Protection of the ischemic myocardium.

It has long been postulated that once a coronary artery becomes occluded, a myocardial infarction of predetermined size develops. Attempts in experimental animals to investigate whether the extent of the necrosis could be influenced by drugs have had limited success because of the extreme variation in infarct size between individual animals, even when occlusions were made at comparable sites. Six years ago we developed a method to measure the extent of myocardial damage in such a way that each dog serves as its own control, obviating the problem of variation of infarct size between different animals. After development of the method, we attempted to answer several questions.