Clinical meaning
Constrictive pericarditis is a chronic inflammatory condition in which the pericardium (the double-layered fibrous sac surrounding the heart) becomes thickened, scarred, fibrotic, and often calcified, creating a rigid, non-compliant shell that encases the heart and restricts diastolic filling. The normal pericardium consists of two layers: the visceral pericardium (epicardium), which is adherent to the heart surface, and the parietal pericardium, a tough fibrous outer layer. Between these layers, the pericardial space normally contains 15 to 50 mL of serous fluid that reduces friction during cardiac contraction. In constrictive pericarditis, chronic inflammation leads to progressive fibrosis of both pericardial layers, which may eventually fuse together. Granulation tissue is replaced by dense collagen, and calcium deposits may form within the fibrotic pericardium, sometimes creating a shell-like calcific encasement referred to as a porcelain heart. The most common causes include idiopathic or viral pericarditis (the most frequent cause in developed countries), previous cardiac surgery, radiation therapy to the chest (especially for Hodgkin lymphoma or breast cancer), tuberculosis (the most common cause in developing countries), and connective tissue disorders. The rigid pericardium prevents the...