Low-level tragus stimulation improves autoantibody-induced hyperadrenergic postural tachycardia syndrome in rabbits

Yankai Guo, MD; Hongliang Li, MD, PhD; Jielin Deng, MD; Gege Zhang, MD; Hayley Fischer, MS; Stavros Stavrakis, MD, PhD, FACC, FHRS; Xichun Yu, MD

Heart Rhythm O2 (Feb 2023)

Low-level tragus stimulation improves autoantibody-induced hyperadrenergic postural tachycardia syndrome in rabbits

Yankai Guo, MD,
Hongliang Li, MD, PhD,
Jielin Deng, MD,
Gege Zhang, MD,
Hayley Fischer, MS,
Stavros Stavrakis, MD, PhD, FACC, FHRS,
Xichun Yu, MD

Affiliations

Yankai Guo, MD: Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
Hongliang Li, MD, PhD: Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
Jielin Deng, MD: Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
Gege Zhang, MD: Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
Hayley Fischer, MS: Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
Stavros Stavrakis, MD, PhD, FACC, FHRS: Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
Xichun Yu, MD: Address reprint requests and correspondence: Dr Xichun Yu, University of Oklahoma Health Sciences Center, 1122 NE 13th Street, ORB 331, Oklahoma City, OK 73117.; Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma

Journal volume & issue: Vol. 4, no. 2
pp. 127 – 133

Abstract

Read online

Background: Recent studies have demonstrated that antiadrenergic autoantibodies are involved in the pathophysiology of postural orthostatic tachycardia syndrome (POTS). Objective: The purpose of this study was to test the hypothesis that transcutaneous low-level tragus stimulation (LLTS) ameliorates autoantibody-induced autonomic dysfunction and inflammation in a rabbit model of autoimmune POTS. Methods: Six New Zealand white rabbits were co-immunized with peptides from the α1-adrenergic and β1-adrenergic receptors to produce sympathomimetic antibodies. The tilt test was performed on conscious rabbits before immunization, 6 weeks after immunization, and 10 weeks after immunization with 4-week daily LLTS treatment. Each rabbit served as its own control. Results: An enhanced postural heart rate increase in the absence of significant change in blood pressure was observed in immunized rabbits, confirming our previous report. Power spectral analysis of heart rate variability during the tilt test showed a predominance of sympathetic over parasympathetic activity in immunized rabbits as reflected by markedly increased low-frequency power, decreased high-frequency power, and increased low-to-high-frequency ratio. Serum inflammatory cytokines were also significantly increased in immunized rabbits. LLTS suppressed the postural tachycardia, improved the sympathovagal balance with increased acetylcholine secretion, and attenuated the inflammatory cytokine expression. Antibody production and activity were confirmed with in vitro assays, and no antibody suppression by LLTS was found in this short-term study. Conclusion: LLTS improves cardiac autonomic imbalance and inflammation in a rabbit model of autoantibody-induced hyperadrenergic POTS, suggesting that LLTS may be used as a novel neuromodulation therapy for POTS.

Published in Heart Rhythm O2

ISSN: 2666-5018 (Online)
Publisher: Elsevier
Country of publisher: United States
LCC subjects: Medicine: Internal medicine: Specialties of internal medicine: Diseases of the circulatory (Cardiovascular) system
Website: https://www.journals.elsevier.com/heart-rhythm-o2

About the journal

Abstract

Keywords