 0.65 (95% confidence interval, 0.33-0.84; P < 0.001). The acoustic radiation force impulse demonstrates a difference in RFM muscle stiffness between the CKD and healthy groups. This method is a feasible imaging method for the noninvasive assessment of muscle weakness in children with CKD.

Neonatal respiratory status predicts longitudinal respiratory health outcomes in preterm infants

OBJECTIVES

To examine the relationship between neonatal respiratory status and longitudinal respiratory health outcomes in preterm infants with very low birth weight (VLBW, birth weight <1500 g).

METHODS

A total of 109 VLBW preterm infants were prospectively assessed for respiratory status using the Toce clinical and radiographic scoring method on a postnatal day 28, and severity of bronchopulmonary dysplasia (BPD) at 36-weeks postmenstrual age (PMA), respiratory morbidity within 1 year of corrected age (CA), pulmonary function test, and six-minute walk test at 4 years of age.

RESULTS

A high Toce clinical score on day 28 was associated with the occurrence of respiratory morbidity within 1 year of CA and poor pulmonary function and functional exercise performance at 4 years of age in VLBW preterm infants (all P < 0.05). BPD at 36-weeks PMA was associated with an increased risk of respiratory morbidity within 1 year of CA and its negative impact on pulmonary function and functional exercise performance at 4 years of age was most pronounced in the severe form (all P < 0.05).

CONCLUSIONS

Early assessments of neonatal respiratory status including Toce clinical score and the severity of BPD are valid to identify VLBW preterm infants who are at risk of adverse longitudinal respiratory health outcomes.

Comparing modalities of conducting the six-minute walk test in healthy children and adolescents

BACKGROUND

The 6-minute walk test (6MWT) in children can be performed in the conventional way, or by using a measuring wheel. This study aimed to compare these test modalities and to determine influencing factors.

METHODS

The study included 317 healthy children (172 boys) between 6 and 15 years from elementary schools and high schools, who were randomly assigned to perform a 6MWT either with or without a measuring wheel according to the guidelines of the American Thoracic Society. The 6-minute walk distance (6MWD) was compared between the two measuring modalities as well as different school types.

RESULTS

The use of a measuring wheel during the 6MWT led to a significantly greater 6MWD compared to conventional walking. Students of sports schools walked substantially farther than those attending general high schools, irrespective of test modality. In multivariate regression analysis height, post-test heart rate, male sex and the measuring wheel itself were all independently associated with greater 6MWD.

CONCLUSIONS

The use of a measuring wheel during a 6MWT reflects physical performance in children and adolescents more accurately as it includes the stretch of way around the cones during lap turns. Test modalities and sports background should be taken into account, especially when performing longitudinal monitoring and multicenter studies.

FUNCTIONAL CAPACITY IN CHILDREN AND ADOLESCENTS WITH CONGENITAL HEART DISEASE

Objective:

To evaluate the physical activity level and functional capacity of children and adolescents with congenital heart disease and to describe correlations between functionality, surgical and echocardiographic findings, metabolic and inflammatory profile and differences between acyanotic and cyanotic heart defects.

Methods:

A cross-sectional study including children and adolescents with congenital heart disease between six and 18 years old that were evaluated with the 6-minute walk test (6MWT) to assess functional capacity. The short version form of the International Physical Activity Questionnaire (IPAQ) was performed to evaluate physical activity levels. Also, echocardiography and blood collection, to evaluate the metabolic (blood glucose, lipids, insulin) and inflammatory markers (C-reactive protein), were assessed.

Results:

Twenty-five individuals were evaluated. Of them, 14 had acyanotic heart defects and 11 cyanotic heart defects. Mean age was 12.0±3.7 years, and 20 (80%) were male. IPAQ showed that six (24%) individuals were very active, eight (32%) were active, nine (36%) had irregular physical activity, and two (8%) were sedentary. The mean distance walked in the 6MWT, considering all studied individuals, was 464.7±100.4 m, which was 181.4±42.0 m less than the predicted (p=0.005). There was a positive correlation between Z score 6MWT and the number of surgical procedures (r=-0.455; p=0.022).

Conclusions:

Children and adolescents with congenital heart disease have low functional capacity, but they are not completely sedentary.

Prediction of Maximal Oxygen Uptake by Six-Minute Walk Test and Body Mass Index in Healthy Boys

OBJECTIVE

To develop an equation to predict maximal oxygen uptake (VO2max) based on the 6-minute walk test (6MWT) and body composition in healthy boys.

STUDY DESIGN

Direct VO2max, 6-minute walk distance, and anthropometric characteristics were measured in 349 healthy boys (12.49 ± 2.72 years). Multiple regression analysis was used to generate VO2max prediction equations. Cross-validation of the VO2max prediction equations was assessed with predicted residual sum of squares statistics. Pearson correlation was used to assess the correlation between measured and predicted VO2max.

