TOPLINE:
Stimulating the vagus nerve reduced orthostatic tachycardia in patients with postural tachycardia syndrome (POTS), possibly through decreased antiadrenergic autoantibodies and inflammatory cytokines, and improved cardiac autonomic function, in a small proof-of-concept study.
METHODOLOGY:
The double-blind study included 25 female patients with POTS, a syndrome of orthostatic intolerance (mean age 31 years and 81% Caucasian), who were randomly assigned to transcutaneous vagus nerve stimulation (tVNS) to the right tragus or sham stimulation to the earlobe, a site devoid of vagal innervation.
After training, patients delivered the tVNS themselves at a frequency of 20 Hz and pulse width of 200 ms during 1-hour daily sessions over 2 months.
At baseline and 2 months, patients underwent a tilt test to determine postural tachycardia; they remained supine for 25 minutes, followed by 10 minutes of standing, as tolerated.
Researchers used electrocardiogram data to examine heart rate and blood samples to assess serum cytokines and antiautonomic autoantibodies.
The primary outcome was a comparison of orthostatic tachycardia (standing – supine) between the two arms at 2 months.
TAKEAWAY:
At 2 months, postural tachycardia was significantly less in the active vs sham arm (mean postural increase in heart rate 17.6 beats/min vs 31.7 beats/min; P = .01).
There was a significant decrease in β
