Postural orthostatic tachycardia syndrome: Difference between revisions

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Latest revision as of 12:45, 14 June 2020

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor-In-Chief: Cafer Zorkun, M.D., Ph.D. [2]

For patient information click here

Synonyms and Keywords: postural tachycardia syndrome, POTS

Overview

Postural orthostatic tachycardia syndrome is a poorly understood autonomic disturbance, which manifests as a change in Heart Rate>30BPM upon the patient standing erect from supine or a head-up tilt without underlying orthostatic hypotension. Sympathetic hyperstimulation secondary to a fall in vascular tone and cerebral hypoperfusion leads to transient symptoms such as inappropriate sinus tachycardia, chronic fatigue and dizziness. Many patients also report non specific symptoms such as GI disturbances and sleep disturbances. This incapacitating syndrome has no known etiology, with theories listing post infectious, autoimmune, cardiac deconditioning and emotional states as possible factors. Antinuclear antibodies along with elevated ganglionic, adrenergic, and muscarinic acetylcholine receptor antibodies have all been reported. Diagnosis involves eliminating all primary cardiac, endocrine, neuropathic and psychiatric causes of postural tachycardia. Treatment is multimodal and consists of patient education, volume replenishment, physical countermaneuvers (graded stockings) and pharmacological therapy.

Historical Perspective

POTS was not identified as a separate entity until 1982, and until then was considered as part of a larger collection known as "irritable heart" syndrome or "Da Costa syndrome" named after Jacob Da Costa. Jacob Mendes Da Costa worked at Satterlee Hospital in Philadelphia. He studied over 400 patients with non-specific cardiac complaints during the American civil war. He recognized a pattern between the patients and named the collection of symptoms "irritable heart" in 1862. By 1871 he compiled and published his results. "irritable heart" encompassed many distinct conditions including POTS and psychiatric conditions which were later separately identified. The condition was described in 1993 by Ronald Schondorf and Phillip A. Low of the Mayo Clinic.

Pathophysiology

The pathophysiology is poorly understood and multifactorial. There are many reported findings across patients with POTS, which are interlinked and present in a variety of combinations, making it difficult to pinpoint one as primary and thereby causative. Evidence suggests that the etiology involves:

Distal denervation with preservation of cardiac innervation. Studies have shown reduced response to stimulation in the lower limbs in patients with POTS. This is thought to be due to a neuropathy arising post infection, however there is also evidence of autoantibodies against the ganglionic acetylcholine receptor, lending support for an autoimmune origin of the disease.
Hypovolemia or possible increased baroreceptor sensitivity. The most significant finding to lead to this theory is the symptomatic relief experienced by patients after infusion of saline, along with findings that suggest a predisposition to volume constriction in these patients. Conversely, constant and prolonged sympathetic activation could cause a mild reduction in circulating volume.
abnormal venous function causing decreased preload on standing. Evidence of venous pooling and therefore reduced venous return has been reported in some studies, along with the reduction of symptoms with the use of compression trousers. This could be due to the denervation of the distal limbs or the increased release of vasodilators.
cardiovasclar deconditioning
hyperadrenergic state (increase in sympathetic activity)
Post infectious etiology.
genetic factors

Differentiating POTS from Other Disorders

Epidemiology and Demographics

POTS is believed to be the most prevalent type of orthostatic intolerance. One study approximates the prevalence to be 500,000 americans. It is also commonly seen in younger patients (<45 years) who present to autonomic dysfunction clinics. Women are more likely to suffer from this disorder, with the ratio between genders being 4-5:1. The cause of this is unknown as yet. There is no racial predilection to this disorder.

Risk Factors

There are no clear risk factors for POTS, however a small minority of patients with the condition have been noted to have a mutated norepinephrine transporter gene. There is increasing evidence of association between POTS and joint hypermobility disorders such as Ehlers-Danlos syndrome. POTS may develop after a viral illness such as mononucleosis, and is also reported to develop after illnesses requiring prolonged hospitalisation and immobility. Patients suffering from celiac disease and Sjogrens syndrome may be at higher risk for developing POTS as well.

Natural History, Complications and Prognosis

Most patients present young, and prognosis is generally favourable.

