Negative T waves are typical findings of subacute pericarditis (stage 3). They are symmetrical (resembling those seen in ischemia) and likely to be noted in the precordial leads. T wave inversion can last for weeks. This finding is only documented if there are old ECG tracings available for comparison.

Pericarditis can cause arrhythmias, although this is rare. When an arrhythmia is present, the clinician should assess for coexisting cardiac pathologies such as myocarditis.