Question: Reviewing the STEMI bypass protocol I noticed that it requires 2mm of elevation in V1-V3 in two contiguous leads and 1mm of elevation in any other contiguous leads.

My question is then twofold:
1. What’s different about V1-V3 that we require 2mm of elevation?
2. Why is V3 included in this since it is not anatomically contiguous with V1 or V2? Should then V4 not be included to give a “partner” to V3?

Thanks for your help!