The Venous Distension Reflex and Orthostatic Hypertension

Part of paid clinical trials in Hershey, Pennsylvania.

Sponsor
Milton S. Hershey Medical Center
Study ID
NCT03496792
Status
Recruiting
Apply to this trial

Conditions

  • Blood Pressure

Eligibility Criteria

Sex
ALL
Age
18 Years - N/A
Healthy Volunteers
Accepted

Interventions

  • Tilt + external pressure — OTHER
    In Visit 1, the anti-shock trousers will be inflated to 20, 40, or 60 mmHg. BP will be measured 3 times from the brachial artery. Then the table will be tilted head up to a maximum of 70o for up to 10 min, while BP will be measured from the brachial artery at 1 min intervals. The tilt table is returned to 0o and the resting supine baseline BP will be collected. Then, the anti-shock trousers will be inflated to a different pressure (20, 40, or 60 mmHg) and the head up tilt will be repeated. Repetitions at the various pressures will be performed in a random order with suitable resting intervals in between the tilting bouts.
  • Tilt + no external pressure. — OTHER
    In Visit 1, the anti-shock trousers will NOT be inflated. Auscultatory BP will be measured 3 times from the brachial artery. Thereafter, the table will be tilted head up to a maximum of 70o for up to 10 min, while BP will be measured from the brachial artery at 1 min intervals.
  • Limb occlusion + negative pressure — OTHER
    In Visit 2, a cuff will be placed on the thigh of a leg that is sealed in an airtight pressure tank. After the cuff is inflated to 250 mmHg, the pressure in the tank will be reduced to -100mmHg for 2 minutes. The application of negative pressure creates a suction effect on the leg, and leads to an overall increase in pressure gradient across the blood vessel wall and induces vascular distension.
  • Limb occlusion + no negative pressure — OTHER
    In Visit 2, a cuff will be placed on the thigh of a leg that is sealed in an airtight pressure tank. The cuff is inflated to 250 mmHg for 2 minutes, but the pressure in the tank is not changed.

Study Details

This research is being done to find out whether distension of veins in legs will cause a rise in blood pressure (orthostatic hypertension).

Key Dates

Start date
Mar 10, 2020
Status verified
Mar 2026
Primary completion
Aug 1, 2026
Completion
Aug 30, 2026

Study Design

Enrollment
30 participants (estimated)
Allocation
NON_RANDOMIZED
Intervention model
PARALLEL
Primary purpose
BASIC_SCIENCE

Arms

  • Experimental: Tilt + external pressure
    Tilt + external pressure on legs performed in both "BP elevated with standing" and "BP maintained with standing" groups.
  • Placebo Comparator: Tilt + no external pressure
    Tilt + no external pressure performed in both "BP elevated with standing" and "BP maintained with standing" groups.
  • Experimental: Limb occlusion + negative pressure
    Limb occlusion + negative pressure performed in both "BP elevated with standing" and "BP maintained with standing" groups.
  • Placebo Comparator: Limb occlusion + no negative pressure
    Limb occlusion + no negative pressure performed in both "BP elevated with standing" and "BP maintained with standing" groups.

Primary Outcome Measure

Muscle Sympathetic Nerve Activity (MSNA) in bursts/min or arbitrary units/min [ Time Frame: Recorded continuously during Visit 2, the 4-5 hr Negative Pressure study visit. ]

Central Contacts

Locations (1)

FacilityCityStateZIPSite coordinators
Penn State Milton S. Hershey Medical CenterHersheyPennsylvania17033
Kristen Gray
[email protected]
7175314589
Jian Cui
[email protected]
717-531-1799

Find similar trials in Hershey, PA

By research site
Penn State Milton S. Hershey Medical Center· Hershey, PA

Related Studies