Unlocking Hope: Nerve Stimulation Offers Relief for POTS

What is POTS?

Postural Tachycardia Syndrome (POTS) is a health condition that causes your heart to beat faster than normal when moving from sitting or lying down to standing up.^1-4

Normally, the body’s autonomic nervous system keeps our heart rate and blood pressure steady, ensuring blood flows smoothly no matter how we move. But with POTS, this balance falters leading to unsteady blood pressure and symptoms such as dizziness, lightheadedness, fatigue, and fainting.^2-4

POTS can affect anyone, but it most commonly occurs in women between the ages of 15­–50.^5,6 The risk of developing POTS also increases following significant health events like viral illnesses or serious infections, pregnancy, physical trauma (such as head injuries), surgery, or if there are already existing autoimmune disorders.³

Scientists have studied POTS in both animals and humans, discovering that specific antibodies (called antiadrenergic autoantibodies), which attack the body’s own nerve cells, can play a role in causing the condition in some patients.^7,8 There is additional evidence proposing that inflammation could also be a culprit in triggering the condition, adding another layer to our understanding of how POTS develops.^9,10

Although dietary changes, medications, and physical activity can help to alleviate symptoms, the exact cause of the condition is unknown, and long-term treatments are unavailable.

The latest puzzle piece

A study in Journal of the American College of Cardiology has made promising new discoveries in improving POTS symptoms using transcutaneous vagus nerve stimulation (tVNS).

The vagus nerve runs from the brain to the abdomen and oversees many bodily functions, a few of which are heart rate, digestion, breathing, and the immune system. Stimulating the vagus nerve with a device from the tragus position of the ear has been an interesting up and coming therapy used for cardiovascular conditions, including atrial fibrillation and heart failure.¹¹

Dr. Stavros Stavrakis and his team noticed the beneficial effects of tVNS on the heart, so they wanted to test if it could help POTS patients. In the study, the scientists stimulated the nerve by placing a small device on the ear to send electrical impulses to the vagus nerve.⁴ In this way, tVNS was able to influence heart activity, blood pressure, and other involuntary body functions.

The scientists randomly grouped participants into one of two groups, where some received real tVNS and others received a fake version. Neither the researchers nor the participants knew what each participant received. They ran the study over two months to see if daily nerve stimulation had any effect on POTS symptoms compared to the fake treatment.

For patients who received genuine tVNS, they found less antibodies that attack nerve cells in the blood and decreased signs of inflammation in the body. Even more excitingly, the patients’ hearts became better at maintaining a steady rhythm when moving from lying down to standing up.

This improved heart functioning helped reduce symptoms of low blood pressure or dizziness. Essentially, the heart’s response to standing up became more stable and less likely to cause discomfort or fainting spells. “The results support the idea that POTS is a condition influenced by multiple factors,” says Dr. Stavrakis.

These discoveries hint that noninvasive tVNS, a low-cost and safe option, can make a big difference for some patients with POTS when applied over a short period of time. Dr. Stavrakis adds, “this is an exciting time, as we have another tool to help patients.” The next steps are to “personalize this therapy for patients who would benefit the most” from using it.

References

1. Postural tachycardia syndrome (PoTS) – NHS. Accessed February 5, 2024. https://www.nhs.uk/conditions/postural-tachycardia-syndrome/
2. Postural Tachycardia Syndrome (POTS) | National Institute of Neurological Disorders and Stroke. Accessed February 5, 2024. https://www.ninds.nih.gov/health-information/disorders/postural-tachycardia-syndrome-pots
3. POTS: Causes, Symptoms, Diagnosis & Treatment. Accessed February 5, 2024. https://my.clevelandclinic.org/health/diseases/16560-postural-orthostatic-tachycardia-syndrome-pots
4. Stavrakis S, Chakraborty P, Farhat K, et al. Noninvasive Vagus Nerve Stimulation in Postural Tachycardia Syndrome: A Randomized Clinical Trial. JACC Clin Electrophysiol. Published online November 22, 2023. doi:10.1016/J.JACEP.2023.10.015
5. Bryarly M, Phillips LT, Fu Q, Vernino S, Levine BD. Postural Orthostatic Tachycardia Syndrome: JACC Focus Seminar. J Am Coll Cardiol. 2019;73(10):1207-1228. doi:10.1016/J.JACC.2018.11.059
6. Mar PL, Raj SR. Postural Orthostatic Tachycardia Syndrome: Mechanisms and New Therapies. Annu Rev Med. 2020;71:235-248. doi:10.1146/ANNUREV-MED-041818-011630
7. Li H, Yu X, Liles C, et al. Autoimmune Basis for Postural Tachycardia Syndrome. J Am Heart Assoc. 2014;3(1). doi:10.1161/JAHA.113.000755
8. Grubb AF, Grubb BP. Postural orthostatic tachycardia syndrome: New concepts in pathophysiology and management. Trends Cardiovasc Med. 2023;33(2):65-69. doi:10.1016/J.TCM.2021.10.007
9. Okamoto LE, Raj SR, Gamboa A, et al. Sympathetic activation is associated with increased IL-6, but not CRP in the absence of obesity: Lessons from postural tachycardia syndrome and obesity. Am J Physiol Heart Circ Physiol. 2015;309(12):H2098-H2107. doi:10.1152/AJPHEART.00409.2015/ASSET/IMAGES/LARGE/ZH40231517380003.JPEG
10. Gunning WT, Stepkowski SM, Kramer PM, Karabin BL, Grubb BP. Inflammatory Biomarkers in Postural Orthostatic Tachycardia Syndrome with Elevated G-Protein-Coupled Receptor Autoantibodies. Journal of Clinical Medicine 2021, Vol 10, Page 623. 2021;10(4):623. doi:10.3390/JCM10040623
11. Stavrakis S, Elkholey K, Morris L, Niewiadomska M, Asad ZUA, Humphrey MB. Neuromodulation of Inflammation to Treat Heart Failure With Preserved Ejection Fraction: A Pilot Randomized Clinical Trial. Journal of the American Heart Association: Cardiovascular and Cerebrovascular Disease. 2022;11(3):23582. doi:10.1161/JAHA.121.023582