Low-Level Transcutaneous Electrical Vagus Nerve Stimulation Suppresses Atrial Fibrillation

Abstract

BACKGROUND Transcutaneous low-level tragus electrical stimulation (LLTS) suppresses atrial fibrillation (AF) in canines. OBJECTIVES We examined the antiarrhythmic and anti-inflammatory effects of LLTS in humans. METHODS Patients with paroxysmal AF who presented for AF ablation, were randomized to either 1 hour of LLTS (n = 20) or sham control (n = 20). Attaching a flat metal clip onto the tragus produced LLTS (20 Hz) in the right ear (50% lower than the voltage slowing the sinus rate). Under general anesthesia, AF was induced by burst atrial pacing at baseline and after 1 hour of LLTS or sham. Blood samples from the coronary sinus and the femoral vein were collected at those time points and then analyzed for inflammatory cytokines, including tumor necrosis factor (TNF)-α and C-reactive protein (CRP), using a multiplex immunoassay. RESULTS There were no differences in baseline characteristics between the 2 groups. Pacing-induced AF duration decreased significantly by 6.3 ± 1.9 min compared to baseline in the LLTS group, but not in the controls (p = 0.002 for comparison between groups). AF cycle length increased significantly from baseline by 28.8 ± 6.5 ms in the LLTS group, but not in controls (p = 0.0002 for comparison between groups). Systemic (femoral vein) but not coronary sinus TNF-α and CRP levels decreased significantly only in the LLTS group. CONCLUSIONS LLTS suppresses AF and decreases inflammatory cytokines in patients with paroxysmal AF. Our results support the emerging paradigm of neuromodulation to treat AF.

The strange case of the ear and the heart: The auricular vagus nerve and its influence on cardiac control

“…In recent years the major sites of interest for delivering electrical stimulation to the ABVN have been the inner surface of the tragus (Busch et al, 2013;Clancy et al, 2014;Kraus et al, 2013;Stavrakis et al, 2015;Weise et al, 2015;Zhou et al, 2016), the concha (Ay et al, 2015b;Fang et al, 2015;He et al, 2013b;Liu et al, 2013), and the cymba concha (Frangos et al, 2015;Kreuzer et al, 2014). In parallel with these ear studies, a method said to allow non-invasive cervical vagus nerve stimulation through the skin of the neck has also been developed and is under investigation in patients with cluster headache (Nesbitt et al, 2015) and migraine (Barbanti et al, 2015).…”

“…In patients with paroxysmal atrial fibrillation, 1 hour of low level tVNS under general anaesthesia significantly decreased atrial fibrillation duration (induced by burst atrial pacing), significantly increased atrial fibrillation cycle length and significantly decreased systemic levels of the inflammatory factors tumour necrosis factor alpha (TNF-alpha) and C-reactive protein (Stavrakis et al, 2015). Meanwhile, in patients with chronic heart failure and severe left ventricular dysfunction, a 15 day course of daily tVNS sessions (increasing duration per session, up to 30 minutes) on the internal surface of the auricle significantly increased distance of a 6 minute walk test and improved the clinical condition in the majority of patients.…”

“…A key consideration is that tVNS increases heart rate variability and, critically, decreases muscle sympathetic nerve activity in healthy humans (Clancy et al, 2014). Further, such cardiovascular diseases are associated with increased inflammation and tVNS reduced plasma levels of non-specific inflammatory markers in conscious dogs with healed myocardial infarction (Wang et al, 2014;Wang et al, 2015), as well as in patients with paroxysmal atrial fibrillation (Stavrakis et al, 2015). Finally, the pathways through which tVNS functions are not yet known (see Figure 2) -it is conceivable that they provide a more selective route of action than those activated through cervical vagus stimulation.…”

Ablation of Ganglionated Plexi in the Long Term

“…Are there alternatives that could be added to the armamentarium of methodologies to treat the various forms of AF? Recent experimental 30 and clinical 31 studies have demonstrated that low-level nerve stimulation (that does not slow the heart rate and is nonsentient) applied at the auricular branch of the vagus nerve (the tragus of the outer ear) can consistently suppress AF. Other alternative therapies that have been proposed for the treatment of AF include acupuncture 32 and Yoga.…”

Interfacing with the nervous system: a review of current bioelectric technologies

“…Similarly, Antonio et al used TNS to modulate activity within the auricular branch of the vagus nerve and treat spontaneous cardiac baroreflex sensitivity [7]. Additionally, transcutaneous vagus nerve stimulation has been demonstrated to reduce atrial fibrillation in humans [144].…”