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$Unique_ID{BRK03855}
$Pretitle{}
$Title{Hypotension, Orthostatic}
$Subject{Hypotension Orthostatic Postural Hypotension Low Blood Pressure
Shy-Drager Syndrome Vasovagal Syncope Idiopathic Orthostatic Hypotension}
$Volume{}
$Log{}
Copyright (C) 1990, 1992 National Organization for Rare Disorders, Inc.
769:
Hypotension, Orthostatic
** IMPORTANT **
It is possible that the main title of the article (Orthostatic
Hypotension) is not the name you expected. Please check the SYNONYM listing
to find the alternate names and disorder subdivisions covered by this
article.
Synonyms
Postural Hypotension
Low Blood Pressure
Information on the following diseases can be found in the Related
Disorders section of this report:
Shy-Drager Syndrome
Vasovagal Syncope
Idiopathic Orthostatic Hypotension
General Discussion
** REMINDER **
The information contained in the Rare Disease Database is provided for
educational purposes only. It should not be used for diagnostic or treatment
purposes. If you wish to obtain more information about this disorder, please
contact your personal physician and/or the agencies listed in the "Resources"
section of this report.
Orthostatic hypotension is an extreme drop in blood pressure which occurs
when a person stands up suddenly. The blood pools in the blood vessels of
the legs. Because of this pooling, there is a temporary decrease in the
amount of blood carried back to the heart by the veins. Subsequently, less
blood is pumped out from the heart, resulting in a sudden drop in blood
pressure. Normally, specialized cells in the body (baroreceptors) quickly
respond to changes in blood pressure. These baroreceptors then activate
automatic reflexes to increase levels of catecholamine in the body.
Increased catecholamine levels rapidly restore the blood pressure. When
there is a defect in this reflex action, reflex mechanisms may be inadequate
to quickly restore the decrease in blood pressure and orthostatic hypotension
results.
Symptoms
Symptoms of orthostatic hypotension which usually appear after sudden
standing may include dizziness, lightheadedness, visual blurring and
fainting.
Causes
A common cause of orthostatic hypotension is the decrease in volume of
circulating blood (hypovolemia) resulting from excessive use of medications
which increase urination (diuretics), or from the use of nitrate preparations
used to treat chest pains (angina pectoris) or heart failure. Orthostatic
hypotension can also result from medications prescribed to treat high blood
pressure, usually if the dosage is too high. It may also occur as a
complication of diabetes, hardening of the arteries or Addison's disease.
Long periods of bed rest, such as recovering after surgery, may also cause
orthostatic hypotension.
Other drugs which may cause hypotension are quinidine, L-dopa,
vincristine, barbiturates and alcohol, monoamine oxidase inhibitors and
tricyclic antidepressants and phenothiazines.
Neurologic disorders that involve the autonomic nervous system may
interrupt or damage the automatic reflexes that occur upon standing.
Orthostatic hypotension may result from neurological damage due to diabetes,
excessive alcohol consumption, syphilis which can destroy the spinal cord
(tabes dorsalis), progressive disease of the spinal cord such as
syringomyelia, or numerous other neurological disorders.
Affected Population
There are no statistics available on whether orthostatic hypotension occurs
more frequently in men or women. However, it is more common in elderly
persons.
Related Disorders
Symptoms of the following disorders can be similar to those of orthostatic
hypotension. Comparisons may be useful for a differential diagnosis:
Shy-Drager Syndrome (Orthostatic Hypotension in Neurological Disease) is
a disorder involving widespread neurological damage due to disease of the
central nervous system. It is characterized by chronically low blood
pressure associated with dizziness or momentary blackouts upon standing
(orthostatic hypotension). Along with low blood pressure, other symptoms may
include impotence, weakness, retention of urine, loss of control of
defecation and features of Parkinson's Disease such as tremors. (For more
information on this disorder, choose "Shy-Drager" as your search term in the
Rare Disease Database).
