Clinical Trial

The Venous Distension Reflex and Orthostatic Hypertension

Study Description

The Venous Distension Reflex and Orthostatic Hypertension

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

Location

Locations Selected Location

Methods

No pharmaceutical medication involved No pharmaceutical medication involved
Patients and healthy individuals accepted Patients and healthy individuals accepted

Tilt + 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. Repet ...read more on ClinicalTrials.org

Tilt + 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.

Limb 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.

Limb 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.

Additional Information

Official Study Title

The Venous Distension Reflex and Orthostatic Hypertension

Clinical Trial ID

NCT03496792

ParticipAid ID

9avWnb