Qualitative Sweat Distribution During Tilt Table Procedure
Condition: Postural Tachycardia Syndrome; Syncope; Anxiety
MeSH terms: Syncope; Postural Orthostatic Tachycardia Syndrome; Tachycardia; Syndrome; Anxiety Disorders
Study type: Interventional

Summary: 
      This study uses an Alizarin Red powder mixture to characterize the sweat distributions in
      youth during tilt table testing. Patients with a known orthostatic sweat response from a
      prior clinical tilt table test in the investigators laboratory will be recruited. The
      Alizarin Red powder will be applied to exposed skin, and quantitative sweat will be measured
      at the thigh. During tilt testing, serial photos will be taken once the sweat response
      occurs. Sweat distributions will be compared during syncope (orthostatic sweat), during
      periods of anxiety (emotional sweat), and in patients with POTS (with and without syncope).
    

Detailed description: 
      The investigators' laboratory has conducted an exploratory study of quantitative sweat during
      tilt table testing over the past year. Some patients with Postural Tachycardia Syndrome
      (POTS) experience excessive sweating. Patients with syncope (without POTS) have an increase
      in sweat during their tilt-induced syncopal episode. Increased warmth and sweating can be
      among the first pre-syncopal symptoms in some individuals. Anxiety can also produce a sweat
      response, so-called "emotional sweating". Emotional sweating tends to affect the palms,
      soles, and forehead prominently, while the distribution of orthostatic sweat has not been
      well-described. The investigators' sweat measure quantifies sweat production, but placement
      of the sweat capsules is limited to four sites on the arms and legs.

      An Alizarin Red powder mixture applied to exposed skin is brown in color when dry and red in
      color when moist. Using Alizarin red, a quantitative sweat measure, and serial photography,
      the investigators will characterize the sweat distribution in patients with syncope, anxiety,
      and POTS. Patients will be recruited if they had a sweat response from prior tilt table
      testing performed in the investigators' laboratory.

      Consenting patients will wear underwear or bathing suits. The investigators will apply
      Alizarin Red to all exposed skin below the angle of the mandible. A single sweat capsule will
      be placed at the right hip. Pre-tilt photos will be taken, and then the patient will be
      tilted head-upright to seventy degrees. Once sweat begins, serial photos will be taken. The
      patient will remain in the tilted position until syncope occurs or the Alizarin powder is
      saturated red. If a sweat response is not prominent and syncope does not occur, the patient
      will be lowered after 30 minutes. The investigators will use the serial photos to describe
      the temporal distribution of sweat with each patient.

      Orthostatic sweat can occur before or after syncope, but based on the investigators' prior
      quantitative sweat measures, there is always an associated drop in blood pressure. The
      investigators can distinguish emotional from orthostatic sweat based on the patient's
      self-report of anxiety/panic, the presence of tachypnea, and the absence of syncope or
      hypotension.

      The current study aims to characterize sweat production during tilt testing and distinguish
      orthostatic and emotional sweat distributions. The primary goal of this study is to compare
      sweat distributions in patients during syncope (orthostatic sweat) and during anxiety
      (emotional sweat). The secondary goal is to characterize tilt-induced sweat distributions in
      POTS patients and compare them to the orthostatic and emotional sweat patterns. The
      investigators hypothesize that emotional sweat will predominantly affect the palms and soles
      (forehead sweat will not be measured), while orthostatic sweat will have a truncal
      predominance. This study is significant because the sweat pattern may help to resolve POTS
      and syncope phenotypes which will ultimately aid in gene discovery for these disorders.
    

Intervention name(s): Alizarin Red
Intervention type(s): Other
Intervention description(s): An Alizarin Red mixture will be applied to all exposed skin below the angle of the mandible. Once applied the patient will be tilted to 70 degrees. Serial photos will be taken once sweat begins and until conclusion of the test.
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Diagnostic
Keywords: Alizarin; Orthostatic; POTS; Tilt table testing; Syncope; Anxiety