What is postural tachycardia syndrome (PoTS)?
PoTS is an abnormal response by the autonomic (involuntary) nervous system to standing up. To be diagnosed with PoTS, a patient must experience the following:
- A group of symptoms in an upright position (usually standing) that are relieved by lying down.
- These symptoms should be associated with an abnormally high and persistent increase in heart rate of 30 beats per minute (40 bpm if under 19 years of age) within ten minutes of standing.
Although symptoms are similar to those experienced by people with abnormally low blood pressure (BP), blood pressure does not usually drop in PoTS.
PoTS can develop in a number of different diseases or situations. The reason for this is not properly understood but it is possible that there is a malfunction of the nervous system that controls autonomic functions in the body.
When a healthy person stands up, to avoid blood dropping down into the limbs and abdominal cavity, blood vessels contract immediately and heart rate increases slightly to maintain blood supply to the heart and brain. In PoTS, this automatic adjustment to standing does not work correctly, resulting in an excessive rise in heart rate, increased epinephrine in the blood and altered blood flow to the brain. PoTS is more common in women and between the ages of 13 and 50 years.
What are the symptoms of PoTS?
Symptoms can be debilitating, ranging from mild to severe and varying from day to day.
- Dizziness or pre-syncope (almost fainting).
- Syncope (fainting).
- Palpitation (awareness of heartbeat).
- Headaches - orthostatic headaches (due to upright posture)/migraine.
- Brain fog (difficulty in thinking).
- Sense of anxiety.
- Visual problems (greying, tunnel or glare).
- Gut problems (nausea, diarrhoea, pain).
- Chest pain.
- Poor sleep.
- Purplish discolouration of skin due to blood pooling in hands and feet.
- Bladder problems.
Triggers that can worsen PoTS
- Excess heat.
- After eating - especially refined carbohydrate: sugar, white flour etc.
- Standing up quickly.
- Time of day (especially rising after wakening).
- Menstrual period.
- Deconditioning or prolonged bed rest.
- Alcohol (as it dilates blood vessels).
- Inappropriately excessive exercise.
- Temporarily during illness such as viral infections or after operations.*
How is PoTS diagnosed?
GPs may recognise the condition, but a clear diagnosis would normally be made by an electrophysiologist (a heart rhythm expert), neurologist or other hospital physician. These specialists are often found in cardiology, blackout or syncope clinics (although only a minority of people with PoTS experience blackouts).
The following tests may be used to confirm a diagnosis or exclude other conditions with similar symptoms:
- Active stand test. The patient rests flat for a few minutes and heart rate and BP are recorded. After standing up, further recordings are taken over 10 minutes.
- Tilt table test. The patient rests flat on a special bed with a footplate whilst BP and heart rate recordings are made. The bed is then tilted (head end up) for up to 45 minutes while further recordings are taken. (Both tests are stopped if the patient faints or if satisfactory recordings have been made).
- Other tests may include 12-lead electrocardiogram (ECG), 24-hour ECG, 24-hour blood pressure monitoring, blood tests (full blood count, kidney and liver function, thyroid function, calcium, diabetes tests, lying and standing norepinephrine levels), echocardiogram, exercise test, autonomic screening tests.
PoTS was first described in medical journals in 1993, but many medical professionals are still unaware of the condition today. Patients are commonly misdiagnosed with other conditions such as anxiety and depression, reflex syncope (vasovagal syncope) and chronic fatigue syndrome.
If you think you could have PoTS, it may help to discuss this leaflet with your doctor and ask for a referral to a specialist with an interest in PoTS. There is a list of such doctors on the PoTS UK and STARS websites (see below).
What causes PoTS?
There are a number of factors and disorders causing or associated with the condition but in some cases a cause is never identified. PoTS can follow a viral illness such as glandular fever, or be linked to pregnancy or a traumatic event. Sometimes teenagers are affected after a rapid growth spurt and most will improve within a few years. Some patients develop PoTS-like symptoms due to lack of fitness and the heart pumping inefficiently after being confined to bed for some time.
