ECG library
Left bundle branch block
core25 mm/s · 10 mm/mV · synthetic tracing
100%
Calipers:2000 ms50.0 small boxes30 bpm if R-RDrag the orange markers. One small box = 40 ms.
Key findings
- QRS ≥ 120 ms
- Monophasic lateral R waves
- Discordant repolarization
Learning points
- LBBB rewrites the whole QRS; ordinary ischemia criteria stop working.
- Concordance-based criteria (Sgarbossa) exist precisely because of that.
Connected