What is POTS Syndrome?
Postural orthostatic tachycardia syndrome (POTS) is a rare syndrome in which patients experience symptoms of lightheadedness, racing pulse, increased heartbeat, low blood pressure and even fainting with postural changes or when standing up. Postural (relating to the posture) orthostatic (caused by an upright position) tachycardia (high heart rate) syndrome is also called POTS. The majority of individuals with POTS syndrome are women although it affects men as well. Several million patients in the United States have been diagnosed with POTS syndrome and experience orthostatic symptoms. This syndrome falls in a class of disorders known as Dysautonomia
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What causes postural orthostatic tachycardia syndrome in patients?
Although POTS may be subcategorized into different forms of the tachycardia syndrome, the underlying pathophysiology of the syndrome is the same. Additionally, the orthostatic symptoms that patients experience are the same. Research has shown that when patients stand up from a seated or reclined position, the body reacts by constricting and squeezing vessels (termed vasoconstriction) thus increasing the pressure in the vessels. This vasoconstriction prevents the pooling of blood in the lower body and ensures that the heart and brain continues to have adequate blood flow and that blood pressure is maintained during postural changes. This blood process occurs automatically with orthostatic movement and is controlled by the body's autonomic nervous system. A malfunction in the autonomic nervous system can lead to the postural tachycardia syndrome
In POTS syndrome, blood flow and blood pressure are not adequately maintained when patients rise to a standing position (termed dysautonomia) and blood may pool in the lower body. This leads to symptoms of POTS. The sudden drop in blood flow causes the heart to beat faster (termed tachycardia) in order to try and increase blood flow and blood pressure and counteract the decreased amount of circulating blood. The result of this blood flow malfunction in patients is orthostatic symptoms of lightheadedness, racing heart beat (tachycardia syndrome), and even fainting.
There are many possible causes of POTS including:
- Autoimmune conditions
- Disorders such as Celiac disease and Lupus
- Post viral infection (including COVID-19)
- Hypermobile syndromes like Ehlers-Danlos
- Puberty, pregnancy and menstruation
- Major surgery or trauma
- Blood loss
What are the symptoms of POTS?
POTS may present with several different symptoms and not all patients will experience every symptom. The most common POTS symptoms that patients experience include:
- Orthostatic (postural) changes in blood flow, including both high blood pressure and low blood pressure
- Orthostatic (postural) changes in heart rate. Fluctuations leading to both high and low heart rate have been found to be associated with POTS
- Fainting with orthostatic changes, usually due to decreased blood circulation and blood pressure
- Chest pain with orthostatic change, usually associated with an increased heart rate and chest palpitations
- Blurry vision with orthostatic changes due to decreased blood circulation and blood pressure
- Shakiness as a result of adrenaline released by the body in order to fight loss of consciousness
- Difficulty focusing due to temporary decreased blood circulation to the brain
- Fatigue and lethargy as a result of adrenaline released by the body wearing off
How is postural orthostatic tachycardia syndrome diagnosed?
Postural orthostatic tachycardia syndrome (POTS) is diagnosed in patients by a Yhysician or other medical professional. The clinic provider will ask about POTS symptoms that occur with orthostatic movements, such as changes in blood circulation. The first step in the diagnosis of POTS usually involves measuring blood pressure and pulse while lying down, sitting down, and standing up. This is termed orthostatic blood pressure. The medical professional will look for changes in the blood flow and pulse with positional changes. Heart and blood tests, like having an electrocardiogram read, provide the clinician with more information and may be used to rule out other disorders. The primary tests to confirm the POTS diagnosis include:
- A tilt table test in which blood pressure and heart rate are measured in different positions
- A complete blood count (CBC) to rule out anemia or other medical disorders
- A complete metabolic panel (CMP) to analyze electrolyte levels which may be abnormal in POTS
- A norepinephrine level which can increase when patients with POTS stand up due to an increased sympathetic response
- An echocardiogram, which is an ultrasound of the heart
How are POTS symptoms and POTS episodes treated?
The treatment of POTS depends on if there is an underlying disorder causing POTS. If there is an underlying syndrome such as anemia or celiac disease, then treatment of POTS is usually aimed at treating these first. Once the underlying disorders are treated then the hope is that POTS symptoms will cease as well. However, POTS may still occur once the underlying disorder is treated. If this is the case or if an underlying cause of POTS is not found, then there are several ways to reduce episodes of POTS. These POTS treatment recommendations include:
- Drinking plenty of fluids and staying hydrated
- Staying active and exercising, however, patients should not overexert themselves
- Avoid large amounts of alcohol
- Patients should avoid laying completely flat and aim to have their head elevated
- Avoid excessive caffeine
- After sitting or lying down, patients should rise to a standing position slowly to avoid postural hypotension
Medications may also help to reduce POTS episodes. These medications include beta blockers, which work by reducing heart rate, thus treating the tachycardia syndrome. Glucocorticoids such as fludrocortisone may help treat POTS by reducing the amount of sodium a person loses in their urine. Retaining sodium helps to keep blood volume levels stable and may help POTS symptoms. Midodrine, an alpha one agonist, may help treat patients with POTS by narrowing blood vessels and maintaining blood flow. Additionally, researchers are continually investigating new treatments for this postural tachycardia syndrome
Treatment of POTS episodes in patients is fairly straightforward. If patients suddenly feel lightheaded or dizzy the first step is to lay down or sit down. If possible, it is also recommended to raise one's legs when laying down in order to increase the circulating blood volume in the body and stop symptoms of POTS. If patients are unable to sit or lay down, there are several postural maneuvers that can be done to reduce POTS symptoms. These include:
- Clenching one's fists
- Flexing muscles in the stomach
- Crossing your legs
- Rocking on one's feet from toe to heel
While these may help reduce POTS symptoms in some patients by helping maintain blood pressure, it is still recommended to lie or sit down until blood circulation is regulated and symptoms are alleviated.
