Clinical Trial: Hemodynamic Mechanisms of Abdominal Compression in the Treatment of Orthostatic Hypotension in Autonomic Failure

Study Status: Recruiting
Recruit Status: Recruiting
Study Type: Interventional

Official Title: Hemodynamic Mechanisms of Abdominal Compression in the Treatment of Orthostatic Hypotension in Autonomic Failure

Brief Summary: Compression garments have been shown to be effective in the treatment of orthostatic hypotension in autonomic failure patients. The purpose of this study is to determine the hemodynamic mechanisms by which abdominal compression (up to 40 mm Hg) improve the standing blood pressure and orthostatic tolerance in these patients, and to compare them with those of the standard of care midodrine. The investigators will test the hypothesis that abdominal compression will blunt the exaggerated fall in stroke volume and the increase in abdominal vascular volume during head up tilt.

Detailed Summary:

Patients with autonomic failure are characterized by disabling orthostatic hypotension (low blood pressure on standing) due to severe impairment of the autonomic nervous system. Compression garments such as waist-high stockings and abdominal binders have been shown to improve orthostatic hypotension in these patients. The purpose of this study is to determine the hemodynamic mechanisms by which abdominal compression (up to 40 mm Hg) improve the standing blood pressure and orthostatic tolerance in these patients, and to compare them with those of the standard of care midodrine. The investigators will test the hypothesis that abdominal compression will blunt the exaggerated fall in stroke volume and the increase in abdominal vascular volume during head up tilt. This study will help us better understand the contribution of the abdominal veins to orthostatic hypotension and the mechanisms underlying this non-pharmacological therapeutic approach.

Participants will be studied in a tilt table in two separate days in a randomized, crossover fashion with sham abdominal compression (~5 mmHg) and active compression (~40 mmHg).


Sponsor: Vanderbilt University

Current Primary Outcome: Stroke volume [ Time Frame: an average of 15 minutes of head up tilt ]

Percent change from supine in stroke volume during head up tilt


Original Primary Outcome: Same as current

Current Secondary Outcome:

  • Systolic blood pressure [ Time Frame: an average of 15 minutes of head up tilt ]
    Change from baseline in systolic blood pressure during head up tilt
  • Splanchnic vascular volume [ Time Frame: an average of 15 minutes of head up tilt ]
    Percent change from supine in splanchnic vascular volume during head up tilt.


Original Secondary Outcome: Same as current

Information By: Vanderbilt University Medical Center

Dates:
Date Received: April 21, 2015
Date Started: April 2015
Date Completion: July 2020
Last Updated: January 16, 2017
Last Verified: January 2017