Clinical Trial: Assessment of Antibodies and Inflammatory Markers in Postural Tachycardia Syndrome

Study Status: Active, not recruiting
Recruit Status: Active, not recruiting
Study Type: Observational

Official Title: Assessment of Antibodies and Inflammatory Markers in Postural Tachycardia Syndrome

Brief Summary: 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.

Detailed Summary:

Postural orthostatic tachycardia syndrome is poorly understood. Many of these patients have elevated levels of plasma norepinephrine, particularly when upright One subgroup of patients has a primary hyperadrenergic state. The majority of patients have a marked deficit in plasma blood volume compared to healthy control subjects. The investigators have previously reported that some patients suffer paradoxically from a partial dysautonomia affecting the lower limbs. Most patients seem to suffer from either a primary or secondary increase in central sympathetic nervous system drive. Recent data have shown that patients with postural orthostatic tachycardia syndrome have a lower cardiac stroke volume than their healthy counterparts and this low stroke volume may drive their orthostatic tachycardia.

The investigators plan to do the following:

The physical examination will include (at minimum):

• Height
• Weight
• Orthostatic vital signs (heart rate and blood pressure) Supine and Standing for up to 10 minutes
• Beighton Criteria for Joint Hypermobility Syndrome (Ehlers-Danlos III)
• Dependent acrocyanosis (during stand test)

Continuous Heart Rate and Blood Pressure Recording A subset of subjects will be given the opportunity to also have continuous recordings of heart rate and blood pressure for 5-10 minutes while lying down quietly. They will be instrumented with EKG patches on their body and a finger blood pressure cuff, and these data will be digitally sampled and acquired on a dedicated laptop computer for later offline analysis.

The primary outcome measure will be the proportion of subjects with alpha-1 Ab titer. The primary comparison will be the proportion of Ab titers between POTS patients compared to control subjects.