ischaemic preconditioning of the human heart. - Leicester Research ...

mitochondrial respiration, and a many fold increase in the rate of glycolysis associated
with an accumulation of anaerobic metabolites.
Different cell types withstand ischaerma for varying periods of time, skeletal muscle
can still recover after several hours of ischaerma, whereas minutes of ischaernia are all
that Is required to cause irreversible neuronal injury [501. Currently it is only possible to
state that myocardial damage which occurs afler 3 hours of ischaemic insult[ 1551 is
unlikely to recover at all. Some recovery of contractile function may occur, upon
reperti.
ision, following 60 minutes of ischaemia, however, full recovery may require up to
several hours to days of reperfusion.
Over the past decade, advances in research have furthered our understanding of
myocardial ischaernia and the important relationship between ischaemia and contractile
function. It is apparent that when the myocardium is subjected to an ischaernic insult, it
undergoes a whole host of changes which can be catergonsed as reversible biochemical
and structural changes, contractile dysfunction (stunning and/or hibernation) with its
specific biochemical and ultrastructural changes, and irreversible myocardial injury (cell
death and infarction). The different types of myocardial injury are
below.
1.2.1 Reversible Injury
described in detail
- Following a short period of global or regional ischaemia
myocardial tissue invariably undergoes biochemical [148,153] and structural changes
[158,250,267] that are associated with anaerobic metabolism and the deprivation of
oxygen and substrates. These changes are reversible in the majority of cases wherc the
ischaernic episodes are limited to short periods [156,252]. Return of ischaemic tissue to
both biochemical and structural normality, following reperfusion, may take from a few
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