Left bundle branch block

Definition

Disorder of the atrioventricular conduction system in which the QRS duration is greater than or equal to 120 ms in adults, greater than 100 ms in children 4 to 16 years of age, and greater than 90 ms in children less than 4 years of age; there is a QS or rS pattern in lead V1 and a wide slurred R wave in leads I and V6.

Subcategories (2)