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

infarction the only technique amenable to manipulation is the re-establishment of the
coronary blood flow to the myocardium at risk.
Once the coronary occlusion is established, the use of therapies designed to limit the
extent of acute myocardial infarction are hampered by the inherent time delay that often
occurs between the onset of occlusion, and the diagnosis and institution of treatment.
Apart from the early restoration of blood flow to the ischaemic myocardium using
intravenous thrombolytics or emergency coronary artery angioplasty or bypass graffing
(CABG), results have mainly been disappointing.
Early restoration of coronary blood flow (reperfusion) to the ischaernic myocardium,
by use of thrombolytics or early CABG, may be thought of as "exogenous" means of
myocardial salvage/protection. The success of these exogenous means of myocardial
protection depends on how quickly thay can be administered to the patient.
It is important to note here that the heart has its own inherent protective mechanisms
designed to diminish the injury sustained during ischaernia, this being independent of
restoration of coronary blood flow. One of these "endogenous" protective mechanisms is
known as "ischaernic preconditioning". It was described by Murry [224] and is triggered
by a short (reversible) burst of ischaernia followed by reperfusion. This renders the
myocardium more resistant to ischaemic injury. The importance and the potential
mechanisms underlying this phenomenon are discussed in more detail later in this
chapter.
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