POTS Overview

 

Postural Orthostatic Tachycardia Syndrome (POTS) is a type of dysautonomia, a set of conditions resulting from malfunction of the Autonomic Nervous System (ANS).  The ANS controls bodily functions we don't have to think about such as heart rate, blood pressure, digestion, temperature regulation, and vascular tone.  The hallmark of POTS is an increase in heart rate upon standing.  

 

POTS Diagnostic Criteria (Raj, 2006)

The following criteria are used to make a diagnosis of POTS:

(1) Heart rate increase greater than or equal to 30 BPM from supine (lying down) position to standing (5-30 minutes)

(2) Symptoms get worse with standing and better with recumbence (lying down)

(3) Symptoms lasting greater than or equal to 6 months

(4) Standing plasma norepinephrine ≥ 600 pg/ml

(5) Absence of other causes of orthostatic symptoms or tachycardia (e.g. active bleeding, dehydration, medications, etc) 

 

Demographics (Grubb & McMann, 2001)

(1) 5:1 ratio of women to men

(2) Ages 15-50

(3) 1 in 100 teens will develop POTS

(4) Familial at times

 

Symptoms (Wikipedia)

The hallmark symptom of POTS is an increase in heart rate from the supine to upright position of more than 30 beats per minute or to a heart rate greater than 120 beats per minute within 12 minutes of head-up tilt.

This tachycardic response is sometimes accompanied by a decrease in blood pressure and a wide variety of symptoms associated with hypotension. Low blood pressure of any kind may promote the following:
• Lightheadedness, sometimes called pre-syncope (pre-fainting) dizziness (but not vertigo, which is also called dizziness)
• Exercise intolerance
• Extreme fatigue
• Syncope (fainting)
• Excessive thirst (polydipsia)

Chronic or acute hypoperfusion of tissues and organs in the upper parts of the body are thought to cause the following symptoms:
• Cold extremities
• Chest pain and discomfort
• Disorientation
• Tinnitus
• Dyspnea
• Headache
• Muscle weakness
• Tremulousness
• Visual disturbances

Autonomic dysfunction is thought to cause additional gastrointestinal symptoms:
• Abdominal pain or discomfort
• Bloating
• Constipation
• Diarrhea
• Nausea
• Vomiting

Cerebral hypoperfusion, when present, can cause cognitive and emotive difficulties. Symptoms that persist in the supine (recumbent) state are difficult to attribute to "cerebral hypoperfusion"
• Brain fog
• Burnout
• Decreased mental stamina
• Depression
• Difficulty finding the right word
• Impaired concentration
• Sleep disorders

Inappropriate levels of epinephrine and norepinephrine lead to anxiety-like symptoms:
• Chills
• Feelings of fear
• Flushing
• Overheating
• Nervousness
• Over-stimulation

 

Causes

The causes of POTS remain uncertain and are believed to be many. It is commonly seen in adolescents after the onset of puberty or sometimes following a period of rapid growth. Infection continues to be a major trigger in this age group with mono being common in North America.

For adults, common triggers include pregnancy or after giving birth, infections (mostly viral), injury or trauma, autoimmune, secondary to chronic illness, and of genetic origin (Grubb, Kanjwal & Kosinski, 2006).   

 

Treatment

No medicines are approved by the United States Food and Drug Administration for the treatment of POTS. Thus all drugs being used for this disorder are "off label" (Raj, 2006). There are a number of medications being tried for POTS currently. The tricky part is finding the right combination of drugs for each individual as each POTS patient is different. There are also many non-medication options listed under helpful tips.

 

Prognosis

Many POTS patients will see an improvement in symptoms over the course of years. Those who develop it as teenagers often have resolution of symptoms by their 20s. Those who have POTS associated with other conditions may experience lifelong symptoms (Wikipedia).

 

The most common course tends to be symptoms that will come and go, vary in intensity, and change on a daily or hourly basis.

 

Continued research is necessary to help further understand this condition, to learn more about the different types, and to better treat POTS patients as the symptoms are life altering and far too often debilitating.  

 

 

 References

(1) Raj Sr. The Postural Tachycardia Syndrome (POTS): Pathophysiology, Diagnosis & Management, Indian Pacing Electrophysiology

       Journal (2006); 6 (2): 84-99

(2) Grubb, B.P., & McMann, M.C. (2001). The Fainting Phenomenon: Understanding why people faint and wat can be done about it.

       New York: Futura Publishing Company

(3) http://en.wikipedia.org/wiki/Postural_orthostatic_tachycardia_syndrome

(4) Grubb B. P., Kanjwal, Y., & Kosinski, D. J. (2006). The postural tachycardia syndrome: A concise guide to diagnosis and management.

       J Cardiovasc Electrophysiol., 17, 108-112.

(5) http://www.dinet.org/pots_an_overview.htm