Hyperdrenergic PoTS may have a genetic cause. When upright, patients tend to complain of a severe sensation of anxiety and tremor, migraine headaches and clammy hands and feet. They may also present with high blood pressure and high blood norepinephrine levels (also elevated in phaeochromocytoma, which needs to be excluded).
Conditions associated with PoTS
- Joint hypermobility syndrome (JHS) is thought by some experts to be the same as Ehlers-Danlos hypermobility type (previously called Ehlers-Danlos type III and benign joint hypermobility syndrome) and is one of the most common conditions associated with PoTS.
- Low blood pressure can be healthy, but if it drops very low on standing it is called orthostatic hypotension and can cause symptoms similar to PoTS. Reflex syncope occurs when a drop in blood pressure results in fainting. PoTS, low blood pressure and reflex syncope can exist together in the same patient as seen in JHS and chronic fatigue syndrome.
- Chronic fatigue syndrome (CFS). PoTS is estimated to affect around one third of people with CFS.
- Inappropriate sinus tachycardia (IST) has similar symptoms to hyperadrenergic PoTS, but the high heart rate may be higher when lying down compared to PoTS and rapidly accelerates with exertion or stress.
- Mast cell activation disorder needs to be considered if flushing or allergies are prominent.
- Autoimmune conditions that have been associated with PoTS include Sjögren’s syndrome and antiphospholipid (Hughes') syndrome. Treatment of underlying conditions can improve symptoms of PoTS.
- Other conditions associated with PoTS include multiple sclerosis, diabetes, alcoholism, pure autonomic failure, multiple system atrophy (MSA), Lyme disease and cancer.
What can I do to improve my condition?
Lifestyle changes may be all that are needed to control symptoms.
- At least 2-3 litres of fluid per day are usually advised to boost blood volume. As symptoms can be worse in the morning, it may help to boost fluids before getting out of bed. In an emergency, drinking 2 glasses of water quickly can rapidly elevate BP and lower heart rate.
- Intravenous fluids have been used, but can cause serious complications with regular use.
- Alcohol dilates blood vessels and may make symptoms worse.
- Coffee and other caffeinated drinks may also worsen symptoms, although some find them helpful.
Food and salt
A high salt diet of up to 10 g per day may be recommended. Extra salt can be dangerous in some conditions such as high blood pressure, and kidney and heart disease, and therefore should only be taken if recommended by your doctor. Salt tablets can also be prescribed. Slow Sodium® tablets are available in the UK on prescription and are coated to reduce nausea.
Eating small amounts and often can be helpful. Symptoms can worsen after a large meal as blood is diverted to the digestive tract and away from other areas. Some people may find refined carbohydrates aggravate symptoms. Avoid rich sugary foods and those containing white flour. Eat lots of unprocessed foods such as vegetables, fruit, beans and foods that contain whole grain.
To avoid fainting or near fainting, take notice of early warning signs such as light-headedness, dizziness, and nausea. Lie down immediately and, if possible, elevate your legs. If your circumstances make this difficult cross your legs while standing or rock up and down on your toes. Clench your fists, buttocks and abdominal muscles.
The risk of fainting can also be minimised by standing up slowly if you have been sitting for a while. Avoiding prolonged standing or sitting. Elevating legs can be helpful.*
Compression tights should be waist high and give at least 30 mm Hg of pressure at the ankle (grade II compression) in order to help reduce the amount of blood pooling in the legs. Sports compression clothing may help.
Heat worsens symptoms. Dress in layers of clothes, so layers can be removed to prevent overheating. Extra salt and fluid intake should be increased if you feel hot or sweat more. A spray bottle of water for your face and neck will cool you down as the water evaporates from your skin. A fan or air conditioning can be helpful. Cooling vests have been used.*
Light to moderate exercise can help or even cure PoTS in some cases. Increasing leg strength and core (central) muscles helps to pump blood back to the heart.
