The aim of this study was to analyse the effect of oral high-frequency oscillation technique (with the Shaker device), applied at different expiratory pressures (EP), onto autonomic heart function and cardiorespiratory parameters. Data were collected from 20 young healthy volunteers (aged 21,6±1,3 years old) who remained at initial rest for 10 minutes and then performed three series of ten expirations each with the Shaker device (with rest intervals of 2 minutes between series) in three EP: free pressure (FP) and pressures of 10 (P10) and of 20 cmH2O (P20), then remained at rest for additional 10 minutes. Data were statistically analysed, with significance level set at 5%. After the breathing technique, a statistically significant difference was noticed at heart rate variability indices at FP and a significant increase in systolic blood pressure at P20. Measures of diastolic blood pressure, respiratory frequency and peripheral oxygen saturation showed no difference before, during and after the technique at any EP. Perceived exertion increased significantly along the series at FP and P20, as well as between P10 and P20 in all series. Heart rate increased and decreased in synchronization with inspiration and expiration, respectively. The application of the technique in this population at different expiratory pressures promoted changes in hear rate behaviour, in perceived exertion and, at FP, in heart autonomic modulation.
Autonomic nervous system; Heart rate; High-frequency ventilation
