Which ECG finding is characteristic of pericarditis?

The characteristic ECG finding for pericarditis is diffuse ST elevation without reciprocal changes. In pericarditis, the inflammation of the pericardium leads to changes in the heart's electrical activity, resulting in ST segment elevation that is typically widespread across multiple leads. This elevation is often concave in shape and does not present with the reciprocal ST segment depression typically seen in myocardial infarction.

The absence of reciprocal changes is a key distinction here; in cases of myocardial ischemia or infarction, you usually see ST elevation in one area of the heart accompanied by ST depression in opposing leads, which is not the case in pericarditis. This differentiation is crucial for correct diagnosis and treatment.

Understanding these features is important for identifying pericarditis and distinguishing it from other conditions that can affect the ECG, like myocardial infarction or other types of cardiac ischemia.