The "Border zone" and myocardial protection: a time for reassessment?

The rather static concept of a potentially salvageable "border zone" of intermediate injury surrounding an area of regional ischemia would no longer seem tenable. This model, which has formed the basis for many approaches to therapeutic infarct size reduction, fails to take adequate account of a number of important factors including the dynamic nature of the ischemic process, the anatomy of the coronary microcirculation and the practical realities of tissue salvage. There is considerable evidence, from a number of species, that spatially identifiable border zones of intermediate injury do not exist, at least in the lateral plane. The apparent absence of a zone of target tissue does not necessitate the abandonment of concepts of myocardial protection but may require a major reappraisal.