Postural Orthostatic Tachycardia Syndrome, aka PoTS is an abnormal response by the autonomic nervous system to becoming upright. There is an abnormally high increase in heart rate and altered blood supply to the brain on standing. It results in a large number of symptoms, the commonest of which are dizziness, fainting, tiredness and palpitations. There are many causes and, in some cases, no cause can be found. Although patients can be very disabled by their symptoms, many get better without treatment. However, some patients will have problems over many years. Fortunately changes in lifestyle and medicines will help and the majority of patients will respond to treatment.
Types of PoTS
This type often starts suddenly, and sufferers may have had a viral illness, pregnancy, immunisations, surgery or trauma prior to their symptoms starting. It is thought that this form of PoTS might be due to an abnormality of the body’s immune system.
This type seems to afflict teenagers. It usually starts between the ages of 12-14 years old and may follow a very rapid growth spurt, with worsening symptoms until the age of 16. By the age of 19 to 24, about 80% of individuals will have no symptoms. The cause is unclear, but it seems to follow a rapid growth spurt.
Deconditioning (being out of shape) is present in some individuals with PoTS. A traumatic event or illness can result in reduced activity or bedrest. Patients become unfit and the heart doesn’t pump as efficiently as before. This can trigger symptoms of orthostatic intolerance so patients avoid exercise which makes their symptoms worse, leading to more physical inactivity. There is a downward spiral of deconditioning which causes or worsens symptoms of PoTS.