ABSTRACT
Acute pericarditis is characterised by ST elevation (concave upward)
in leads facing the effusion (ECGs 281-283). Usually there are
widespread T wave inversions. In addition, the ECG can exhibit P
wave changes, low voltage QRS complexes arrhythmias and electrical
alternans (alternating size of P, QRS and T waves [ECG 284]). Lead
aVR shows ST segment depression (reflecting heart cavity signals).