Physical exertion can initially worsen PoTS so factor in recovery time afterwards. Begin with recumbent (sitting or lying down) exercise if you are starting for the first time, gradually increasing time and intensity. Upright exercise can be added after 2-3 months of recumbent exercise. Twenty to thirty minutes of aerobic exercise should be undertaken at least three times a week in combination with resistance training.
Exercise recommended in PoTS
- Recumbent biking, progressing on to upright biking
- Pilates - mostly horizontal exercise focusing on core strength
- Lower limb resistance training
Elevating the head of the bed is recommended to boost blood volume. PoTS patients often have poor quality sleep. Potential causes of sleep disturbance need to be identified such as underlying anxiety and depression.
Symptoms tend to be worse in the morning so it may be best to plan activities for later in the day. Set yourself achievable goals and avoid rushing. Factor in time for rest.
Drink a glass of fluid before and after showering. Avoid taking a hot or long shower or bath as this dilates your blood vessels and can make symptoms worse. Finishing your shower with cool water may help. Sit on a stool by the basin and in the shower. Dry shampoo spray and wet wipes may be an option on a bad day!
Cognitive behavioural therapy (CBT) is a structured talking therapy that can help you work towards accepting your limitations, adjust to the unpredictability of chronic illness, and help you pace yourself to achieve the challenges of daily living whilst still maintaining activities which most help you feel positive and fulfilled.
Driving - by law you must tell the DVLA of any health condition that may affect your ability to drive. Failure to do so could lead to prosecution and invalidate your insurance. Problems that you should consider reporting include tachycardia, syncope and dizziness.
Education and work
Eat and drink regularly. Working or studying with your feet elevated may help avoid brain fog. Don’t sit too long in one position. Move around or fidget. Keep as fit as you can - consider swimming or Pilates. If you cannot meet deadlines, tell your teachers or employer as soon as possible. Keep everyone informed. Providing a copy of this leaflet may be helpful.
Medication for PoTS
When these lifestyle changes are insufficient to control symptoms, medication may be recommended. All medicines used in PoTS are unlicensed which means that they have not been officially approved for this use. For this reason, GPs usually prefer that they are recommended or prescribed by a specialist. For the more expensive drugs, special funding approval may be required.
Medicines most commonly used in PoTS
- SSRI antidepressants for their effect on the autonomic nervous system
To ensure the best possible outcome for mum and baby, speak to your doctor BEFORE becoming pregnant. The effects on the unborn baby of taking most medicines are unknown and some women choose to stop medication before conceiving - ask your doctor first. The benefits of staying on medication versus the consequences of stopping need to be discussed with a specialist who is very knowledgeable about PoTS and its treatment.
Some women experience an improvement in symptoms, but for others there can be a deterioration in early pregnancy, especially if nausea or vomiting cause dehydration. The majority of women have a normal delivery. Caesarean section and epidurals are also safe in PoTS. It is important to maintain fluid intake during labour and an intravenous infusion may be helpful. Medication containing epinephrine should be avoided.
It is helpful to ensure that your obstetrician and anaesthetist have some knowledge of PoTS and this leaflet may be useful to them. If you feel too unwell or are taking large amounts of medicines, it may be sensible to delay becoming pregnant. Ask your GP or practice nurse about contraception.
For many, PoTS will improve with time and in some individuals it will disappear altogether. There are some forms of PoTS that are unlikely to go away but can improve through lifestyle changes and, if necessary, medication. The majority of patients learn to manage the condition and return to something close to their previous level of functioning.
*Means there is no evidence and is based on clinician or patient experience.
Content used with permission from PoTS UK: Postural Tachycardia Syndrome (PoTS) Information Booklet (November 2014, due for review August 2017). Copyright for this leaflet is with PoTS UK.
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