What ECG finding is associated with acute pericarditis?

Acute pericarditis is characterized by inflammation of the pericardial sac surrounding the heart, and one of its hallmark ECG findings is diffuse ST segment elevation. This elevation typically occurs in multiple leads across the ECG, rather than being confined to specific leads as seen in conditions like myocardial infarction.

This diffuse ST segment elevation is a result of the inflammatory processes affecting the myocardium and, importantly, is not accompanied by reciprocal ST segment depression, which distinguishes it from ischemic changes that might occur with myocardial infarction. In acute pericarditis, the ST segment elevation generally does not have the appearance of the "tombstone" pattern commonly linked to myocardial injury. Instead, the elevation is often concave and widespread, which can help clinicians differentiate it from other causes of ST segment changes.

Overall, understanding these characteristic findings helps in diagnosing acute pericarditis and assists in managing the patient's condition appropriately.