Written by Ben Sonnenburg
For an average person, performing any form of cardiac exercise is not incredibly difficult. However, for people who have Postural orthostatic Tachycardia Syndrome (POTS) it can be incredibly challenging.
Not only exercising, but even changing postures from sitting to standing with someone who has POTS causes the body to have an increase of 30 or more beats per minute. In this transition, it is not aggressive and happens even with a normal, passive standing posture.
Due to the increase in heart rate and inability for the cardiorespiratory system to properly function in transition, someone with POTS often deals with life-altering and debilitating conditions. They have an increase in lightheadedness, sleep disturbances, fatigue, cognitive complaints, work performance, and even study habits due to POTS.
Continually, people diagnosed with POTS tend to lead more sedentary lives which further worsens these issues due to physical de-conditioning. This also leads to impairments in the workforce due to being unable to stand for prolonged periods of time due to the increased demand on the body.
Therefore, researchers sought to evaluate exactly what people with POTS are able to do in the workplace and the role of cardiovascular responses to orthostatic stimulus (an upright posture/standing or sitting) in work ability.
In the research study, there were 22 people chosen that were diagnosed with POTS.
Each one of them had an elevated heart rate when standing and abided by the diagnosing criteria. These subjects were also currently in a working environment. Additionally, 18 healthy subjects were chosen as a control to be able to compare their work activity.
The patients with POTS were given a questionnaire that delves into six areas of autonomic functions: orthostatic intolerance, vasomotor, secretomotor, gastrointestinal, bladder, and pupillomotor. Additionally, they filled out a Work Ability Index (WAI) that self-assesses their own work capabilities.
Along with questionnaires, those diagnosed with POTS were placed on a motorized tilt-table for twenty minutes. In this test, the subjects are strapped to a table and placed at a 75-degree incline in order to collect blood samples. After another five minutes, another sample was taken along with collecting their norepinephrine and epinephrine levels by high-performance liquid chromatography with electrochemical detection.
Furthermore, while in this position RR intervals, arterial pressure, heart rate, and respiratory activity variables were gathered in this position. All of these tests and questionnaires were done over a period of two years between August 2016 and December 2018.
Both the subjects diagnosed with POTS and the healthy individuals within the control group were able to complete their normal work activities. Nevertheless, those with POTS had a much more reduced work capacity. This was due to musculoskeletal pain recorded in the questionnaire (77%), gastrointestinal (60%), and nervous system (50%).
Continually, 91% of the patients were obtaining medication to help reduce their heart rate. While performing the tilt table test, there was also a significant increase in Heart rate by an average of 32 beats/minute.
Though the POTS patients were able to complete their normal work activities, they struggled to maintain normal work capacities. They had an increase of their normal bodily symptoms, an increased heart rate and overall pain that those in the control group did not have.
This led to a higher cardiac overactivity that lowered their bodies ability to do work. Generic interventions have also proven to be ineffective and a greater demand for less physically exhausting tasks are recommended. Many working conditions also require those with POTS to switch from a seated to standing position often which further brought a decrease in work capacity.
Additionally, the WAI had a strong correlation with the intensity of cardiac sympathy overactivity. Therefore, the higher the WAI scores, the higher the intensity of cardiac over activities which demonstrated a greater degree of lack of performance.
In all the POTS patients, the higher their scores were on the WAI, the less likely they were able to do more work.
Their heart rate was more uncontrolled, they experienced brain fog that made it difficult to concentrate when seated, and they experienced overall much more skeletal muscular pain. Those with POTS experience problems constantly and cannot even escape them while laying down. If they are afraid to move due to the onset of issues and become sedentary, overtime their issues become worse.
Their heart rate will become even more uncontrolled, and they will become bedridden. There needs to be cardiac training in each of these individuals to be able to get used to the fluctuations in heart rate and better control their cardiac output.
The better a grasp they have on their heart rate and even blood pressure the better the body will be able to function.
In my opinion, the study seemed to be greatly lacking in data from normal healthy individuals. The POTS patients went through rigorous testing, but often this testing is what is already required to be diagnosed in the first place. It seemed un-needed, and a greater comparison could be made if the healthy individuals were also tested.
Nevertheless, the importance of cardiovascular training cannot be stressed enough with those that have POTS.
It helps regulate the heart rate better so the heart does not overact especially while changing positions.
Reference:
Barbic, F., Minonzio, M., Cairo, B., Shiffer, D., Zamuner, A. R., Cavalieri, S., Dipaola, F., Magnavita, N., Porta, A., & Furlan, R. (2020). Work Ability Assessment and Its Relationship with Cardiovascular Autonomic Profile in Postural Orthostatic Tachycardia Syndrome. International Journal of Environmental Research and Public Health, 17(21). https://doi.org/10.3390/ijerph17217836