Pericarditis is an inflammation (-itis) of the pericardium (the fibrous sac surrounding the heart). Classification Pericarditis can be classified according to the composition of the inflammatory exudate. Types include: serous purulent fibrinous caseous hemorrhagic Pericardiocentesis can be performed to permit analysis of the pericardial fluid. Acute vs. chronic Acute pericarditis is more common than chronic pericarditis, and can occur as a complication of infections, immunologic conditions, or… (More on Pericarditis)