Is POTS a serious condition?
Although POTS syndrome is not directly life-threatening, it is very important to take care and ensure the syndrome is properly managed. If loss of consciousness occurs due to POTS, serious harm can result. For this reason, it is important to find and treat the underlying disorder causing POTS if possible. Otherwise, it is vital to recognize when POTS symptoms are occurring and do one's best to alleviate them, such as sitting or laying down.
Does POTS syndrome go away?
Curing POTS syndrome usually depends on if an underlying disorder is found to be causing the syndrome. If it is, then treatment is aimed at the underlying disorder or issue. When the underlying disorder is treated, POTS syndrome may be cured. For individuals that do not have a clear etiology causing POTS syndrome, curing it may be more difficult. However, this does not mean that POTS syndrome unassociated with an underlying disorder cannot be cured. Ensuring adequate rest, diet, lifestyle changes, and water intake may also cure POTS syndrome, or at least help to minimize the symptoms.
Does this postural disorder affect men and women equally?
The short answer is no. POTS syndrome does not affect men and women equally. POTS by far affects women more than it affects men. Women aged 15-45 are particularly prone to having POTS.
Is this disorder helped by exercise?
Yes, POTS can be helped by exercise and physical therapy. However, due to the symptomatology of POTS it is encouraged for patients to undertake exercise very slowly and gradually. Practice rising from a laying position to a sitting position and from a sitting position to a standing position. This is when POTS symptoms are most likely to occur. If POTS symptoms do occur when changing positions, revert back to the previous position until blood circulation normailizes and symptoms recede. Patients should continue to practice slow orthostatic movements in order to reduce symptoms of POTS. Light exercise such as walking may also help POTS patients manage their symptoms.
Is Tachycardia a serious heart problem?
POTS is classified as a tachycardia syndrome that occurs with orthostatic changes. Tachycardia is an elevation in heart rate, the speed at which the heart pumps blood. A normal resting heart rate is between 60 and 100 bpm (beats per minute). This may increase when engaged in activity or exercising, as the muscles and organs require more blood during this time. Tachycardia is an elevated heart rate above 100 bpm and may cause symptoms such as chest pain (angina), intense heart beats (palpitations) or shortness of breath. Smart exercise trackers often measure health information which can include heart rate and pulse. However, heart rate may also be measured by finding one's pulse and counting the beats. The most accurate way to measure heart rate is to count the number of beats in a minute. This time may be shortened by counting the beats during a 30 or 15 second interval and multiplying the beats by 2 or 4 respectively. Although tachycardia can be a normal physiological response to exercise or stress, its occurrence as one of the orthostatic symptoms of POTS can cause an alarming feeling of palpitations or speeding heart rate.
Is there a blood test for POTS?
Unfortunately, there is not a simple blood test that may be done to diagnose the syndrome in POTS patients. However, during the workup for the syndrome, POTS patients will most likely have other blood tests done in order to rule out other conditions that may be causing symptoms. The diagnostic steps needed in order to accurately confirm the disease are previously discussed.
It is worth mentioning, that there is some evidence that POTS may be linked to a defect in the immune system. This causes immune cells to assault the body's tissues by mistake (termed an autoimmune response). Evidence to support this includes elevated autoimmune levels such as those found in thyroid illness, celiac disease and rheumatoid arthritis. These molecular levels can be an indication of inflammation throughout the body, including the heart.
How is Pots syndrome and Covid 19 related?
As discussed, POTS can occur on its own or due to an underlying etiology. One of the possible causes of POTS is previous viral illness. This includes COVID 19. Individuals with prolonged symptoms of COVID 19 have been termed "COVID long haulers". Long haulers continue to experience a myriad of symptoms after an active COVID infection including shortness of breath, lethargy, elevated heart rate, dizziness, and POTS. The severity of COVID 19 infection does not necessarily predict whether or not individuals will experience POTS. However, some factors appear to predispose individuals to developing POTS syndrome. These include:
- History of concussions
- Frequent dizziness
- Passing out or lightheadedness
- Heart pounding or skipping (palpitations)
Callie Torres is a Captain in the United States Air Force and a resident at Wash U/Barnes Jewish Hospital in St Louis. She is a freelance writer with many published medical articles as well as multiple peer-reviewed medical publications