Shuttle walking test: a new approach for evaluating patients with pacemakers

A comparison of the effects of inspiratory muscle strength and endurance training on exercise capacity, respiratory muscle strength and endurance, and quality of life in pacemaker patients with heart failure: A randomized study

BACKGROUND

Studies have widely investigated the effects of inspiratory muscle strength training in patients with heart failure (HF). The effects of inspiratory muscle strength or endurance training on outcomes in patients with pacemakers have not been adequately studied.

OBJECTIVES

The aim was to compare the effects of inspiratory muscle strength and endurance training on exercise capacity, quality of life (QoL), peripheral and respiratory muscle strength, respiratory muscle endurance, pulmonary function, dyspnea, fatigue, and physical activity levels in pacemaker patients with HF.

METHODS

A randomized, controlled, double-blind study was conducted. Fourteen pacemaker patients with HF received inspiratory muscle strength training (IMST) at 50% of maximal inspiratory pressure (MIP), and 18 patients received endurance training (IMET) at 30% of MIP 7 days/8 weeks. Exercise capacity [6 min. walking test (6MWT) and the Incremental Shuttle Walking Test (ISWT)], pulmonary function, respiratory muscle strength [MIP, maximal expiratory pressure (MEP)], endurance, peripheral muscle strength, dyspnea, fatigue, QoL, and physical activity level were evaluated before and after.

RESULTS

Demographic characteristics were similar in IMST (3F/11M, 56.92 ± 7.61y, EF: 25%, ICD/CRT:11/3) and IMET (4F/14M, 56 ± 10.77y, EF: 30%, ICD/CRT:16/2) groups (p > 0.05). Significant improvements were present in MIP, MEP, respiratory muscle endurance, peripheral muscle strength, 6MWT and ISWT walking distances, dyspnea, QoL, physical activity level, fatigue scores within groups (p ≤ 0.05). However, there were no significant differences between the groups (p > 0.05). There were no significant improvements in FEV₁%, FVC%, FEV₁/FVC%, and FEF_25-75 within and between the groups (p > 0.05).

CONCLUSIONS

Inspiratory muscle strength and endurance training similarly improves respiratory and peripheral muscle strength, exercise capacity, QoL, physical activity level, and decreases dyspnea and fatigue and are safe and effective in pacemaker patients with HF.

TRIAL REGISTRATION

www.

CLINICALTRIALS

gov; study number: NCT03501355.

Incremental shuttle walking test to assess functional capacity in cardiac rehabilitation: a narrative review

Background/Aims

Low functional capacity has been recognised to be the most important predictor of overall mortality compared to all other cardiovascular risk factors in patients with cardiovascular disease. Walk tests, such as the incremental shuttle walking test and the 6-Minute Walk Test, are used to assess functional capacity in patients, the effectiveness of a cardiac rehabilitation programme and the prognosis of cardiovascular diseases. The aim of this review was to provide a narrative review of the literature and identify the key features of the incremental shuttle walking test as a measure of functional capacity testing in cardiac rehabilitation patients.

Methods

The PubMed, MEDLINE, Elsevier and Google Scholar databases were searched for relevant scientific articles published up to March 2021 with no restriction on start day. The key words defined by researchers were ‘incremental shuttle walking test’, ‘exercise test’, ‘functional capacity’, ‘cardiovascular disease’, ‘cardiac rehabilitation’, ‘reliability’ ‘prediction; ‘walk tests’. A final set of 31 articles was included in this narrative review.

Results

Evidence-based findings suggest that the incremental shuttle walking test is a valid, reliable, sensitive, useful tool for detecting and predict cardiorespiratory capacity.

Conclusions

Clinicians can be confident that they can use the incremental shuttle walking test to monitor changes in functional capacity in patients with cardiovascular disease.

Cardiac implantable devices during exercise: Normal function and troubleshooting

Normal function and the most common problems that occur during pacemaker operation while performing physical exercise, are discussed. Physically active individuals with an implantable cardiac device, should be evaluated during exercise, because some conflicts issues may arise that are not detectable during routine, at rest, telemetry.

Influence of Mild Peripheral Arterial Obstructive Disease in the Functional Capacity

