The "border zone" in evolving myocardial infarction: controversy or confusion?

Considerable controversy has arisen over the existence of a "border" zone of intermediate injuries during regional myocardial ischemia. Much of this controversy arises from the inappropriate use of terminology and the misquotation or misinterpretation of previously published studies. This article considers the nature of the interface between normal and ischemic tissues; proposes a series of definitions based on current knowledge of etiology of tissue injuries; reviews critically the existing evidence for an against the "border zone" concept; and considers the quantitative significance of a "border zone" of salvageable tissue if it exists.