Abstract
Ventilatory efficiency is reduced in patients (pts) with COPD or chronic heart failure (CHF) resulting in abnormal dyspnoea during exercise. The aim of the study was to evaluate the effect of exercise training on ventilation in these pts.
Methods: 25 COPD pts (11 males; 64±9 years old, GOLD 3-4) and 25 CHF pts (23 males, 55±10 years old, NYHA class II-III, ejection fraction ≤ 35%) underwent maximal exercise test pre and post rehabilitation programme (RP) measuring oxygen uptake (V'O2), carbon dioxide output (V'CO2) and ventilation (V'E). The ventilatory efficiency was evaluated using the V'E/V'CO2 slope. Breathing pattern was evaluated using iso-ventilation, i.e. maximal V'E, tidal volume (VT) and respiratory rate (RR) pre RP compared to the same parameters during iso-V'O2 post RP. Exercise training in the RP consisted of endurance and strength training 5 days a week for six weeks.
Results: Exercise endurance increased and ventilatory requirements reduced post RP. Breathing pattern was improved in COPD pts but ventilatory efficiency was unchanged in both groups (Table 1).
Conclusion: Exercise training did not improve ventilatory efficiency but reduced ventilatory requirements during heavy exercise giving prospect of less dyspnoea during effort in these pts.
- © 2012 ERS