Autoimmunity and postural orthostatic tachycardia syndrome: Implications in diagnosis and management.

Postural orthostatic tachycardia syndrome (POTS)-sustained tachycardia upon standing without orthostatic hypotension-can be diagnosed clinically without an extensive diagnostic evaluation unless certain atypical features suggest an alternative diagnosis. A unifying pathophysiologic mechanism has not been identified, although several have been proposed. Similarities between POTS and various autoimmune disorders suggest an immune mechanism in a subset of patients. However, no causative antibody has been identified, and associated antibodies are rarely clinically relevant. Moreover, immunotherapies are not currently recommended for POTS, although clinical trials are underway to clarify their utility.