RESULTS

Objectively measured VO2max had a significant correlation with demographic and 6MWT characteristics (R = 0.11-0.723, P < .01). Multiple regression analysis revealed the following VO2max prediction equation: VO2max (mL/kg/min) = 12.701 + (0.06 × 6-minute walk distance _m) - (0.732 × body mass index_kg/m2) (R² = 0.79, standard error of the estimate [SEE] = 2.91 mL/kg/min, %SEE = 6.9%). There was strong correlation between measured and predicted VO2max (r = 0.875, P < .001). Cross-validation revealed minimal shrinkage (R²p = 0.78 and predicted residual sum of squares SEE = 2.99 mL/kg/min).

CONCLUSIONS

This study provides a relatively accurate and convenient VO2max prediction equation based on the 6MWT and body mass index in healthy boys. This model can be used for evaluation of cardiorespiratory fitness of boys in different settings.

Learning and Encouragement Effects on Six-Minute Walking Test in Children

OBJECTIVES

To evaluate learning and encouragement effects on the 6-minute walk test in children between 6 and 12 years of age.

STUDY DESIGN

Two 6-minute walk tests separated by a 10-minute resting period were performed by healthy children between 6 and 12 years of age to evaluate the learning (part 1) and encouragement effects (part 2; randomization with and without encouragement). Distance and cardiorespiratory variables were used as outcomes.

RESULTS

148 children were recruited. The intraclass correlation coefficient estimates were 0.927 (95% CI, 0.893-0.951; part 1) and 0.844 (95% CI, 0.744-0.907; part 2). The test-retest agreement was verified for distance (P = .679) with a bias of 1.1 m (95% CI, -4 to 6), but the increase in distance with encouragement was significantly and clinically relevant (P < .001; +41 m; 95% CI, 33-50).

CONCLUSION

No training is required for the 6-minute walk test in children, in contrast with adults, but there was an encouragement effect on the walked distance in these children. Guidelines should take these results into account.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT03276299.

Can endurance training improve physical capacity and quality of life in young Fontan patients?

OBJECTIVE

Children after Fontan palliation have reduced exercise capacity and quality of life. Our aim was to study whether endurance training could improve physical capacity and quality of life in Fontan patients.

METHODS

Fontan patients (n=30) and healthy age- and gender-matched control subjects (n=25) performed a 6-minute walk test at submaximal capacity and a maximal cycle ergometer test. Quality of life was assessed with Pediatric Quality of Life Inventory Version 4.0 questionnaires for children and parents. All tests were repeated after a 12-week endurance training programme and after 1 year.

RESULTS

Patients had decreased submaximal and maximal exercise capacity (maximal oxygen uptake 35.0±5.1 ml/minute per·kg versus 43.7±8.4 ml/minute·per·kg, p<0.001) and reported a lower quality of life score (70.9±9.9 versus 85.7±8.0, p<0.001) than controls. After training, patients improved their submaximal exercise capacity in a 6-minute walk test (from 590.7±65.5 m to 611.8±70.9 m, p<0.05) and reported a higher quality of life (p<0.01), but did not improve maximal exercise capacity. At follow-up, submaximal exercise capacity had increased further and improved quality of life was sustained. The controls improved their maximal exercise capacity (p<0.05), but not submaximal exercise capacity or quality of life after training. At follow-up, improvement of maximal exercise capacity was sustained.

CONCLUSIONS

We believe that an individualised endurance training programme for Fontan patients improves submaximal exercise capacity and quality of life in Fontan patients and the effect on quality of life appears to be long-lasting.

Impact of the initial fitness level on the effects of a structured exercise therapy during pediatric stem cell transplantation

BACKGROUND

Before and after hematopoietic stem cell transplantation (HSCT), most patients suffer from psychophysical limitations due to the treatment. Exercise interventions demonstrate beneficial effects on, for example, strength, endurance, or health-related quality of life during and after HSCT, but with a great variation among patients concerning the response to exercise. This study examines the influence of the initial fitness on the effects of an exercise therapy in pediatric HSCT.

PROCEDURE

Fifty-three children and adolescents (10.9 ± 3.5 years) scheduled for HSCT were randomized into an exercise intervention group (IG) or a control group (CG). During hospitalization, the IG performed endurance, strength, and flexibility training three times per week. The CG included a nonexercise program. A 6-min walk test was completed before and after the inpatient period. Baseline results (6-min walking distance [6MWD]) were used to split both groups into the following: IG_UNFIT , n = 14; IG_FIT , n = 12; CG_UNFIT , n = 16; CG_FIT , n = 11. Differences in outcome changes between groups were analyzed with H-test.

RESULT

Intergroup comparison revealed significant differences between IG_UNFIT and CG_UNFIT (P < 0.05). The IG_UNFIT increased their 6MWD by +8% (vs. IG_FIT , +1%); both CGs presented a decline in 6MWD (CG_UNFIT , -14%; CG_FIT , -16%). At discharge, the IG_FIT achieved 85.5 ± 10.3% of healthy reference values.

CONCLUSIONS

The current results indicate that exercise during pediatric HSCT is feasible and contributes to prevention of treatment-related loss of physical function. As seen in healthy persons, patients' benefits might depend on their initial fitness level. As a diminished physical capability may result in higher training effects, impaired especially patients should engage in exercise.

Functional Capacity in Congenital Heart Disease: A Systematic Review and Meta-Analysis

Background

Children and adolescents with congenital heart disease often have alterations in their exercise capacity that can be evaluated by various functional testing.

