title: Postural tachycardia syndrome: clinical features and follow-up study.
abstract: OBJECTIVE
  To define the clinical features and outcome of postural tachycardia syndrome (POTS).
  
  
  METHODS
  In this cross-sectional study of the autonomic symptom profile, inclusion criteria were orthostatic heart rate increment of 30 beats/min or greater, orthostatic symptoms, completion of a standardized autonomic test battery, and follow-up of 18 months or longer. We used 2 instruments. The first part was a structured and validated autonomic symptom profile (108 patients). The second part was a structured questionnaire focused on autonomic status on prospective follow-up (40 patients) (mean +/- SD follow-up, 67+/-52 months).
  
  
  RESULTS
  Most patients had frequent, persistent, and at least moderately severe symptoms for less than 5 years. The following orthostatic symptoms occurred in more than 75% of subjects: light-headedness or dizziness, lower extremity or diffuse weakness, disequilibrium, tachycardia, and shakiness. Nonorthostatic symptoms included dry eyes or mouth, gastrointestinal complaints of bloating, early satiety, nausea, pain, and alternating diarrhea and constipation. Half of the patients reported an antecedent illness presumed to be of viral origin. On follow-up, 80 % of patients were improved, 60% were functionally normal, and 90% were able to return to work. Patients who had an antecedent event appeared to do better than those with spontaneous POTS. Salt supplementation and beta-blockers were the most efficacious therapies.
  
  
  CONCLUSIONS
  In the majority of patients, POTS is self-resolving, especially in those with a triggering event.
authors.affiliation: Autonomic Disorders Center, Department of Neurology, Mayo Clinic Rochester, Minn 55905, USA.
authors.forename: P
authors.initials: P
authors.lastname: Sandroni
authors.forename: T L
authors.initials: TL
authors.lastname: Opfer-Gehrking
authors.forename: B R
authors.initials: BR
authors.lastname: McPhee
authors.forename: P A
authors.initials: PA
authors.lastname: Low
mesh_terms: D000328:Adult; D003430:Cross-Sectional Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007024:Hypotension, Orthostatic / Q000150:complications* / Q000503:physiopathology; D008297:Male; D011187:Posture; D011446:Prospective Studies; D013610:Tachycardia / Q000150:complications / Q000209:etiology* / Q000503:physiopathology