Postural Orthostatic Tachycardia Syndrome (POTS) is a common form of dysautonomia and a subset of orthostatic intolerance that is associated with excessive tachycardia on standing.[i] 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, typically done through a Tilt Table Test.[ii] Although the focus is on excess heart rate increase upon standing, POTS usually presents with additional symptoms as well. Some of these common symptoms include: changes in blood pressure upon standing, heart palpitations, chest pain, lightheadedness, dizziness, fainting, headaches, shortness of breath, exercise intolerance, nausea, diminished concentration, and extreme/chronic fatigue.[iii] This makes a full history an important aspect of diagnosis. Symptoms may vary from patient to patient. Some people with POTS have mild symptoms and can continue with normal work, social activities and daily responsibilities. For others, symptoms may be severe that normal activities of daily living(ADLs), such as walking, housework, dressing, and bathing, can be limited. Even within an individual, POTS symptoms may vary daily; one day the person may have mild symptoms and be functional but the next day may be a very “symptomatic day”, causing the person to lose ability to function for that day. Physicians have compared the functional impairment seen in POTS patients to the impairment seen in chronic obstructive pulmonary disease (COPD) or congestive heart failure. [iv]
What Causes POTS?
POTS itself is not a disease, but a group of symptoms. POTS is classified as being either primary or secondary. The primary forms are idiopathic and not associated with other diseases. The secondary forms occur in association with a known disease or disorder.[v] When is POTS believed to be caused by a primary disease or disorder, it is important to determine that cause for management and treatment. Determining the cause of POTS symptoms in each patient can be very difficult and in many cases, physicians may not be able to determine that underlying cause. Some of the common causes are autoimmune diseases, Ehler Danlos Syndrome[vi], genetic disorders, viruses[vii], or bodily stressors.
Treatment for each person with POTS is different, so thus consulting with a specialist who has experience in treating POTS is critical. Sometimes treatment can be a trial and error process. If an underlying cause of the POTS can be identified, treating the underlying cause is the first step. The most common treatments for POTS include lifestyle changes such as increasing fluid intake to 2-3 liters per day; increasing salt consumption; wearing compression stockings; exercise that is tolerated; a healthy diet; avoiding substances and situations that worsen symptoms(such as alcohol consumption, sitting too long, energy drinks, and heat). In conjunction with lifestyle change, medications can also be used, such as: Midodrine, Fludrocortisone, Beta Blockers, and SSRIs.[viii]
Currently, there is no cure for POTS, however physicians and researchers believe many people with POTS will be fully symptom free over time. Doctors believe that most patients who develop POTS during puberty or adolescence usually recover by their mid teen to early 20s. Estimates are that about 50% of patients who have post-viral POTS will fully or almost fully recover within a two to five year period. With proper lifestyle and medical treatments, many patients will see a substantial improvement in their quality of life. While the prognosis is good for most patients, researchers have noted that some patients will not improve and may actually worsen over time.[ix] [x]
[i] Grubb BP. Postural Tachycardia Syndrome. Circulation 2008: 117: 2814-2817
[ii] Grubb BP, Row P, Calkins H. Postural tachycardia, orthostatic intolerance and the chronic fatigue syndrome. In: Grubb BP, Olshansky B, eds. Syncope: Mechanisms and Management 2nd Ed. Malden, Mass: Blackwell/Future Press; 2005: 225–244.
[iii] Kanjwal Y, Kosinski D, Grubb BP: The postural tachycardia syndrome: Definition, diagnosis and management. Pacing Clin Electrophysiol 2003;26: 1747-1757.
[iv] Kanjwal Y, Kosinski D, Grubb BP: The postural tachycardia syndrome: Definition, diagnosis and management. Pacing Clin Electrophysiol 2003;26: 1747-1757.
[v] Kanjwal Y, Kosinski D, Grubb BP: Treatment of postural orthostatic tachycardia syndrome and inappropriate sinus tachycardia. Curr Cardiol Rep 2003;5: 402-406.
[vi] Rowe PC, et al. J Orthostatic intolerance and chronic fatigue syndrome associated with Ehlers-Danlos syndrome. Pediatr. 1999 Oct;135(4):494-9.
[vii] Itoh Y, Oishi T, Ohnishi A, et al. Acute cerebellar ataxia with sympathotonic orthostatic hypotension following Epstein_barr virus infection: a case report. Rinsho Shinkeigaku. 1993: 44: 503-506
[viii] Kanjwal Y, Kosinski D, Grubb BP: The postural tachycardia syndrome: Definition, diagnosis and management. Pacing Clin Electrophysiol 2003;26: 1747-1757
[ix] Grubb BP. Postural Tachycardia Syndrome. Circulation 2008: 117: 2814-2817