Objective

To evaluate the functional capacity of children and adolescents with congenital heart disease (CHD) with systematic review and meta-analyses.

Methods

The review included observational studies, data from the first evaluation of randomized clinical trials or observational follow-up periods after clinical trials which evaluated functional capacity by cardiopulmonary exercise test, stress testing, six-minute walk test or step test, in children and adolescents with CHD, aged between six and 18 years, and comparisons with healthy controls in the same age group. The quantitative assessment was performed by meta-analysis, by comparing the maximal oxygen consumption (VO₂max) of children and adolescents with CHD and respective control groups.

Results

Twenty-five of 2.683 studies identified in the search met the inclusion criteria. The VO₂max measurement showed that patients with CHD have a decrease of 9.31 ml/Kg/min (95% CI. -12.48 to -6.13; I², 94.3%, P for heterogeneity < 0.001) compared with the control group. The meta-analysis of the data of maximum heart rate (HR) reached during cardiopulmonary test and stress testing, retrieved from 18 studies, showed a HR value of -15.14 bpm (95% CI. -20.97 to -9.31; I², 94.3%, P for heterogeneity < 0.001) compared with the control group.

Conclusion

Children and adolescents with CHD have lower VO₂max and HR compared to controls.

Rehabilitación cardiaca en pediatría: ¿qué dice la evidencia?

Introducción. En las últimas cuatro décadas, las organizaciones de la salud han reconocido que la rehabilitación cardíaca es un elemento esencial para la recuperación de pacientes con enfermedades cardiovasculares.Objetivo. Realizar un análisis de la evidencia sobre la implementación de un programa de rehabilitación cardiaca, basado en ejercicio físico, en una población pediátrica con alteraciones congénitas cardiacas.Materiales y métodos. Se buscó y analizó la evidencia disponible de programas de rehabilitación cardiaca, basada en ejercicio físico, en pacientes pediátricos con alteraciones congénitas. Para la búsqueda se emplearon los términos MeSH: “Rehabilitation”, “Exercise”, “Resistance Training” y “Pediatrics” y se hizo revisión en las bases de datos Ebsco, Pedro, Hinari, Elsevier, Science Direct, Springer y Medline.Resultados. Se encontró que la implementación de un programa de rehabilitación cardiaca en población pediátrica tiene resultados significativos en la calidad de vida de estos pacientes, pero necesita de parámetros como evaluación, protocolo de rehabilitación, prescripción del ejercicio físico y evaluación de la calidad de vida.Conclusiones. Es necesario crear un protocolo estandarizado y validado de rehabilitación cardiaca, basada en ejercicio físico, para la población pediátrica con enfermedades cardiacas congénitas.

Evaluation of predictive models for six minute walk test among children with pulmonary hypertension

BACKGROUND

Existing six minute walk distance (6MWD) prediction equations were developed using healthy children and include relatively small sample sizes. Children with congenital heart disease and pulmonary hypertension (PH) are often small-for-age, so the existing pediatric prediction equations are likely a poor fit for children with PH. Currently, there are no equations for 6MWD among children with PH.

OBJECTIVES

Evaluate the validity of five existing pediatric prediction equations among the 6MWD of children with PH, including for each World Health Organization (WHO) class. Develop a validated predictive equation for use in children with PH.

METHODS/RESULTS

The 6MWDs from 711 six minute walk tests (6MWTs) of children aged four through 18years with PH were analyzed retrospectively and were evaluated against existing pediatric prediction equations. Existing pediatric prediction equations overestimated the walk distance among our population. The predicted distances versus actual distances were significantly different for each WHO class, with higher class associated with greater difference. A new prediction equation for 6MWD among children with PH was developed and validated with 65 additional 6MWTs. Our prediction equation demonstrates higher goodness of fit for all WHO classes than the preexisting pediatric equations.

CONCLUSIONS

Existing prediction equations for 6MWD among healthy children are not accurate for children with PH, particularly for children with more advanced stages of the disease (WHO classes III and IV). We present a new prediction equation for children with PH (WHO classes I through IV) that provides reference for medical care and management.

Six-Minute Walking Test: Normal Reference Values for Taiwanese Children and Adolescents

BACKGROUND

The 6-minute walking test (6MWT) is a simple method used to evaluate exercise capacity in adults and children with cardiac diseases. Normal reference values in pediatric populations have been reported, but significant variations in the walking distance (6MWD) were noted among different studies. We aimed to provide and validate normal reference values of the 6MWD for healthy Taiwanese pediatric population between 7 and 17 years of age.

METHODS

Healthy children and adolescents were recruited from 13 randomly selected schools in Kaohsiung City. From that recruitment effort, 762 participants (50.1% male) were included, and the 6MWT was conducted using standardized protocols. The main outcome measure utilized was the 6MWD, which was used to construct centile charts and Z score equations. Data from additional 64 healthy volunteers recruited from the National Taiwan University Children's Hospital were used to validate these standards.

RESULTS

There was an overall linear trend of increase in the 6MWD between 7 and 17 years of age (p < 0.001). Males covered significantly more distance than females after the age of 14 years, when the 6MWD essentially plateaued in female adolescents. Upon multivariate analysis, height was the most significant positive predictor of the 6MWD, while body mass index negatively correlated with the 6MWD. The height-based normal reference values of the 6MWD, derived from the 6MWT conducted in the school settings, were validated by a second cohort who received 6MWT inside the hospital.

