bundle branch block
A conduction abnormality where electrical impulses are delayed or blocked in one of the heart's bundle branches.
Full Definition
Bundle branch block is a cardiac conduction disorder affecting the specialized electrical pathways that carry impulses from the atrioventricular node to the ventricles. The condition can involve the right bundle branch (RBBB) or left bundle branch (LBBB), resulting in delayed activation of the corresponding ventricle. This manifests on ECG as a widened QRS complex (≥120 ms) with characteristic morphology patterns. While RBBB may occur in healthy individuals, LBBB often indicates underlying structural heart disease. Bundle branch blocks can be complete or incomplete and may progress to complete heart block requiring pacemaker implantation.
Usage
Usage note: Specify left or right when documenting; commonly abbreviated as LBBB or RBBB.
In Context
- "The ECG demonstrated a new left bundle branch block consistent with anterior myocardial infarction." — Emergency cardiac evaluation
- "Right bundle branch block was noted as an incidental finding on routine screening." — Preventive cardiology report