Left bundle branch block

(Redirected from LBBB)


Bundle Branch Block.png
  • ST Depression and T wave inversion are common
  • QRS > 0.12 in limb leads
  • Leads
    • Large and wide R waves — leads I, aVL, V5, and V6
    • Small R wave followed by deep S wave —leads II, III, aVF, V1–V3

Differential Diagnosis

Wide-complex tachycardia

Assume any wide-complex tachycardia is ventricular tachycardia until proven otherwise (it is safer to incorrectly assume a ventricular dysrhythmia than supraventricular tachycardia with abberancy)

^Fixed or rate-related

See Also

External Links


  • Journal of Electrocardiology. Vol 43 (2010). 40-42.