Dr. Hain on OI / Orthostatic Hypotension

[xchocoholic]

This doctor has a familiar view of OH but IMHO is worth reviewing because he actually goes into some details than I haven't seen before. He even looks for some causes ... I only copied in a tiny bit of this article. He has a section called "Laboratory TESTS for orthostatic hyptension" that I want to look at further. tc ... x

http://www.dizziness-and-balance.com/disorders/medical/orthostatic.html

ORTHOSTATIC HYPOTENSION


Timothy C. Hain, MD.

Page last modified: January 21, 2012

Translations: Belorussion

Orthostasis means upright posture, and hypotension means low blood pressure. Thus, orthostatic hypotension consists of symptoms of dizziness, faintness or lightheadedness which appear only on standing, and which are caused by low blood pressure. Only rarely is spinning vertigo caused by orthostasis.

Symptoms that often accompany orthostatic hypotension include chest pain, trouble holding the urine, impotence, and dry skin from loss of sweating. Fainting (syncope) is covered in another page.

How common is orthostatic hypotension ?


According to Wu et al (2008), symptoms of dizziness provoked by standing ranges from 4.4% (young) to 5.8% (>=70). Thus orthostatic dizziness is common and much more frequent than dizziness due to inner ear disturbances.


What Causes Orthostatic Hypotension ?
Blood pressure is maintained by a combination of several things. The heart is the central pump, and a weak or irregular heart can cause orthostatic hypotension. Conditions such as arrhythmia, heart failure, deconditioning, and pregnancy are examples where the heart may not be up to the task of providing an adequate blood pressure.

The heart pumps blood, and if there is too little blood volume (anemia, dehydration, dialysis), the pressure drops. The blood vessels in the body also can squeeze (constrict) to raise blood pressure, and if this action is paralyzed, blood pressure may fall. Numerous medications affect blood vessels including most of the medications used for blood pressure, and many of the medications used in psychiatry and for anginal heart pain. Heat, such as a hot shower or from a fever can also dilate blood vessels and cause orthostasis. The nervous system senses and responds to regulate blood pressure. If something is wrong in this control system, blood pressure may fluctuate.

Blood pressure is usually lowered (in persons with orthostasis) by upright posture, food, infection, hyperventilation, hot weather, and lifting of heavy objects. General anesthesia may be unusually dangerous due to blood pressure fluctuations (Bevan et al, 1979).

Vestibular disorders may interact with blood pressure and heart rate control. The vestibular system is one source of information about uprightness (the otoliths), there are some effects of vestibular stimulation on the heart (Radtke, 1992), and there are some patients who have a combination of autonomic and vestibular symptoms.

Neurological disorders can also be caused by orthostasis. This usually takes the form of a transient ischemic attack (TIA) precipitated by a blood pressure drop (Brozman et al, 2002).



Diagnosis of Orthostatic Hypotension


Syndromes with orthostatic dizziness or lightheadedness, not associated with low blood pressure include:

1. Positional orthostatic tachycardia (POT) syndrome. Here, the pulse races on standing. See below for more information.
2. Low CSF pressure syndrome
3. Primary orthostatic tremor
4. Positional vertigo (i.e. BPPV)

Syndromes with orthostatic hypotension that may be diagnosed include:

