Typical ECG changes in acute pericarditis includes: stage 1 - diffuse, positive, ST elevations with reciprocal ST depression in aVR and V1. Elevation of PR segment in aVR and depression of PR in other leads especially left heart V5, V6 leads indicates atrial injury. stage 2 - normalization of ST and PR deviations stage 3 - diffuse T wave inversions (may not be present in all patients) stage 4 - ECG becomes normal OR T waves may be indefinitely inverted #Diagnosis #EM #IM #Cardiology #EKG #Pericarditis #Spodick #ECGEducator