Pericarditis secondary to transmural infarction is very common and most cases appear within 4 days. The most common manifestation of pericarditis is a friction rub along the left sternal border. It is evanescent, lasting only a few days. The pain is usually perceived by the patient to be different than that of the infarct. It is worsened by inspiration, swallowing, coughing, or lying down. It frequently is associated with a low-grade fever.