Postural tachycardia syndrome (PoTS)
Patient Information Leaflet
Postural tachycardia syndrome (PoTS) is an abnormal increase in heart rate that occurs after sitting up or standing. It typically causes dizziness, fainting and other symptoms.
It’s sometimes known as postural orthostatic tachycardia syndrome.
PoTS affects many different people, but is most common in girls and women aged 15 to 50. Some people have mild symptoms, while others find the condition affects their quality of life. PoTS often improves gradually over time, and there are a number of selfcare measures and medications that can help.
What happens in PoTS
Normally when you sit up or stand, gravity pulls some of your blood down to your belly area, hands and feet. In response, your blood vessels quickly narrow and your heart rate increases slightly to maintain blood flow to the heart and brain, and prevent blood pressure dropping. This is all done without needing to think about it by the autonomic nervous system – the nervous system in charge of automatic body functions. In PoTS, the autonomic nervous system doesn’t work properly. There’s a drop in blood supply to the heart and brain when you become upright and the heart races to compensate for this.
Symptoms of PoTS
You can develop PoTS suddenly, or it can come on gradually over time. It causes a range of symptoms that occur within a few minutes of sitting up or standing. Lying down may relieve some of the symptoms.
Typical symptoms of PoTS include:
- dizziness or light-headedness
- heart palpitations
- shaking and sweating
- weakness and fatigue
- poor sleep
- chest pain
- feeling sick
- shortness of breath
Some people notice that things such as feeling hot, eating, strenuous exercise and being on their period make their symptoms worse.
When to get medical advice
See your GP if you think you have PoTS. The symptoms can have a number of causes, such as medication or low blood pressure, so it’s a good idea to get a proper diagnosis. Sometimes it can be misdiagnosed as anxiety or panic attacks.
Some doctors may not be aware of PoTS, so it may help to print out this page and take it with you to the consultation.
Tests for PoTS
A diagnosis of PoTS is made if your heart rate increases by 30 beats per minute (bpm) or more (40bpm in those aged 12-19) after 10 minutes of standing, or if it increases to more than 120bpm.
You may have a range of tests to confirm a diagnosis and rule out other conditions, including:
- the tilt table test – your heart rate and blood pressure are measured while lying on a bed, and the bed is then tilted into a more upright position while further measurements are taken
- the active stand test – your heart rate and blood pressure are measured after lying down, immediately upon standing, and after 2, 5 and 10 minutes
- an electrocardiogram (ECG) – a test of your heart’s electrical activity an echocardiogram 24-hour ambulatory blood pressure and heart rate monitoring – small devices attached to your belt take regular readings while you’re doing normal activities blood tests – to test your kidney, liver and thyroid function, and measure blood count and your calcium and glucose levels
Causes of PoTS
In many cases, the cause of the problem with the nervous system in people with PoTS is unknown. Teenagers will sometimes develop PoTS and find it gradually disappears a few years later. Sometimes it can develop suddenly after a viral illness or traumatic event, or during or after pregnancy
Some of the other known causes are:
- joint hypermobility syndrome – a condition (often inherited) that results in unusually flexible joints and abnormally elastic blood vessels
- other underlying conditions – such as diabetes, amyloidosis, sarcoidosis, lupus, Sjogren’s syndrome or cancer
- poisoning – with alcohol or certain metals
- inheriting a faulty gene that causes too much of the “fight or flight” hormone noradrenaline to be produced PoTS also occurs quite commonly alongside chronic fatigue syndrome (CFS).
Treatments for PoTS
Self-care measures can sometimes help reduce the symptoms of PoTS. If these don’t work, you may need to take medication. Treating an episode
- If you suddenly feel faint or dizzy, you can try countering the fall in blood flow by: lying down and, if you can, raising your legs
- crossing your legs in front of each other while standing, rocking up and down on your toes, clenching your buttocks and tummy muscles and/or clenching your fists if you’re unable to lie down
Reducing your symptoms
You may be able to reduce your symptoms in the long-term by following this advice:
- drink plenty of fluids until your urine is pale yellow
- keep active, but pace yourself and choose your exercise wisely – swimming, rowing, lower limb resistance training, walking, jogging and pilates can help you keep fit and build muscle (strong calf muscles should help pump blood back to your heart)
- elevate the head end of your bed, so you’re not sleeping fully horizontal try wearing support tights or other forms of compression clothing, to improve blood flow in your legs
- avoid long periods of standing
- come up from lying slowly – sit for a while before standing
- avoid drinking lots of caffeine or alcohol
- include more salt in your diet – this isn’t advisable if you have high blood pressure or kidney or heart disease though, so ask your specialist first The PoTS UK website has more general advice about reducing your symptoms and the charity STARS has information about managing your symptoms.
