Pericarditis, Constrictive

Introduction

The pericardium is a sac that surrounds the heart and serves to protect the heart, as well as maintain its position and shape. The pericardium is comprised of an outer fibrous layer and an inner serous layer. The fibrous outer layer is composed of collagen and elastin. The serous layer is composed of a single layer of mesothelial cells. The serous pericardium lines the inside of the fibrous layer, where it is known as the parietal layer, and also overlies the heart, where it is referred to as the visceral layer of the serous pericardium. The pericardial cavity is the space between the visceral and parietal layers, which usually contains a very small amount of fluid.

Constrictive pericarditis results from thickening and fibrosis of the parietal and/or visceral pericardium, which become very rigid. This prevents the heart from filling adequately in diastole. The pericardial layers may fuse, obliterating the pericardial space, or the pericardial space may contain a small volume of fluid (constrictive-effusive disease).