CONCLUSIONS

Normal reference values of the 6MWD in healthy Taiwanese children and adolescents may serve as useful references for future clinical and research studies.

KEY WORDS

Adolescents; Children; Six-minute walking test; Taiwan.

Passive movement and active exercise for very young infants with congenital heart disease: a study protocol for a randomized controlled trial

Background

Delayed motor development is reported in patients with congenital heart disease (CHD). Exercise is widely used to facilitate motor development and improve motor ability. Exercise for adolescents and adults with CHD has been extensively studied. However, the evidence of exercise for infants with CHD is sparse. This study aims to identify the effect of passive movement and active exercise on motor development within very young CHD infants with cardiac catheterization.

Methods/Design

A prospective and randomized controlled trial will be conducted in very young CHD infants with cardiac catheterization. A total of 147 infants with CHD will be randomized by a 1:1:1 allocation ratio by computer to an exercise intervention group, a home-based intervention group and a control group. The exercise intervention group will receive passive movement and active exercise from experienced physiotherapists in pediatrics three times a week for 12 weeks. The home-based intervention group will receive passive movement and active exercise from their parents or caregivers at home three times a week for 12 weeks. The control group will receive follow up only. The follow-up duration is 20 months. The primary outcome measures are the motor quotient measured by the Peabody Developmental Motor Scales-II. The secondary outcome measures are the Ross score, ventricular function, bone quality, body length, weight, head circumference, upper arm circumference, and adverse events.

Discussion

This study has several important features, including the randomization process, the long follow-up duration, the control group, and the large sample size. The aim of this study is to determine whether 12-week passive movement and active exercise promotes motor development and produces other beneficial effects for very young CHD infants with cardiac catheterization. Therefore, this study will contribute new knowledge regarding the rehabilitation program in very young CHD infants with cardiac catheterization.

Trial registration

Current Controlled Trials ChiCTR-IOR-15005909 (January 31, 2015).

Exercise capacity in children and adolescents with corrected congenital heart disease

Congenital heart disease promotes hemodynamic changes that can contribute to reduce exercise capacity. The aim of the study was to evaluate the exercise capacity of children and adolescents with cyanotic congenital heart disease and to assess respiratory muscle strength, plasma levels of B-type natriuretic peptide and ventricular ejection fraction, as well the associations between these variables. Cross-sectional study that evaluated 48 patients between 6 and 18 years-old that underwent a six-minute walk test (6MWT), respiratory muscle strength, dosage of B-type natriuretic peptide and echocardiography. The mean age was 13.3 ± 4.1 years, and the most prevalent heart disease was tetralogy of Fallot (54.2 %). The average distance walked was 452.7 ± 73.2 m, significantly below the predicted (69 %) (p < 0.001). The maximum inspiratory pressure was above the predicted result (111.4 %), average 58.2 ± 22.3 (p = 0.56), and the maximum expiratory pressure was 63.2 ± 23.3 cm H2O, significantly below the predicted (63 %) (p < 0.001). The level of B-type natriuretic peptide was elevated in all patients, with a median of 2087.17 (502.54-4,768.05). The ventricular ejection fraction showed a median of 65.9 (41-100). There was no correlation between the 6MWT, ventricular ejection fraction (r = -0.05; p = 0.72), inspiratory muscle strength (r = 0.03; p = 0.81), expiratory muscle strength (r = 0.09; p = 0.05) and B-type natriuretic peptide (r = -0.04; p = 0.77). Children and adolescents with cyanotic congenital heart disease present a lower exercise capacity and expiratory muscle strength. No associations were found between exercise capacity, respiratory muscle strength, B-type natriuretic peptide and left ventricular ejection fraction.

The effects of passive smoking on the six-minute walk test in obese pediatric cases

OBJECTIVE

The aim of this study was to evaluate whether exposure to second-hand smoke affected the six-minute walk test (6 MWT) of obese non-asthmatic pediatric cases.

METHODS

Obese pediatric patients (body mass index >95th p) with no existing co-morbidities were included in the study. Smoke exposure was assessed with a self-reported questionnaire completed by the parents. The subjects were divided into two groups: Group 1 consisting of obese children exposed to passive smoking and Group 2 of obese children not exposed to passive smoking. In addition to 6 MWT, spirometric flow and volume, including forced expiratory volume in 1 s and peak expiratory flow rate, were also measured in all subjects. The results of the 6 MWT were assessed to determine any association with passive smoking.

RESULTS

The study included 75 obese pediatric cases (40 male, 35 female) with a mean age of 9.06 ± 0.97 years. The 6 MWT results in Group 1 was 501.88 ± 62.12 meters and in Group 2 559.63 ± 72.93 meters. The difference was statistically significant (p=0.001).

CONCLUSIONS

Passive smoking may negatively affect the respiratory and cardiovascular capacity in obese children, who are already at risk of lower cardiopulmonary function. The evaluation of 6 MWT in these pediatric patients may be useful for monitoring and families should be warned about potential problems due to smoking.

