Arrange the following steps in the pathophysiologic progression from acute pericarditis to cardiac tamponade in the correct chronological order.

The appropriate sequence begins with **pericardial inflammation**, which can lead to accumulation of fluid in the pericardial space. As the volume increases, pressure initially rises slowly, but after a critical point it can rise rapidly. Sufficient pressure then interferes with cardiac filling and may produce tamponade. This ordering describes a possible progression, not an inevitable outcome of every episode of acute pericarditis. **Key takeaway:** An effusion becomes dangerous when pressure within the pericardial space impairs cardiac filling. **Glossary:** **Pericardial pressure**: pressure exerted by contents of the pericardial space. **Cardiac filling**: blood entering the heart chambers, particularly during diastole.