Ischemic preconditioning: the endogenous power--a review of the literature.

With the re-emergence of surgery on a beating heart, it is important to examine the unique phenomenon of ischemic preconditioning (IPC) and its role as a form of myocardial protection under these circumstances. Ischemic preconditioning is defined as a short period of ischemia, regional or global, imposed before a more prolonged period of ischemia, which increases the myocardium's tolerance to ischemia by endogenous adaptive mechanism. Until recently, it was generally held that repeated ischemic episodes would have a cumulative adverse effect and could lead to a "stuttering infarction."