Author: Matjaz Sinkovec1, Roman Trobec2, Bernard Meglic3
Affiliation: <sup>1</sup> Department of Cardiology, University Medical Center Ljubljana, Zaloška c. 7, 1000 Ljubljana, Slovenia. Electronic address: matjaz.sinkovec@kclj.si.
<sup>2</sup> Department of Communication Systems, Jožef Stefan Institute, Jamova 39, 1000 Ljubljana, Slovenia. Electronic address: roman.trobec@ijs.si.
<sup>3</sup> Department of Neurology, University Medical Center Ljubljana, Zaloška c. 7, 1000 Ljubljana, Slovenia. Electronic address: bernard.meglic@kclj.si.
Conference/Journal: Auton Neurosci
Date published: 2021 Jul 14
Other:
Volume ID: 236 , Pages: 102851 , Special Notes: doi: 10.1016/j.autneu.2021.102851. , Word Count: 229
Aims:
The aim was to determine cardiovascular responses to an arbitrary protocol of transcutaneous low-level vagus nerve electrical stimulation (tVNS).
Methods:
Study was performed in 15 male volunteers, mean age 23 years. Data were collected during two sessions - sham stimulation (no stimulation) and stimulation. Each session included one-hour resting phase followed by 15-min autonomic nervous system testing phase (Valsalva, deep breathing, wet-cold face tests), all in supine position. The right tragus stimulation parameters were: 20 Hz, constant current at sensation threshold, 1 ms rectangular pulse width. The ECG, noninvasive arterial blood pressure and thoracic impedance cardiography measurements were recorded and analyzed continuously with the Task Force® Monitor (CNSystems Medizintechnik GmbH, Graz, Ver. 2.2.10.0). t-Test for paired samples, paired Wilcoxon signed-rank, and one-way ANOVA for repeated measurements were carried out. P < 0.05 was considered significant.
Results:
We demonstrated significant reductions of left ventricular contractility and output parameters, a trend for heart rate reduction, and resulting beneficial reduction of left ventricular work load. However, significant increases of blood pressure and total peripheral resistance were recognized, possibly as a reflex response.
Conclusion:
It seems that our tVNS protocol has a potential for cardiac autonomic modulation. This gives us opportunity to advance our stimulation parameters with participant-specific adjustments. Further studies are however needed to prove the therapeutic potential of such approach in different patient groups.
Keywords: Cardiovascular system; Neuromodulation; Transcutaneous; Vagus nerve stimulation.
PMID: 34274638 DOI: 10.1016/j.autneu.2021.102851