If the initial ECG is non-diagnostic (i.e. only one lead meeting ST-elevation criteria but the second contiguous lead ST-elevation is less than 0.1 mV) but the suspicion for ACS is present, then serial ECGs (every 15 minutes for the first hour) should be performed to ensure STEMI is not missed.17,19

In contrast to STEMI, UA/NSTEMI can present with a myriad of ECG findings. These may include normal ECGs, nonspecific T-wave inversions, ST-depression or transient ST-elevation.