Diffuse ST elevations in almost all ECG leads are most consistent with which diagnosis?

• A. Aortic dissection
• B. Pulmonary embolism
• C. Myocardial infarction
• D. Pericarditis

Answer: (D)

Diffuse ST elevations across almost all ECG leads happen when the pericardium is inflamed, producing a global injury current that affects the heart's electrical activity in many directions. This pattern is characteristic of acute pericarditis. The ST segments tend to rise in a concave, saddle-shaped way, and a helpful accompanying clue is PR-segment depression (often with PR elevation in lead aVR).

In contrast, a myocardial infarction usually shows ST elevations confined to a specific coronary territory and often with a more punch‑through, convex (tombstone) appearance, along with evolving Q waves and biomarker rise. Aortic dissection and pulmonary embolism can cause chest pain and ECG changes, but they do not produce the diffuse, global ST-elevation pattern that points to pericarditis.