Right Bundle Branch block (RBBB) is an electrocardiogram finding that occurs when the physiologic electrical conduction system of the heart, specifically in the His-Purkinje system, is altered or interrupted resulting in a widened QRS and electrocardiographic vector changes. RBBB is caused by diseases that affect the right bundle branch or the myocardial region, where the right bundle branch is located. Possible causes include trauma, structural changes, infiltrative diseases (eg, sarcoidosis), myocarditis, and myocardial infarction
