Which test helps differentiate pericarditis from other causes of chest pain?

In the context of differentiating pericarditis from other causes of chest pain, the electrocardiogram (ECG) plays a crucial role due to its ability to detect specific changes associated with this condition. In pericarditis, the ECG typically shows characteristic findings such as widespread ST-segment elevation and PR segment depression, which help to distinguish it from other types of chest pain related to different cardiac or pulmonary issues.

While each of the other imaging modalities has its uses, they do not provide the same immediate and interpretable insights into the electrical activity of the heart as the ECG does. The chest X-ray can help rule out other conditions such as pneumonia or heart failure but does not specifically indicate pericarditis. CT scans and cardiac MRIs can visualize the heart and surrounding structures, helping to determine the presence of effusions or inflammation but are not as direct in identifying pericarditis specifically. Thus, the ECG remains the most effective initial test for differentiating pericarditis from other causes of chest pain.