ECG changes in bundle branch block

Last reviewed 12/2020

The ECG changes in left or right bundle branch block is dealt with in full under the relevant section. However, the problem for the student is often remembering which is which, and for this the name "William Marrow" may be used as an aid, thus:

  • W  i   LL  ia   M - LLeft block
  • M  a   RR o   W - RRight block
  • ^         ^          ^  
  • V1     Side      V6