title: The self-perception of dyspnoea threshold during the 6-min walk test: a good alternative to estimate the ventilatory threshold in chronic obstructive pulmonary disease.
abstract: To determine and/or adjust exercise training intensity for patients when the cardiopulmonary exercise test is not accessible, the determination of dyspnoea threshold (defined as the onset of self-perceived breathing discomfort) during the 6-min walk test (6MWT) could be a good alternative. The aim of this study was to evaluate the feasibility and reproducibility of self-perceived dyspnoea threshold and to determine whether a useful equation to estimate ventilatory threshold from self-perceived dyspnoea threshold could be derived. A total of 82 patients were included and performed two 6MWTs, during which they raised a hand to signal self-perceived dyspnoea threshold. The reproducibility in terms of heart rate (HR) was analysed. On a subsample of patients (n=27), a stepwise regression analysis was carried out to obtain a predictive equation of HR at ventilatory threshold measured during a cardiopulmonary exercise test estimated from HR at self-perceived dyspnoea threshold, age and forced expiratory volume in 1 s. Overall, 80% of patients could identify self-perceived dyspnoea threshold during the 6MWT. Self-perceived dyspnoea threshold was reproducibly expressed in HR (coefficient of variation=2.8%). A stepwise regression analysis enabled estimation of HR at ventilatory threshold from HR at self-perceived dyspnoea threshold, age and forced expiratory volume in 1 s (adjusted r=0.79, r=0.63, and relative standard deviation=9.8 bpm). This study shows that a majority of patients with chronic obstructive pulmonary disease can identify a self-perceived dyspnoea threshold during the 6MWT. This HR at the dyspnoea threshold is highly reproducible and enable estimation of the HR at the ventilatory threshold.
authors: aAgiraDom, Meylan bClinique du Souffle La Vallonie, Fontalvie-5-Santé Group, Lodève cDepartment of Clinical Physiology, CHRU Montpellier, INSERM U-1046 dEuromov Laboratory, Faculty of Sport Sciences, University of Montpellier, Montpellier, France.
authors: Annabelle
authors: A
authors: Couillard
authors: Emilie
authors: E
authors: Tremey
authors: Christian
authors: C
authors: Prefaut
authors: Alain
authors: A
authors: Varray
authors: Nelly
authors: N
authors: Heraud
mesh_terms: D059026:Diagnostic Self Evaluation; D004417:Dyspnea / Q000175:diagnosis* / Q000523:psychology / Q000534:rehabilitation; D005240:Feasibility Studies; D005260:Female; D005541:Forced Expiratory Volume; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis* / Q000523:psychology / Q000534:rehabilitation; D015203:Reproducibility of Results; D012131:Respiratory Insufficiency / Q000175:diagnosis* / Q000523:psychology / Q000534:rehabilitation; D000070857:Walk Test