AbstractThe peripheral arterial obstructive disease (PAOD) is a chronic illnes that has as main symptom intermittent claudication and causes a progressive functional impairment of the patient. The literature is still inconclusive when it addresses the relationship among functional capacity, endurance, muscle contraction speed, and degree of blood flow impairment in patients with PAOD. The objective of this study was to evaluate the physical fitness individuals with bilateral PAOD, claudication and ankle-brachial index between 0.8 and 0.9, to verify the impact of the disease in this outcome and to analyze the association among the tests. Forty individuals, with mean age 56 years were divided in: group PAOD (n=20) and control group (n=20) were subjected to the following tests: Five-Times-Sit-to-Stand Test (FTSST), Heel-rise test (HRT), test of gait speed usual (UV) and maximum (MV), shuttle walking test (SWT). There was a significant difference among the variables obtained through HRT, UV, MV and SWT, showing a worse performance of the group with PAOD compared to the control. The FTSST test showed no differences among the groups. Analyzing the whole sample, the presence of PAOD is an indicator of poor performance in TDBP. This study suggests that people with mild PAOD present reduced performance in functional endurance tests of the lower limbs and that there is a direct relationship between walking speed and patency of local arterial flow, demonstrating in an unprecedented way the need for evaluation of this public, considering the possibility of initial identification of the symptoms and giving greater efficiency in the therapeutic planning of maintenance of the functionality.Keywords: Physical Fitness. Intermittent Claudication. Peripheral Vascular Diseases.ResumoA doença arterial obstrutiva periférica (DAOP) é uma doença crônica que tem como sintoma principal a claudicação intermitente e causa um progressivo comprometimento funcional do paciente. A literatura ainda é inconclusiva quando aborda a relação entre a capacidade funcional, endurance, velocidade de contração muscular e grau de comprometimento de fluxo sanguíneo em pacientes com DAOP. O objetivo deste estudo foi avaliar a aptidão física de indivíduos com DAOP bilateral, claudicantes e Índice tornozelo-braço entre 0,8 e 0,9, verificar o impacto da doença neste desfecho e analisar a associação entre os testes. Quarenta indivíduos, com faixa etária média de 56 anos, divididos em grupo DAOP (n=20) e grupo controle (n=20), foram submetidos aos testes: Teste senta-levanta (TSL), teste ponta de pé (TPP), testes de velocidade usual (VU) e máxima (VM), teste de deslocamento bidirecional progressivo (TDBP). Houve diferença significativa entre as variáveis do TPP, VU, VM e TDBP, mostrando pior performance do grupo com DAOP comparado ao controle. O teste TSL não apresentou diferença entre os grupos. Analisando os grupos em conjunto a presença de DAOP foi indicadora de pior desempenho no TDBP. Este estudo sugere que pacientes com DAOP leve apresentam redução da performance nos testes funcionais de endurance dos membros inferiores e que existe uma relação direta entre a velocidade da marcha e a patência do fluxo arterial local, demonstrando de forma inédita, a necessidade de avaliação deste público, considerando a possibilidade de identificação inicial dos sintomas e conferindo maior eficiência no planejamento terapêutico de manutenção da funcionalidade.Palavras-chave: Aptidão Física. Claudicação Intermitente. Doenças Vasculares Periféricas.

Comparison of functional and maximal exercise capacity, respiratory and peripheral muscle strength, dyspnea, and fatigue in patients with heart failure with pacemakers and healthy controls: a cross-sectional study

Background: Despite major breakthroughs that have recently been made in pacemakers implanted in patients with heart failure (HF), it is clear that functional impairments and symptoms often remain. However, only limited studies have investigated exercise capacity, muscle strength, pulmonary function, dyspnea, and fatigue in these patients. Therefore, we aimed to compare aforementioned outcomes in patients and healthy controls. Methods: A cross-sectional study. Fifty patients with HF with pacemakers (58.90 ± 10.69 years, NYHA II-III, LVEF: 30.79 ± 8.78%) and 40 controls (56.33 ± 5.82 years) were compared. Functional (6-Minute Walking test (6-MWT)) and maximal exercise capacity (Incremental Shuttle Walk test (ISWT)), respiratory (Mouth pressure device) and peripheral muscle strength (Dynamometer), pulmonary function (Spirometry), dyspnea (Modified Medical Research Council Dyspnea scale), and fatigue (Fatigue Severity scale) were evaluated. ClinicalTrial number: NCT03701854. Results: 6-MWT (412.62 ± 96.51 m versus 610.16 ± 59.48 m) and ISWT (279.97 m versus 655 m) distances (p ˂ 0.001), pulmonary function (p˂0.001), respiratory and peripheral muscle strength (p ˂ 0.001) were significantly lower; dyspnea (p ˂ 0.001) and fatigue (p = .030) scores were higher in patients compared with controls. Conclusion: Maximal and functional exercise capacity is impaired in the majority of patients with HF with pacemakers, respiratory and peripheral muscles are weakened, dyspnea and fatigue perceptions are increased. Patients with pacemakers have to be included in cardiac rehabilitation programs to improve impairments.

Lumbar Spinal Stenosis: Objective Measurement Scales and Ambulatory Status

Lumbar spinal stenosis (LSS) is one of the most common affecting the elderly population that may lead to loss of function and the inability to execute basic activities of daily living. While surgical decompression remains the standard of care, choosing an optimal management strategy is usually guided by a set of clinical, radiological, and measurement indices. However, to date, there is a major uncertainty and discrepancy regarding the methodology used. There is also inconsistent adoption of outcome measures across studies, which may result in huge limitations in predicting the efficacy and cost-effectiveness of different treatment paradigms. Herein, we review the various measurement indices used for outcome assessment among patients with LSS, and delineate the major advantages and disadvantages of each index. We call for the development of a single objective outcome measure that encompasses and addresses all issues encountered in this heterogeneous group of patients, including monitoring the patient's progression after treatment.

