|This is part of: Myocardial Infarction|
High R-waves with ST-depression in V1-V3.
The posterior wall is usually supplied of blood by the RCA. Because no leads "look" at the posterior wall in the normal ECG, no leads show ST-elevation in case of a posterior wall infarction. The ST depressions in V1-V3 that can be observed in case of a posterior wall infarction are in fact mirrored ST elevations and the high R-waves are the Q-waves of the infarct. To be able to confirm a posterior-infarct, leads V7, V8 and V9 may be helpful. These leads are horizontally placed from V6 to the back and do show the ST elevations of the posterior wall.