Evaluation of postural tachycardia syndrome (POTS).

The diagnostic evaluation of a patient with suspected postural tachycardia syndrome (POTS) requires a thoughtful diagnostic approach utilizing a careful clinical history and examination, laboratory, and autonomic testing. This article outlines the importance of a thorough history in identifying mechanism of symptom onset, clinical features, associated clinical conditions or disorders, and factors that may result in symptom exacerbation. The clinical examination involves an assessment of pupillary responses, an evaluation for sudomotor and vasomotor signs, and an assessment for joint hypermobility. Laboratory testing helps to exclude mimics of autonomic dysfunction, recognize conditions that may exacerbate symptoms, and to identify conditions that may cause or be associated with autonomic nervous system disease. The purpose of autonomic testing is to confirm a POTS diagnosis, exclude other causes of orthostatic intolerance, and may provide for characterization of POTS into neuropathic and hyperadrenergic subtypes. Other diagnostic studies, such as epidermal skin punch biopsy, exercise testing, radiographic studies, sleep studies, gastrointestinal motility studies, and urodynamic studies should be considered when clinically appropriate.