Orthostatic Intolerance & POTS

Orthostatic Intolerance, POTS and Dysautonomia

Orthostatic Intolerance and Postural Orthostatic Tachycardia Syndrome (OI/POTS) are characterised by a drop in blood pressure of 20mmHg as seen in OI and an increase in heart rate of 30bpm as seen in POTS when a person moves from lying down to standing (postural change). OI/POTS is often seen associated with other conditions such as CFS/ME but can also be a stand alone condition.

The symptoms of OI/POTS include:

  • Postural dizziness (from lying/sitting to standing)
  • Postural vision spots or blindness
  • Sensitivity / intolerance to the heat and/or change in temperature
  • Nausea / over fullness / lack of appetite
  • Swelling in the feet after periods of sitting or standing still
  • Cold hands and feet
  • Salt cravings
  • Irregular sweating patterns
  • Fatigue with standing for periods of time
  • Light headed in shower or abnormal fatigue after
  • Intolerance to alcohol
  • Fidgeting

It is not necessary to have all of these symptoms, you may just have some

What causes OI/POTS?

The cause of OI/POTS is unknown however it is most likely multi-factorial and of differing pathologies. We believe that OI/POTS can be differentiated into peripheral and central types:

Peripheral causes of OI/POTS refer to non neurological causes. People often presenting with OI/POTS also present with joint hyper elasticity defined by the Beighton’s hyper mobility scale (>3/9). It is postulated that people presenting with joint hyper elasticity are not only more susceptible to joint injuries but also OI/POTS due to increased artery/vein elasticity which can lead to poor blood vessel constriction and therefore poor blood pressure control. If you imagined that you were trying to push water through a clowns balloon they make hats with, when you push down in one area it can bulge in another whereas if you has a garden hose it would not bulge but push the water out the other end at a greater pressure. People with OI/POTS and hyper mobility are postulated to have more elastic blood vessels leading to poor constriction.

Central causes of OI/POTS are most likely to be linked with the sympathetic nervous system which controls blood pressure, heart rate and other functions that we can not directly change. There are many theories to what specific pathway this takes but at this time there is no known pathway. It is postulated that one of the pathways is due to an increased sympathetic load leading to a delayed or irregular response as seen in the below diagram (this can often be seen in CFS/ME).

Increased sympathetic loadBeaumont A, Burton AR, Lemon J, Bennett BK, Lloyd A, et al. (2012) Reduced Cardiac Vagal Modulation Impacts on Cognitive Performance in Chronic Fatigue Syndrome. PLoS ONE 7(11): e49518. doi:10.1371/journal.pone.0049518

Treatment of OI/POTS

Although we do not know the exact cause of OI/POTS there are treatment options available. Exercise, hydration, salt and medication are often used:

  • Cardiovascular exercise will improve your heart, pulmonary, circulatory and skeletal function and enhance your body’s neurological messaging capacity. Start with exercise types such as recumbent cycling or cool water based activity and gradually progress to more upright types of activity (eg. walking, jogging, sport etc.).
  • Strength training will increase your muscle bulk and muscle activation capacity therefore allowing these muscles to be used as “pumps” for blood return. It is especially important to maintain good leg strength through a resistance exercise program provided by your Exercise Physiologist.
  • Keeping well hydrated will increase your blood volume and allow for better constriction of your blood vessels
  • Increasing your salt intake helps the body retain fluid and increase blood volume
  • Some medications may aid in the management of severe cases of OI and POTS. Your GP and/or Specialist will be able to inform you if this is the right avenue for you

For more details click here on Orthostatic Intolerance and POTS management strategies. If you have any questions about OI or POTS, the above information or would like some more guidance please contact us