Assessment of Antibodies and Inflammatory Markers in Postural Tachycardia Syndrome

In this pilot study, the investigators will test the hypothesis that patients with postural tachycardia syndrome will have an elevated percentage of functional antibodies to adrenergic receptors compared with control subjects without POTS. The investigators further hypothesize that the percentage of POTS patients with antibodies will be higher in those patients with a viral infection at the onset of their illness than in those patients with other or undefined illness onsets.