Functional capacity after pediatric liver transplantation: a pilot study

The prospective cross-sectional study investigated the 6MWT performance in pediatric group of liver transplant recipients (6-17 yr, median post-transplantation time of 22 months) and compared to the normal values obtained in healthy children as well as evaluated the reproducibility of the 6MWT. We analyzed the relationship between walked distance and the 6MWw, distance walked × body weight) with the anthropometric, clinical, and pulmonary functions. In post-transplanted group, the average walked distance was significantly shorter compared with control (687 ± 80 m vs. 511 ± 72 m, p < 0.001). The calculated ICC coefficient confirmed the reproducibility among tests. The Pearson correlation revealed that only walked distance in the 6MWT was moderately correlated with tidal volume. Conversely, the 6MWw was significantly correlated with age, weight, height, BMI, FVC, PEF rate, and volume expiratory. According to multiple regression analysis, age, VE and FVC factors explained 80% of the variance in the 6MWw. In conclusion, the pediatric liver transplant recipients' performance in the 6MWT is significantly lower than the values for healthy children of the same age. Notably, the 6MWw may provide relevant information, constituting an additional parameter in the determination of functional capacity.

Perceived difficulty with physical tasks, lifestyle, and physical performance in obese children

We estimated perceived difficulty with physical tasks, lifestyle, and physical performance in 382 children and adolescents (163 obese, 54 overweight, and 165 normal-weight subjects) and the relationship between perceived physical difficulties and sports participation, sedentary behaviors, or physical performance. Perceived difficulty with physical tasks and lifestyle habits was assessed by interview using a structured questionnaire, while physical performance was assessed through the six-minute walking test (6 MWT). Obese children had higher perceived difficulty with several activities of daily living, were less engaged in sports, and had lower physical performance than normal-weight or overweight children; on the contrary, they did not differ with regard to time spent in sedentary behaviors. Perceived difficulty in running and hopping negatively predicted sports participation (P < 0.05 and <0.01, resp.), while perceived difficulty in almost all physical activities negatively predicted the 6 MWT, independently of BMI (P < 0.01). Our results indicate that perception of task's difficulty level may reflect an actual difficulty in obese children. These findings may have practical implications for approaching physical activity in obese children. Exploring both the perception of a task's difficulty level and physical performance may be useful to design exercise programs that allow safe and successful participation.

Functional capacity, strength, and quality of life in children and youth with familial Mediterranean fever

PURPOSE

To examine functional capacity and muscle strength in children and youth with familial Mediterranean fever (FMF) as compared with controls, and to assess whether these factors influence quality of life (QOL) in FMF.

METHODS

A total of 100 subjects with FMF and 55 control subjects (8-18 years old) without known health issues were enrolled in the study. The 6-Minute Walk Test (6MWT) was used to evaluate functional capacity. Quadriceps strength was measured with a hand-held dynamometer. Quality of life was evaluated with the Pediatric Quality of Life Inventory 4.0 (PedsQL 4.0).

RESULTS

Significant differences were found between subjects with FMF and controls in the 6MWT and strength test. PedsQL scores of subjects with FMF were significantly lower than the scores of the controls. The 6MWT and quadriceps strength were weakly correlated with the PedsQL.

CONCLUSION

Subjects with FMF displayed lower functional capacity and QOL than peers who are healthy. Decreased functional capacity was correlated with decreased QOL in those with FMF.

Aerobic exercise intensity assessment and prescription in cardiac rehabilitation: a joint position statement of the European Association for Cardiovascular Prevention and Rehabilitation, the American Association of Cardiovascular and Pulmonary Rehabilitation, and the Canadian Association of Cardiac Rehabilitation

Aerobic exercise intensity prescription is a key issue in cardiac rehabilitation, being directly linked to both the amount of improvement in exercise capacity and the risk of adverse events during exercise. This joint position statement aims to provide professionals with up-to-date information regarding the identification of different exercise intensity domains, the methods of direct and indirect determination of exercise intensity for both continuous and interval aerobic training, the effects of the use of different exercise protocols on exercise intensity prescription and the indications for recommended exercise training prescription in specific cardiac patients' groups. The importance of functional evaluation through exercise testing prior to starting an aerobic training program is strongly emphasized, and ramp incremental cardiopulmonary exercise test, when available, is proposed as the gold standard for a physiologically comprehensive exercise intensity assessment and prescription. This may allow a shift from a 'range-based' to a 'threshold-based' aerobic exercise intensity prescription, which, combined with thorough clinical evaluation and exercise-related risk assessment, could maximize the benefits obtainable by the use of aerobic exercise training in cardiac rehabilitation.

The six-minute walk test in chronic pediatric conditions: a systematic review of measurement properties

BACKGROUND

The Six-Minute Walk Test (6MWT) is increasingly being used as a functional outcome measure for chronic pediatric conditions. Knowledge about its measurement properties is needed to determine whether it is an appropriate test to use.

PURPOSE

The purpose of this study was to systematically review all published clinimetric studies on the 6MWT in chronic pediatric conditions.

DATA SOURCES

The databases MEDLINE, EMBASE, CINAHL, PEDro, and SPORTDiscus were searched up to February 2012.