Measurement properties of the incremental shuttle walk test. a systematic review

Background: The incremental shuttle walk test (ISWT) was developed > 20 years ago and has been used to assess peak exercise capacity in a variety of chronic diseases. The aim of this systematic review is to describe the measurement properties of the ISWT in a clinical population.Methods: Of 800 articles identified by electronic and hand searches, 35 were included. Twenty-one articles included data on the validity of the ISWT, 18 on the reliability, four on the responsiveness,and four on the interpretability.Results: Most of the studies were conducted in patients with COPD (n = 13) or cardiac disease(n = 8). For criterion validity, comparisons between distance covered during the ISWT and peak oxygen consumption reported correlations ranging from 0.67 to 0.95 ( P <.01). Intraclass correlation coefficients for test-retest reliability ranged from 0.76 to 0.99. The ISWT was shown to be responsive to pulmonary rehabilitation and bronchodilator administration. The minimal clinically important difference (MCID) in patients with COPD was 48 m. Predictive equations for the distance in the ISWT are available for healthy individuals.Conclusions: The ISWT can be considered a valid and reliable test to assess maximal exercise capacity in individuals with chronic respiratory diseases. The ISWT has been shown to be responsive to pulmonary rehabilitation and bronchodilator use in individuals with COPD, cystic fibrosis,and asthma. Further studies examining responsiveness and the MCID of the ISWT in patients with conditions other than lung diseases are required for the interpretation of interventions in other populations.

Exploring adaptations to the modified shuttle walking test

OBJECTIVE

The 10 m modified shuttle walking test (MSWT) is recommended to determine the functional capacity in older individuals and for patients entering cardiac rehabilitation. Participants are required to negotiate around cones set 1 m from the end markers. However, consistent comments indicate that for some individuals manoeuvring around the cones can be quite difficult. Therefore, the objective of this study was to explore differences within and between non-cardiac and postmyocardial infarction (MI) males during MSWT with and without the cones.

DESIGN

Comparative study.

PARTICIPANTS

20 post-MI (64.8±6.6, range 51-74 years) and 20 non-cardiac male controls (64.1±5.7, range 52-74 years) participated.

METHODS

Participants performed MSWT with and without cones. Throughout, the participants expired air, and the heart rate (bpm) (HR) and ratings of perceived exertion (RPE) were measured. Participant protocol preference was recorded verbatim.

RESULTS

One-way analysis of variance found no significant difference in VO2 peak (cones 20.4±5.1 vs no-cones 21.9±4.8 ml/kg/min, p=0.197) or distance ambulated (cones 631.8±132.9 m vs no-cones 662.4±164.1 m, p=0.371) between protocols or groups. Analysis comparing lines of regression showed a significant trajectory difference in VO2 (ml/kg/min) (p<0.01) between protocols with higher HR (p<0.01) and respiratory exchange ratio (RER, p<0.001) values during cones. RPEs were higher for post-MIs versus controls during both protocols (p<0.05). Post-MIs taking β-blockers produce significantly lower HR values. The χ(2) analysis found no significant difference in protocol preference (no-cones: all n=25, 63%; post-MIs n=13, 65%; and controls n=12, 60%).

CONCLUSIONS

Post-MIs found both protocols subjectively harder than controls with no significant difference in the VO2 peak. However, both groups worked at a lesser percentage of their anaerobic threshold during no-cones protocol as indicated by lower RER values. Importantly, for the post-MIs, this would reduce their risk of functional impairment. Therefore, though more research is required, indicators at present are more favourable for the use of the no-cones with post-MIs.

Physiological responses to maximal exercise testing and the modified incremental shuttle walk test in adults after thermal injury: a pilot study

The ongoing hypermetabolic response associated with burn injury contributes significantly to loss of function, morbidity, and mortality. Exercise is strongly recommended to assist recovery and overall functional outcome. To date, there have been limited studies investigating the validity and practicality of both maximal laboratory and field tests in adult burns survivors. The objective of this study was to determine the metabolic and ventilatory response to cardiopulmonary maximal exercise testing (CPET) and the modified shuttle walk test (MSWT) in adult burns patients. Fifteen people (13 male) with a mean TBSA of 38.5% (16.0%) underwent both MSWT and CPET within a 5-day period in random order. The majority of participants demonstrated a normal response to CPET. Two participants with a history of inhalation burns demonstrated a respiratory limitation to exercise with desaturation (91 and 89%) at the end of the CPET, which returned to normal within 2 minutes after exercise. The correlation between VO(2peak) as measured via CPET and distance as measured in MSWT was 0.7. Mean results measured in MSWT for maximal heart rate and perceived exertion scores were lower than those achieved with CPET results: 91 and 88%, respectively. There were no adverse events during both the MSWT and CPET. This study demonstrates that after burn injury, CPET and MSWT can be performed safely in the majority of patients early in the postdischarge rehabilitation period. MSWT is likely to be submaximal at 80 to 90% of CPET results but is easy to replicate and cost-effective, thus a viable mechanism for monitoring aerobic capacity.

Degenerative spondylolisthesis in patients with neurogenic claudication effects functional performance and self-reported quality of life

STUDY DESIGN

The effect of degenerative spondylolisthesis on functional performance and self reported quality of life in patients with lumbar spinal stenosis was compared to patients with lumbar spinal stenosis and no degenerative spondylolisthesis.

OBJECTIVE

To define the relationship degenerative spondylolisthesis shares with functional performance and self reported quality of life in patients with symptomatic lumbar spinal stenosis.

SUMMARY OF BACKGROUND DATA

Neurogenic claudication is a clinical syndrome that reflects symptoms caused by anatomic spinal stenosis. This condition limits functional status and impacts overall health satisfaction. Degenerative spondylolisthesis is one cause of spinal stenosis and is present to different degrees in patients with neurogenic claudication.

