This semester, I am taking a course in physiological psychology. Although this class entails an incredible amount of work (as my teacher is the head of the whole psychology department at my school), it definitely appeals to me since the majority of the course material involves learning about the functions occurring in the human body, the chemical and biological processes that take place, and how all of this influences the brain and individual behavior. Needless to say, it’s right up my ally. One of our weekly assignments is to submit a reaction paper to a research article that relates to the particular topic of the week. So last week, the topic was on the human nervous systems. Obviously, I chose to review an article on POTS and Dysautonomia. I figured that it was a great way to spread awareness to both my professor and fellow classmates on this condition, seeing as though we were only learning about a FUNCTIONING autonomic nervous system. Anyways, I thought I’d share it, even though the article I reviewed had to be torn apart due to some inconsistencies in the writing. Nevertheless, I figured it was still relevant since I finally got my official diagnosis of POTS after so many years and many of my friends/followers also live with some form of dysautonomia. Hope you enjoy!
Postural Orthostatic Tachycardia Syndrome:
Reviewing Research on a Highly Underdiagnosed Form of Dysautonomia
Health officials in the U.S. define a rare disease or disorder whenever it affects fewer than 200,000 people. However, it has been estimated that over 500,000 people in the United States are living with a debilitating condition known as postural orthostatic tachycardia syndrome (POTS), despite the fact that this disorder is still considered medically to be a rare condition. This is primarily a result of a doctor’s misdiagnosis or failure to diagnose. More often than not, patients receive a psychological diagnosis first, mainly as having some form of anxiety disorder, long before they obtain an actual diagnosis of having POTS. The average number of years it takes to get a diagnosis of POTS after onset of symptoms is about four years, alt hough I personally lived with this condition for almost 20 years before receiving my diagnosis two weeks ago. Given the limitations that this disorder can cause in an individual’s quality of life, more recognition and awareness in the medical profession is essential, including research into developing a diagnosis and treatment plan for this disorder. In the article, Postural orthostatic tachycardia syndrome: an under recognized disorder, the authors discuss the clinical manifestations of POTS syndrome, as well as clinical testing methods and patient outcomes. (Pandian, Dalton, Henderson, & McCombe, 2007).
POTS syndrome is a form of dysautonomia, which is a term used to describe medical conditions caused as a result of a dysfunctional autonomic nervous system. The autonomic nervous system is responsible for most of the automatic functions in the human body, including heart rate, blood pressure, temperature regulation, digestion, and even breathing. In dysautonomia, however, anyone of the autonomic functions can be dysregulated. In POTS, for instance, symptoms are defined through orthostatic intolerance where an individual develops “excessive tachycardia and symptoms of cerebral hypoperfusion on standing” (Pandian et al., 2007, p. 529). Often, those with POTS will experience dizziness and fainting shortly after they stand up, due to the increase in heart rate and decreased in blood pressure caused by blood pooling away from the brain and into the lower extremities instead. Given that POTS is an autonomic disorder, patients can additionally experience other wide-spread symptoms, including symptoms of gastrointestinal disorders, migraines, hot and cold intolerance, chronic fatigue, exercise intolerance, hypoxemia, and shortness of breath. While there is no cure for POTS, researchers are investigating therapies to reduce the amount and level of symptoms experienced.
While a lot information is still unknown about POTS, the researchers note in the article that there are several ideas as to the possible causes of this condition. This was most interesting, as many research studies have not focused on the potential for varying causes of POTS. One thought is that POTS patients have a “form of autonomic neuropathy manifested by an inability of the peripheral vasculature to constrict adequately in response to orthostatic stress”, which would explain the increasing heart rate and lowering blood pressure (Pandian et al., 2007, p. 529). Other views mentioned in the article focused on neurotransmitters and hormones as being the primary cause of POTS. For instance, one idea is that POTS is a type of β-adrenergic receptor hypersensitivity. Another is that “the serum catecholamine levels are often significantly increased when upright” (Pandian et al., 2007, p. 529). Finally, other theories mentioned in this article included patients having a genetic predisposition to developing the disorder, POTS being secondary to other disorders (like diabetes, sarcoidosis, or Sjorgen’s syndrome), or POTS being an unrecognized autoimmune disorder. Personally, I believe POTS, like many other neurological and physical disorders, can be explained by the combination of environmental, biological, and genetic situations.
In order to study symptomatology and medical testing on POTS, Pandian et al. (2007) studied 250 patients from 2003 to 2006. Researchers’ recorded demographic details, such as age and sex, as well as the patient’s individual symptoms, including duration, severity, and frequency of symptoms. Tests were performed to test level of autonomic dysfunction by using a tilt table study, heart rate response to deep breathing, and the Valsalva maneuver test. Researcher were able to assess outcome on the patient’s ability (or disability) to function normally; by being able to stand up without symptoms for 30 minutes, to maintain work, and ability to participate in recreational activities, without worsening of symptoms. The results of this study determined that the duration of symptoms lasted anywhere from three months to 20 years. “The common presenting orthostatic symptoms were light-headedness (100%), palpitations (90%), pallor (90%), weakness (80%), and clammy skin (80%). The mean heart rate increment during the tilt study was 51.7 14.3 b.p.m.” (Pandian et al., 2007, p. 531). Other symptoms noted by patients during the study were dry eyes and mouth, decreased saliva and sweating, nausea, bloating of the abdomen, cramping, diarrhea, constipation, weight gain or loss, satiety, and vomiting. Finally, out of the 250 participants, only five of the patients were functioning normally at follow-up visits as defined by the outcome criteria and four patients were considered worse off than when the study was initiated. Some of these patients were managing their POTS with pharmaceuticals, including beta-blockers, antidepressants, fludrocortisone, and pyridostigmine. Pandian et al. (2007) concluded that not only is POTS an under-recognized disorder presented by a variety of symptoms, but it also has the potential to be treated, although with inconsistent outcomes.
Overall, while I believe that this article provided a great deal of detailed information regarding the symptoms associated with POTS, there was quite a bit of data that was lacking as far as the actual research that was performed. The tests used on the patients are diagnostic tests that are considered current protocol in the diagnosis of POTS, and by using patients who have already received this diagnosis, the findings in this study are relatively insignificant, other than they confirm a patient’s original diagnosis. Also, in the introduction researchers mentioned the potential causes of POTS syndrome, but those ideas were not investigated in this study. It would have been interesting to compare the measurements of symptoms with the various testing they ran to other studies, such as DNA or blood testing, to determine the genetic or neurological causes of POTS. Considering I recently had my cortisol levels ran, which came back as being particularly low, my personal theory is that the neurotransmitter and hormone connection must have some sort of significance in the development of both POTS and other forms of dysautonomia, in addition to having a genetic predisposition to the disease that is environmentally influenced.
Also, Pandian et al. (2007) use the phrase ‘under recognized’ in their title and throughout their paper as a problem being associated with POTS, although they did not pursue studying the actual number of individuals with POTS that may not have received a diagnosis as of yet. While the researchers were using a true statement, since lack of a diagnosis has been identified in a variety of other research, I would have liked to have seen a random selection of participants, consisting of the general population, also studied using current diagnostic tests for POTS. Still, any research or information that brings awareness to this highly underdiagnosed and limiting health condition benefits all of those affecting by POTS, including the ones still left undiagnosed.
Pandian, J. D., Dalton, K., Henderson, R. D., & McCombe, P. A. (2007). Postural orthostatic tachycardia syndrome: An under recognized disorder. Internal Medicine Journal, 37(8), 529-535. doi:10.1111/j.1445-5994.2007.01356.x