Postural Orthostatic Tachycardia Syndrome (POTS) is a form of dysautonomia that is estimated to impact between 1,000,000 and 3,000,000 Americans, and millions more around the world. POTS is a form of orthostatic intolerance that is associated with the presence of excessive tachycardia and many other symptoms upon standing.
Signs and Symptoms
While the diagnostic criteria focus on the abnormal heart rate increase upon standing, POTS usually presents with symptoms much more complex than a simple increase in heart rate. It is fairly common for POTS patients to have a drop in blood pressure upon standing, but some POTS patients have no change or even an increase in blood pressure upon standing.1 POTS patients often have hypovolemia (low blood volume) and high levels of plasma norepinephrine while standing, reflecting increased sympathetic nervous system activation.3 Approximately 50% of POTS patients have a small fiber neuropathy that impacts their sudomotor nerves. Many POTS patients also experience fatigue, headaches, lightheadedness, heart palpitations, exercise intolerance, nausea, diminished concentration, tremulousness (shaking), syncope (fainting), coldness or pain in the extremities, chest pain and shortness of breath.1,3,4 Patients can develop a reddish purple color in the legs upon standing, believed to be caused by blood pooling or poor circulation. The color change subsides upon returning to a reclined position.
History of POTS
The term “POTS” was coined in 1993 by a team of researchers from Mayo Clinic, led by neurologist Dr. Philip Low.8However, POTS is not a new illness; it has been known by other names throughout history, such as DaCosta’s Syndrome, Soldier’s Heart, Mitral Valve Prolapse Syndrome, Neurocirculatory Asthenia, Chronic Orthostatic Intolerance, Orthostatic Tachycardia and Postural Tachycardia Syndrome.3 In the past, it was mistakenly believed to be caused by anxiety. However, modern researchers have determined that POTS is not caused by anxiety.2,6,7 It is caused by a malfunction of the patient’s autonomic nervous system. Thankfully, in the last 20 years, researchers have gained much more insight into imbalances of the autonomic nervous system.
Who Develops POTS?
POTS can strike any age, gender or race, but it is most often seen in women of child bearing age (between the ages of 15 and 50).2 Men and boys can develop it as well, but approximately 80% of patients are female.2
What Causes POTS?
POTS is a heterogeneous (meaning it has many causes) group of disorders with similar clinical manifestations.1,4 POTS itself is not a disease; it is simply a cluster of symptoms that are frequently seen together. This is why the ‘S’ in POTS stands for “Syndrome.” Since POTS is not a disease, it is fair to say that POTS is caused by something else. However, figuring out what is causing the symptoms of POTS in each patient can be very difficult, and in many cases, patients and their doctors will not be able to determine the precise underlying cause. When doctors cannot pinpoint the underlying cause of a patient’s POTS, it may be called Primary or Idiopathic POTS.1 Idiopathic simply means “of an unknown origin.”
While researchers are still working to identify the root causes and pathology of POTS, there are several underlying diseases and conditions that are known to cause or be associated with POTS or POTS like symptoms in some patients. This is a partial list:
- Autoimmune Diseases such as Autoimmune Autonomic Ganglionopathy, Sjogren’s Syndrome, Lupus, Sarcoidosis, Antiphospholipid Syndrome;1,3, 22
- Chiari Malformation19
- Delta Storage Pool Deficiency13
- Diabetes and pre-diabetes
- Ehlers Danlos Syndrome – a collagen protein disorder than can lead to joint hypermobility and “stretchy” veins;3,12
- Genetic Disorders/Abnormalities;3
- Infections such as Mononucleosis, Epstein Barr Virus, Lyme Disease, extra-pulmonary Mycoplasma pneumonia and Hepatitis C;1,2,3,4,10,11
- Multiple Sclerosis;14
- Mitochondrial Diseases;15
- Mast Cell Activation Disorders;3
- Paraneoplastic Syndrome – rare small tumors of the lung, ovary, breast and pancreas that produce antibodies;1
- Toxicity from alcoholism, chemotherapy and heavy metal poisoning.1
- Traumas, pregnancy or surgery;1,2,3
- Vitamin Deficiencies/Anemia;
Currently, there is no cure for POTS, however researchers believe that some patients will see an improvement in symptoms over time. Detailed long term follow up studies on the course of POTS are sparse, but Dysautonomia International is working with researchers to begin to collect long-term follow up data. With proper lifestyle adjustments, exercise, diet and medical treatments, many patients see an improvement in their quality of life.1 If an underlying cause can be identified, and if that cause is treatable, the POTS symptoms may subside. While the prognosis is good for most patients, researchers have noted that some patients will not improve and may actually worsen over time.1
The longest follow-up study done to date comes from Mayo Clinic.20 Mayo Clinic did a survey of their pediatric POTS patients seen between 2003 and 2010. Of those who responded to the survey, 18.2% reported a complete resolution of their POTS symptoms, while 52.8% reported persistent but improved symptoms. Male patients were twice as likely to report recovery. The average survey respondent had been diagnosed for about 5 years. Both patients who fully recovered and those who did not had mental health scores similar to the national norm.