METHODS

Thirty-eight women and 39 men diagnosed with lumbar spinal stenosis and neurogenic claudication were prospectively enrolled in the study. All underwent routine, screening side-lying, lateral flexion and extension radiographs. The evaluation included a shuttle walking test, as well as patient self-assessment using the Swiss Spinal Stenosis Questionnaire, and Short Form 36.

RESULTS

The overall walking distance did not differ based on the presence of degenerative spondylolisthesis. No correlation between magnitude of deformity and decreased walking distance was identified. Men walked on average 231.3 m (SD: 159.2) and women walked 251.3 m (SD: 138.4). No statistical difference was noted between men and women and their walking ability (P < 0.56). The Swiss Spinal Stenosis Questionnaire and the Short Form 36 were both strongly correlated with decreased walking ability (P < 0.05).

CONCLUSION

The presence and magnitude of degenerative spondylolisthesis does not correlate with decreased functional capacity. The Swiss Spinal Stenosis Questionnaire and Short Form 36 are accurate in defining the functional status of a patient. Comprehensive evaluation of patients with symptomatic lumbar spinal stenosis using functional assessment and self-assessment questionnaires are helpful in determining the severity of a patient's disability. Plain radiographs may be valuable adjuncts for surgical decision-making, but are not useful in quantifying the degree to which a patient is impaired.

The effect of atrial-based pacing on exercise capacity as measured by the 6-minute walk test: A substudy of the Canadian Trial of Physiological Pacing (CTOPP)

BACKGROUND

Although several randomized trials have detected no reduction in major cardiovascular events with the routine use of dual-chamber as opposed to ventricular pacemakers, many individuals continue to advocate their use as a means of improving exercise capacity.

METHODS

The Canadian Trial of Physiological Pacing (CTOPP) trial is the largest trial comparing ventricular pacing to atrial-based pacing (atrial or dual-chamber) in patients with bradycardia. All patients in this trial were asked to complete a 6-minute hall walk test (6MWT) at the time of their first study follow-up. The distance walked in 6 minutes and the patient's heart rate before and immediately after the walk were recorded.

RESULTS

Of the 2568 patients in the CTOPP, 76% completed the 6MWT. The mean distance walked was 350 +/- 127 m in the ventricular pacing group and 356 +/- 127 m in the atrial-based group (P = NS). Similarly, there was no difference in the change in heart rate between the two groups (17 +/- 13 vs. 18 +/- 12 bpm: P = NS). However, among patients with an unpaced heart rate of </=60 bpm, patients assigned to atrial-based pacing walked farther than those randomized to ventricular pacing (361 +/- 127 vs. 343 +/- 121 m; P = .04). This was not associated with a difference in heart rate. The use of rate-adaptive pacing, irrespective of the pacing mode, resulted in a greater increase in heart rate with the 6MWT but no increase in the total distance walked.

CONCLUSION

The routine use of atrial-based pacemakers, instead of ventricular pacemakers, does not improve exercise capacity, as measured by the 6MWT. However, patients with an unpaced heart rate of </=60 bpm may achieve a modest increase in their exercise capacity with atrial-based pacing.

Reproducibility and safety of the incremental shuttle walking test for cardiac rehabilitation

The incremental shuttle walking test (ISWT) is recommended to assess the exercise capacity of patients attending cardiac rehabilitation (CR) as a cost-effective alternative to the treadmill test. We used the Bland Altman limits of agreement method on 353 paired ISWTs to explore whether the recommended practice test is necessary. The mean increase in distance from the practice to the second walk was 29.5 m (95% CI 23.0, 36.0) p<0.001, confirming the need for the practice walk when undertaking the ISWT.

Responsiveness of objective, disease-specific, and generic outcome measures in patients with chronic low back pain: an assessment for improving, stable, and deteriorating patients

STUDY DESIGN

Analysis of outcome data collected prospectively from 250 patients recruited to the UK Spine Stabilization Trial.

OBJECTIVES

To compare the responsiveness of the Shuttle Walking Test (SWT), which is an objective outcome measure, with that of a disease-specific (the Oswestry Disability Index) and 2 generic (the EQ-5D and SF-36) instruments in patients with chronic low back pain (LBP).

SUMMARY OF BACKGROUND DATA

Studies assessing the performance of subjective disease-specific and generic measures have increased in recent years, although there is a paucity of research reporting the responsiveness of objective measures in patients with LBP. The focus of investigation has been on responsiveness to improvements in LBP symptoms. For patients with deteriorating health, it remains largely unclear how outcome instruments perform.

METHODS

Baseline and 12-month outcome data collected on 250 patients with chronic LBP recruited to the Spine Stabilization Trial were analyzed using traditional measures of responsiveness. Analyses were performed for 3 groups of patients: those who rated their health status as improved, deteriorated, and stable at 12 months.

RESULTS

The SWT was shown by all measures to be responsive to health improvement, although less so than other instruments. All instruments were able to detect small-to-moderate reductions in health. Instrument floor effects may be responsible for small SF-36 change scores recorded for deteriorating patients.

CONCLUSIONS

Although shown to be responsive, including the SWT alongside disease-specific and generic instruments is unlikely to add additional information. All instruments appear responsive to patient deterioration, however, further research for the SF-36 is required.