Diagnosis

Treatment

ACC/AHA/ESC Treatment Guidelines | Medical Therapy | Cost-Effectiveness of Therapy | Future or Investigational Therapies

Template:WikiDoc Sources

@@ Line 7: / Line 7: @@
 '''''Synonyms and Keywords:''''' postural tachycardia syndrome, POTS
-==Overview==
+==[[Postural orthostatic tachycardia syndrome overview|Overview]]==
+Postural orthostatic tachycardia syndrome is a poorly understood autonomic disturbance, which manifests as a change in Heart Rate>30BPM upon the patient standing erect from supine or a head-up tilt without underlying orthostatic hypotension. Sympathetic hyperstimulation secondary to a fall in vascular tone and cerebral hypoperfusion leads to transient symptoms such as inappropriate sinus tachycardia, chronic fatigue and dizziness. Many patients also report non specific symptoms such as GI disturbances and sleep disturbances. This incapacitating syndrome has no known etiology, with theories listing post infectious, autoimmune, cardiac deconditioning and emotional states as possible factors. Antinuclear antibodies along with elevated ganglionic, adrenergic, and muscarinic acetylcholine receptor antibodies have all been reported. Diagnosis involves eliminating all primary cardiac, endocrine, neuropathic and psychiatric causes of postural tachycardia. Treatment is multimodal and consists of patient education, volume replenishment, physical countermaneuvers (graded stockings) and pharmacological therapy.
-==Historical Perspective==
+==[[Postural orthostatic tachycardia syndrome historical perspective|Historical Perspective]]==
+POTS was not identified as a separate entity until 1982, and until then was considered as part of a larger collection known as "irritable heart" syndrome or "Da Costa syndrome" named after Jacob Da Costa. Jacob Mendes Da Costa worked at Satterlee Hospital in Philadelphia. He studied over 400 patients with non-specific cardiac complaints during the American civil war. He recognized a pattern between the patients and named the collection of symptoms "irritable heart" in 1862. By 1871 he compiled and published his results. "irritable heart" encompassed many distinct conditions including POTS and psychiatric conditions which were later separately identified. The condition was described in 1993 by Ronald Schondorf and Phillip A. Low of the Mayo Clinic.
-==Pathophysiology==
+==[[Postural orthostatic tachycardia syndrome pathophysiology|Pathophysiology]]==
+The pathophysiology is poorly understood and multifactorial. There are many reported findings across patients with POTS, which are interlinked and present in a variety of combinations, making it difficult to pinpoint one as primary and thereby causative. Evidence suggests that the etiology involves:
-==Differentiating POTS from Other Disorders==
-==Risk Factors==
-==Natural History, Complications, Prognosis==
+* Distal denervation with preservation of cardiac innervation. Studies have shown reduced response to stimulation in the lower limbs in patients with POTS. This is thought to be due to a neuropathy arising post infection, however there is also evidence of autoantibodies against the ganglionic acetylcholine receptor, lending support for an autoimmune origin of the disease.
+* Hypovolemia or possible increased baroreceptor sensitivity. The most significant finding to lead to this theory is the symptomatic relief experienced by patients after infusion of saline, along with findings that suggest a predisposition to volume constriction in these patients. Conversely, constant and prolonged sympathetic activation could cause a mild reduction in circulating volume.
+* abnormal venous function causing decreased preload on standing. Evidence of venous pooling and therefore reduced venous return has been reported in some studies, along with the reduction of symptoms with the use of compression trousers. This could be due to the denervation of the distal limbs or the increased release of vasodilators.
+* cardiovasclar deconditioning
+* hyperadrenergic state (increase in sympathetic activity)
+*Post infectious etiology.
+* genetic factors<br />
+==[[Postural orthostatic tachycardia syndrome differential diagnosis|Differentiating POTS from Other Disorders]]==
+<br />
+==[[Postural orthostatic tachycardia syndrome epidemiology and demographics|Epidemiology and Demographics]]==
+POTS is believed to be the most prevalent type of orthostatic intolerance. One study approximates the prevalence to be 500,000 americans. It is also commonly seen in younger patients (<45 years) who present to autonomic dysfunction clinics. Women are more likely to suffer from this disorder, with the ratio between genders being 4-5:1. The cause of this is unknown as yet. There is no racial predilection to this disorder.  <br />
