This paper is by friend of blog, Vitaly Napadow. In this study he is doing something I’ve been working on. He uses ear stimulation to increase parasympathetic activity in subjects with hypertension and monitors autonomic activity using HRV. It has helped me to hone my protocol, and encourages me to determine what patient populations would benefit from using this device at home. Full text here.Sclocco_EMBC2017_003 napadow hypertension RAVANS
In light of this recent study, I’m feeling validated and motivated to continue in this direction.
Respiratory-gated Auricular Vagal Afferent Nerve Stimulation (RAVANS) effects on autonomic outflow in hypertension.
Transcutaneous stimulation of the auricular branch of the vagus nerve (ABVN) has been proposed as a non-invasive alternative to vagus nerve stimulation (VNS). However, its cardiovagal effects are inconsistent across studies, likely due to inhomogeneity in the stimulation parameters. Here, we evaluate respiratory-gated ABVN stimulation (Respiratory-gated Auricular Vagal Afferent Nerve Stimulation, RAVANS), where the stimuli are delivered in 1 s bursts during the exhalation phase of respiration, thus mimicking the breathing-induced modulation of cardiac vagal activity. In this study, we present preliminary results from an ongoing single-arm, open label trial investigating the effects of different intensities of RAVANS in hypertensive subjects. We found that a mid-intensity RAVANS stimulation (rated as a 5 on a 0-10 scale) increases the cardiovagal tone and reduces the sympathetic tone during a paced breathing task. The present results could contribute to optimize RAVANS as a non-invasive, low-cost therapeutic intervention for hypertension.a