LBBB
Medical abbreviation · Cardiology
| Stands for | Left bundle branch block |
|---|---|
| Categories | Medical |
LBBB stands for Left bundle branch block, a cardiology abbreviation.
Conduction block in the left bundle branch, so the left ventricle is activated slowly from right to left. The ECG shows a QRS of 120 ms or more, broad notched R waves in leads I, aVL, V5 and V6, and deep S waves in V1.
Example: New LBBB with QRS 168 ms and EF 28%; candidate for cardiac resynchronization therapy.
Usage notes
Unlike RBBB, LBBB usually indicates underlying heart disease such as hypertension, cardiomyopathy or coronary disease. It distorts ST segments, which makes infarction hard to diagnose; the Sgarbossa criteria help. LBBB causes ventricular dyssynchrony, and heart failure patients with LBBB and a wide QRS benefit most from biventricular pacing (CRT).
Related abbreviations
More cardiology abbreviations
- LA – Left atrium
- LAA – Left atrial appendage
- LAAO – Left atrial appendage occlusion
- LAD – Left anterior descending artery
- LAE – Left atrial enlargement
- LAFB – Left anterior fascicular block
- LCx – Left circumflex artery
- LHC – Left heart catheterization
- LIMA – Left internal mammary artery
- LM – Left main coronary artery
- Lp(a) – Lipoprotein(a)
- LQTS – Long QT syndrome
See all 229 cardiology abbreviations →
This entry is for general education and is not medical advice. Abbreviation use varies between institutions; always confirm in context.