STUDY SELECTION

Studies designed to evaluate measurement properties of the 6MWT in a chronic pediatric condition were included in the systematic review.

DATA EXTRACTION

The methodological quality of the included studies and the measurement properties of the 6MWT were examined.

DATA SYNTHESIS

A best evidence synthesis was performed on 15 studies, including 9 different chronic pediatric conditions. Limited evidence to strong evidence was found for reliability in various chronic conditions. Strong evidence was found for positive criterion validity of the 6MWT with peak oxygen uptake in some populations, but negative criterion validity was found in other populations. Construct validity remained unclear in most patient groups because of methodological flaws. Little evidence was available for responsiveness and measurement error. Studies showed large variability in test procedures despite existing guidelines for the performance of the 6MWT.

LIMITATIONS

Unavailability of a specific checklist to evaluate the methodological quality of clinimetric studies on performance measures was a limitation of the study.

CONCLUSIONS

Evidence for measurement properties of the 6MWT varies largely among chronic pediatric conditions. Further research is needed in all patient groups to explore the ability of the 6MWT to measure significant and clinically important changes. Until then, changes measured with the 6MWT should be interpreted with caution. Future studies or consensus regarding modified test procedures in the pediatric population is recommended.

Teste de caminhada de seis minutos em pediatria: relação entre desempenho e parâmetros antropométricos

INTRODUÇÃO: Diferenças antropométricas podem influenciar o desempenho no teste de caminhada de seis minutos (TC6). OBJETIVO: Analisar publicações referentes ao TC6 realizado em crianças e adolescentes e identificar a influência de parâmetros antropométricos no desempenho do teste. MATERAIS E MÉTODOS: Pesquisa nas bases de dados eletrônicas SciELO e MEDLINE, utilizando as palavras-chave: six-minute walk test, children, adolescents, anthropometric measures/variables, growth e exercise tolerance, na busca de estudos envolvendo TC6 em crianças e adolescentes, que apresentem correlação entre dados antropométricos e variáveis do teste. Foram identificados 45 trabalhos relacionados à busca e, após análise dos títulos, resumos e artigos na íntegra, foram incluídos 13 estudos compatíveis com o tema proposto. RESULTADOS: O material elencado aborda o TC6 e sua aplicação em diferentes situações: análise de reprodutibilidade, correlação com teste cardiopulmonar máximo, indicação em diferentes doenças, valores de referência em saudáveis, parâmetro de efeito de programas de prevenção/reabilitação. Muitos trabalhos relacionam a distância percorrida no TC6 com idade e sexo, bem como com variáveis antropométricas, evidenciando frequente correlação com altura, além de idade, peso e índice de massa corporal. Outros dados como comprimento e força de membros inferiores, porcentagem de massas gorda/magra e força muscular respiratória, relacionados às mudanças do período de desenvolvimento infanto-juvenil, também parecem influenciar no desempenho do teste. CONCLUSÃO: Estudos indicam forte influência entre variáveis antropométricas e distância percorrida no TC6 em crianças e adolescentes, e a necessidade de que se esclareça essa associação para que não haja comprometimento do desfecho de estudos e de terapêuticas.

Effects of an acute, outpatient physiotherapy exercise program following pediatric heart or lung transplantation

This prospective interventional study investigated the impact of a three-month, ambulatory HA or HB, semi-individualized, PT-prescribed exercise program following pediatric HTx or LTx. SMW distance, strength, and flexibility were assessed at start and completion of the program and one yr after enrollment. Subjects received either an HB or HA exercise program three times per week. The cohort demonstrated clinically and statistically significant improvements in SMW distances at three months (425.7 ± 109.4-500.6 ± 93.6 m, p < 0.001) and at one yr (528.5 ± 66.6 m, p = 0.001), although there was no difference between the two groups at any time. Similar improvements were also observed in strength and flexibility measures. Correlates with higher SMW distance at three months and one yr included older age, male gender, and underlying diagnosis other than CHD. Male gender and diagnosis other than CHD were associated with a slower improvement in the SMW distance. This is the first report of institutionally based, outpatient exercise rehabilitation in the recovery following pediatric thoracic transplantation. We found similar improvements to HB interventions up to one yr after surgery. Further study of the role of exercise rehabilitation and long-term fitness outcomes is needed.

Test-retest reliability and developmental evolution of the 6-min walk test in Caucasian boys aged 5-12 years

The 6-min walk test (6MWT) assesses functional capacity and has been used as outcome measure in therapeutic studies in childhood neuromuscular disorders. The objectives were to evaluate test-retest reliability of the 6MWT and to generate normative data for healthy boys aged 5-12 years. Ninety boys (mean age 8 years 10 months) were recruited over four age subcategories (5-6, 7-8, 9-10, 11-12 years). Mean 6MWT distance and velocity (±standard deviation) for the total group were 555.5±93 m and 92.6±16.6 m/min. The 6MWT distance increased significantly with age. Test-retest reliability (mean interval 12 days) was very high for the total group (ICC>0.95) and for all age subcategories (ICC>0.80) a moderately high reliability (ICC>0.75) was found from 3 min onwards for each age subcategory. There was a mean difference of 5.2 m between test and retest without systematic bias. The standard error of measurement and smallest detectable difference were 20.7 and 57.4 m, respectively. These findings demonstrate the reliability of the 6MWT in young children, underscore its evolution with age, and indicate that a shorter version of the test is also reliable.

