Article

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.

Langue : ANGLAIS