Postural Orthostatic Tachycardia Syndrome is a genetic disorder characterized by orthostatic intolerance—too little blood returning to the heart when moving from a lying down to standing up position. This syndrome affects 1 in 100 people, and is generally diagnosed between ages 15 and 50. It is most frequently seen in young women, less than 35 years of age. The cause of this disease is poorly understood, but researchers suspect that the syndrome may have more than one cause.
- POTS is first recognized by its common signs and symptoms, and additional testing is common to confirm diagnosis. Because POTS has a wide variety of causes, there isn’t one specific treatment. Generally, POTS is managed by improving low blood pressure and heart problems through lifestyle changes.
Recent research on POTS
Autoimmunity in postural orthostatic tachycardia syndrome: Current understanding
- (April 2018) Postural Orthostatic Tachycardia Syndrome is a disease that is defined by outward manifestation, or symptoms, rather than underlying causes. This is primarily due to the fact that very little is known about the exact cause of the disease. However, the above paper presents statistical and biochemical evidence that autoimmune disease or immune dysregulation due to a stress inducing event could be the cause of POTS in a subset of patients. It has been found that approximately 20% of POTS patients have an identifiable autoimmune disease in conjunction with their diagnosis of POTS. Other patients have reported a stressful event, such as concussion or viral illness, occurring soon before the onset of POTS symptoms. When the body is inflicted with a stressful situation or believes it has been invaded by a threat, it activates the immune system. For patients who may be more susceptible, the body can go into chronic immune activation. When the immune system is over activated and inflammatory mediator levels are high, the body will experience volume dysregulation (presented as low blood pressure), cardiovascular deconditioning (presented as an increase in resting heart rate and decrease in physical capability) and enter a hyperadrenergic state (heart palpitation). The research presented in this paper has shown that POTS patients have autoantibodies directed against targets in the autonomic nervous system. This means that the immune system is attacking the part of the nervous system that controls processes that happen automatically in the body, such as digestion and heart regulation. This link found between the immune system and the autonomic nervous system is strong evidence that an underlying autoimmune related disorder could be the cause of POTS in a subset of patients. These researchers hope to continue their research in hopes to develop a greater understanding of POTS and possibly a medicinal treatment that is more effective.
Activity and Exercise Intolerance After Concussion: Identification and Management of Postural Orthostatic Tachycardia Syndrome
- (April 2018) This article presents clinical features of POTS that may arise in some individuals post-concussion, proposes routine POTS screenings as a standard post-concussion procedure, and introduces a modification to currently established concussion exercise training programs in the presence of POTS. The researchers note that concussions can damage the cortical and subcortical regions of the brain. These regions are important in autonomic functions (the processes in the body that happen automatically or without intentional thought) such as cardiovascular regulation. It has been found that patients that have experienced severe concussion may impair these areas and thus develop POTS. They have found that the exercise protocol created by the Children’s Hospital of Philadelphia, CHOP POTS exercise program, available through the Dysautonomia International Web site, is a highly effective treatment for POTS due to its gradual increase into high activity exercise. In this way, the heart can become stronger so that it can better regulate blood flow around the body.
Angiotensin II Type 1 Receptor Autoantibodies in Postural Tachycardia Syndrome
- (April 2018) This study determined that most patients with POTS harbor an activating autoantibody for angiotension II type 1. This autoantibody, along with two others, seems to be creating cardiac instability in POTS patients. The evidence found in this study help to validate the claim that POTS could be caused by an autoimmune response. This information could be important for determining a better medicinal treatment for POTS, but because the evidence for the study was done outside the body (in vitro), there will have to be further research done inside the body (in vivo) to determine if immunotherapy could be utilized to help control POTS symptoms.
Efficacy of Propranolol, Bisoprolol, and Pyridostigmine for Postural Tachycardia Syndrome: a Randomized Clinical Trial
- (March 2018) This clinical trial compared four treatment options typically prescribed to POTS patients to determine the efficacy of sustained medical treatment. The randomized clinical trial ran for a 3 month period and included four groups of four varying treatment option. The first group was treated with only propranolol, a beta blocker that typically helps with uneven heartbeat. The second group was treated with bisoprolol, a different beta blocker that works by relaxing blood vessels and slowing heart rate to improve blood pressure. The third group was treated with a combination of propranolol and pyridostigmine. Pyridostigmine is a muscle strengthener to help blood vessel constrict when the patient changes position so that blood flow remains consistent despite positional changes. The final group was given a combination of bisoprolol and pyridostigmine. It was found that all four groups showed improvement during the three months in comparable amounts. The groups that took pyridostigmine experienced a greater improvement in gastrointestinal motility (which can be a symptom in some POTS patients). The patients in group 3 reported to have greater improvement in psychological issues such as depression and anxiety. Overall, the clinical trial determined that treatment was better than no treatment and determining which treatment is best depends on the secondary symptoms of each patient.
Postural orthostatic tachycardia syndrome in children and adolescents
- (May 2018) Although POTS is often exclusively defined by the singular symptom of excessive tachycardia, the article above notes that other symptoms such as light-headedness, nausea, dyspnea (labored breathing), diaphoresis (abnormal sweating), headache, fatigue, brain fog (trouble concentrating) and gastrointestinal problems are also very common in POTS patients. The article further remarks that one of the best ways to treat all the varying symptoms of POTS is to start consistent healthy habits. This includes eating foods with good protein levels, increasing salt intake if experiencing low blood pressure, exercising daily by starting very slow and working up to more intense work outs, and having good and consistent sleep hygiene. The doctors at Children’s Hospital of Philadelphia (CHOP) have seen that POTS symptoms often lead to children and adolescents having trouble staying in school, although these patients most often have a strong desire to do so. The article states that a 504 plan should be put in place so that kids can have more success in their school environment. Some accommodations include longer test taking time, no requirement for physical education class, and more flexible days with accessibility to an audio copy of class discussion. Even with lifestyle changes symptoms will most like persist, but gradually lessen over time. The article reports that many patients experience great relief of symptoms with minor flairs after two years and some state they are without any symptoms after 5 years.
For a complete list of articles about POTS, visit PubMed