Aerobic exercise intensity assessment and prescription in cardiac rehabilitation: a joint position statement of the European Association for Cardiovascular Prevention and Rehabilitation, the American Association of Cardiovascular and Pulmonary Rehabilitation and the Canadian Association of Cardiac Rehabilitation

Aerobic exercise intensity prescription is a key issue in cardiac rehabilitation, being directly linked to both the amount of improvement in exercise capacity and the risk of adverse events during exercise. This joint position statement aims to provide professionals with up-to-date information regarding the identification of different exercise intensity domains, the methods of direct and indirect determination of exercise intensity for both continuous and interval aerobic training, the effects of the use of different exercise protocols on exercise intensity prescription and the indications for recommended exercise training prescription in specific cardiac patients' groups. The importance of functional evaluation through exercise testing prior to starting an aerobic training program is strongly emphasized, and ramp incremental cardiopulmonary exercise test, when available, is proposed as the gold standard for a physiologically comprehensive exercise intensity assessment and prescription. This may allow a shift from a 'range-based' to a 'threshold-based' aerobic exercise intensity prescription, which, combined with thorough clinical evaluation and exercise-related risk assessment, could maximize the benefits obtainable by the use of aerobic exercise training in cardiac rehabilitation.

Training effects on peripheral muscle oxygenation and performance in children with congenital heart diseases

We investigated the effect of training on peripheral muscular performance and oxygenation during exercise and recovery in children with congenital heart diseases (CHD). Eighteen patients with CHD aged 12 to 15 years were randomly assigned into either an individualized 12-week aerobic cycling training group (TG) or a control group (CG). Maximal voluntary contraction (MVC) and endurance at 50% MVC (time to exhaustion, Tlim) of the knee extensors were measured before and after training. During the 50% MVC exercise and recovery, near-infrared spectroscopy (NIRS) was used to assess the fall in muscle oxygenation, i.e., deoxygenation ([Formula: see text]) of the vastus lateralis, the mean rate of decrease in muscle oxygenation, the half time of recovery (T1/2R), and the recovery speed to maximal oxygenation (RS). There was no effect of time on any parameter in the CG. After training, significant improvements were observed in TG for MVC (101.6 ± 14.0 vs. 120.2 ± 19.4 N·m, p < 0.01) and Tlim (66.2 ± 22.6 vs. 86.0 ± 23.0 s, p< 0.01). Increased oxygenation (0.20 ± 0.13 vs. 0.15 ± 0.07 a.u., p < 0.01) and faster mean rate of decrease in muscle oxygenation were also shown after training in TG (1.22 ± 0.45 vs. 1.71 ± 0.78%·s–1, p < 0.001). Moreover, a shorter recovery time was observed in TG after training for T1/2R (27.2 ± 6.1 vs. 20.8 ± 4.2 s, p < 0.01) and RS (63.1 ± 18.4 vs. 50.3 ± 11.4 s, p < 0.01). A significant relationship between the change in [Formula: see text] and both MVC (r = 0.95, p < 0.001) and Tlim (r = 0.90, p < 0.001) in TG was observed. We concluded that exercise training improves peripheral muscular function by enhancing strength and endurance performance in children with CHD. This improvement was associated with increased oxygenation of peripheral muscles and faster recovery.

Six-minute walking test predicts maximal fat oxidation in obese children

BACKGROUND

Obesity is associated with reduced exercise maximal fat oxidation rate (FATmax), which is generally assessed by cardiopulmonary cycling test. The six-minute walking test (6MWT) presents an alternative method in patients.

OBJECTIVE

The aim of this study was to establish a practical reference equation facilitating the prediction of FATmax from the 6 MWT in obese children of both genders.

DESIGN

This study is a cross-sectional study using mixed linear and multiple regression models.

RESEARCH METHODS AND PROCEDURES

Anthropometric measurements were recorded and submaximal cycling test and 6 MWT conducted for 131 school-aged obese children, 68 boys and 63 girls. A multiple regression analysis for FATmax, including six-minute walking distance (6 MWD), anthropometric and cardiac parameters as the dependent variables, was performed for the two genders separately.

RESULTS

Mean 6 MWD and FATmax were 564.9 ± 53.7 m and 126.5 ± 12.1 mg min(-1) for boys and 506.7 ± 55.0 m and 120.7 ± 10.0 mg min(-1) for girls, respectively. The 6MWD, body mass index, Z-score, fat-free mass, waist and hip circumferences (WC and HC), rest heart rate, and systolic and diastolic blood pressures were highly correlated with FATmax for both genders. There was a significant correlation between 6 MWD and FATmax in both boys and girls (r = 0.88 and r = 0.81, P<0.001, respectively). Stepwise regression analyses revealed that the combinations of 6 MWD with HC for boys and 6MWD with WC for girls improved the predictability of the model (R(2) = 0.81 for boys and R(2) = 0.72 for girls; P<0.001).