+==[[Postural orthostatic tachycardia syndrome risk factors|Risk Factors]]==
+There are no clear risk factors for POTS, however a small minority of patients with the condition have been noted to have a mutated norepinephrine transporter gene. There is increasing evidence of association between POTS and joint hypermobility disorders such as Ehlers-Danlos syndrome. POTS may develop after a viral illness such as [[mononucleosis]], and is also reported to develop after illnesses requiring prolonged hospitalisation and immobility. Patients suffering from [[celiac disease]] and [[Sjögren's syndrome|Sjogrens syndrome]] may be at higher risk for developing POTS as well.
+==[[Postural orthostatic tachycardia syndrome natural history, complications and prognosis|Natural History, Complications and Prognosis]]==
+Most patients present young, and prognosis is generally favourable.
 ==Diagnosis==
-===Laboratory Studies===
-===Tilt Table Testing===
+[[Postural orthostatic tachycardia syndrome history and symptoms|History and Symptoms]] | [[Postural orthostatic tachycardia syndrome physical examination|Physical Examination]] | [[Postural orthostatic tachycardia syndrome laboratory findings|Laboratory Findings]] | [[Postural orthostatic tachycardia syndrome electrocardiogram|Electrocardiogram]] | [[Postural orthostatic tachycardia syndrome chest x ray|Chest X Ray]] | [[Postural orthostatic tachycardia syndrome echocardiography|Echocardiography]] | [[Postural orthostatic tachycardia syndrome other diagnostic studies|Other Diagnostic Studies]]
+<br />
 ==Treatment==
-There is at this time only one drug approved by the [[Food and Drug Administration|FDA]] to treat [[orthostatic intolerance]], however several classes of drugs often provide symptom control and relief. Treatments must be carefully tested due to medication sensitivity often associated with POTS patients, and each patient will respond to different therapies in different ways. Most patients will respond to some form of treatment.
-===Fludrocortisone===
-The first line of treatment for POTS is usually [[fludrocortisone]], or Florinef, a [[corticosteroid]] used to increase sodium retention and thus increase blood volume and blood pressure. An increase in sodium and water intake must coincide with fludrocortisone therapy for effective treatment. Dietary increases in sodium and sodium supplements are often used. [[Gatorade]] is also effective in providing both sodium and fluid.
-===Beta Blockers===
-[[Beta blockers]] such as [[atenolol]] and [[propanolol]] are often prescribed to treat POTS. These medications work by blocking the effects of [[epinephrine]] and [[norepinephrine]] released by the autonomic nervous system. Beta blockers also reduce sympathetic activity by blocking sympathetic impulses.
-===Midodrine===
-[[Midodrine]] (Proamatine), is approved by the U.S. [[FDA]] to treat [[orthostatic hypotension]], a condition related to POTS.  It is a stimulant that causes [[vasoconstriction]] and thereby increases [[blood pressure]] and allows more blood to return to the upper parts of the body. Use of midodrine is often discontinued due to intolerable side-effects, and it is known to cause supine hypertension (high blood pressure when lying down).
-===Antidepressants===
-Antidepressants, especially [[selective serotonin reuptake inhibitors]] (SSRIs) such as [[Prozac]], [[Zoloft]], [[Celexa]], [[Lexapro]], and [[Paxil]], can be extremely effective in re-regulating the autonomic nervous system and raising blood pressure. Some studies indicate that [[serotonin-norepinephrine reuptake inhibitor]]s (SNRIs) such as [[Effexor]] and [[Cymbalta]] are even more effective. [[Tricyclic antidepressants]], tetracyclic antidepressants, and [[monoamine oxidase inhibitors]] are also occasionally, but rarely, prescribed. A combination of two antidepressants, usually an [[SSRI]] or [[SNRI]] with [[Wellbutrin]] or [[Remeron]], is also shown to be very effective.
-===Stimulants===
-Medications used to treat [[attention deficit disorder|ADD]] and [[attention deficit hyperactivity disorder|ADHD]] such as [[Ritalin]] and [[Adderall]] are used to balance dopamine levels, increase vasoconstriction, and increase blood pressure.
-===Anxiolytics===
-Anti-anxiety medications, such as [[Xanax]], [[Ativan]], and [[Klonopin]], can be used to combat imbalances of [[adrenaline]] usually seen with POTS patients.
-===Other Medications===
-*[[Angiotensin converting enzyme inhibitors]], or ACE inhibitors, are used to increase [[vasoconstriction]], cardiac output, and sodium and water retention.
-*[[Clonidine]] can work in patients with reduced sympathetic activity. Ironically an anti-hypertensive drug, Clonidine promotes production and release of [[epinephrine]] and [[norepinephrine]].
