Key Points

• The pericardium is a serous sac that surrounds, supports, and protects the heart.
• Impairment of pericardial compliance or elevation of intrapericardial pressure may lead to pathophysiologic and hemodynamically significant restriction of cardiac function.
• Prompt recognition of cardiac tamponade and drainage of pericardial fluid may be lifesaving.
• Differentiating constrictive pericarditis from restrictive cardiomyopathy is challenging but critical because only constriction is improved by pericardiectomy.

The pericardium is a serous sac that surrounds, supports, and protects the heart. The smooth pericardial surface adjacent to the heart and the small amount of pericardial fluid normally present within the pericardial sac provide a frictionless chamber for cardiac motion, thus improving the efficiency of myocardial contractions. The pericardium, however, is subject to disease, including inflammation, infection, trauma, and malignancy. Impairment of pericardial compliance or intrapericardial fluid accumulation, resulting in reduction of the relative volume of the pericardial space secondary to disease processes, may lead to pathophysiologic and hemodynamically significant restriction of cardiac function. Prompt recognition and treatment of pericardial disease is often lifesaving.