Diferentes frequências da estimulação elétrica nervosa transcutânea sobre o balanço simpato-vagal

Abstract

Transcutaneous electrical nerve stimulation (TENS) is a electrotherapeutic mode used in physical medicine and rehabilitation, particularly for pain control. This therapeutic approach also has cardiovascular effects that are dependent on application parameters, and different types of frequency alter the reflex responses of the autonomic nervous system. However, these effects are still questionable in the literature. Therefore, this case-control study evaluated the effects of TENS at different frequencies (10Hz and 100Hz) on autonomic balance in fourteen healthy subjects (28±3.9 years). Interventions were randomized and applied for 30 minutes in the nervous plexus trajectory from the superior member non-dominant. Before and after the intervention was assessed the autonomic balance by variability of heart rate, and ECG signal was obtained through a pulse frequency meter. Statistical analysis was used to two-way analysis of variance for repeated measures (ANOVA) followed by post-hoc by the Least Significant Difference test. From the results obtained, it was observed that the application of TENS at high frequency (100Hz) decreased sympathetic activity and increased parasympathetic, resulting in improved sympathetic-vagal balance, while the low frequency (10Hz) TENS showed opposite results. Thus, it concludes that different frequencies of TENS applied in the nervous plexus trajectory interfere in the autonomic nervous system, modifying the sympathetic-vagal balance. These results favor the application of this therapeutic resource in different clinical conditions.