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Disease Profile

Postural orthostatic tachycardia syndrome

Prevalence
Prevalence estimates on Rare Medical Network websites are calculated based on data available from numerous sources, including US and European government statistics, the NIH, Orphanet, and published epidemiologic studies. Rare disease population data is recognized to be highly variable, and based on a wide variety of source data and methodologies, so the prevalence data on this site should be assumed to be estimated and cannot be considered to be absolutely correct.

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US Estimated

Europe Estimated

Age of onset

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ICD-10

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Inheritance

Autosomal dominant A pathogenic variant in only one gene copy in each cell is sufficient to cause an autosomal dominant disease.

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Autosomal recessive Pathogenic variants in both copies of each gene of the chromosome are needed to cause an autosomal recessive disease and observe the mutant phenotype.

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X-linked
dominant X-linked dominant inheritance, sometimes referred to as X-linked dominance, is a mode of genetic inheritance by which a dominant gene is carried on the X chromosome.

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X-linked
recessive Pathogenic variants in both copies of a gene on the X chromosome cause an X-linked recessive disorder.

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Mitochondrial or multigenic Mitochondrial genetic disorders can be caused by changes (mutations) in either the mitochondrial DNA or nuclear DNA that lead to dysfunction of the mitochondria and inadequate production of energy.

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Multigenic or multifactor Inheritance involving many factors, of which at least one is genetic but none is of overwhelming importance, as in the causation of a disease by multiple genetic and environmental factors.

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Not applicable

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Other names (AKA)

POTS; Postural tachycardia syndrome; Chronic othostatic intolerance

Categories

Heart Diseases; RDCRN

Summary

Postural orthostatic tachycardia syndrome (POTS) is a condition characterized by too little blood returning to the heart when moving from a lying down to a standing up position (orthostatic intolerance). Orthostatic Intolerance causes lightheadedness or fainting that can be eased by lying back down. In people with POTS, these symptoms are also accompanied by a rapid increase in heart rate.[1] Although POTS can affect men and women of all ages, most cases are diagnosed in women between the ages of 15 and 50.[1] The cause of POTS is unknown. However, episodes often begin after major surgery, trauma, or a viral illness. In women, episodes may also begin after pregnancy and the symptoms may worsen or the number of episodes may increase right before menstruation.[1][2] The goal of treatment is to increase blood flow and improve circulatory problems that may be causing POTS.[1][3][4]

Symptoms

Postural orthostatic tachycardia syndrome (POTS) is characterized by orthostatic intolerance and a rapid increase in heart rate.[1] People with POTS often have hypovolemia (low blood volume) and high levels of plasma norepinephrine while standing, reflecting increased sympathetic nervous system activation. Approximately half of affected people have a small fiber neuropathy that impacts their sudomotor nerves (those that activate the sweat glands). Some individuals develop a reddish-purple color in the legs when they stand, thought to be due to blood pooling or poor circulation. The color change subsides upon returning to a reclined position.[5]

Other symptoms that have been reported in people with POTS include:[2][4][3][5]

  • Blurred vision
  • Lightheadedness, dizziness or fainting
  • Heart palpitations
  • Headache
  • Poor concentration
  • Tiredness
  • Gastrointestinal symptoms (for example, nausea, cramps, bloating, constipation, diarrhea)
  • Shortness of breath
  • Head, neck or chest discomfort
  • Weakness
  • Sleep disorders
  • Difficulty exercising
  • Anxiety
  • Coldness or pain in the extremities

While the underlying causes of POTS are still being studied, a number of underlying conditions have been associated with POTS or with symptoms seen in POTS.[5] More information about these conditions can be viewed on Dysautonomia International's website.

Cause

The cause of postural orthostatic tachycardia syndrome (POTS) is poorly understood. However, episodes often begin after a pregnancy, major surgery, trauma, or a viral illness and may increase right before a menstrual period.[1]

Many researchers suspect that the condition may have more than one cause. The following abnormalities can be associated with POTS and may play a role in it's development:[1][4]

  • Impaired function of nerves in certain muscles, especially those in the legs and feet.
  • An abnormal decrease in the amount of blood circulating in the body (caused, for example, by blood pooling in the abdomen and legs).
  • Too little blood returning to the heart when moving from a lying down to a standing up position.
  • Changes in heart and blood vessel function.
  • Abnormal regulation of blood pressure.
  • Increased fight-or-flight response.

