JK: The recognition of strictly posterior myocardial infarction by conventional scalar electrocardiography. Circulation 30: 706

ogy commonly refers to inferior or diaphragmatic infarction as "posterior."'-5 Strictly posterior infarction as a separate en-tity (fig. la) is generally not mentioned.1-6 Inclusion of this category permits identifica-tion of five individual locations of infarction:7 diaphragmatic, lateral, apical, strictly anterior, and strictly posterior. Myocardial infarction characteristically produces Q waves of abnormal duration in one or more of the 12 standard electrocardio-graphic leads.1 ' 2 These Q waves are written because the initial portion of the QRS is directed away from the area of inert myocar-dium. If this inert area is electrically posterior (fig. la), the initial forces will be directed anteriorly (fig. lb) (perpendicular to the frontal plane) and no abnormal Q waves will appear in either limb or chest leads.8 ' 9 Be-cause of this absence of pathologic Q waves, strictly posterior infarction is one of the most commonly overlooked electrocardiographic abnormalities. Textbooks of electrocardiog-raphy, with few exceptions,7 ' contain little or no reference to this category.'-6 Although some authors have commented upon individ-ual changes that might occur in right pre-cordial leads,8 ' 10-15 others have stated that diagnostic signs do not appear in the electro-cardiogram as a rule.'6-18 On the other hand, the vectorcardiographic recognition of strict-ly posterior infarction is generally ac