PoTS (Postural Orthostatic Tachycardia Syndrome) is a condition that is caused by a dysfunction of what is called the autonomic nervous system – a part of the nervous system that helps to control pulse rate, blood vessel size and blood flow to crucial parts of the body, including the brain.
So it can cause symptoms such as palpitations (awareness of the heart beating), feeling lightheaded, dizziness, pre-syncope (almost fainting) or syncope (blackouts), headaches and brain fog/cognitive dysfunction.
PoTS can exist on its own or form part of other conditions – ME/CFS and hypermobility syndromes for example – that also involve dysfunction of the autonomic nervous system.
We know that a significant minority of people with ME/CFS have PoTS as part of their ME/CFS. You will find these especially in younger age groups and at the more severe end of the spectrum.
But the condition often remains unrecognised by doctors because there is a serious lack of medical education about both diagnosis and management of PoTS. Consequently, it is quite frequently misdiagnosed as anxiety or panic attacks.
There was an excellent workshop on PoTS at the UK CFS/ME Research Collaborative conference last week. This was led by Professor Julia Newton (a leading UK expert on PoTS) and representatives from PoTS UK.
Following on from this, I will be preparing a new MEA Management File on PoTS and ME/CFS for the November issue of our ME Essential membership magazine.
MORE INFORMATION ON POTS – TAKEN FROM THE MEA’S PURPLE BOOKLET 2016 EDITION
PoTS sometimes forms part of autonomic nerve dysfunction in ME/CFS.
Ita is defined as symptoms of orthostatic intolerance associated with an increase of heart rate from supine to upright position of > 30 beats per minute (or 40 beats per minute in the 12-19 year age group) or with a heart rate of > 120 beats per minute on standing, can occur in ME/CFS (Hoad et al 2008; Kavi et al 2016).
In the recent British Journal of Cardiology review of patients with PoTS and their experience of healthcare in the UK, Kavi et al (2016) found that 81% of respondents were between the ages of 18 and 49 years and 92% were female. The most common symptoms at presentation were fatigue (91%), light-headedness, dizziness or presyncope (90%) and palpitations (86%). Syncope or blackouts were experienced by 58%. Other commonly presenting symptoms (in over 40%) included difficulty thinking (often described as brain fog), physical weakness, visual disturbances, breathlessness, vertigo, shakiness, chest pain, sweating, bloating, symptoms of anxiety, poor sleep, daily headache, acrocyanosis (purple-blue discolouration of hands and lower limbs), tingling in peripheries, nausea, abdominal pain, heat and exercise intolerance and ‘coat hanger’ pain (thought to be due to ischaemia of neck and shoulder muscles).
Clinical evaluation should therefore include a response to standing. Research aimed at characterising ME/CFS patients with or without PoTS found that those with PoTS were younger, less fatigued, less depressed and had reduced daytime somnolence (Lewis et al 2013a). They also had greater orthostatic intolerance and autonomic dysfunction. Those with PoTS may require further investigation and consideration for therapy to control heart rate (Lewis et al 2013a).
Further evidence relating to the important subgroup of ME/CFS patients who also have PoTS comes from Nijs and Ickmans (2013).
For a review of PoTS, see Benarroch (2012) and Kavi et al (2016).
NB: In patients presenting with chronic fatigue and/or orthostatic intolerance, low ferritin levels and hypovitaminosis D may be present, especially in those with postural tachycardia (Antiel et al 2011).
Dr Charles Shepherd
Hon Medical Adviser
The ME Association