Which statement about ST elevations in diffuse pericarditis is correct?

• A. They occur in most leads
• B. They occur only in a single lead
• C. They are never seen
• D. They occur only in limb leads

Answer: (A)

Diffuse pericarditis inflames the entire pericardium, so the ECG changes appear across many areas of the heart rather than being confined to one vascular territory. This produces a broad pattern of ST elevations that show up in most leads, often with a concave upward shape and sometimes with PR-segment depression, which helps distinguish it from a myocardial infarction where changes are localized to specific leads and may have opposite reciprocal depressions. Therefore, the statement that ST elevations occur in most leads captures the diffuse, widespread nature of the ECG findings in this condition. The idea that elevations are confined to a single lead, or that they are never seen, or that they occur only in limb leads, does not fit the diffuse pattern seen with pericarditis.