Although most cases of POTS occur in people with no history of the condition in their family, some affected people report a family history of orthostatic intolerance. This suggests that in some cases, genetic factors may play a role in the development of POTS. Some studies also suggest that normal variations (polymorphisms) in certain genes (NOS3, ADRB2) may be associated with an increased risk of developing the condition. A mutation in the norepinephrine transporter gene (SLC6A2) has been found in one family with POTS.[4][3]

Diagnosis

A diagnosis of postural orthostatic tachycardia syndrome (POTS) is often suspected based on characteristic signs and symptoms. Additional testing can then be ordered to confirm the diagnosis. Many physicians will conduct a physical examination that includes measurement of blood pressure and heart rate while lying, sitting, and standing. A tilt table test, in which blood pressure and heart rate are checked while a person is safely moved from a lying down position to standing upright, may also be recommended.[2][4]

Treatment

Because research suggests that postural orthostatic tachycardia syndrome (POTS) has a variety of causes, no single treatment is effective for all affected people. Management of POTS aims to improve low blood pressure and problems with the heart and blood vessels that may be causing the condition. In some people with POTS, simple lifestyle changes such as adding extra salt to the diet, drinking more fluids, exercising, and avoiding factors that make the condition worse, may lessen symptoms. Certain medications may also be helpful in treating POTS.[1][2][4] Some researches suggest volume repletion and fludrocortisone (0.05 to 0.2 mg per day) as the first line of therapy. Some patients may benefit from midodrine or beta blocking agents. Other treatment options remain under investigation, and further confirmation of benefit is needed before they can be recommended.[4]

Organizations

Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

Organizations Supporting this Disease

    Learn more

    These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

    Where to Start

      In-Depth Information

      • Medscape Reference provides information on this topic. You may need to register to view the medical textbook, but registration is free.
      • PubMed is a searchable database of medical literature and lists journal articles that discuss Postural orthostatic tachycardia syndrome. Click on the link to view a sample search on this topic.

        References

        1. NINDS Postural Tachycardia Syndrome Information Page. National Institute of Neurological Disorders and Stroke. December 2015; https://www.ninds.nih.gov/Disorders/All-Disorders/Postural-Tachycardia-Syndrome-Information-Page.
        2. Postural Tachycardia Syndrome (POTS). Autonomic Disorders Consortium. https://www.rarediseasesnetwork.org/ARDCRC/patients/learnmore/POTS/index.htm.
        3. Mohini Gurme, MD. Idiopathic Orthostatic Hypotension and other Autonomic Failure Syndromes. Medscape Reference. November 2015; https://emedicine.medscape.com/article/1154266-overview.
        4. Kaufmann H & Freeman R. Postural tachycardia syndrome. UpToDate. March 2015; https://www.uptodate.com/contents/postural-tachycardia-syndrome.
        5. Postural Orthostatic Tachycardia Syndrome. Dysautonomia International. https://www.dysautonomiainternational.org/page.php?ID=30. Accessed 3/6/2016.
        6. Kimpinski K, Figueroa JJ, Singer W, Sletten DM, Iodice V, Sandroni P, Fischer PR, Opfer-Gehrking TL, Gehrking JA, Low PA. A prospective, 1-year follow-up study of postural tachycardia syndrome. Mayo Clin Proc. August 2012; 87(8):746-752.
        7. What is dysautonomia?. Dysautonomia International. 2012; https://www.dysautonomiainternational.org/page.php?ID=34.
        8. Autonomic Disorders Information for Patients and Families. Autonomic Disorders Consortium. https://www.rarediseasesnetwork.org/cms/autonomic/Learn-More/Disorder-Definitions.
        9. A K Agarwal, R Garg, A Ritch, and P Sarkar. Postural orthostatic tachycardia syndrome. Postgrad Med J. July, 2007; 83(981):478-480. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2600095/#__sec1title.

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