Dynamic Hyperinflation Impairs Cardiac Performance During Exercise in COPD

Purpose: To investigate the correlation between a plateau in minute ventilation (E) during cardiopulmonary exercise tests (CPETs) and its impact on cardiac performance. Methods: This retrospective study analyzed 2575 CPETs of patients with chronic obstructive pulmonary disease. The study randomly selected 10 patients with a plateau in the (E) curve, suggesting dynamic hyperinflation, 10 patients with normal pattern for the (E) curve, and 10 healthy persons. Classic CPET variables, the new ventilation hyperinflation index, and the dynamic cardiac constraint index were analyzed. Results: The patients with dynamic hyperinflation presented with lower ventilation at 100% work rate (P < .0001), without significant differences in (E) at 50% and 100% work rate. Patients with dynamic hyperinflation also presented with a lower oxygen pulse (O-2 pulse) at 100% (P < .0001), without significant difference in O-2 pulse at 50% and 100% work rate. The subjects with dynamic hyperinflation had a higher ventilation hyperinflation index (P < .0001) and dynamic cardiac constraints index (P < .0001). The ventilation hyperinflation index correlated with the dynamic cardiac constraints index (r = 0.81, P < .0001); oxygen pulse variation (r =-0.63, P < .001); (E)/co(2) slope (r =-0.57, P < .01); work rate (r =-0.86, P < .0001); o(2) (r =-0.80, P < .0001), and (E) (r =-0.83, P < .0001). Conclusion: There is a correlation between a plateau in the (E) during CPET, suggesting hyperinflation, and it has an impact on cardiac performance.