There is often a low-grade fever associated with viral and idiopathic pericarditis, while purulent pericarditis is associated with very high fevers and systemic sepsis. The electrocardiogram represents the most useful diagnostic test in acute pericarditis . In contrast to the regional ST changes of myocardial ischemia, pericarditis produces widespread ECG changes in limb and precordial leads. The ECG abnormalities should be differentiated most importantly from acute myocardial ischemia. Most patients with acute pericarditis remain in sinus rhythm.
Chest radiography contributes relatively little to the diagnosis of acute pericarditis.
The presence of cardiomegaly may be seen in the minority of cases where a significant pericardial effusion has accumulated. The following diagnostic algorithm has been proposed. All patients should have a complete history and physical examination, electrocardiography, and chest radiography. Diagnosis specific testing should include tuberculin skin testing, rheumatoid factor and antinuclear antibody, viral studies from pharyngeal, and fecal swabs. I hope you find this information useful.