Left bundle-branch block associated with acute inferior wall myocardial infarction

The electrocardiographic manifestations of left bundle-branch block associated with acute inferior wall myocardial infarction are presented. The classic features of uncomplicated left bundle-branch block are modified in the following manner. The QRS complex is diminished in amplitude, and the S-T segment and T wave reflect primary changes: a coved, elevated S-T segment and an inverted, symmetrical T wave. These changes occur in leads orientated to the infarcted surface.