Postural orthostatic tachycardia syndrome
|
Postural orthostatic tachycardia syndrome Microchapters |
|
Diagnosis |
|---|
|
Treatment |
|
Case Studies |
|
Postural orthostatic tachycardia syndrome On the Web |
|
American Roentgen Ray Society Images of Postural orthostatic tachycardia syndrome |
|
Directions to Hospitals Treating Postural orthostatic tachycardia syndrome |
|
Risk calculators and risk factors for Postural orthostatic tachycardia syndrome |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor-In-Chief: Cafer Zorkun, M.D., Ph.D. [2]
For patient information click here
Synonyms and Keywords: postural tachycardia syndrome, POTS
Overview
Postural orthostatic tachycardia syndrome is a poorly understood autonomic disturbance, which manifests as a change in HR>30BPM upon the patient standing erect from supine or a head-up tilt without underlying orthostatic hypotension. Sympathetic hyperstimulation secondary to a fall in vascular tone and cerebral hypoperfusion leads to transient symptoms such as inappropriate sinus tachycardia, chronic fatigue and dizziness. Many patients also report non specific symptoms such as GI disturbances and sleep disturbances. This incapacitating syndrome has no known etiology, with theories listing post infectious, autoimmune, cardiac deconditioning and emotional states as possible factors. Antinuclear antibodies along with elevated ganglionic, adrenergic, and muscarinic acetylcholine receptor antibodies have all been reported. Diagnosis involves eliminating all primary cardiac, endocrine, neuropathic and psychiatric causes of postural tachycardia. Treatment is multimodal and consists of patient education, volume replenishment, physical countermaneuvers (graded stockings) and pharmacological therapy.
Historical Perspective
Pathophysiology
The pathophysiology is poorly understood and multifactorial. There are many reported findings across patients with POTS with a variety of combinations, making it difficult to pinpoint one as primary and thereby causative. The mechanisms suggested here are also interdependent.
Distal denervation with preservation of cardiac innervation
Hypovolemia or possible increased baroreceptor sensitivity
abnormal venuous function causing decreased preload on standing
cardiovasclar deconditioning
hyperadrenergic state (increase in sympathetic activity)
genetic factors
Differentiating POTS from Other Disorders
Epidemiology and Demographics
POTS is believed to be the most prevalent type of orthostatic intolerance. One study approximates the prevalence to be 500,000 americans. It is also commonly seen in younger patients (<45 years) who present to autonomic dysfunction clinics. Women are more likely to suffer from this disorder, with the ratio between genders being 4-5:1. The cause of this is unknown as yet. There is no racial predilection to this disorder.
Risk Factors
Natural History, Complications and Prognosis
Most patients present young, and prognosis is generally favourable.
Diagnosis
History and Symptoms | Physical Examination | Laboratory Findings | Electrocardiogram | Chest X Ray | Echocardiography | Other Diagnostic Studies
Treatment
ACC/AHA/ESC Treatment Guidelines | Medical Therapy | Cost-Effectiveness of Therapy | Future or Investigational Therapies