-*[[Disopyramide]], or Norpace, is an antiarrhythmic medication that inhibits the release of [[epinephrine]] and [[norepinephrine]].
-*[[Erythropoietin]], used to treat anemia via [[intravenous infusion]], is very effective at increasing blood volume. It is seldom used, however, due to the dangers of increasing the [[hematocrit]], the inconvenience of intravenous infusion, and its prohibitively expensive cost.
-*[[Pregabalin]], or Lyrica, an [[anticonvulsant]] drug, has been shown to be especially effective in treating [[neuropathic pain]] associated with POTS. In fact, Lyrica is currently the only prescription drug approved by the FDA to treat [[fibromyalgia]]. Some POTS patients also report improvement in concentration and energy while on Lyrica.
-*[[Pseudoephedrine]] and [[phenylephrine]], over the counter [[decongestants]], increase [[vasoconstriction]] by promoting the release of [[norepinephrine]].
-*[[Pyridostigmine]], or Mestinon, inhibits the breakdown of [[acetylcholine]], promoting autonomic nervous system activity. It is especially effective in patients who exhibit symptoms of excessive sympathetic activity.
-*[[Theophylline]], a drug used to treat respiratory diseases such as [[COPD]] and [[asthma]], is occasionally prescribed at low doses for POTS patients. Theophylline increases cardiac output, increases blood pressure, and stimulates [[epinephrine]] and [[norepinephrine]] production. Due to its very narrow [[therapeutic index]], Theophylline is known to cause a wide variety of side-effects and even [[toxicity]].
-*Women who report a worsening of symptoms during [[menstruation]] will often use combined (containing both estrogen and progestin) forms of [[hormonal contraception]] to prevent hormonal changes and an aggravation of their condition.
-===Dietary Changes===
-*[[Alcohol]] has been shown to drastically exacerbate all types of [[orthostatic intolerance]] due to its [[vasodilation]] and [[dehydration]] properties. It should be avoided whenever possible because of its adverse effects and its [[interactivity]] with many of the medications prescribed to POTS patients.
-*[[Caffeine]] helps some POTS patients due to its stimulative effects, however, other patients report a worsening of symptoms with caffeine intake. Each patient should experiment to determine whether caffeine helps or hurts his or her condition.
-*Diets high in [[carbohydrates]] have been connected to impaired vasoconstrictive action. Eating foods with lower carbohydrate levels can mildly improve POTS symptoms.
-*Eating frequent, small meals can reduce gastrointestinal symptoms associated with POTS by requiring the diversion of less blood to the abdomen.
-*Patients diagnosed with POTS will usually be advised to maintain a high sodium diet in order to augment the effects of their medication regimen, especially if that regimen includes [[fludrocortisone]]. Patients should also drink plenty of fluids, with a recommended intake of at least two liters per day and as much as 500 milliliters every two hours throughout the day.
-===Physical Therapy===
-POTS symptoms can be worsened by postural asymmetries, restrictions in mobility, and areas of adverse mechanical tension in the nervous system. These physical abnormalities can be relieved with gentle manual therapies including neural mobilization (or neural tension work), myofascial release, and cranio-sacral therapy.
-===External Body Pressure===
-Pressure garments can reduce symptoms associated with [[orthostatic intolerance]] by constricting blood pressures with external body pressure. Compression hose and anti-embolism stockings, both knee and thigh-high, provide relief for many patients. For especially severe cases, military anti-shock trousers and anti-gravity suits, or g-suits can be helpful but also limiting.
-===Exercise===
+[[Postural orthostatic tachycardia syndrome treatment guidelines|ACC/AHA/ESC Treatment Guidelines]] | [[Postural orthostatic tachycardia syndrome medical therapy|Medical Therapy]] | [[Postural orthostatic tachycardia syndrome cost-effectiveness of therapy|Cost-Effectiveness of Therapy]] | [[Postural orthostatic tachycardia syndrome future or investigational therapies|Future or Investigational Therapies]]
-Exercise is very important for maintaining muscle strength and avoiding [[deconditioning]]. Though many POTS patients report difficulty exercising, some form of exercise is essential to controlling symptoms and eventually, improving the condition.
-==Resources==
-*[http://www.ndrf.org National Dysautonomia Research Foundation (NDRF)]
-*[http://www.dynakids.org Dysautonomia Youth Network of America, Inc.]
-*[http://www.potsplace.com/ Dysautonomia Information Network (aka POTS Place)]
-*[http://home.att.net/~potsweb/POTS.html POTS, Patient's Report (aka POTSweb)]
 [[Category:Cardiology]]