A prospective, 1-year follow-up study of postural tachycardia syndrome.
OBJECTIVE
To prospectively evaluate patients who met standard criteria for postural tachycardia syndrome (POTS), at baseline and 1-year follow-up, using standard clinical and laboratory methods to assess autonomic function.


METHODS
Fifty-eight patients met the study criteria (orthostatic symptoms and a heart rate increment of ≥ 30 beats/min on head-up tilt) and completed 12 months of follow-up. All patients were enrolled and completed the study from January 16, 2006, through April 15, 2009. Patients underwent standardized autonomic testing, including head-up tilt, clinical assessment, and validated questionnaires designed to determine the severity of autonomic symptoms.


RESULTS
Patients were predominantly young females (n=49, 84%), with 20 patients (34%) reporting an antecedent viral infection before onset of symptoms. More than one-third (37%) no longer fulfilled tilt criteria for POTS on follow-up, although heart rate increment on head-up tilt did not differ significantly at 1 year (33.8 ± 15.1 beats/min) compared with baseline (37.8 ± 14.6 beats/min) for the entire cohort. Orthostatic symptoms improved in most patients. Autonomic dysfunction was mild as defined by a Composite Autonomic Severity Score of 3 or less in 55 patients (95%) at baseline and 48 patients (92%) at 1 year.


CONCLUSIONS
To our knowledge, this is the first prospective study of the clinical outcomes of patients with POTS. Orthostatic symptoms improved in our patients, with more than one-third of patients no longer fulfilling tilt criteria for POTS, although the overall group change in heart rate increment was modest. Our data are in keeping with a relatively favorable prognosis in most patients with POTS.
Department of Clinical Neurological Sciences, University Hospital, University of Western Ontario, London, Ontario, Canada.
Kurt
K
Kimpinski
Juan J
JJ
Figueroa
Wolfgang
W
Singer
David M
DM
Sletten
Valeria
V
Iodice
Paola
P
Sandroni
Philip R
PR
Fischer
Tonette L
TL
Opfer-Gehrking
Jade A
JA
Gehrking
Phillip A
PA
Low
D058646:Adrenergic alpha-1 Receptor Agonists / Q000627:therapeutic use; D058671:Adrenergic beta-1 Receptor Antagonists / Q000627:therapeutic use; D000328:Adult; D000893:Anti-Inflammatory Agents / Q000627:therapeutic use; D001262:Atenolol / Q000627:therapeutic use; D002800:Cholinesterase Inhibitors / Q000627:therapeutic use; D005260:Female; D005438:Fludrocortisone / Q000627:therapeutic use; D005500:Follow-Up Studies; D006339:Heart Rate; D006801:Humans; D008297:Male; D008790:Metoprolol / Q000627:therapeutic use; D008879:Midodrine / Q000627:therapeutic use; D009248:Nadolol / Q000627:therapeutic use; D009638:Norepinephrine / Q000097:blood; D054972:Postural Orthostatic Tachycardia Syndrome / Q000188:drug therapy / Q000453:epidemiology*; D011433:Propranolol / Q000627:therapeutic use; D011446:Prospective Studies; D011729:Pyridostigmine Bromide / Q000627:therapeutic use; D012720:Severity of Illness Index; D012964:Sodium / Q000652:urine; D018667:Tilt-Table Test; D014777:Virus Diseases / Q000453:epidemiology
D058646:Adrenergic alpha-1 Receptor Agonists; D058671:Adrenergic beta-1 Receptor Antagonists; D000893:Anti-Inflammatory Agents; D002800:Cholinesterase Inhibitors; D009248:Nadolol; D001262:Atenolol; D008879:Midodrine; D012964:Sodium; D011433:Propranolol; D008790:Metoprolol; D011729:Pyridostigmine Bromide; D005438:Fludrocortisone; D009638:Norepinephrine