Bundle branch block in acute Q wave inferior wall myocardial infarction: A high risk subgroup of inferior myocardial infarction patients

The aim of this study was to determine the incidence and impactof right and left bundle branch block on the in-hospital, 5-yearand 10-year mortality of patients with acute inferior Q wavemyocardial infarction. A retrospective analysis of clinicalcharacteristics, hospital, 1-, 5-, and 10-year mortality of2215 consecutive patients with acute inferior Q wave myocardialinfarction hospitalized in 13 coronary care units in Israelwas performed Bundle branch block during acute Q wave inferior wall myocardialinfarction was present in 108 patients (4.9%), 85 of whom hadright and 23 left bundle branch block. Patients with bundlebranch block had more in-hospital complications than those without,irrespective of the site and time of appearance of the block.In addition, a trial fibrillation (19%), complete atrioventricularblock (21%) and congestive heart failure (45%) appeared morefrequently in patients with, than in those without, bundle branchblock (11%, 9% and 31%, respectively), and in-hospital and 5-yearmortality were higher in patients with the block (22%, 33%)than in those without it (13% and 23%, respectively). Bundle branch block emerged as an independent predictor of deathonly among patients with new right bundle branch block, andright bundle branch block emerged as an independent predictorfor the development of complete atrioventricular block (oddsratio 2.13; 90% confidence interval 1.39–3.28). However,hospital mortality among patients with inferior myocardial infarctionand complete atrioventricular block was virtually independentof bundle branch block (39% with vs 36% without bundle branchblock, respectively). Patients with inferior Q wave myocardial infarction and bundlebranch block comprise a high risk subgroup of patients witha complicated hospital course and increased hospital and long-termmortality.