ABSTRACT
INTRODUCTION The pericardium is a thin covering around the heart that separates it from other mediastinal structures and provides structural support to the heart. The pericardium has substantial hemodynamic and metabolic impacts on the heart; however it is not essential for one’s survival. The normal pericardium consists of two sacs: an outer (fibrous) pericardium and an inner double-layered serous pericardium. The serous pericardium comprises visceral pericardium (or epicardium) and parietal pericardium. The visceral pericardium surrounds the heart and proximal great vessels and is reflected to form a parietal layer which lines the fibrous pericardium. The visceral pericardium has an external layer of flat mesothelial cells, which lies on a stroma of fibrocollagenous support tissue. The parietal pericardium contains elastic fibers, as well as the large arteries supplying blood to the heart wall, and the larger venous tributaries carrying blood from the heart wall. The visceral and parietal pericardial layers are separated by a pericardial cavity, which in the healthy population contains about 20-50 ml of pericardial fluid produced by the visceral layer. The pericardium provides lubrication to prevent friction between the heart and surrounding structures, and also serves as a mechanical and immunological barrier. The spectrum of the pericardial diseases includes congenital pericardial defects, pericarditis (acute, chronic and recurrent forms), neoplasms and cysts (1,2). Acute pericarditis is the most common form of pericardial disease, constituting approximately 5% of nonischemic chest pain presentations to the emergency room (3).
