Dysautonomia

What is Postural Orthostatic Tachycardia Syndrome (POTs)?

Postural Orthostatic Tachycardia Syndrome (POTs) is a form of dysautonomia that is estimated to impact millions around the world. POTs is a form of orthostatic intolerance that is associated with the presence of excessive tachycardia and many other symptoms upon changes in elevation of the body – for example when shifting from a laying down position to an upright position, or from a sitting position to standing .

Diagnostic Criteria

The current diagnostic criteria for POTs is a heart rate increase of 30 beats per minute (bpm) or more, or over 120 bpm, within the first 10 minutes of standing, in the absence of orthostatic hypotension. In children and adolescents, a revised standard of a 40 bpm or more increase has recently been adopted.

POTs is often diagnosed by a Tilt Table Test, but if such testing is not available, POTs can be diagnosed with bedside measurements of heart rate and blood pressure taken in the supine (laying down) and standing up position at 2, 5 and 10 minute intervals.

Signs and Symptoms
While the diagnostic criteria focus on the abnormal heart rate increase upon standing, POTs usually presents with symptoms much more complex than a simple increase in heart rate.

Symptoms include:

• Increased heart rate
• Small fiber neuropathy
• Fatigue
• Headaches
• Light-headedness/dizzyness
• Heart palpatations
• Exercise intolerance
• Nausea
• Diminished concentration often referred to as “Brain Fog”
• Tremulousness (shaking)
• Syncope (fainting)
• Coldness or pain in extremities
• Chest pains
• Shortness of breath
• Blood pooling (reddish/purple legs when standing, which changes to normal when lying down)
• Temperature disregulation

What causes Postural Orthostatic Tachycardia Syndrome?

Sometimes the cause of this problem with your autonomic nervous system is not known. Sometimes it develops suddenly after a viral illness or traumatic event, or during or after pregnancy.

Other known causes are:

• Ehlers-Danlos syndrome
• An underlying condition such as diabetes, amyloidosis, sarcoidosis, lupus, Sjögren’s syndrome or cancer
• Poisoning with alcohol or certain metals
• Inheriting a gene that causes too much of the ‘fight or flight’ hormone noradrenaline to be produced. 
• Long Covid symptoms in some patients are being linked to POTs

What is the treatment for Postural Orthostatic Tachycardia Syndrome?

The self-care measures described below can sometimes help to reduce the symptoms of POTs. If these do not work, you may need to take medicine. The important thing is to understand the issue and not panic.

There are 3 main approaches to treating POTs:

• Treating an episode without medication
• Taking preventative steps to reduce your symptoms without medication
• Taking medication

Treating an episode without medication

If you suddenly feel faint or dizzy, try to counter 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
• Clenching your fists if you can’t lie down. 

Taking steps to prevent symptoms developing without medication

You may be able to reduce your symptoms in the long term if you: 

• Drink plenty of fluids until your pee is pale yellow
• Keep active, but pace yourself and choose your exercise carefully – 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)
• Raise the head end of your bed, so you’re not sleeping fully flat
• Try wearing support tights or other forms of compression clothing, to improve blood flow in your legs
• Avoid long periods of standing, particularly in the heat
• Avoid long, hot showers
• Cross your legs and draw up your knees if sitting for long periods of time
• Get up slowly after lying down and sit for a while before standing
• Avoid drinking lots of caffeine or alcohol
• Add more salt to your diet through the day (provided you don’t have high blood pressure or kidney or heart disease)
• Use electrolyte drinks in hot weather or before sport, when you may sweat a lot.

Taking medicine

There’s currently no medicine licensed for the treatment of POTs, but your specialist might suggest trying a medicine ‘off label’, such as:

• Beta blockers – which decreases heart rate
• Midodrine – which narrows blood vessels
• Fludrocortisone – which helps your kidneys retain sodium
• A selective serotonin reuptake inhibitor (SSRI) – a type of antidepressant that can affect how your nervous system works.

If a medicine is used off label, it hasn’t gone through clinical trials for it to be used in this way, but many experts believe it’s likely to be effective. Your doctor can discuss the possible benefits and risks with you.

Incidence of Dysautonomia and EDS 

There is an increasing amount of literature showing a large amount of overlap between these two disorders. Of the possible reasons behind the mechanisms to explain this overlap of Dysautonomia in EDS can include adreno-receptor hyperresponsiveness, molecular defect in connective tissue of the blood vessel and peripheral neuropathy. In recent studies up to 88% of patients with EDS concurrently also had a diagnosis of POTs.

Source: [1 Dysautonomia International l What is dysautonomia? ] [2 Science Direct l Frequency and Co-occurrence of Comorbidities in the Ehlers-Danlos Syndromes ] [3 NHI National Library of Medicine l Postural Orthostatic Tachycardia Syndrome as a sequela of Covid-19 ] [4 Health Navigator l Postural Orthostatic Tachycardia Syndrome (POTS) ]