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| '''Postural orthostatic tachycardia syndrome''' (or '''POTS''') is a condition of ] in which a change from the ] to an upright position causes an abnormally large increase in heart rate, often, but not always accompanied by a fall in blood pressure. Patients with POTS |
'''Postural orthostatic tachycardia syndrome''' (or '''POTS''') is a condition of ], and more specifically, ], in which a change from the ] to an upright position causes an abnormally large increase in heart rate, often, but not always, accompanied by a fall in blood pressure. Patients with POTS have problems maintaining homeostasis when changing position, i.e. moving from one chair to another or reaching above their heads. Many patients also experience symptoms when stationary or even while lying down. | ||
| ==History== | |||
| The syndrome was identified as such by Schondorf and Low in ]. Similar symptoms were collectively described as "] ]" by Fouad in ]. A comprehensive historical account is given by Grubb (2002). | |||
| POTS was first named and identified by Schondorf and Low in ], however the syndrome has been described in medical studies dating back to at least 1940. Hypotension associated with POTS has been previously described as the "hyperadrenergic syndrome" by Streeten and "idiopathic hypovolemia" by Fouad. | |||
| Symptoms include an abnormally large increase in heart rate upon standing, ], extreme ], ], ], ], ] and impaired concentration. Patients may exhibit mild ] while standing, but most do not experience ]. Patients with POTS may frequently be misdiagnosed as having ], ] or chronic ] (Grubb, 2002). POTS patients are usually significantly debilitated by their symptoms. | |||
| ==Symptoms== | |||
| The hallmark symptom of POTS is an increase in heart rate from the supine to upright position of more than 30 beats per minute or to a heart rate greater than 120 beats per minute within 10 minutes of head-up tilt. This tachycardic response is often accompanied by a profound decrease in blood pressure and a wide variety of symptoms associated with hypotension including: | |||
| * ] | |||
| * ] | |||
| * extreme ] | |||
| * ] or presyncope | |||
| * exercise intolerance | |||
| Chronic or acute hypoperfusion of tissues and organs in the upper parts of the body are thought to cause the following symptoms: | |||
| * ] | |||
| * ] and discomfort | |||
| * ] | |||
| * ] | |||
| * tremulousness | |||
| * visual disturbances | |||
| * ] | |||
| * cold extremities | |||
| Autonomic dysfunction is thought to cause additional gastrointestinal symptoms: | |||
| * ] | |||
| * ] or discomfort | |||
| * ] | |||
| * ] | |||
| * ] | |||
| * ] | |||
| Cerebral hypoperfusion can cause cognitive and emotive difficulties: | |||
| * impaired concentration | |||
| * brain fog | |||
| * difficulty finding the right word | |||
| * ] | |||
| * decreased mental stamina | |||
| * ] | |||
| * sleep disorders | |||
| Inappropriate levels of ] and ] lead to anxiety-like symptoms: | |||
| * ] | |||
| * ] | |||
| * feelings of fear | |||
| * over-stimulation | |||
| * ] | |||
| * ] | |||
| Symptoms of POTS overlap considerably with those of ], and a misdiagnosis of an anxiety disorder is not uncommon. | |||
| ==Associated Conditions== | |||
| POTS is often accompanied by ], also called "neurally mediated hypotension" (NMH) or "neurocardiogenic syncope" (NCS). Vasovagal syncope is a fainting reflex due to a profound drop in blood pressure. Autonomic disfunction that occurs with these disorders causes blood to inappropriately pool in the limbs away from the heart, lungs, and brain. The combination of misdirected bloodflow and hypotension will invoke syncope. Tachycardia associated with POTS may be a cardiac response to restore cerebral hypoperfusion. | |||
| POTS may be a cause of ] in patients that exhibit signs of ]. Treating POTS will greatly improve or even eliminate disabling fatigue for these patients. | |||
| Some patients with ] complain of dysautonomia-related symptoms. Treating these patients for POTS will often improve myofascial and neuropathic pain. | |||
| Autonomic dysfunction is most likely responsible for ] in many patients as well. | |||
| ==Diagnosis== | |||
| POTS is often difficult to diagnose. A routine physical examination and standard blood tests usually will not indicate POTS. A ] is vital to diagnosing POTS although all symptoms must be considered before a final diagnosis is made. A test to rule out ] is usually performed. Other tests such as multi-site photoplethysmography a measure of how well the blood vessels constrict can also be useful. A blood test may be performed to verify abnormally high levels of ] usually present in POTS patients (Raj, 2006). ] must also be considered as there is an overlap in symptoms of IST and POTS. About 80 percent of patients diagnosed with POTS are female and of ] age. | POTS is often difficult to diagnose. A routine physical examination and standard blood tests usually will not indicate POTS. A ] is vital to diagnosing POTS although all symptoms must be considered before a final diagnosis is made. A test to rule out ] is usually performed. Other tests such as multi-site photoplethysmography a measure of how well the blood vessels constrict can also be useful. A blood test may be performed to verify abnormally high levels of ] usually present in POTS patients (Raj, 2006). ] must also be considered as there is an overlap in symptoms of IST and POTS. About 80 percent of patients diagnosed with POTS are female and of ] age. | ||
| ==Causes== | |||
| The causes of POTS are not fully known. It is generally believed to be a case of ]. Its onset is sometimes associated with an inflammatory condition such as a viral infection. An overlap of symptoms with ] may suggest a pathological overlap in some cases. | The causes of POTS are not fully known. It is generally believed to be a case of ]. Its onset is sometimes associated with an inflammatory condition such as a viral infection. An overlap of symptoms with ] may suggest a pathological overlap in some cases. | ||
Revision as of 23:33, 29 March 2008
Postural orthostatic tachycardia syndrome (or POTS) is a condition of dysautonomia, and more specifically, orthostatic intolerance, in which a change from the supine position to an upright position causes an abnormally large increase in heart rate, often, but not always, accompanied by a fall in blood pressure. Patients with POTS have problems maintaining homeostasis when changing position, i.e. moving from one chair to another or reaching above their heads. Many patients also experience symptoms when stationary or even while lying down.
