Análise da variabilidade da frequência cardíaca, variáveis cardiopulmonares e catecolaminas plasmáticas durante recuperação pós-exercício

Abstract

Introduction: Exercises promote changes in the Autonomic Nervous System, the mainly responsible for neurodegenerative functions. Due to its importance, several methods are used in evaluation such as Heart Rate Variability (HRV) analysis, considered an indirect technique to assess autonomic functions, but its use is still questioned. Objectives: To analyze the correlation between HRV indices and concentration of epinephrine and norepinephrine, and observe post-exercise recovery, by HRV linear and nonlinear indices and cardiopulmonary parameters. Methods: 28 participants, divided into two groups (N = 14) had their recovery after exercise evaluated. One group performed submaximal effort (55% V̇O2peak), for 5 minutes, and the other, supramaximal (110% of peak V̇O2) until exhaustion. During 90 minutes post-exercise, blood samples were collected, cardiopulmonary variables were registered and HRV was analyzed. Results: Between baseline and immediately postexercise, we detected that adrenaline and noradrenaline showed significant nonlinear correlation with RR intervals, heart rate, HRV linear indices and nonlinear parameters related to complexity and fractality. After exercise performed at 55% of peak V̇O2, recovery was observed between 30 and 60 minutes, whereas for exercise at 110%, 90 minutes were not enough for returning of variables to baseline levels. Conclusions: Plasma catecholamine concentrations after exercise presented correlation with HRV linear indices and nonlinear parameters related to complex and fractal characteristics of heartbeats, especially the Lyapunov exponent. The variables recovery occurred at different times, but the changes caused by supramaximal exercise were more expressive and lasting.