TY - JOUR
T1 - Non-invasive vagus nerve stimulation acutely improves spontaneous cardiac baroreflex sensitivity in healthy young men: A randomized placebo-controlled trial.
AU - Antonino, D
AU - Teixeira, AL
AU - Maia-Lopes, PM
AU - Souza, MC
AU - Sabino-Carvalho, JL
AU - Murray, AR
AU - Deuchars, J
AU - Vianna, LC
PY - 2017/5/19
Y1 - 2017/5/19
N2 - BackgroundDespite positive outcomes of transcutaneous vagus nerve stimulation (tVNS) via the auricular branch of the vagus nerve (ABVN), the mechanisms underlying these outcomes remain unclear. Additionally, previous studies have not been controlled the possible placebo effects of tVNS.ObjectiveTo test the hypothesis that tVNS acutely improves spontaneous cardiac baroreflex sensitivity (cBRS) and autonomic modulation, and that these effects are specific to stimulation of ABVN.MethodsThirteen healthy men (23±1yrs) were randomized across three experimental visits. In active tVNS, electrodes were placed on the tragus of the ear and electrical current was applied by using a Transcutaneous Electrical Nerve Stimulation device. A time-control visit was performed with the electrodes placed on tragus, but no current was applied (sham-T). Additionally, to avoid a placebo effect, another sham protocol was performed with same electrical current of the active visit, but the electrodes were placed on the ear lobe (an area without cutaneous nerve endings from the vagus – tLS). Beat-to-beat heart rate (HR) and blood pressure (BP) were monitored at rest, during stimulation (active, sham-T and tLS) and recovery. cBRS was measured via sequence technique. Both HR (HRV) and BP variability (BPV) were also measured.ResultsArterial BP and BPV were not affected by any active or sham protocols (P > 0.05). Resting HR and LF/HF ratio of HRV decreased (Δ–3.4 ± 1% and Δ–15 ± 12%, P < 0.05, respectively) and cBRS increased (Δ24 ± 8%, P < 0.05) during active tVNS, but were unchanged during both sham protocols.ConclusiontVNS acutely improves cBRS and autonomic modulation in healthy young men.
AB - BackgroundDespite positive outcomes of transcutaneous vagus nerve stimulation (tVNS) via the auricular branch of the vagus nerve (ABVN), the mechanisms underlying these outcomes remain unclear. Additionally, previous studies have not been controlled the possible placebo effects of tVNS.ObjectiveTo test the hypothesis that tVNS acutely improves spontaneous cardiac baroreflex sensitivity (cBRS) and autonomic modulation, and that these effects are specific to stimulation of ABVN.MethodsThirteen healthy men (23±1yrs) were randomized across three experimental visits. In active tVNS, electrodes were placed on the tragus of the ear and electrical current was applied by using a Transcutaneous Electrical Nerve Stimulation device. A time-control visit was performed with the electrodes placed on tragus, but no current was applied (sham-T). Additionally, to avoid a placebo effect, another sham protocol was performed with same electrical current of the active visit, but the electrodes were placed on the ear lobe (an area without cutaneous nerve endings from the vagus – tLS). Beat-to-beat heart rate (HR) and blood pressure (BP) were monitored at rest, during stimulation (active, sham-T and tLS) and recovery. cBRS was measured via sequence technique. Both HR (HRV) and BP variability (BPV) were also measured.ResultsArterial BP and BPV were not affected by any active or sham protocols (P > 0.05). Resting HR and LF/HF ratio of HRV decreased (Δ–3.4 ± 1% and Δ–15 ± 12%, P < 0.05, respectively) and cBRS increased (Δ24 ± 8%, P < 0.05) during active tVNS, but were unchanged during both sham protocols.ConclusiontVNS acutely improves cBRS and autonomic modulation in healthy young men.
U2 - 10.1016/j.brs.2017.05.006
DO - 10.1016/j.brs.2017.05.006
M3 - Article
C2 - 28566194
SN - 1935-861X
VL - 10
SP - 875
EP - 881
JO - Brain stimulation
JF - Brain stimulation
IS - 5
ER -