bundle branch block
Conduction delay or block in the right or left bundle branches of the cardiac conduction system.
Full Definition
Bundle branch block refers to a delay or complete interruption of electrical conduction through either the right bundle branch (RBBB) or left bundle branch (LBBB) of the His-Purkinje system. This results in characteristic electrocardiographic patterns with QRS widening (≥120 milliseconds) and specific morphological changes. RBBB may be seen in healthy individuals or associated with right heart strain, while LBBB more commonly indicates underlying cardiac pathology. New-onset LBBB, particularly in the setting of acute coronary syndrome, warrants urgent evaluation. The presence of bundle branch block can affect the interpretation of other ECG findings and may influence pacing decisions.
Usage
Usage note: Specify right or left bundle branch involvement for clinical accuracy.
In Context
- "The ECG demonstrated a new left bundle branch block concerning for acute coronary syndrome." — Emergency department evaluation
- "Right bundle branch block was noted as an incidental finding on routine electrocardiography." — Annual physical examination