RecruitingNot ApplicableNCT03496792

The Venous Distension Reflex and Orthostatic Hypertension

Sponsor

Milton S. Hershey Medical Center

Enrollment

30 participants

Start Date

Mar 10, 2020

Study Type

INTERVENTIONAL

Conditions

Blood Pressure

Summary

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

Eligibility

Min Age: 18 Years

Plain Language Summary

Simplified for easier understanding

This trial is studying why some people's blood pressure rises when they stand up (a condition called orthostatic hypertension), and how the veins in the legs may play a role in this response. **You may be eligible if...** - You are 18 years of age or older - You can give informed consent and read/speak English - You either have blood pressure that rises when you stand up, OR you have normal blood pressure changes with standing (to serve as a comparison group) - If you have stage 1 high blood pressure but no other chronic diseases, you may still qualify **You may NOT be eligible if...** - You are under 18 years old - You are pregnant or nursing - You are currently incarcerated Talk to your doctor to see if this trial is right for you.

This summary was AI-generated to explain the trial in plain language. It is not medical advice. Always discuss eligibility with your doctor before enrolling in a clinical trial.

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Interventions

OTHERTilt + external pressure

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.

OTHERTilt + no external pressure.

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.

OTHERLimb occlusion + negative pressure

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.

OTHERLimb occlusion + no negative pressure

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.