Download PDF
Left Bundle Branch Block
Definition:
Conduction abnormality of the left ventricle, causing wide QRS complexes and ST changes mimicking STEMI.
History/Physical Exam:
History of CAD, hypertension, previous MI.
Key 12-Lead Features:
- QRS > 120ms
- Prominent S (V1-3) / prominent R (V5/6, I/aVL)
- ST Elevation common in V1-4
- See Sgarbossa Criteria for Diagnosing MI in the presence of LBBB
12 Lead Sample
References
- Da Costa D, et al. Bradycardias and atrioventricular conduction block. 2002. [Link]