Postural Tachycardia Syndrome (POTS)

Original Editors - Brian Blevins and Allison Lesousky from Bellarmine University's Pathophysiology of Complex Patient Problems project.

Top Contributors - Allison Lesousky, Brian Blevins, Kim Jackson, Lucinda hampton, Admin, Elaine Lonnemann, Thomas Janicky, Hugh Jones, WikiSysop, Heba El Saeid, Wendy Walker, Karen Wilson, Vidya Acharya, 127.0.0.1 and Rachael Lowe  

Definition/Description

Postural Orthostatic Tachycardia Syndrome (POTS ) is described by a patient's intolerance to the change of body position from supine to an upright position - it is characterized by a dramatic and excessive increase in heart rate. POTS is theorized to be due to an autonomic dysregulation regulating blood flow and more specifically its' responsibility to control cerebral blood flow. POTS be classified as; primary or idiopathic with no known cause; secondary, which arises from a known disease or disorder.

Prevalence

The prevalence of POTS is currently unknown, with it currently estimated to be about 5-10 times as common as orthostatic hypotension in clinical practice. Some studies have indicated estimates of as much as 170/100,000 but also based on the estimate that 40% of chronic fatigue patients have POTS.

Characteristics/Clinical Presentation

POTS is a complex, multi-system, chronic disorder of the autonomic nervous system characterized by orthostatic intolerance with excessive heart rate (HR) increase and symptoms on standing while blood pressure is maintained. Orthostatic symptoms improve rapidly after returning to a supine position. Apart from the abnormal circulatory response to standing, patients with POTS may experience a variety of other persistent symptoms such as low energy, headache, cognitive impairment, muscle fatigue, chest pain, and non-specific generalized weakness, along with numerous gastrointestinal symptoms. POTS has been defined by major international neurologic, autonomic, cardiac, and pediatric societies to include the following:

1. A sustained HR increment of not less than 30 beats/minute within 10 min of standing or head-up tilt. For individuals who are 12 to 19 years old, the required HR increment is at least 40 beats/minute; and

2. An absence of orthostatic hypotension (i.e. no sustained systolic blood pressure [BP] drop of 20 mmHg or more); and

3. Frequent symptoms of orthostatic intolerance during standing, with rapid improvement upon return to a supine position. Symptoms may include lightheadedness, palpitations, tremulousness, generalized weakness, blurred vision, and fatigue; and

4. Duration of symptoms for at least 3 months; and 5. Absence of other conditions explaining sinus tachycardia such as anorexia nervosa, primary anxiety disorders, hyperventilation, anemia, fever, pain, infection, dehydration, hyperthyroidism, pheochromocytoma, use of cardioactive drugs (e.g. sympathomimetics, anticholinergics) or severe deconditioning caused by prolonged bed rest                

Associated Co-morbidities

POTS is primarily idiopathic, but secondary POTS is characterized by the presence of a disease or disorder. The most common associated co-morbity that presents with POTS is Myalgic Encephalomyelitis or Chronic Fatigue Syndrome (CFS). Currently it is thought that POTS may cause CFS with patients demonstrating orthostatic intolerance and the treatment of POTS usually improves the disabling fatigue in patients with both POTS and CFS. Other associated co-morbidities are found to include, vasovagal syncope, or specifically named "neurocardiogenic syncope" characterized by similar symptoms such as syncope upon position change and autonomic dysregulationPOTS has been also associated with patients with fibromyalgia due to the improvement in myofascial and neuropathic pain symptoms when treated for POTS. Irritable Bowel Syndrome often associated with POTS due to the presence of the related autonomic dysfunction. It has also been proposed that Ehlers-Danlos Syndrome (EDS), a connective tissue disorder, is found in some POTS patients . This syndrome tends to occur with POTS due to the abnormal connective tissue development in dependent blood vessels which allow excessive amounts of blood to pool in the lower limbs when they stand.

Other associated co-morbidities include:

• Addison's Disease
• Anemia
• Diabetes
• Guillan-Barré & Systematic Lupus Erythematosus
• Cardiovascular disease/atrophy
• Gastric Bipass Surgery
• Lesions of the Autonomic Nervous System
• Syringomyelia
• Thyroid Disease
• Tumors

Medications

There are many medical interventions available for the management of POTS. The primary drug of choice for symptoms relief in POTS is a fludrocortisone used to increase sodium retention in order to increase blood volume which subsequently increases blood pressure. Beta-blockers are also often prescribed in order to control the signature excessive heart rate of POTS. The stimulant midodrine is often used to treat orthostatic hypotension by causing vasoconstriction which increases blood pressure allowing blood to return to the upper body more efficiently. Beta-blockers are often used in conjunction with midodrine due to the tendancy for supine hypertension. Furthermore, with the likely involvement of the autonomic nervous system, antidepressants such as SSRI's have been found to be effective in re-establishing proper autonomic functioning and there-by regulating blood pressure in all positions

Diagnostic Tests/Lab Tests/Lab Values

Currently, POTS is difficult to diagnose and patients usually endure symptoms for a year or longer. However, once all other differentials are excluded, patients are often diagnosed with POTS through a tilt table test. A patient is strapped to a mechanical tilt table in which it will tilt them upright at angles of at least 60 degrees. Measurements of HR and BP are taken in supine and then at intervals during the change in position and this test can take up to 40 minutes or until the patient faints Often the tilt table test is used concurrently with a transcranial doppler ultrasonography which proves useful in determining cerebral blood flow perfusion during position changes. It is very important to rule out all differentials that could indicate a more serious systemic pathology such as Addison's, Lyme Disease, thyroid dysfunction, etc.

