What is PoTS?

• Postural              position of the body
• Tachycardia       fast heart rate
• Syndrome          a combination of symptoms

Postural tachycardia syndrome is an abnormality of the functioning of the autonomic (involuntary) nervous system. 

Definition and diagnostic criteria:

• Patient must experience PoTS symptoms mostly when upright and relieved by lying down over a period of at least 3 months
• A sustained increase in heart rate of greater than 30 beats per minute (bpm) within 10 minutes of standing
• Those aged 12-19 years require an increase of at least 40 beats per minute
• There is usually no drop in blood pressure on standing (apart from the normal brief drop in blood pressure lasting under 1 minute that occurs in healthy people called head rush or initial postural hypotension)
• In patients with heart rates below 60 beats pm), the baseline heart rate will be taken as 60bpm
• Changes in heart rate of 30bpm (40 in children) do not need to be met at every visit (ie the diagnosis should not change from visit to visit to the doctor if the heart rate increase reduces to under the diagnostic threshold)

Patients can be very disabled by their symptoms.  Many patients’ symptoms will improve with lifestyle changes, although some people will require medication.  However, some will have significant symptoms over many years.

Many healthcare professionals do not know that PoTS exists and so may not think of the diagnosis. If you think you may have this condition, it may help to take a printout of information from this website to your appointment, such as our Guide for GPs.

The Autonomic Nervous System

The Postural Tachycardia Syndrome (PoTS) is an abnormality of the autonomic nervous system (ANS) (a malfunctioning ANS is sometimes called ‘dysautonomia’). The autonomic nervous system controls all bodily functions that we don’t have to think about, such as:

• Heart rate and blood pressure regulation
• Digestion
• Bladder control
• Sweating
• Stress response

The sympathetic nervous system is part of the autonomic nervous system. It produces the ‘fight or flight’ or ‘stress’ response. When activated, a chemical called norepinephrine is released. Amongst other things, this causes an increase in heart rate and blood pressure.

What should happen to my blood when I stand up?

When a healthy person stands up, blood vessels narrow, and heart rate increases slightly to maintain blood supply to heart and brain.

What happens when I have PoTS and stand up?

In PoTS, this automatic adjustment to upright posture is not working correctly, resulting in an excessive rise in heart rate, increased norepinephrine in the blood and altered blood flow to the brain.

Thank you to Ruby Usiskin for producing the image. Subject to copyright by PoTS UK.