Bundle Branch Block

The development of bundle brach block during the course of an acute myocardial infarction is a serious complication. It suggests extensive myocardial damage and the likelihood of developing significant pump failure. Bundle branch block may also lead to high-grade A-V block that may require electronic pacing. While the electrocardiographic changes of acute myocardial infarction may still be read in the presence of right bundle branch block, left bundle branch block typically obscures the electrocardiographic changes of acute infarction.