Postural tachycardia syndrome (POTS) is a debilitating disorder resulting from cardiovascular autonomic dysfunction, has many causes and is very difficult to treat effectively. The investigators have identified the presence of autoantibodies (immune proteins) directed against some receptors of the autonomic nervous system that can cause patient's symptoms on standing.~The present study is designed to test the hypothesis that patients with POTS harbor functional autoantibodies to adrenergic receptors that lead to an excessive tachycardia characteristic of POTS. For this purpose, this study will define the prevalence, burden, and the in vivo physiological significance of these adrenergic antibodies in a well-phenotyped and representative cohort of patients with POTS and a matched cohort of healthy control subjects, and will characterize the stability of these autoantibodies over time in affected POTS patients.
The purpose of this study is to see if some people with postural tachycardia syndrome (POTS) have higher levels of immune proteins (autoantibodies) directed against receptors of the autonomic nervous system, and if these autoantibodies make a difference in their POTS symptoms. The investigators also want to see if the levels of these autoantibodies stay the same over time.