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Sponsored by: |
Department of Veterans Affairs |
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Information provided by: | Department of Veterans Affairs |
ClinicalTrials.gov Identifier: | NCT00248807 |
The purpose of this study is to determine how blood pressure and blood flow are controlled during head-up tilt in a semi-upright position. In this investigation we are studying blood pressure and blood flow to the brain, with and without a medication which lowers blood pressure (Vasotec). We will determine how persons with a spinal cord injury are able to maintain blood flow to the brain (not get dizzy) as they assume a more upright position and their blood pressure decreases.
Condition | Intervention |
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Orthostatic Hypotension Spinal Cord Injuries |
Drug: 1.25 mg enalaprilat IV Other: Head up tilt (HUT) |
Study Type: | Interventional |
Study Design: | Health Services Research, Non-Randomized, Open Label, Parallel Assignment |
Official Title: | Systemic Hemodynamics and Cerebral Blood Flow in Persons With Tetraplegia |
Estimated Enrollment: | 36 |
Study Start Date: | October 2005 |
Estimated Study Completion Date: | October 2009 |
Estimated Primary Completion Date: | October 2009 (Final data collection date for primary outcome measure) |
Arms | Assigned Interventions |
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1: Experimental
1.25 mg enalaprilat IV and/or 45 degree HUT to lower BP and measure CBF
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Drug: 1.25 mg enalaprilat IV
an ACE inhibitor given to lower BP and measure CBF
Other: Head up tilt (HUT)
45 degree HUT to lower BP and measure CBF
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Individuals with tetraplegia lack normal sympathetic nervous system regulation of blood pressure and therefore, relative hypotension is a common occurrence, which may be more pronounced with postural stress. Loss in mental acuity and sometimes even consciousness is an associated symptom of postural hypotension in individuals with tetraplegia.
There is some evidence to suggest however, that although mean arterial blood pressure (MAP) is relatively low in these individuals, middle cerebral arterial blood flow (CBF) may be maintained. Consequently, individuals with chronic tetraplegia often compensate and are stable in the seated upright position.
Autoregulation of CBF has been defined as the stability of cerebral blood flow throughout a range of systemic blood pressures (MAP). This proposal will examine systemic hemodynamics and middle cerebral artery blood flow during HUT with and without Vasotec, an angiotensin II inhibitor. By partially or completely ablating the renin-angiotension system, which is postulated to play a major role in blood pressure regulation, the potential dissociation between systemic blood pressure and middle cerebral artery blood flow in individuals with tetraplegia may be demonstrated. The aim is to determine whether persons with chronic tetraplegia are able to maintain similar CBF, or similar CBF changes, as able-bodied controls despite a greater decrease in MAP to the same hypotensive challenge. The relationship between MAP and CBF has not been defined in this population. Understanding this relationship may lead to improved screening and treatment for prevention of postural hypotension in persons with tetraplegia.
Ages Eligible for Study: | 18 Years to 65 Years |
Genders Eligible for Study: | Both |
Accepts Healthy Volunteers: | Yes |
Inclusion Criteria:
Exclusion Criteria:
Contact: Jill Wecht, EdD | jm.wecht@va.gov | |
Contact: John P Handrakis, PT EdD | (718) 584-9000 ext 3128 | John.Handrakis@va.gov |
United States, New York | |
VA Medical Center, Bronx | Recruiting |
Bronx, New York, United States, 10468 | |
Contact: Dwindally Rosado Rivera, EdD 718-584-9000 ext 3128 dwindally.rosadorivera@va.gov | |
Principal Investigator: Jill Wecht, EdD |
Principal Investigator: | Jill Wecht, EdD | VA Medical Center, Bronx |
Responsible Party: | Department of Veterans Affairs ( Wecht, Jill - Principal Investigator ) |
Study ID Numbers: | B3346V, 00517 |
Study First Received: | November 2, 2005 |
Last Updated: | September 9, 2008 |
ClinicalTrials.gov Identifier: | NCT00248807 |
Health Authority: | United States: Federal Government |
Blood Pressure, Low Hypotension, Postural Injuries, Spinal Cord Spinal Cord Transection Spinal Cord Trauma |
Hypotension Hypotension, Orthostatic Spinal Cord Diseases Wounds and Injuries Vascular Diseases Central Nervous System Diseases Disorders of Environmental Origin |
Quadriplegia Trauma, Nervous System Spinal Cord Injuries Enalapril Postural hypotension Enalaprilat |
Molecular Mechanisms of Pharmacological Action Therapeutic Uses Nervous System Diseases Angiotensin-Converting Enzyme Inhibitors Enzyme Inhibitors |
Cardiovascular Diseases Cardiovascular Agents Antihypertensive Agents Pharmacologic Actions Protease Inhibitors |