1. Cardiogenic (heart related) orthostatic hypotension. In this instance the heart doesn't respond adequately to demands for greater pumping and blood pressure drops. Conditions such as arrhythmia, heart failure, deconditioning, and pregnancy are examples.
2. Low blood volume (e.g. anemia, dehydration, dialysis)
3. Medication related (usually too high doses of blood pressure medications or medications for depression)
4. Primary adrenal insufficiency. Persons with primary adrenal insufficiency usually also have symptoms of glucocorticoid (cortisone) deficiency. The skin may be dark, serum potassium high, and there may be associated hypothyroidism, diabetes, and vitiligo (Salvatori, 2005).
5. Neurogenic orthostatic hypotension
   1. Sensory neuropathies (diabetes, alcohol, syphilis, Holmes-Adie syndrome, carotid sinus obliteration by endarterectomy, Riley-Day syndrome)
   2. Central types:
      1. MSA - multiple system atrophy or Shy-Drager, Parkinson's, dementia with Lewy bodies. Orthostatic hypotension is nearly universal in MSA, present in about 50% of patients with dementia with Lewy bodies (Akaogi et al, 2009), and in 5-50% of patients with Parkinson's. (Thaisetthawatkul et al, 2004; Akaogi et al, 2009). However, since Parkinsonism is by far the most common disorder, there may be as many patients with orthostatic hypotension and Parkinson's disease as any of the former. Patients with MSA have intact sympathetic noradrenergic innervation.
      2. Medullary strokes or injuries (rare)
      3. Wernickes syndrome (rare, related to thiamine deficiency)
   3. Output types:
      1. Peripheral neuropathy, especially diabetes and amyloidosis
      2. Spinal cord lesions
      3. PAF - pure autonomic failure or idiopathic orthostatic hypotension. These patients have loss of cardiac sympathetic neurons, and in particular have loss of sympathetic noradrenergic innervation.
      4. Parkinson's disease(post-ganglionic sympathetic denervation). These patients also have loss of cardiac sympathetic neurons.
      5. Dopamine beta-hydroxylase deficiency (hereditary, very rare -- has very high serum dopamine, often ptosis (droopy eyes) and hyperextensible joints. Prolactin may be high)
6. Unknown type
   1. Orthostatic intolerance in chronic fatigue syndrome (this mainly seems to be a syndrome of adolescents)
   2. Orthostatic intolerance associated with basilar migraine
   3. Delayed orthostatic hypotension. Possibly due to fatigue of autonomic system over 3-20 minutes.

The diagnosis of orthostasis is made by finding that the systolic/diastolic blood pressure drops at least 25/10 mm mercury on going from lying to standing. After measuring the supine blood pressure, it is recommended that one should have the subject stand for 2 minutes (if tolerated) before measuring the upright blood pressure (Tarazi and Fouad, 1983).

 

[xchocoholic]

Just the last part of the previous quote ...

An alternative and more quantitative method of determining if there is orthostatic hypotension is the tilt table test. This procedure uses equipment to record blood pressure and pulse after a 70 degree tilt using a motorized table.

Recently it has been point out that subjects who are stood for longer periods of time may exhibit progressive decline in blood pressure (Gibbons and Freeman, 2006). Delayed orthostatic hypotension (DOH ?) is defined as a greater than 20 mm Hg fall after 3 minutes or more of tilt-table or active standing. This seems to take a rather long time -- many (39%) subjects were positive only after 10 minutes of standing or tilt. A tilt (or stand) of 20 minutes was recommended by these authors for diagnosis.

The pulse (heart rate) should be checked also. The lack of a pulse response increase when the blood pressure drops implies a neurological cause.


An excessive pulse response is termed "POTS" or positional orthostatic tachycardia syndrome. POTS can be associated with considerable disability (Benrud-Larson et al, 2002). Note that pulse can increase due to anxiety and deconditioning as well as autonomic disorders and considerable caution must be used in making this diagnosis. http://cogprints.org/4802/2/raj.pdf is an external web page written for health-care providers concerning this condition.

Once an orthostatic syndrome is determined, additional tests are used to determine why the blood pressure isn't properly regulated.

Laboratory TESTS for orthostatic hyptension

 

[INKY]

I have had bouts of this, usually after exertion, on standing up, have to hold on till body catches up. I understood it to be a 'normal', (if any M.E. symptoms can be regarded as such) also have low blood pressure, which seems to run in the family.
Since ensuring my Vitamin D intake at about four times RDA, by using Evaporared Milk ,it has reduced. British milk apparently no longer contains Vit.D. The process whereby milk no longer seperates apparently destroys or removes it, although even recently published articles still cite milk as source of Vit.D.
Recently there have been News articles of children being removed from parents when Rickets fractures presumed to be abuse because the Doctors have no experience of Rickets. Odd as according to food industry our various foodstuffs are being mightily fortified with Vit.D and others.