Septal MI relates to leads V1 and V2.
An anterior MI would cause changes suggestive of MI in leads V3 and V4.
Tall R waves in leads V1-3, a classic finding of posterior myocardial infarctions. As the infarct is posterior the lead findings are reversed, meaning pathological Q waves become tall R waves. A non-posterior infarction would give the classic findings of pathological Q waves, ST-elevation and T-wave inversion.
A lateral MI would cause changes in leads I, aVL, V5 and V6.
