Postural Orthostatic Tachycardia Syndrome Summary
|Postural Orthostatic Tachycardia Syndrome (POTS) is a form of dysautonomia. POTS is a subset of orthostatic intolerance that is associated with the presence of excessive tachycardia on standing. The current diagnostic criteria for POTS is a heart rate increase of 30 beats per minute (bpm) or more, or over 120 bpm, within the first 10 minutes of standing. In children and adolescents, a revised standard of a 40 bpm or more increase has recently been adopted. POTS is often diagnosed by a Tilt Table Test, but if such testing is not available, POTS can be diagnosed with bedside measurements of heart rate and blood pressure taken in the supine (laying down) and standing up position at 2, 5 and 10 minute intervals.
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 noticeable 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 Many POTS patients also experience fatigue, headaches, lightheadedness, heart palpitations, exercise intolerance, nausea, diminished concentration, tremulousness (shaking), syncope (fainting), coldness or pain in the extremeties, chest pain and shortness of breath.
Some patients have fairly mild symptoms and can continue with normal work, school, social and recreational activities. For others, symptoms may be so severe that normal life activities, such as bathing, housework, eating, sitting upright, walking or standing can be significantly limited. Physicians with expertise in treating POTS have compared the functional impairment seen in POTS patients to the impairment seen in chronic obstructive pulmonary disease (COPD) or congestive heart failure.1 They note that while the symptoms are real and can severely limit a patient’s ability to function, POTS patients are too often misdiagnosed as having severe anxiety or panic disorder. Modern research has shown that POTS patients are similarly or even less likely to suffer from anxiety or panic disorder than the general public.
Who Develops POTS?
What Causes POTS?
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:
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