Efeito agudo da eletroestimulação transcutânea auricular do nervo vago no controle autonômico cardíaco em pessoas vivendo com HIV: um ensaio clínico randomizado

Abstract

Introduction. The aim of the study is to evaluate the acute effect of transcutaneous auricular electrical stimulation of the vagus nerve on cardiac autonomic control of PLHIV. Methodology. The research is characterized as a controlled clinical trial, randomized, crossover and double blind, with a sample of 21 PLHIV who have been using ART for more than 6 months and are physically inactive. Individuals were randomly allocated to two groups: taVNS (active stimulation) and Sham-t (inactive stimulation), after which the subjects were crossed between groups. A TENS device with modified electrodes was used for auricular transcutaneous electrical stimulation of the vagus nerve. To assess the cardiac autonomic control, the heart rate variability process was performed, where 5 minutes were analyzed and the measures of HRmean, RMSSD, LF, HF, LF/HF, SD1, SD2 and SD1/SD2 were selected. For all analyses, a significance level of 5% was adopted. Results. The RMSSD measurement showed a statistical difference between the conditions at baseline (∆= 0.102, 95%CI= 0.002 – 0.202, p = 0.046), but not after the end of the experimental protocol (∆= 0.053, 95%CI= -0.049 – 0.154, p = 0.292). The Sham-t group increased LF from the start of the protocol 5'-10' (∆=0.334, 95%CI= 0.120 – 0.548, p = 0.001), 25'-30' (∆= 0.356, 95%CI= 0.190 – 0.523, p < 0.001) and after the session (∆= 0.421, 95%CI= 0.156 – 0.686, p = 0.001). Sham-t presented the highest LF/HF value in the initial moments of the 5’-10’ protocol (∆= 0.235, 95%CI= 0.083 – 0.386, p = 0.004). There was no statistical difference for the sham-t group. However, Sham-t presented higher values of Sd1/Sd2 compared to taVNS at the 5’-10’ moment (∆= 0.07, 95%CI= 0.01 – 0.13, p < 0.003). Conclusion. TaVNS in PLHIV can be a strategy to improve cardiac autonomic control, however, new protocols need to be tested and over a period of time to demonstrate the possible benefits of an intervention with taVNS.