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Myocardial ischemic conditioning: Pathogenesis

Derek J Hausenloy, MD, PhD, FRCP, FACC, FESC
Derek M Yellon, PhD, DSc, Hon FRCP, FACC, FESC
Section Editor
Bernard J Gersh, MB, ChB, DPhil, FRCP, MACC
Deputy Editor
Gordon M Saperia, MD, FACC


The myocardium possesses adaptive mechanisms that render it resistant to potentially lethal ischemia and reperfusion injury. (See "Reperfusion injury of the heart", section on 'Definition'.)

Myocardial ischemic conditioning refers to interventions that protect the heart from injury due to exposure to prolonged ischemia. The conditioning may be delivered before, during or after the prolonged ischemic insult. Other protective mechanisms include the long-term development of coronary collateral vessels, and myocardial hibernation and stunning. (See "Coronary collateral circulation" and "Pathophysiology of stunned or hibernating myocardium".)

The definition and pathogenesis of ischemic preconditioning and postconditioning will be reviewed here. The clinical implications of these phenomena in the human myocardium and possible future therapeutic applications are discussed separately. (See "Myocardial ischemic conditioning: Clinical implications".)


Myocardial ischemic preconditioning refers to the protection conferred to ischemic myocardium by brief periods of sublethal ischemia separated by periods of short bursts of reperfusion delivered before the ischemic insult [1]. It provides the myocardium with a powerful means of protecting against acute myocardial ischemia.

Ischemic preconditioning has been reproducibly demonstrated in all animal species studied as well as humans [1-5]. It may occur as part of some naturally occurring ischemic syndromes [6]. Furthermore, in addition to enhanced tolerance to lethal cell injury, preconditioning is protective against other end points of ischemia-reperfusion injury, including postischemic contractile dysfunction [7] and ischemia- and reperfusion-induced ventricular arrhythmias [8,9]. Ischemic preconditioning also decreases apoptosis in animals, another mechanism that can contribute to cell death after myocardial ischemia and reperfusion [10]. (See "Reperfusion injury of the heart", section on 'Apoptosis'.)

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Literature review current through: Nov 2017. | This topic last updated: Nov 08, 2017.
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