History
POTS was first named and identified by Schondorf and Low in 1993, however the syndrome has been described in medical studies dating back to at least 1940. Hypotension associated with POTS has been previously described as the "hyperadrenergic syndrome" by Streeten and "idiopathic hypovolemia" by Fouad.
Symptoms
The hallmark symptom of POTS is an increase in heart rate from the supine to upright position of more than 30 beats per minute or to a heart rate greater than 120 beats per minute within 10 minutes of head-up tilt. This tachycardic response is often accompanied by a profound decrease in blood pressure and a wide variety of symptoms associated with hypotension including:
- lightheadedness
- dizziness
- extreme fatigue
- syncope or presyncope
- exercise intolerance
Chronic or acute hypoperfusion of tissues and organs in the upper parts of the body are thought to cause the following symptoms:
- dyspnea
- chest pain and discomfort
- muscle weakness
- headache
- tremulousness
- visual disturbances
- disorientation
- cold extremities
Autonomic dysfunction is thought to cause additional gastrointestinal symptoms:
- nausea
- abdominal pain or discomfort
- vomiting
- bloating
- diarrhea
- constipation
Cerebral hypoperfusion can cause cognitive and emotive difficulties:
- impaired concentration
- brain fog
- difficulty finding the right word
- depression
- decreased mental stamina
- burnout
- sleep disorders
Inappropriate levels of epinephrine and norepinephrine lead to anxiety-like symptoms:
- flushing
- nervousness
- feelings of fear
- over-stimulation
- chills
- overheating
Symptoms of POTS overlap considerably with those of generalized anxiety disorder, and a misdiagnosis of an anxiety disorder is not uncommon.
Associated Conditions
POTS is often accompanied by vasovagal syncope, also called "neurally mediated hypotension" (NMH) or "neurocardiogenic syncope" (NCS). Vasovagal syncope is a fainting reflex due to a profound drop in blood pressure. Autonomic disfunction that occurs with these disorders causes blood to inappropriately pool in the limbs away from the heart, lungs, and brain. The combination of misdirected bloodflow and hypotension will invoke syncope. Tachycardia associated with POTS may be a cardiac response to restore cerebral hypoperfusion.
POTS may be a cause of chronic fatigue syndrome in patients that exhibit signs of orthostatic intolerance. Treating POTS will greatly improve or even eliminate disabling fatigue for these patients.
Some patients with fibromyalgia complain of dysautonomia-related symptoms. Treating these patients for POTS will often improve myofascial and neuropathic pain.
Autonomic dysfunction is most likely responsible for irritable bowel syndrome in many patients as well.
Diagnosis
POTS is often difficult to diagnose. A routine physical examination and standard blood tests usually will not indicate POTS. A tilt table test is vital to diagnosing POTS although all symptoms must be considered before a final diagnosis is made. A test to rule out pheochromocytoma is usually performed. Other tests such as multi-site photoplethysmography a measure of how well the blood vessels constrict can also be useful. A blood test may be performed to verify abnormally high levels of norepinephrine usually present in POTS patients (Raj, 2006). Inappropriate sinus tachycardia must also be considered as there is an overlap in symptoms of IST and POTS. About 80 percent of patients diagnosed with POTS are female and of menstruating age.
Causes
The causes of POTS are not fully known. It is generally believed to be a case of dysautonomia. Its onset is sometimes associated with an inflammatory condition such as a viral infection. An overlap of symptoms with chronic fatigue syndrome may suggest a pathological overlap in some cases.
References
- Schondorf R, Low PA. Idiopathic postural orthostatic tachycardia syndrome: an attenuated form of acute pandysdautonomia? Neurology. 1993;43:132-137. (PMID: 8423877)
- Fouad FM, Tadena-Thome L, Braro EL et al: Idiopathic hypovolemia. Ann Intern Med. 1986; 104:298-303. (PMID: 3511818)
- Grubb, BP. The Postural Tachycardia Syndrome: a Brief Review of Etiology, Diagnosis and Treatment. Hellenic J Cardiol. 2002;43:47-52.
- Raj, SR. The Postural Tachycardia Syndrome (POTS): Pathophysiology, Diagnosis & Management. Indian Pacing and Electrophysiology Journal (ISSN 0972-6292). 2006; 6(2): 84-99. online
- Newton et al: Symptoms of autonomic dysfunction in chronic fatigue syndrome. QJM 2007 Aug;100(8):519-26 Epub 2007 Jul 7
External links
- Dysautonomia Information Network (aka POTS Place)
- Dysautonomia Youth Network of America, Inc.
- Dysautonomia Support Network (aka POTS Support Network)
- National Dysautonomia Research Foundation (NDRF)
- POTS, Patient's Report {aka POTSweb)