The pathological diagnosis of acute myocardial infarction: preliminary results of a WHO cooperative study.

A cooperative study was undertaken to correlate the various methods by which acute myocardial infarction is studied post mortem and to evaluate the histological criteria upon which the diagnosis of acute myocardial infarction should be based. The preliminary results indicate that (1) NBT staining of transverse slices of the heart is of value in indicating areas of infarction, (2) coronary angiography rarely provides more information than routine sectioning of the coronary arteries, and (3) the following histological criteria are of the highest discriminating power in the diagnosis of early (6+/-2 hours) myocardial infarction: (a) cytoplasmic hypereosinophilia, coagulation, clumping, increased absorbance, decreased translucence, and alteration of striations; (b) loss of nuclei of the myofibres; (c) infiltration or margination of polymorphonuclear leucocytes; (d) leucocytosis; and (e) oedema.