Non-pharmacological measures should be tried first.
Dehydration and excess alcohol should be avoided. Patients are advised to increase their fluid (at least two litres a day) and salt (3–5 grams/day) intake, except those patients diagnosed with the hyperadrenergic form.
Aerobic exercise of the lower extremities to augment the skeletal muscle pumps may be helpful
Patients with dysautonomia may benefit from using compression hose extending up to the waist. If the above measures are not enough, drugs can be used
There’s currently no medication licensed for the treatment of PoTS, but your specialist might suggest trying a medication “off label”, such as:
- a beta-blocker or ivabradine – which decreases the heart rate
- midodrine – which narrows the blood vessels
- fludrocortisone – which decreases the amount of sodium lost in your urine
- selective serotonin reuptake inhibitors (SSRIs) – a type of antidepressant that can affect how your nervous system works
If a medicine is used “off label”, it means it hasn’t undergone clinical trials for this use, but many experts believe it’s likely to be effective and your doctor will discuss the possible benefits and risks with you.
Patients with dysautonomia may benefit from fludrocortisone, which has been tried with success. It causes salt and water retention and sensitises the alpha-adrenergic receptors. The average dose is 50–100 μg/day and the maximum dose is 400 μg/day.
If the patient continues to be symptomatic, a serotonin reuptake inhibitor (SSRI) or a serotonin and noradrenaline reuptake inhibitor (SNRI) can be added.These agents stimulate the standing vasoconstrictor reflex.The most commonly used SSRI is fluoxetine 10–20 mg once daily. Of the SNRIs, bupropion 150–300 mg/day is usually used.
Venlafaxine 75–150 mg/day also can be useful. Pyridostigmine, an acetylcholine esterase inhibitor that facilitates neural transmission at the ganglionic level of the sympathetic and parasympathetic nerves, gave good results in POTS secondary to viral infection and autoimmune disorders. The usual dose is 60 mg orally once daily, either alone or in combination with low-dose propranolol. Pyridostigmine can cause diarrhoea and abdominal cramps.If all the above are not effective, erythropoietin is worth tryinG] provided that the haematocrite is less than 50. It causes volume expansion and has a potent direct vasoconstrictor effect. However, it is an expensive medicine and needs continuous monitoring of the haematocrite. The dose used in POTS is 800 IU subcutaneously once weekly. It might predispose to stroke. Another option in these cases is octreotide; a potent vasoconstrictor which is given subcutaneously at a dose of 25 μg twice daily, titrated to 100–200 μg three times daily. Some patients, particularly, those with partial dysautonomic POTS, improve on small doses of beta blockers (e.g. metoprolol 25– 50 mg once or twice daily), but the majority feel worse on beta blockers. The hyperadrenergic form of POTS can be treated with sympatholytic agents. One option is clonidine, an alpha2-agonist that acts centrally to decrease sympathetic nervous system tone. The dose is 0.1 mg/day, which can be increased up to 0.2 mg twice daily. It is also available in a ‘patch form’. Unfortunately, it can cause bradycardia, hypotension and mental clouding in some patients. The combined alpha1/beta blocker labetalol is useful in some patients, as beta-blockade alone may worsen symptoms due to unopposed alpha-receptor stimulation. A starting dose of 100–200 mg twice daily is used, and the maximum dose is 400 mg twice daily.Methyldopa, a false neurotransmitter, may be effective in a dose of 125 mg to 250 mg three times daily. SSRIs or SNRIs are also useful in controlling patients’ symptoms. In the secondary forms of POTS, the main aim is to treat the underlying disorder; some patients may improve. Patients with diabetes or joint hypermobility syndrome tend to respond to treatment as do those with the partial dysautonomic form. Those with paraneoplastic POTS may respond to therapy with pyridostigmine, and symptoms often abate with treatment of the malignancy.