Elsevier

Mayo Clinic Proceedings

Volume 87, Issue 8, August 2012, Pages 746-752
Mayo Clinic Proceedings

Original article
A Prospective, 1-Year Follow-up Study of Postural Tachycardia Syndrome

https://doi.org/10.1016/j.mayocp.2012.02.020Get rights and content

Abstract

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.

Conclusion

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.

Section snippets

Study Patients

Study patients needed to meet all 3 of the following criteria to be enrolled in the study: (1) males or females 13 to 50 years of age, (2) orthostatic heart rate increment of 30 beats/min within 5 minutes of HUT, and (3) symptoms of orthostatic intolerance, including weakness, light-headedness, blurred vision, nausea, palpitations, and difficulty with concentration and thinking for a period of greater than 3 months. The Mayo Clinic Institutional Review Board approved this study. All patients

Patient Characteristics

Fifty-eight patients met the criteria for POTS, were enrolled in the current study, and completed 1 year of follow-up. Fifty-four patients were followed up at 1 year. The remaining patients completed their forms but did not return for the follow-up visit. One patient was pregnant. Most patients were female (49) and young (27.4±10.9 years of age). Patients were symptomatic with the disorder for a mean of 3.4 years, 14 (24%) of patients had a history of remote orthostatic intolerance or syncope

Discussion

The main findings of our study were that overall symptoms and functional status (Autonomic Symptom Profile averaged over time) improved and 20 (38%) no longer met orthostatic heart rate criteria for POTS. Other key points are as follows. First, our cohort of patients with POTS consisted of predominantly young females with a variable onset of symptoms, with approximately one-third reporting an antecedent viral infection before the onset of symptoms. Second, heart rate increment on HUT for the

Conclusion

To our knowledge, the current study is the first large cohort of patients studied in a prospective manner with respect to clinical outcomes in POTS. Our patient group revealed improvement in their orthostatic symptoms with minimal mean change in heart rate increment on HUT. The autonomic dysfunction in our patients was mild but yielded evidence of sympathetic denervation in the lower limbs and mild adrenergic dysfunction in keeping with our prior assertion that many of these patients are

Acknowledgments

We thank Pamela Bass, Anita Zeller, and Lauri Louwagie for their administrative help.

References (17)

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Grant Support: This work was supported in part by National Institutes of Health (NS 32352 Autonomic Disorders Program Project, NS 44233 Pathogenesis and Diagnosis of Multiple System Atrophy, U54 NS065736 Autonomic Rare Disease Clinical Consortium), Mayo CTSA (UL1 RR24150), and Mayo Funds. The Autonomic Diseases Consortium is a part of the National Institutes of Health Rare Diseases Clinical Research Network (RDCRN). Funding and/or programmatic support for this project has been provided by U54 NS065736 from the National Institute of Neurological Diseases and Stroke and the National Institutes of Health Office of Rare Diseases Research.

Disclaimer: The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institute of Neurological Disorders and Stroke or the National Institutes of Health.

Potential Competing Interests: Dr Low is a consultant to WR Medical, Stillwater, MN.

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