Left Bundle-Branch Block

Of 27 patients with left bundle-branch block following acute myocardial infarction, five died. Left bundle-branch block was present on admission in 26 patients, and subsequently appeared in one. Fourteen of 16 patients who did not have a temporary pacemaker placed prophylactically survived the acute myocardial infarction. Of the 22 survivors, 16 are still alive, an average of 12.7 months after the acute myocardial infarction. Thus, left bundle-branch block in acute myocardial infarction does not affect prognosis, and is not an indication for prophylactic insertion of a transvenous pacemaker or of a permanent pacemaker.