You get a EKG that’s a sinus rhythm but it has widened QRS waves. You remember learning about bundle branch blocks at some point back in medical school but thought it was confusing and never bothered to learn the difference. Here’s a quick and easy way to differentiate the two in most cases.

Look at V1. This is where the money is…usually.


So lets test it out.

Identify this EKG:

Did you say LBBB?

How about this one?


LBBB also.

And this one?


This one is a RBBB

Now go save some lives!