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Updated: Jul 20, 2026
14:09
Tilt Testing with Combined Lower Body Negative Pressure: a "Gold Standard" for Measuring Orthostatic Tolerance
Published on: March 21, 2013
Orthostatic intolerance. A historical introduction to the pathophysiological mechanisms
1Department of Medicine, SUNY Health Science Center, Syracuse, New York 13210, USA.
The American Journal of the Medical Sciences
|February 26, 1999
Summary
Orthostatic intolerance, often causing tachycardia, involves autonomic dysfunction leading to blood pooling and hypovolemia. Understanding these mechanisms is key to developing better treatments for this condition.
Area of Science:
- Cardiovascular Physiology
- Autonomic Nervous System Research
- Clinical Pathophysiology
Background:
- Orthostatic intolerance (OI) and orthostatic hypotension (OH) share underlying pathophysiological mechanisms.
- Historical recognition of individual OI mechanisms predates current definitions.
Observation:
- Newer definitions of normal orthostatic vital signs aid in identifying shared disorders.
- Autonomic dysfunction in leg veins causes significant gravitational blood pooling.
- Hypovolemia, affecting erythrocytes and plasma, is often associated with OI.
Findings:
- Impaired autonomic stimulation of erythropoietin production contributes to hypovolemia.
- Reduced renin release and, less consistently, aldosterone secretion are linked to hypovolemia in OI.
- Lower body dysautonomia plays a crucial role in OI pathophysiology.
Implications:
- Improved understanding of lower body dysautonomia can enhance OI treatment strategies.
- Targeting autonomic dysfunction may lead to more effective therapies for OI and OH.
- Further research into shared mechanisms can refine diagnostic and therapeutic approaches.
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