Another indication of acute cardiac ischemia on the ECG is flat or down-sloping ST-depression ≥ 0.5 mm in 2 contiguous leads (Figure 11). If the ST-depressions are seen in leads V1-V3 then the next step should be to obtain a 12-lead ECG with posterior leads. This is accomplished by removing leads V4-V6 from the patient and placing them at the inferior margin of the left scapula, as shown in Figure 12. If these leads (now called V7-V9) show ST-elevation this will be consistent with a posterior STEMI (Figure 13).