**Core Concept**
Acute pericarditis is characterized by inflammation of the pericardium, leading to electrical changes on the electrocardiogram (ECG). The ECG in acute pericarditis typically shows widespread ST-segment elevations in multiple leads.

**Why the Correct Answer is Right**
The ST-segment elevations in acute pericarditis are due to the inflammatory process affecting the pericardium, which leads to the activation of the inflammatory cells and the release of various mediators. This results in the depolarization of the myocardium and the subsequent elevation of the ST-segments on the ECG. The widespread nature of the ST-segment elevations is due to the diffuse involvement of the pericardium.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because ST-segment depressions are not typically seen in acute pericarditis. While ST-segment depressions can be seen in other conditions such as myocardial infarction, they are not characteristic of acute pericarditis.

**Option B:** This option is incorrect because PR-segment depressions are not typically seen in acute pericarditis. While PR-segment depressions can be seen in other conditions such as atrial infarction, they are not characteristic of acute pericarditis.

**Option C:** This option is incorrect because Q-wave formation is not typically seen in acute pericarditis. Q-wave formation is characteristic of myocardial infarction, not acute pericarditis.

**Clinical Pearl / High-Yield Fact**
In acute pericarditis, the ECG changes typically resolve within 2-3 days as the inflammation resolves. However, in some cases, the ECG changes may persist for longer periods, and in these cases, further evaluation, such as echocardiography or cardiac MRI, may be necessary to rule out other conditions.

**Correct Answer: A. ST-segment depressions are not typically seen in acute pericarditis.**