What is typically seen on an ECG in patients with pericarditis?

In patients with pericarditis, the characteristic ECG finding is the presence of ST elevation in the precordial leads, particularly leads V2 to V6, as well as sometimes in limb leads. This ST segment elevation is generally concave upwards and is distinct from the ST elevation seen in myocardial infarction.

The evolution of the ECG in pericarditis often follows a specific pattern: initially, it presents with widespread ST segment elevation, followed by the normalization of the ST segments and possibly leading to T-wave inversions later on. This pattern reflects the inflammatory process affecting the pericardium and the resulting changes in the heart's electrical activity.

Other ECG findings such as ST depression or T-wave inversion in inferior leads typically indicate ischemia or infarction rather than pericarditis. Therefore, the distinct ST elevation observed in the precordial leads is a key diagnostic point that physicians look for when evaluating a patient suspected of having acute pericarditis.