Dual chamber versus single chamber ventricular pacemakers for sick sinus syndrome and atrioventricular block

BACKGROUND

Dual chamber pacing or single chamber atrial pacing ('physiologic' pacing) is believed to have an advantage over single chamber ventricular pacing in that it resembles cardiac physiology more closely by maintaining atrioventricular (AV) synchrony and dominance of the sinus node, which in turn may reduce cardiovascular morbidity and mortality thus contributing to patient survival and quality of life. However, a significant proportion of pacemakers currently implanted are single chamber ventricular pacemakers.

OBJECTIVES

The objective of this review was to assess the short- and long-term clinical effectiveness of dual chamber pacemakers compared to single chamber ventricular pacemakers in adults with AV block, sick sinus syndrome or both. An additional objective was to assess separately any potential differences in effectiveness between dual chamber pacing and single chamber atrial pacing. The clinical effectiveness of single chamber atrial pacing versus single chamber ventricular pacing was not examined.

SEARCH STRATEGY

The Cochrane Controlled Trials Register (The Cochrane Library Issue 3, 2002), MEDLINE (1966 to 2002), EMBASE (1980 to 2002) and the Science Citation Index (1980 to 2002) were searched on 19th August 2002. Citation lists and web sites were checked and researchers in the field contacted.

SELECTION CRITERIA

Parallel group or crossover randomised controlled trials of at least 48 hours duration comparing dual chamber pacing and single chamber ventricular pacing, and investigating cardiovascular morbidity, mortality, patient related quality of life, exercise capacity and complication rates.

DATA COLLECTION AND ANALYSIS

Data was extracted onto pre-piloted data extraction forms. Quality assessment was undertaken using a checklist, with a sub-sample of quality data independently extracted by a second reviewer. Where appropriate data was available, meta-analysis was performed. Where meta-analysis was not possible, the number of studies showing a positive, neutral or negative direction of effect and statistical significance were simply counted.

MAIN RESULTS

Five parallel and 26 crossover randomised controlled trials were identified. The quality of reporting was found to be poor. Pooled data from parallel studies shows a statistically non-significant preference for physiologic pacing (primarily dual chamber pacing) for the prevention of stroke, heart failure and mortality, and a statistically significant beneficial effect regarding the prevention of atrial fibrillation (odds ratio (OR) 0.79, 95% CI 0.68 to 0.93). Both parallel and crossover studies favour dual chamber pacing with regard to pacemaker syndrome (parallel: Peto OR 0.11, 95% CI 0.08 to 0.14; crossover: standardised mean difference (SMD) -0.74, 95% CI - 0.95 to -0.52). Pooled data from crossover studies shows a statistically significant trend towards dual chamber pacing being more favourable in terms of exercise capacity (SMD -0.24, 95% CI -0.03 to -0.45). No individual studies reported a significantly more favourable outcome with single chamber ventricular pacing.

REVIEWERS' CONCLUSIONS

This review shows a trend towards greater effectiveness with dual chamber pacing compared to single chamber ventricular pacing, which supports the current British Pacing and Electrophysiology Group's Guidelines regarding atrioventricular block. Additional randomised controlled trial evidence from ongoing trials in this area will further inform the debate.

Cardiorespiratory fitness and functional capacity assessed by the 20-meter shuttle walking test in patients with coronary artery disease

OBJECTIVE

To validate the 20-meter shuttle walking test (20MST) in the assessment of maximal oxygen consumption (VO(2)max) and maximal speed in patients with coronary artery disease (CAD).

DESIGN

Single-sample validity study.

SETTING

Cardiac rehabilitation service in France.

PARTICIPANTS

Seventeen men with CAD.

INTERVENTIONS

Subjects underwent a symptom-limited treadmill test (SLTT) in a laboratory, with a speed starting at 2.5km/h and increasing by 0.5km/h every minute, and performed an adapted 20MST in a corridor, with a speed starting at 3km/h and increasing by 1km/h every minute until exhaustion.

MAIN OUTCOME MEASURES

VO(2) measured during the 20MST with the Cosmed K2 telemetric gas analyzer (K2 VO(2)), estimated VO(2) calculated by the Léger equation (Léger VO(2)) from the maximal speed obtained during the 20MST, and VO(2) measured during the SLTT (SLTT VO(2)). Maximal speeds attained on the treadmill and on the 20MST were also compared.

RESULTS

A significant (P<.0001) difference was observed between the Léger estimate of VO(2) and those of K2 VO(2) and SLTT VO(2) (mean +/- standard deviation, 12.28+/-5.90mL. min(-1).kg(-1) vs 23.04+/-7.17 and 22.56+/-6.29mL.min(-1).kg(-1)). No difference was found between the treadmill and the 20MST maximal speeds (6.73+/-0.91km/h, 6.78+/-1.23km/h, respectively). Measured with the Cosmed K2, a significant relationship existed between VO(2) and each speed level (r=.95, P<.0001; VO(2)=4.24x speed-7.37, standard estimation error=2.29mL.min(-1).kg(-1)).

CONCLUSION

Maximal VO(2) and maximal speed measured on the treadmill did not differ significantly from those obtained on the 20MST. The current 20MST equation (Léger equation) was not valid to estimate VO(2) in CAD patients. A modified prediction equation of VO(2) was given and would need a larger number of patients to be generalized.

