<prompt> Which of the following ECG findings is associated with acute myocardial infractionElevation of S waveProlonged QT intervalTall T waves with increased amplitudeProlonged PR interval  <response>: Ref Harrison 19 th ed pg 1594 ST-segment depression occurs in 20 to 25 of patients; it may be transient in patients without biomarker evidence of myocardial necrosis, but may be persistent for several days in NSTEMI. T-wave changes are common but are less specific signs of ischemia, unless they are new and deep T-wave inversions 0.3 mV. 