Phenotyping of Postural Orthostatic Tachycardia Syndrome (POTS)
This is an observational study to deeply phenotype the disorder of POTS using multiple testing modalities.
- EligibilityCriteria: Inclusion Criteria:  POTS Patients  Age ≥ 14 years, able to provide informed consent (assent with parental consent for age < 18) and comply with procedures Meets consensus criteria for POTS: (1) sustained increase in heart rate ≥ 30 bpm above supine baseline within 10 min of quiet standing or upright tilt (≥ 40 bpm in individuals 12 to 19 years of age) OR sustained upright HR >120 bpm, (2) absence of orthostatic hypotension, (3) symptoms with standing that improve with sitting or lying down, (4) resting supine heart rate < 100 bpm, (5) orthostatic symptoms present for at least 6 months Stable oral medication regimen for at least 14 days  Non-POTS Control Patients  Healthy women, age 18 - 30 years, able to provide informed consent and comply with study procedures Does NOT meet consensus criteria for postural tachycardia syndrome No symptoms of orthostatic intolerance or dysautonomia. No history of other major medical disorder Resting supine heart rate < 100 bpm  Exclusion Criteria:  None of the following exclusion criteria:  Use of amphetamine-type stimulants, diuretics, selective norepinephrine reuptake inhibitor, anticholinergic medications (including tricyclic antidepressant medications), fludrocortisone, desmopressin in past 14 days Use of other autonomic drugs (adrenergic agents, pyridostigmine, droxidopa, triptans, ivabradine) in past 48 hours Currently receiving IVIG, subcutaneous IgG, or any investigational medication (in past year) Infusion of iv fluids in past 7 days History or evidence of another condition explaining symptoms or orthostatic tachycardia (e.g. structural heart disease, CSF hypovolemia, or severe traumatic brain injury) - HealthyVolunteers: Accepts Healthy Volunteers - Gender: All - MinimumAge: 14 Years - StdAgeList: Child, Adult, Older Adult - StudyPopulation: POTS patients and Normal Control - SamplingMethod: Non-Probability Sample