The shuttle walk exercise test in idiopathic pulmonary fibrosis

The shuttle walk test (SWT) is a validated, incremental walking test for chronic obstructive pulmonary disease, but not for idiopathic pulmonary fibrosis (IPF). The measurement of maximal oxygen consumption (VO2 max) is considered to be the gold standard measurement of functional capacity. This study examines the relationship between IPF patients' performance on the SWT and VO2 max. Twenty patients were recruited for the study, which consisted of two separate experiments. Firstly, the relationship between SWT performance on a conventional corridor SWT, with that on a programmable treadmill SWT designed to reproduce the corridor SWT was examined (n=10). In the second experiment, the relationship between performance on the treadmill equivalent SWT and VO2 max measurements was studied (n=10). There was a significant correlation between distance walked on the corridor SWT, and that walked on the treadmill equivalent SWT without VO2 max measurements (367 m vs. 410 m) (r=0.91, P=0.0003). There was a significant correlation between distance walked on the treadmill equivalent SWT (277 m), and the directly determined VO2 max (14.87 ml/kg/min) (r=0.74, P=0.01). During both experiments, a significant correlation was also observed between baseline PaO2 and SWT performance, and between DLCO and SWT performance. The shuttle walk test is a simple objective measure of functional capacity in IPF patients, which should facilitate the evaluation of new therapeutic compounds for IPF.

Repeatability of measurements of oxygen consumption, heart rate and Borg's scale in men during ergometer cycling

The coefficient of repeatability (COR), expressed as 2-SD of differences, was calculated between two measurements of oxygen consumption (V O2), heart rate (HR) and rating of perceived exertion (RPE) during ergometer cycling by men. The two sets of measurements were performed 5 to 6 weeks apart. Nineteen healthy men performed an incremental maximal exercise test on an ergometer cycle. The load started at 50 W and increased by 5 W 20 s-1 until exhaustion was reached. At 40% of the individual maximum load of the pretest, the load was kept constant for 4 min in order to reach steady state. Gas measurements were recorded continuously by computerized instrumentation. The HR was monitored with electrocardiography (ECG) and the perceived exertion was evaluated using Borg's scale. The COR of V O2 at sub-maximal load was 14% and at maximum load 11%. The values in absolute figures were 209 and 332 ml min-1. The corresponding COR of the HR was 16% at sub-maximum load and 6% at maximum load, and an evaluation of the perceived exertion yielded CORs in absolute values of 4.8 and 1.3, respectively. The COR for V O2, HR and ratings of perceived exertion when cycling on an ergometer cycle thus indicate a better agreement between the measurements at maximum load. The COR of the heart at sub-maximal loads must be kept in mind when using HR for estimation of V O2max. The reported findings should be considered when using tests on an ergometer cycle for evaluating exercise capacity.

The reliability of the Shuttle Walking Test, the Swiss Spinal Stenosis Questionnaire, the Oxford Spinal Stenosis Score, and the Oswestry Disability Index in the assessment of patients with lumbar spinal stenosis

STUDY DESIGN

The Shuttle Walking Test (SWT), the Swiss Spinal Stenosis (SSS) Questionnaire, the Oxford Claudication Score (OCS), and the Oswestry Disability Index (ODI) were administered to patients with lumbar spinal stenosis and neurogenic claudication.

OBJECTIVE

To determine reliability of the SWT, the SSS (Q1-12), the OCS, and the ODI in lumbar spinal stenosis assessment.

SUMMARY OF BACKGROUND DATA

Reliability data for exercise tests in lumbar spinal stenosis are lacking.

METHODS

To determine reliability, 32 clinic patients with lumbar spinal stenosis were assessed twice, with 1 week between assessments. Retrospective data from 17 patients assessed before surgery and 18 months after surgery for lumbar spinal stenosis were used to investigate the use of reliability in a clinical setting.

RESULTS

Test-retest reliability in terms of the intraclass correlation coefficient (ICC) was 0.92 for the SWT, 0.92 for the SSS, 0.83 for the OCS and 0.89 for the ODI. The mean percentage scores were 51 for the SSS, 45 for the OCS, and 40 for the ODI. To achieve 95% certainty of change between assessments for a single patient, the SSS would need to change by 15, the OCS by 20, and the ODI by 16. The mean SWT was 150 m, with a change of 76 m required for 95% confidence. Cronbach's alpha was 0.91 for the SSS, 0.90 for the OCS, and 0.89 for the ODI. The change in ODI correlated most strongly with patient satisfaction after surgery (rho = 0.80; P < 0.001).

CONCLUSIONS

Fluctuations in a patient's symptoms result in wide individual confidence intervals. Performance on the SSS, OCS, and ODI questionnaires are broadly similar, the most precise being the condition-specific SSS. The SWT gives a snapshot of physical function, which is acceptable for group analysis. Use of the SWT for individual assessment after surgery is feasible.

The incremental shuttle walking test in elderly people with chronic airflow limitation

BACKGROUND

There is a concern that comorbidity or frailty in older people could limit the usefulness of currently available exercise tests for chronic lung disease. This study evaluated the feasibility and reproducibility of the incremental shuttle walking test (SWT) in people aged 70 years or over, compared exercise tolerance with other disability markers, and assessed whether the SWT is responsive to change after bronchodilators.

