The six-minute walk test (6MWT) is a self-paced, submaximal exercise test used to assess functional exercise capacity in patients with chronic diseases (Chang 2006, Solway et al 2001). It has been used widely in adults, and is being utilised increasingly in paediatric populations; it has been used as an estimate of physical fitness in, for example, children with severe cardiopulmonary disease, cystic fibrosis, and juvenile idiopathic arthritis (Hassan et al 2010).
Objective: Despite the common occurrence of lower levels of physical activity and physical fitness in youth with spina bifida (SB) who use a wheelchair, there are very few tests available to measure and assess these levels. The purpose of this study was to determine reliability and the physiologic response of the 6-minute push test (6MPT) in youth with SB who self-propel a wheelchair. Methods: In this reliability and observational study, a sample of 53 youth with SB (5-19 years old; mean age = 13 years 7 months; 32 boys and 21 girls) who used a wheelchair performed 2 exercise tests: the 6MPT and shuttle ride test. Heart rate, minute ventilation, respiratory exchange ratio, and oxygen consumption were measured using a calibrated mobile gas analysis system and a heart rate monitor. For reliability, intraclass correlation coefficients (ICCs), SE of measurement, smallest detectable change for total covered distance, minute work, and heart rate were calculated. Physiologic response during the 6MPT was expressed as percentage of maximal values achieved during the shuttle ride test. Results: The ICCs for total distance and minute work were excellent (0.95 and 0.97, respectively), and the ICC for heart rate was good (0.81). The physiologic response during the 6MPT was 85% to 89% of maximal values, except for minute ventilation (70.6%). Conclusions: For most youth with SB who use a wheelchair for mobility or sports participation, the 6MPT is a reliable, functional performance test on a vigorous level of exercise. Impact: This is the first study to investigate physiologic response during the 6MPT in youth (with SB) who are wheelchair using. Clinicians can use the 6MPT to evaluate functional performance and help design effective exercise programs for youth with SB who are wheelchair using. Keywords: 6-minute push test; adolescent; disabled children; spinal diseases; wheelchairs.
BACKGROUND: Patients who underwent surgery for aortic coarctation (COA) have an increased risk of arterial hypertension. We aimed at evaluating (1) differences between hypertensive and non-hypertensive patients and (2) the value of cardiopulmonary exercise testing (CPET) to predict the development or progression of hypertension. METHODS: Between 1999 and 2010, CPET was performed in 223 COA-patients of whom 122 had resting blood pressures of <140/90 mmHg without medication, and 101 were considered hypertensive. Comparative statistics were performed. Cox regression analysis was used to assess the relation between demographic, clinical and exercise variables and the development/progression of hypertension. RESULTS: At baseline, hypertensive patients were older (p=0.007), were more often male (p=0.004) and had repair at later age (p=0.008) when compared to normotensive patients. After 3.6 ± 1.2 years, 29/120 (25%) normotensive patients developed hypertension. In normotensives, VE/VCO2-slope (p=0.0016) and peak systolic blood pressure (SBP; p=0.049) were significantly related to the development of hypertension during follow-up. Cut-off points related to higher risk for hypertension, based on best sensitivity and specificity, were defined as VE/VCO2-slope ≥ 27 and peak SBP ≥ 220 mmHg. In the hypertensive group, antihypertensive medication was started/extended in 48/101 (48%) patients. Only age was associated with the need to start/extend antihypertensive therapy in this group (p=0.042). CONCLUSIONS: Higher VE/VCO2-slope and higher peak SBP are risk factors for the development of hypertension in adults with COA. Cardiopulmonary exercise testing may guide clinical decision making regarding close blood pressure control and preventive lifestyle recommendations.