1. Postural Tachycardia Syndrome. Blair P. Grubb, Circulation. 2008; 117: 2814-2817.
2. National Institute of Health, Neurological Institute of Neurological Disorders and Stroke, Postural Tachycardia Syndrome Information Page.
3. The Postural Tachycardia Syndrome (POTS): Pathophysiology, Diagnosis & Management. Satish R Raj, MD MSCI, Indian Pacing Electrophysiol J. 2006 April-Jun; 6(2): 84-99.
4. Consensus statement on the definition of orthostatic hypotension, neurally mediated syncope and the postural tachycardia syndrome. Autonomic Neuroscience: Basic and Clinical 161 (2011) 46-48.
5. Postural tachycardia in children and adolescents: what is abnormal? Singer W, Sletten DM, Opfer-Gehrking TL, Brands CK, Fischer PR, Low PA, J Pediatr. 2012 Feb;160(2):222-6. Epub 2011 Oct 11.
6. Excessive heart rate response to orthostatic stress in postural tachycardia syndrome is not caused by anxiety; Masuki S, Eisenach JH, Johnson C et al. Journal of Applied Physiology 2006; 102: 1134-42.
7. Experimental induction of panic-like symptoms in patients with postural tachycardia syndrome; Khurana RK, Clinical Autonomic Research 2006; 16: 371-7.
8. Idiopathic postural orthostatic tachycardia syndrome: an attenuated form of acute pandysautonomia. Schondorf R, Low PA; Neurology 1993 Jan;43(1):132-7.
9. Increased plasma angiotensin II in postural tachycardia syndrome (POTS) is related to reduced blood flow and blood volume. Stewart JM, Glover JL, Medow MS. Clin Sci (Lond). 2006 Feb;110(2):255-63.
10. Postural orthostatic tachycardia syndrome following Lyme disease. Kanjwal K, Karabin B, Kanjwal Y, Grubb BP; Cardiol J. 2011;18(1):63-6.
11. Postural Orthostatic Tachycardia Syndrome Associated With Mycoplasma pneumoniae. Kasmani, Rahil MD, MRCP; Elkambergy, Hossam MD; Okoli, Kelechi MD, MRCP; Infectious Diseases in Clinical Practice: September 2009 – Volume 17 – Issue 5 – pp 342-343.
12. Dysautonomia in the joint hypermobility syndrome. Gazit Y, Nahir AM, Grahame R, Jacob G. Am J Med. 2003 Jul;115(1):33-40.
13. Platelet Delta Granule and Serotonin Concentrations Are Decreased in Patients with Postural Orthostatic Tachycardia Syndrome Presented at the 51st Annual Meeting of the American Society of Hematology, December 6, 2009.
14. Autonomic dysfunction presenting as postural orthostatic tachycardia syndrome in patients with multiple sclerosis. Kanjwal K, Karabin B, Kanjwal Y, Grubb BP. Int J Med Sci, 2010 Mar 11;7:62-7.
15. Autonomic dysfunction presenting as orthostatic intolerance in patients suffering from mitochondrial cytopathy. Kanjwal K, Karabin B, Kanjwal Y, Grubb BP. Clin Cardiol. 2010 Oct;33(10):626-9.
16. Iron insufficiency and hypovitaminosis D in adolescents with chronic fatigue and orthostatic intolerance. Antiel RM, Caudill JS, Burkhardt BE, Brands CK, Fischer PR. South Med J. 2011 Aug;104(8):609-11.
17. Autonomic function tests in cases of chronic severe anaemia. Nand N, Mohan R, Khosla SN, Kumar P. J Assoc Physicians India. 1989 Aug;37(8):508-10.
18. Postural tachycardia syndrome after vaccination with Gardasil. Blitshteyn, Svetlana. European Journal of Neurology; 2010; Letter to the Editor
20. Long-term outcomes of adolescent-onset postural orthostatic tachycardia syndrome. S.J. Kizilbash, S.P. Ahrens, R. Bhatia, J.M. Killian, S. A. Kimmes, E.E. Knoebel, P. Muppa, A.L. Weaver, P.R. Fischer. Clin. Auton. Res. October 2013. Abstract presented at the 24th International Symposium on the Autonomic Nervous System.
21. Estimation of sleep disturbances using wrist actigraphy in patients with postural tachycardia syndrome. Bagai K1, Wakwe CI, Malow B, Black BK, Biaggioni I, Paranjape SY, Orozco C, Raj SR. Auton Neurosci. Oct 2013; 177(2): 260?265.
22. POTS – A World Tour, lecture presented by Dr. Satish Raj during the 2013 Dysautonomia International Conference.
23. Postural tachycardia syndrome (POTS) and other autonomic disorders in antiphospholipid (Hughes) syndrome (APS). Schofield J1, Blitshteyn S, Shoenfeld Y, Hughes G. Lupus. 2014 Feb 25.