CONCLUSION

In obese children, the 6MWT can be used to predict FATmax when formal test of exercise capacity and gas exchange analysis are unavailable or impractical. It is therefore possible to prescript targeted exercises at FATmax, without performing indirect calorimetry, just from a field test.

Assessment of late cardiotoxicity of pirarubicin (THP) in children with acute lymphoblastic leukemia

BACKGROUND

Pirarubicin (tetrahydropyranyl-adriamycin: THP) is a derivative of doxorubicin with reportedly less cardiotoxicity in adults. However no studies of cardiotoxicity in children treated with THP have been reported. This study was performed to assess the THP-induced cardiotoxicity for children with acute lymphoblastic leukemia (ALL).

PATIENTS AND METHODS

This study comprised 61 asymptomatic patients aged from 7.6 to 25.7 years old. Median follow-up time after completion of anthracycline treatment was 8.1 years (range: 1.7-12.5). The cumulative dose of THP ranged from 120 to 740 mg/m(2) with a median of 180 mg/m(2) . Patients underwent electrocardiogram (ECG), echocardiography, the 6-min walk test (6MWT), and measurements of serum brain natriuretic peptide (BNP) before and after exercise.

RESULTS

All subjects showed normal left ventricular function assessed by echocardiography. Ventricular premature contraction in Holter ECG and reduced exercise tolerance in the 6MWT were detected in 2/46 (3.3%) and 5/41(12.2%), respectively. Abnormal BNP levels were detected in 6/60 (10%) both before and after exercise. The cumulative dose of THP was significantly correlated with BNP levels after exercise (r = 0.27, P = 0.03), but not with any other cardiac measurements. Further analysis revealed that subjects with a high cumulative dose ≧300 mg/m(2) had significantly higher BNP levels after exercise compared with subjects with a low cumulative dose <300 mg/m(2) (P = 0.04).

CONCLUSIONS

No significant cardiac dysfunction was detected in long-term survivors who received THP treatment. The use of post-exercise BNP level to indicate high cardiotoxicity risk should be verified by further study.

Physical activity participation in youth with surgically corrected congenital heart disease: Devising guidelines so Johnny can participate

While most youth with congenital heart disease have simple structural lesions and near-normal activity tolerance and functioning, youth with complex structural defects may be affected by significant morbidity. Efforts are being made to consider the impact of exercise and physical activity on quality of life. The benefits of physical activity are well documented; however, the levels of participation and self-efficacy for activity remain low, thus increasing the risk of obesity and cardiovascular morbidity. Rehabilitation is a novel and emerging area, and decisions regarding advocacy versus restriction of physical activity may pose a challenge for both cardiologists and nonspecialists. The present article outlines the rationale for physical activity recommendations in youth with surgically corrected congenital heart disease and the psychosocial determinants of participation. Clinical recommendations and future directions are proposed.

Cardiopulmonary exercise testing in congenital heart disease: (contra)indications and interpretation

Cardiopulmonary exercise testing (CPET) in paediatric cardiology differs in many aspects from the tests 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 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 the main indications for CPET in children with congenital heart disease, the contraindications for exercise testing and the indications for terminating an exercise test. Moreover, we will address the interpretation of gas exchange data from CPET in children with congenital heart disease. (Neth Heart J 2009;17:385-92.).

Reference values on the 6-minute walk test for children living in the United States

PURPOSE

: The purpose of this study was to investigate reference values for the 6-minute walk test (6MWT) and the relationship between 6-minute walk distance (6MWD) and age, sex, and anthropometric variables in children who are healthy, aged 7 to 11 years and living in the United States.

METHODS

: The sample included 100 children, 57 female, 43 male, mean age 9.66 ± 1.08 years. Measures included height, weight, body mass index, leg length, and 6MWD.

RESULTS

: Mean 6MWD was 518.50 ± 73.56 m. Values were lower than those reported for children living in other countries with the exception of England. There were no significant associations between the 6MWD and other variables with the exception of body mass index in males.

CONCLUSION

: Our findings suggest 6MWT values for children living in other countries may not be directly applicable to children living in the United States.

Reference values for the 6-min walk test in healthy children aged 6-12 years

OBJECTIVE

To establish reference values for the 6-min walk test in healthy children and adolescents aged 6-12 years.

METHODS

This cross-sectional, prospective study selected healthy children and adolescents aged 6-12 years, at three elementary schools in Porto Alegre. The anthropometric data of all the individuals were evaluated and two 6-min walk tests were performed. Based on this, a reference equation was generated, and the test reproducibility was evaluated.

RESULTS

One hundred eighty-eight children (92 boys) performed the test. Pearson correlation showed that age (r = 0.51), height (r = 0.49), difference in heart rate before and after the test (dif. HR) (r = 0.30), and weight (r = 0.29) were significantly correlated with the distance covered in 6 min. The best multiple regression model included these four variables resulting in the following equation: 145.343 + [11.78 x age (years)] + [292.22 x height (m)] + [0.611 x dif. HR (bpm)] - [2.684 x body weight (kg)]. The intraclass correlation coefficient confirmed the reproducibility among tests.

CONCLUSION

The reference equation for the 6-min walk test was generated and the distance covered is influenced by age, height, difference in heart rate before and after the test, and body weight.