Postural orthostatic tachycardia syndrome

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.

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:

• 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.

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.

Most cases of postural orthostatic tachycardia syndrome (POTS) do not appear to be inherited. However, some people with POTS do report a family history of orthostatic intolerance. This suggests that inherited factors may play a role in the development of POTS in some families.

Yes. It is possible for a person to have both POTS and basilar migraine. A 2011 study by Khurana RK et al., found that two out of three people with POTS have orthostatic headache (especially those under age 30) and nearly all had migraines. However, people with migraines may also have a higher risk for syncope (fainting spells) and orthostatic intolerance without clear signs of autonomic nervous system dysfunction. We strongly recommend that you discuss your concerns regarding her diagnosis with a healthcare professional.

The long-term outlook (prognosis) for people with postural orthostatic tachycardia syndrome (POTS) is generally good, but may be poor in some cases. While many people have fairly mild symptoms and can continue with regular daily activities, others may be severely affected with limited abilities. Some people with POTS report significantly improved symptoms within a year, while others don't improve with treatment and may worsen over time.

With proper lifestyle changes (for example, exercise and diet) and medical treatments, many affected people see an improvement in symptoms and quality of life. In some cases, people with POTS may even become symptom-free over time.

According to Dysautonomia International, POTS is estimated to affect 1 out of 100 teenagers and, including adult patients, a total of 1 million to 3 million Americans. It is most frequently seen in young women, often less than 35 years of age. The female to male ratio is 5:1. It is common after stress such as sepsis, pregnancy, fever, surgery or trauma.

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. 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.

The Autonomic Rare Diseases Clinical Research Consortium is a team of doctors, nurses, research coordinators, and research labs throughout the U.S., working together to improve the lives of people with many types of autonomic disorders through research. The Autonomic Rare Diseases Clinical Research Consortium has a registry for patients who wish to be contacted about clinical research opportunities.

For more information on the registry see: RDCRN Autonomic Disorders Consortium Contact Registry

Dysautonomia International offers an information page on Postural orthostatic tachycardia syndrome. Please click on the link to access this resource.