Old age, left bundle branch block and acute myocardial infarction: a vexing and lethal combination.

The evolution of reperfusion therapy in the treatment of acute myocardial infarction (AMI) has highlighted the extraordinary importance of rapid and accurate diagnosis of infarcts due to thrombosis of a major epicardial vessel, the so-called Q-Wave Myocardial Infarction or Transmural Myocardial Infarction. The presence of AMI can be established by a wide variety of diagnostic tests, but the narrow temporal window for significant myocardial salvage with reperfusion dictates that the clinical presentation and the 12-lead ECG remain the principal tools available to make the decision about reperfusion therapy. Although reperfusion therapy has been embraced enthusiastically for treatment of all ST segment elevation AMI, the benefit is greatest in those subsets of patients with the highest absolute risk for mortality, anterior myocardial infarction and subsets of inferior infarction and other locations (1,2). In subsets of very-low-risk infarcts, mortality benefit for reperfusion therapy is marginal or has not been demonstrated (3). Age is a powerful determinant of outcome (4–7). The mortality risk of AMI increases almost logarithmically with age and 70% of fatal infarcts occur in patients over the age of 65 years. These well-known features concerning AMI and reperfusion therapy make the observational study of Shlipak et al. (8), concerning the treatment and outcomes of left bundle branch block (LBBB) in patients with AMI reported in this issue of the Journal, of particular interest.