There are innumerable stresses to human beings in daily life .
Heart experiences a few either directly or indirectly.
- Physical stress
- Pharmacological stress
- Mechanical stress
- Hemodynamic stress
- Mental stress
Squatting is rarely realised as a form of physical stress to heart . Rather , squatting can also be termed as a good exercise ( Western toilets sans it !)
Squatting raises the afterload at the level of aorta due to increments in SVR (exact mechanism not clear ,neural reflex ?) and temporary reduction in venous return.
After load raise is synonymous with increased ventricular wall stress . So, it is logical to expect wall motion defect in vulnerable hearts* when confronted with sudden increase in afterload .(*Ischemic hearts with delicate coronary blood flow ) .Hence , sudden squatting , a seemingly simple maneuver , can unmask silent CAD .It can be aptly be named as poor man’s stress echo.
Of course , it doesn’t mean in any way , it should not be used in rich ! The purpose of science is to make things simpler and cheaper . If squatting can replace dobutamine with fair degree of accuracy atleast in a few , it can help control the escalating costs of cardiology triaging due to many futile diagnostics !
http://content.onlinejacc.org/cgi/reprint/46/5/931.pdf
When squatting is a stress in normal persons , paradoxically it gives relief to patients with cyanotic heart disease
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