Vasovagal Syncope is a disorder in which there is a temporary impairment
of blood circulation in the brain. It may occur during emotional stress,
pain or mild shock. It may also result from prolonged bed rest, anemia,
fever, fasting or mild heart disease. Symptoms include low blood pressure
(orthostatic hypotension), a brief loss of consciousness (fainting), pale and
cold extremities (fingers and toes). Attacks may last from a few minutes to
hours, and occurrence is at irregular intervals.
Idiopathic Orthostatic Hypotension is a syndrome in which there is
suspected damage to the autonomic nervous system, possibly due to disease.
However, the term "idiopathic" means the cause is unknown. Symptoms may
include lowered blood pressure when standing (orthostatic hypotension), the
inability to perspire, impotence, and decreased salivation.
Therapies: Standard
Treatment of orthostatic hypotension depends upon the cause. When it is due
to a decrease in volume of circulating blood (hypovolemia) because of
medications, orthostatic hypotension is easily and rapidly reversed by
correcting the dosage or discontinuing the medication under a doctor's
supervision. Low blood pressure resulting from extended bed rest can be
corrected by allowing the patient to sit up each day at certain times with
increasing frequency. The drug ephedrine may be administered orally, and in
some cases salt intake may be increased. Salt-retaining drugs may be
prescribed. In extreme cases, the legs may be fitted for elastic hose which
raise the blood pressure upon standing. Inflatable aviator-type antigravity
suits may also be used to produce sufficient leg and abdominal
counterpressure to raise the blood pressure in severe cases.
Therapies: Investigational
Roy L. Freeman, M.D., Ph.D., of New England Deaconess Hospital, Boston, MA
was awarded a grant in 1988 by the FDA Orphan Products Division for his work
on using the drug DL-Threo-3, 4-Dihydrozyphenylserine as a treatment for
Orthostatic Hypotension.
The drugs phenylpropanolamine, midodrine, oral ergotamine tartrate or
subcutaneous dihydroergotamine and caffeine are currently being investigated
as treatment for Orthostatic Hypotension. Subcutaneous somatostatin also
appears to help certain individuals with hypotension following a meal
(postprandial hypotension).
Clinical trials are underway to study taxonomy and therapy of Orthostatic
Hypotension. Interested persons may wish to contact:
Dr. Italo Biaggioni
AA 3228 MCN
Vanderbilt University GCRC
Nashville, TN 37232
(615) 343-6499
This disease entry is based upon medical information available through
January 1992. Since NORD's resources are limited, it is not possible to keep
every entry in the Rare Disease Database completely current and accurate.
Please check with the agencies listed in the Resources section for the most
current information about this disorder.
Resources
For more information on Orthostatic Hypotension, please contact:
National Organization for Rare Disorders (NORD)
P.O. Box 8923
New Fairfield, CT 06812-1783
(203) 746-6518
NIH/National Institute of Neurological Disorders & Stroke (NINDS)
9000 Rockville Pike
Bethesda, MD 20892
(301) 496-5751
(800) 352-9424
For more information on orthostatic hypotension, physicians may contact:
Dr. David Robertson
Autonomic Dysfunction Clinic
Vanderbilt University
Nashville, TN 37232-2195
(615) 343-6499
References
THE MERCK MANUAL, Volume 1, 14th Ed.: Robert Berkow, M.D., ed.-in-chief;
Merck Sharp & Dohme Laboratories, 1982. Pp. 406-408.
POSTURAL HYPOTENSION: ITS MEANING AND MANAGEMENT IN THE ELDERLY. M.J.
Rosenthal et al.; GERIATRICS (December, 1988; issue 43(12): Pp. 31-34, 39-
42).
ORTHOSTATIC HYPOTENSION. J. Susman; AM FAM PHYSICIAN. (June, 1988; issue
37(6): Pp. 115-118).
TREATMENT OF ORTHOSTATIC HYPOTENSION: INTERACTION OF PRESSOR DRUGS AND
TILT TABLE CONDITIONING. R.D. Hoeldtke et al.; ARCH PHYS MED REHABIL
(October, 1988; issue 69(10): Pp. 895-898).