Preconditioning the heart with a brief period of ischemia followed by reperfusion renders it very resistant to injury from a subsequent prolonged ischemic result.The protection by preconditioning has been described in dogs

pigs

rats and rabbits

which lies in limiting infarct size

reducing the incidence of arrhythmia and improving postischemic ventricular recovery.Although little is known about the mechanisms afforded by ischemic preconditioning

stimulation of cardiac adenosine receptors

release of endogenous active substances and signal transduction pathway.Pharmacological preconditioning protection against heart injury is trigged by medicines which can mimic beneficial effects of cardiac ischamic preconditioning.According to mechanisms

these medicines can be classified into two kinds:specificreceptor-dependent and non-specific receptor-dependent like kinin receptor agonist and ATP-regulated potassium channel opener

which appears a novel access to treatment of cardiovascular diseases.