Non-Q wave versus nontransmural infarction.

The classification of myocardial infarction into transmural and subendocardial types has previously been based on the presence or absence of abnormal Q waves. The pathologic anatomy of necrosis in myocardial infarction does not necessarily correspond to these electrocardiographic criteria. It is therefore more appropriate to describe these infarcts as Q wave or non-Q wave myocardial infarctions. The importance of this classification is underscored by their clinical and pathologic differences and the tendency for more serious prognosis in the non-Q wave infarcts.