METHODS

Fifty elderly patients with chronic airflow limitation (CAL) and 32 controls without airflow limitation attempted the SWT before and after combined nebulised salbutamol/ipratropium bromide. Subjects also completed the Nottingham Extended Activities of Daily Living index (NEADL) and the London Handicap score (LHS).

RESULTS

Forty four subjects with CAL (88%) and 29 controls (84%) completed the SWT, including many with co-morbidities. Two week repeatability was good and the SWT was strongly associated with EADL (r=0.51, p<0.001) and LHS (r=0.43, p<0.004), but only weakly with forced expiratory volume in 1 second (FEV1) (r=0.31, p=0.05). Subjects with CAL walked a mean distance of 177.7 m compared with 243.3 m in controls (p<0.001); following bronchodilator therapy the distance walked increased in the CAL group by 13.2% (p=0.009).

CONCLUSION

The SWT is a feasible and reproducible measure of exercise tolerance in elderly people with and without airflow obstruction and correlates with other markers of disability. It is sensitive to change following bronchodilation in subjects with CAL, although the change correlates less well with improvements in FEV1. Overall, these results suggest that the SWT might be an appropriate measure to assess interventions in elderly people.

Incremental shuttle walk test in the assessment of patients for heart transplantation

OBJECTIVE

To compare the incremental shuttle walk test (ISWT) with treadmill exercise testing (TT) derived measurement of peak oxygen consumption (peak VO(2)) in patients undergoing assessment for cardiac transplantation.

DESIGN

Prospective comparison. All investigations occurred during a single period of admission for transplant assessment.

SETTING

Single UK cardiothoracic transplantation unit.

PATIENTS

25 patients recruited (21 men). Mean age was 53 years.

INTERVENTIONS

Patients underwent two TT of peak VO(2) using the modified Naughton protocol and three (one practice) ISWT. Investigations were performed on consecutive days.

MAIN OUTCOME MEASURES

Main outcome measures were repeatability of TT and ISWT assessments; relation between peak VO(2) and distance walked in the ISWT; and receiver operating characteristic (ROC) analysis to establish a distance walked in the ISWT that predicted which patients would have a peak VO(2) greater than 14 ml/min/kg.

RESULTS

Both the ISWT and the TT were highly reproducible. Following the first practice walk, mean (SD) ISWT distances were 400.0 (146) m (ISWT2) and 401.3 (129) m (ISWT3), r = 0.90, p < 0.0001. Mean peak VO(2) by TT was 15.2 (4.4) ml/kg/min (TT1) and 15.0 (4.4) ml/kg/min (TT2), r = 0.83, p < 0.0001. The results revealed a strong correlation between distance covered in the ISWT and peak VO(2) obtained during TT (r = 0.73, p = 0.0001). ROC analysis showed that a distance walked of 450 m allowed the selection of patients with a peak VO(2) of over 14 ml/min/kg.

CONCLUSIONS

This work confirms the utility of the ISWT in the assessment of exercise capacity in patients with severe heart failure undergoing assessment for cardiac transplantation. ISWT may provide a widely applicable surrogate measure for peak VO(2) estimation in this population. Shuttle distance walked may therefore allow the convenient, serial assessment of patients with heart failure before referral for transplantation.

Incremental shuttle walk test in the assessment of patients for heart transplantation

OBJECTIVE

To compare the incremental shuttle walk test (ISWT) with treadmill exercise testing (TT) derived measurement of peak oxygen consumption (peak Vo2) in patients undergoing assessment for cardiac transplantation.

DESIGN

Prospective comparison. All investigations occurred during a single period of admission for transplant assessment.

SETTING

Single UK cardiothoracic transplantation unit.

PATIENTS

25 patients recruited (21 men). Mean age was 53 years.

INTERVENTIONS

Patients underwent two TT of peak Vo2 using the modified Naughton protocol and three (one practice) ISWT. Investigations were performed on consecutive days.

MAIN OUTCOME MEASURES

Main outcome measures were repeatability of TT and ISWT assessments; relation between peak Vo2 and distance walked in the ISWT; and receiver operating characteristic (ROC) analysis to establish a distance walked in the ISWT that predicted which patients would have a peak Vo2 greater than 14 ml/min/kg.

RESULTS

Both the ISWT and the TT were highly reproducible. Following the first practice walk, mean (SD) ISWT distances were 400.0 (146) m (ISWT2) and 401.3 (129) m (ISWT3),r = 0.90, p < 0.0001. Mean peak Vo2 by TT was 15.2 (4.4) ml/kg/min (TT1) and 15.0 (4.4) ml/kg/min (TT2), r = 0.83, p < 0.0001. The results revealed a strong correlation between distance covered in the ISWT and peak Vo2obtained during TT (r = 0.73, p = 0.0001). ROC analysis showed that a distance walked of 450 m allowed the selection of patients with a peak Vo2 of over 14 ml/min/kg.

CONCLUSIONS

This work confirms the utility of the ISWT in the assessment of exercise capacity in patients with severe heart failure undergoing assessment for cardiac transplantation. ISWT may provide a widely applicable surrogate measure for peak Vo2 estimation in this population. Shuttle distance walked may therefore allow the convenient, serial assessment of patients with heart failure before referral for transplantation.

