doc4life
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What is the difference between myocardial ischemia and infarction?
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| Alina T
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Ischemia: decreased irrigation of the myocardium due to partial occlusion of a coronary artery;
Infarction: complete stop of blood flow in the area, due to a complete occlusion of the artery.
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| doc4life
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thanks
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infarction is the necrosis that a tissue suffers as a consequence of inadequate perfusion, it is not just the complete occlusion to a given area.
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| mjl1717
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I remember the cardiology resident saying that M.I. meant" dead cardiac muscle."
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| smitha
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well guys to my knowledge...........ischemia occurs due to , wat u call ,a temporary damage to the cardiac muscle due to the partial(thrombus) or temporary(embolus) blockade of the supply/decreased irrigation, to the cardiac muscle, in one of the coronary arteries or it's branches...........  , and infarction, as again alina truely said, occurs due to complete blockade of the artery/supply to the muscle, which then causes , as again mjl and guest said, a"dead muscle/necrosed muscle"..................
So, ischemia is reversible, but infarction isn't...........
hmmmm, so i guess, it's a combination of alina's(which gives the aetiology/physiology ) and guest's and mjl's (which gives the outcome/pathology), answers................a total "pathophysiology" of ischemia and infarction...........
Any additions further r appreciated.........
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| Alina T
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Dear guest and mjl1717...
the q posted by doc4life was a....generous one :lol: , meaning that the perfect answer could have been a novel, or a chapter in a pathology book by itself.....
Therefore, i just treated the differences from the pathological mechanism point of view...assuming that this is the most important in figuring the further differences...
It's logical that to a complete obstruction of a coronary artery would follow myocardial necrosis due to the lack of oxygen in the served area.
My point was to underline the DIFFERENCES between the 2 processes, regarding the pathological underlying mechanism.
...But maybe the guest can develop the subject that he started and show the histological differences between myocardial ischemia and necrosis.. It would be an interesting review for all of us!! :wink:
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There are 3 types of people: those who make things happen, those who watch things happen, and those who wonder what happened.
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Ischemia is the lack of oxygen and nutrients due to inadequate blood supply to a tissue, which can be caused by obstruction (embolus, trombus, extrinsic occlusion, etc), whether be it complete or not. Depending on the metabolism of the cell, on collateral blood flow, on how complete the obstruction is, etc. will determine the fate of the tissue. This can be reversible or irreversible damage which irrevocably leads to necrosis. Angina is an example of the clinical manifestation of ischemia to the myocardium, which calms if blood flow is restored to adequate levels as when the patient rest or takes nitroglycerine.
Infarction is the irreversible end result of ischemia. Anatomo-pathologically it can be pale or red, depending on the consistency of the tissue, collateral blood flow and venous congestion. It is a tissue that is dead or necrotic, and therefore will be replaced by fibrous tissue, as occurs with the scars that are left after a heart attack.
Hope this helps a little! 8)
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| waqastariq
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ISCHemia...emia refers to blood and it means that lack of oxygen in the blood supply to an organ 
may that be due to anything
INFRACTION: is an area of NECROSIS caused by either occlusion of arterial supply or venous supply...or both..
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| spjokes
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HYPOXIA is reduced oxygen availability. It may be due to reduced amounts or saturation of Hb.
ISCHEMIA is reduced blood supply, usually due to mechanical arterial obstruction. it can also be due to hypotension or blood loss.
INFARCT is a clinical term for necrosis.
please see ROBBINS p 23 e7
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