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C F S
- Information International COI,
NMH & POTS
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OI, COI, NMH - or POTS ?
OI, short for Orthostatic Intolerance, a condition with
disruption of heart rhythm (tachycardia) and low orthostatic blood pressure
(hypotension) when standing up suddenly or standing up for prolonged time. COI, short for Chronic Orthostatic Intolerance. NMH, short for Neural Mediated Hypotension, meaning
hypotension (low blood pressure) due to disturbance of the nervous blood
pressure control. POTS or PTS, short for Postural Tachycardia
Syndrome. The above terms are often used interchangeably, some
more well-defined than others,
mail, Stewart, 1999. Vertigo is
not the same thing as Orthostatic Intolerance (OI), vertigo.woodruff04.txt. Causes of COI and
POTS
The causes of POTS are studied
widely, press, Furlan et al., 1998, Narkiewitcz & Somers, 1998 and Jacob et al., 1999. Dr. Jacob's team
demonstrated postural tachycardia to be caused by sympathetic denervation in
the legs, Jacob et al., 2000. These conditions are more prevalent than
previously thought, carothers.etal03.txt. Sympathetic Nerve Activity in Response to
Hypotensive Stress in the PTS, bonyhay.freeman04.txt. Renin-Aldosterone paradox and
perturbed blood volume regulation underlying PTS, satish.etal05.txt. Cerebral Blood Pressure
The cerebral blood pressure can
be low despite normal body arterial pressure, Jacob et al., 1999. On the role
of capillaries in COI,
Brown & Hainsworth, 1999. A study from Taiwan discovered problems with the
auto-regulation of the brain blood pressure in people with syncopes, Hsu et al., 1999. Autonome Dysfunction
It is being discussed whether
there is a connection between CFS and a syndrome called Autonome Dysfunction
(or Dysautonomia), possibly an autonomic neuropathy, Low, 1998. In agreement with this theory, impaired
oxygen delivery to muscles has been found, McCully & Natelson, 1999. One study on autonomic dysfunction in CFS
found very small changes, Soetekouw et al., 1999. Dysautonomias: Clinical
Disorders of the Autonomic Nervous System, goldstein.etal02.txt. Aberrations of cardiovascular reactivity (CVR), an expression
of autonomic function, occur in a number of clinical conditions, but lack
specificity for a particular disorder.
Recently, however, one research group has announced that particular
patterns can be defined in diseases, naschitz.etal04.txt, including a CVR pattern particular to CFS, naschitz.etal.04.txt, naschitz.etal.04.pdf. Acetylcholinesterase inhibition: a novel approach in
the treatment of neurogenic orthostatic hypotension, singer.etal04.txt.
Ehlers-Danlos Syndrome
EDS is caused by a genetic
defect resulting in skin and connective tissue disease, including orthostatic
pooling of the blood in the legs. The connection between OI, CFS and
EDS has been studied, Rowe
et al., 1999. The genetics underlying type IV EDS is
studied, Pepin et al., 2000 (abstract), Pepin et al., 2000 (pdf) and discussed
editorially, editorial, Pyeritz, 2000. ß2-Adrenergic receptors
The control of blood pressure
in the normal body is highly dependent on the function of ß2-adrenergic
receptors. These receptors may be dysfunctional due to genetic defects
(polymorphisms),
Hoit et al., 2000. A genetic factor involving the norepinephrine
transporter gene has been found in some cases, Shannon et al., 2000. |
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Index Welcome CFS
case def. Prevalence Prognosis Brain
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