Why is MI very likely (particularly due to LAD occlusion)?
In RBBB, we sometimes see ST depression in V1 and V2, this is called a secondary repolarization abnormality, also we see isoelectric ST segment in V5 and V6 but sometimes very subtle ST elevation in V5 and V6 for the same reason.
In this patient, with RBBB, we don't expect to find ST elevation in V1 and V2, also we don't expect to see ST depression in V6. It means these ST changes are unrelated to the RBBB, so it is primary ST changes due to ischemia.
The ST depression in V6 is actually a reciprocal change of lead V1, which shows ST elevation. Many people don't know that V1 and V6 show reciprocal changes of each other, as they are set on the chest, opposing each other.
This is anterior MI due to LAD occlusion until proven otherwise.
The ST depressions in inferior leads further support anterior MI, as the reciprocal changes of the anterior wall are sometimes seen in inferior leads.
