Dynamic pulmonary hyperinflation occurs without expiratory flow limitation in chronic heart failure during exercise

To assess the occurrence of tidal expiratory flow limitation (EFL) and/or dynamic pulmonary hyperinflation (DH) in chronic heart failure (CHF) during exercise 15 patients with stable systolic CHF, aged 69 ± 6 yr, underwent pulmonary function testing and incremental cardio-pulmonary exercise testing. They subsequently performed constant load exercise testing at 30, 60 and 90% of respective maximum workload. At each step the presence of EFL, by negative expiratory pressure technique, and changes in inspiratory capacity (IC) were assessed. Ejection fraction amounted to 36 ± 6% and V˙O2, peak (77 ± 19% pred.) was reduced. EFL was absent at any step during constant load exercise. In 6 patients IC decreased more than 10% pred. at highest step. Only in these patients TLC, FRC, RV FEF25-75% and DLCO were decreased at rest. V˙O2, peak correlated with DLCO, TLC and IC at rest and with IC (r2 = 0.59; p < 0.001) and decrease in IC (r2 = 0.44; p < 0.001) at 90% of maximum workload. During exercise CHF patients do not exhibit EFL, but some of them develop DH that is associated with lower V˙O2, peak.