From your 2021 MCME Online module on Bundle Branch Blocks:
Appropriate Discordance is the phenomenon that occurs in Bundle Branch Block, wherein the J-points and ST segment move opposite the direction of the widened QRS complex, due to the change in conduction from the bundle branch block. In LBBB, the QRS complex points downward in the anterior precordial leads, which would mean the J-point and ST-segment are elevated, just by nature of its morphology. This is why LBBB is a STEMI mimic and a contraindication for the STEMI Bypass Protocol.
Check out the 2021 MCME Precourse on Bundle Branch Block for a deeper dive on this ECG finding.
*Please note that only partial tracings are shown here. Please use the T-P segment (not the PR-segment) to measure the isoelectric line.