Diseases of the pericardium

Abstract

The pericardium is the name given to the membranes which cover the heart. It is a double layer forming a closed sac. The layer which covers the heart is called the epicardium and consists of a glistening smooth surface of epithelium attached to the heart by connective tissue. Around the veins and arteries entering the heart this membrane is turned back over itself and the smooth epithelial surface is continued to cover the heart with a second layer called the pericardium. The movements of the beating heart are made easier by this double layer, which is lubricated by serous fluid just like the pleura and the peritoneum. The space between the layers of pericardium is called the pericardial sac and corresponds to the pleural cavity of the lung covering and the abdominal cavity of the peritoneum. As with the pleura and peritoneum, the epicardium is often called the visceral layer of the pericardium and the outer layer called the parietal layer. There are no pain nerve endings in the visceral layer, but the parietal layer has pain nerve endings so that acute infections affecting this layer cause pain. Infections of the parietal pleura cause the pain of ‘pleurisy’ and infections of the parietal pericardium cause the pain of ‘pericarditis’.