Etiology/Causes

The current etiology of POTS are not fully known. POTS is theorized to be due to an autonomic dysregulation regulating blood flow and more specifically its' responsibilty to control cerebral blood flow. Many patients will develop POTS in their teens after periods of rapid growth, especially in males, and will see symptom improvements as age advances. Other patients will develop POTS after a significant viral or bacterial infections such as pneumonia, or even after trauma such as an MVA. Women also tend to develop symptoms of POTS after pregnancy, in which prognosis for symptoms tend to be less optimistic.

Systemic Involvement

POTS can have significant systemic involvement given all other differentials are excluded. Systemic involvement usually involves hypo-perfusion of blood to upper body, and in particular the organs. This includes symptoms presenting related to reduced cerebral blood flow such as decreased mental stamina, depression, difficulty finding the right word, impaired concentration, sleep disorders. Symptoms can also present as hypo-perfusion to viscera and/or related to autonomic dysregulation such as abdominal pain or discomfort, bloating, constipation, diarrhea, nausea & vomiting . Other systemic involvement usually related to chronic fatigue and general malaise, thus the common co-diagnosis of Chronic Fatigue Syndrome.

Medical Management

The survery by Junghans-Rutelonis and his colleagues suggests adopting an interdisciplinary team to determine the ideal combinations of treatments (pharmacologic, physical therapy, integrative medicine, cognitive-behavioral therapy, psychoeducation approaches) that address the child's condition. Management includes the following recommendations:

• Dietary Recommendations - Patients are encouraged to manage their symptoms through diet, including a high fluid intake (2L/day) and at least 3-5 g of salt.

• Non-Pharmacological Treatment - Acute blood volume expansion has been shown to be effective at controlling the heart rate and acutely improving symptoms.  Jacob et al. found that 1L of physiological saline infused intravenously over 1 hour decreased the orthostatic tachycardia immediately following the infusion.

• Pharmacological Treatment - If non pharmacological treatments are not successful medications may be trialled. There are no specific types of drugs treatments for POTS because it primarily depends on the type of etiology responsible for the syndrome. Drugs that have been shown to produce some success include: fludrocortisone, β-blockers, selective serotonin reuptake inhibitors (SSRIs), and norepinephrine reuptake inhibitor (NRI).

• Fludrocortisone helps by increasing the sodium and fluid retention, while also sensitizing α-adrenergic receptors.
• β-blockers can be used to treat the hyperadrenergic form of POTS
• SSRIs increase nerve stimulation and communication of the standing vasoconstriction reflex, which reduces the venous blood pooling and in turn increased the patient’s orthostatic tolerance. In symptomatic patients, the addition of a NRI would also be beneficial.

A multi-disciplinary approach is required as the patient’s activities of daily living become increasingly more difficult and require help in all aspects. It is essential to involve the knowledge of occupational/physical therapists, social workers, and clinical psychologists as well as legal counsellors.

Physical Therapy Management

Patient education focusing on

• the patient’s understanding of respiratory physiology, specifcally respiratory control and normal breathing pattern
• the mind—body link and how external factors such as anxiety, stress and lifestyle influences breathing patterns resulting in breathlessness.

Breathing re-training should include the following techniques

• breathing control at rest and during activity.
• controlled pause technique.

The following video clip shows a young woman's journey of 15 years living with POTS and her symptoms and treatment approach.

Include; Inappropriate Sinus Tachycardia Syndrome; Myalgic Encephalomyelitis or Chronic Fatigue Syndrome; Pheochromocytoma; Neurally Mediated Syncope 

Case Reports/ Case Studies

• Anaesthetic management of a parturient with the postural orthostatic tachycardia: a case report http://bja.oxfordjournals.org/content/97/2/196.full.pdf
• Study: Postural Orthostatic Tachycardia Syndrome http://www.alter-g.com/case-study/postural-orthostatic-tachycardia-syndrome
• Care of an adolescent with postural orthostatic tachycardia syndrome http://www.saudija.org/article.asp?issn=1658-354X;year=2010;volume=4;issue=1;spage=23;epage=27;aulast=Kernan
• A review of postural orthostatic tachycardia syndrome http://europace.oxfordjournals.org/content/11/1/18.full
• POTS following traumatic stress http://www.ncbi.nlm.nih.gov/pubmed/25708501

  Resources

• National Dysautonomia Research Foundation (NDRF) http://www.ndrf.org/
• Dysautonomia Youth of America, Inc. (DYNA) http://www.dynakids.org/
• POTS Place: A Guide to Postural Orthostatic Tachycardia Syndrome (DINET) http://www.dinet.org/
• NINDS Postural Tachycardia Syndrome Information Page http://www.ninds.nih.gov/disorders/postural_tachycardia_syndrome/postural_tachycardia_syndrome.htm
• Chronic Fatigue Immune Dysfunction Syndrome (CFIDS) Association http://www.cfids.org/
• American Autonomic Society (AAS) http://www.americanautonomicsociety.org/
• North American Society for Pacing and Electrophysiology (NASPE) http://www.hrsonline.org/
• Vanderbilt Autonomic Center http://www.mc.vanderbilt.edu/root/vumc.php?site=adc
• The Mayo Clinic, Rochester, MN http://www.mayo.edu/
• The American Association for Chronic Fatigue Syndrome (AACFS) http://www.cfids.org/
• New Jersey CFS Center http://njms.umdnj.edu/centers_institutes/pain_fatigue/
• CDC (Centers for Disease Control and Prevention): CFS Home Page http://www.cdc.gov/cfs/
• MyHeart POTS Syndrome Center http://myheart.net/pots-syndrome/