Authors

1. Frazao, Murillo MSc, PT
2. Silva, Paulo Eugenio MSc, PT
3. Frazao, Wanessa PT
4. da Silva, Vinicius Zacarias Maldaner PhD, PT
5. Correia, Marco Aurelio de Valois Jr MSc, PT
6. Neto, Mansueto Gomes PhD, PT

Abstract

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 (O₂ pulse) at 100% (P < .0001), without significant difference in O₂ 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/

CO₂ slope (r =-0.57, P < .01); work rate (r =-0.86, P < .0001);

O₂ (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.