The shuttle walking test: a reproducible method for evaluating the impact of shortness of breath on functional capacity in patients with advanced cancer

BACKGROUND

Breathlessness leading to exercise limitation is common in patients with advanced cancer and is ineffectively treated. There are few research data to guide clinicians on best practice. The shuttle walking test has been validated for some conditions such as chronic obstructive pulmonary disease but not for advanced cancer. One of the well documented difficulties of doing clinical research in palliative care is the acceptability of assessment tests. This study examined the reproducibility of the shuttle walking test in patients with advanced cancer to help facilitate the systematic evaluation of interventions designed to improve breathlessness.

METHODS

Patients performed three shuttle walks on separate days with continuous monitoring of arterial oxygen saturation and heart rate; simple pulmonary function (FEV(1)) was also recorded. Data on quality of life, anxiety, and depression were collected throughout the study period using appropriate questionnaires. Breathlessness was measured before and after exercise using a visual analogue scale.

RESULTS

Data from 22 patients were compared between visits 2 and 3. There were no significant differences between the FEV(1) (1.89 v 1.90, p=0.73), distance walked on each test (245 m v 256 m, p=0.14), end-exercise levels of heart rate (107/min v 108/min, p=0.11), oxygen saturation (93.4% v 93.2%, p=0.38), or breathlessness scores (p=0.62) on the two occasions. Indices of quality of life, anxiety, and depression were also not different between the two tests. The investigation was very acceptable to patients, families, and staff.

CONCLUSIONS

The shuttle walking test is a reproducible test of functional capacity in ambulant patients with advanced cancer, WHO performance status 1 or 2. The data indicate that a practice session is needed. It is easy to carry out and acceptable for patients with advanced cancer.

A qualitative systematic overview of the measurement properties of functional walk tests used in the cardiorespiratory domain

OBJECTIVE

To perform a qualitative systematic overview of the measurement properties of the most commonly utilized walk tests in the cardiorespiratory domain: the 2-min walk test (2MWT), 6-min walk test (6MWT), 12-min walk test (12MWT), self-paced walk test (SPWT), and shuttle walk test (SWT).

DATA SOURCES

MEDLINE (1966 to January 2000) and CINAHL (1982 to December 1999) electronic databases were searched. Bibliographies of the retrieved articles were reviewed.

STUDY SELECTION

Clinical trials and observational studies were included if they reported data on the validity, reliability, interpretability, or responsiveness of the 2MWT, 6MWT, 12MWT, SPWT, or SWT. Only studies conducted on patients with cardiac and/or respiratory involvement were included.

RESULTS

Fifty-two studies examining measurement properties of the various walk tests were found: 5 studies on the 2MWT, 29 studies on the 6MWT, 13 studies on the 12MWT, 6 studies on the SPWT, and 4 studies on the SWT. Measurement properties were most strongly demonstrated for the 6MWT. Correlations of 6MWT distance and maximal oxygen consumption ranged from 0.51 to 0.90. A change in distance walked of at least 54 m was found to be clinically significant for the 6MWT. Reliability was shown to be optimized when the administration of walk tests was standardized and at least two practice walks were performed. Patients with increased likelihood of postoperative complications, hospitalization, and death were identified by analysis of distance walked.

CONCLUSIONS

Measurement properties of the 6MWT have been the most extensively researched and established. In addition, the 6MWT is easy to administer, better tolerated, and more reflective of activities of daily living than the other walk tests. Therefore, the 6MWT is currently the test of choice when using a functional walk test for clinical or research purposes.

Reproducibility of the six-minute walking test in chronic heart failure patients

The six-minute walking test (WT) is used in trials and clinical practice as an easy tool to evaluate the functional capacity of chronic heart failure (CHF) patients. As WT measurements are highly variable both between and within individuals, this study aims at assessing the contribution of the different sources of variation and estimating the reproducibility of the test. A statistical model describing WT measurements as a function of fixed and random effects is proposed and its parameters estimated. We considered 202 stable CHF patients who performed two baseline WTs separated by a 30 minute rest; 49 of them repeated the two tests 3 months later (follow-up control). They had no changes in therapy or major clinical events. Another 31 subjects performed two baseline tests separated by 24 hours. Collected data were analysed using a mixed model methodology. There was no significant difference between measurements taken 30 minutes and 24 hours apart (p = 0.99). A trend effect of 17 (1.4) m (mean (SE)) was consistently found between duplicate tests (p < 0.001). REML estimates of variance components were: 5189 (674) for subject differences in the error-free value; 1280 (304) for subject differences in spontaneous clinical evolution between baseline and follow-up control, and 266 (23) for the within-subject error. Hence, the standard error of measurement was 16.3 m, namely 4 per cent of the average WT performance (403 m) in this sample. The intraclass correlation coefficient was 0.96. We conclude that WT measurements are characterized by good intrasubject reproducibility and excellent reliability. When follow-up studies > or = 3 months are performed, unpredictable changes in individual walking performance due to spontaneous clinical evolution are to be expected. Their clinical significance, however, is not known.

Reproducibility of the six-minute walking test in patients with chronic congestive heart failure: practical implications

This study assesses the reproducibility of the 6-minute walking test in patients with chronic heart failure using 2 different measurement protocols. Practical suggestions for the clinical setting are given.