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 impact of rig ht and left bundle branch block on the in-hospital, 5-year and 10-year mortality of patients with acute inferior Q wave myocardial infarctio n. A retrospective analysis of clinical characteristics hospital, 1-, 5-, and 10-year mortality of 2215 consecutive patients with acute infe rior Q wave myocardial infarction hospitalized in 13 coronary care uni ts in Israel was performed. Bundle branch block during acute Q wave in ferior wall myocardial infarction was present in 108 patients (4.9%), 85 of whom had right and 23 left bundle branch block. Patients with bu ndle branch block had more in-hospital complications than those withou t, irrespective of the sire and time of appearance of the block In add ition, atrial fibrillation (19%), complete atrioventricular block (21% ) and congestive heart failure (45%) appeared more frequently in patie nts with, than in those without, bundle branch block (11%, 9% and 31%, respectively), and in-hospital and 5-year mortality were higher in pa tients with the block (22%, 33%) than in those without it (13% and 23% , respectively). Bundle branch block emerged as an independent predict or of death only among patients with new right bundle branch block, an d right bundle branch block emerged as an independent predictor for th e development of complete atrioventricular block (odds ratio 2.13; 90% confidence interval 1.39-3.28). However, hospital mortality among pat ients with inferior myocardial infarction and complete atrioventricula r block was virtually independent of bundle branch block (39% with vs 36% without bundle branch block, respectively). Patients with inferior Q wave myocardial infarction and bundle branch block comprise a high risk subgroup of patients with a complicated hospital course and incre ased hospital and long-term mortality.