Bundle branch block in acute myocardial infarction. Current concepts and indications.

The blood supply to the conducting system is reviewed. As a result of discrete lesion in individual coronary arteries, specific patterns of conduction disturbances arise during myocardial infarction. Inferior wall infarctions produce relatively benign arrhythmia with blocks proximal to the bundle of His. Anterior infarctions tend to produce malignant arrhythmias, with blocks distal to the bundle of His. The appearance of intraventricular conduction blocks and bundle branch blocks may often be the only indication of the development of high grade atrioventricular block. The mortality of patients post-myocardial infarction with different conduction disorders increases but varies according to the nature of the conduction disturbance. Based upon such information, recommendations for temporary and permanent pacing are developed.