Early-Phase Recovery of Cardiorespiratory Measurements after Maximal Cardiopulmonary Exercise Testing in Patients with Chronic Obstructive Pulmonary Disease.

. This study investigated respiratory gas exchanges and heart rate (HR) kinetics during early-phase recovery after a maximal cardiopulmonary exercise test (CPET) in patients with chronic obstructive pulmonary disease (COPD) grouped according to airflow limitation. . Thirty control individuals (control group: CG) and 81 COPD patients (45 with "mild" or "moderate" airflow limitation, COPD, versus 36 with "severe" or "very severe" COPD, COPD) performed a maximal CPET. The first 3 min of recovery kinetics was investigated for oxygen uptake ([Formula: see text]O), minute ventilation ([Formula: see text]), respiratory equivalence, and HR. The time for [Formula: see text]O to reach 25% (T[Formula: see text]O) of peak value was also determined and compared. . The [Formula: see text]O, [Formula: see text], and HR recovery kinetics were significantly slower in both COPD groups than CG ( < 0.05). Moreover, COPD group had significantly higher [Formula: see text]O and [Formula: see text] during recovery than COPD group ( < 0.05). T[Formula: see text]O significantly differed between groups ( < 0.01; 58 ± 18 s in CG, 79 ± 26 s in COPD group, and 121 ± 34 s in COPD) and was significantly correlated with forced expiratory volume in one second in COPD patients ( < 0.001, = 0.53) and with peak power output ( < 0.001, = 0.59). . The COPD groups showed slower kinetics in the early recovery period than CG, and the kinetics varied with severity of airflow obstruction.