A man with sharp chest pain that worsens with inspiration and fever has ST-segment elevations in all leads except aVR and V1. What is the most likely diagnosis?

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

Answer: (A)

Diffuse inflammation of the pericardium produces a characteristic electrocardiogram pattern: widespread ST-segment elevations across many leads with little to no elevation in aVR, and often PR-segment depression. When a patient presents with sharp, pleuritic chest pain and fever, these features point toward acute pericarditis rather than ischemic heart disease. In myocardial infarction, ST elevations are localized to a specific coronary territory and fever is not a typical finding. Pulmonary embolism can cause pleuritic chest pain and fever, but the ECG usually shows tachycardia or nonspecific changes rather than diffuse ST elevations. Aortic dissection presents with sudden, severe tearing chest pain and typically unequal blood pressures or pulse deficits, with non-specific ECG findings. The described pattern fits acute pericarditis best.