Pericardial effusion may produce QRS voltages less than 5 mm in all limb leads
Sub‐epicardial myocardial damage causes time dependent change:
- Initial ST segment elevation in the left ventricular leads
- ST segment returns to normal within 2‐3 days
- T wave inversion (with isoelectric ST segment) 2‐4 weeks after the onset of pericarditis
