Bundle Branch Blocks





-  Disease of or damage to the Bundle of His causing abnormal conductance as detected by ECG



-  Relatively frequent finding on ECG

-  Left BBB

-  Left Ant. Fascicular Block

-  Left Post. Fascicular Block

-  Right BBB

-  LBBB + RBBB = complete heart block (3o)



-  ECG

-  Wide QRS (>3 sm sq)

-  Sinus + BBB has normal P wave & PR interval

-  Abnormal appearance esp in precordial leads

-  Initial deflection in direction of BBB

-  WiLLiaM MaRRoW

-  LBBB: W in V1, M in V6

-  RBBB: M in V1, W in V6