The electrocardiographic features of high posterolateral myocardial infarction

The cardiographic features of anterior and posterior myocardial infarction are well recognized. The occurrence of high lateral infarction has also been established, but infarction confined to the posterolateral aspect of the heart has in contrast received little attention. It is the purpose of this paper to stress the diagnostic cardiographic features of infarction in this area. Anatomically the heart is an irregular and slightly flattened cone, with a base, an apex, and three surfaces, described anatomically as the sterno-costal, the diaphragmatic, and the left. Cardio-graphically, lesions of the sterno-costal and diaphragmatic surfaces are classified respectively as anterior and posterior. The left surface faces backwards, upwards, and to the left. It is not in close relationship to any of the six routine precordial leads, but does in part face towards the left shoulder. Infarction confined to this left surface is posterolateral in position. As there is no lesion of the diaphragmatic surface, the infarct should be classed cardiographically as a " high" posterolateral infarct. In 1944 Wilson pointed out that the combination of diagnostic changes of infarction in the left leg lead, unusual prominence of the R and T waves in leads to the right of the prncordium, and significant abnormalities in leads V5 and V6, was associated with infarction of the posterolatera