398 DISEASES OF THE PERICARDIUM. 



chronic pericarditis, a disease which, during life, permits of onr recog 

 nizing repeated outbreaks of the inflammation. 



If young cells (pus-corpuscles) be commingled in any great amount 

 with the exudation, the efiiised liquid becomes yellow and opaque, like 

 thin pus. The fibrinous deposits are remarkably yellow, unelastic, 

 rotten, and even pasty. This we call purulent exudation (pyop&ricar- 

 dium). It arises precisely like empyema, sometimes from protracted 

 pericarditis, with sero-fibrinous exudation ; sometimes the inflammation 

 shows strong tendency to formation of pus-cells from the outset, so 

 that even the recent exudation is purulent. Such a disposition is often 

 seen in the pericarditis of septicaemia, puerperal fever, etc. In pyo- 

 pericardium, pus-cells sometimes form in the substance of the serous 

 membrane, producing ulceration ; although this is more rare than in 

 empyema. 



In cases of extraordinary rarity, pericardial effusion becomes putrid, 

 fetid, discolored, emits gas ; and here, too, erosion may take place in 

 the membranes. Ichorous exudation is the product of such decom- 

 position. 



In recent cases, the substance of the heart often suffers no material 

 alteration. In cases of longer standing, however, or when the disease 

 has been very intense, it appears soon to become sodden with serum, 

 softened, and flabby, so that extensive dilatation of the heart super- 

 venes upon the pericarditis. In cases of haemorrhagic and purulent 

 exudation, the muscles of the heart become very much discolored, 

 flabby, and softened, the epicardial surface undergoing fatty degenera- 

 tion ( Virchow). Myocarditis, too, is a not unfrequent accompaniment 

 of the disease. 



The effects of pericarditis depend greatly upon the degree of thick- 

 ening of the pericardium, and the quantity of coagulated matter con- 

 tained in the effusion. If the thickening be slight, and the amount of 

 fibrin in the effusion small, it is soon absorbed, the liquid first, and 

 then the solids, undergoing fatty degeneration, and thus becoming 

 capable of absorption. Thickening of the pericardium leaves behinc 1 

 it thick tendinous spots, or else adhesions from between the two sur 

 faces, a circumstance of but little moment if the pericardium be but 

 moderately thickened, so that such a termination of the disease may 

 be regarded as a recovery. If the pericarditis be of long standing, 

 the thickening generally becomes so great that permanent and serious 

 disorder remains, even after the exudation has been absorbed. The 

 young connective tissue is converted into a firm fibrous mass, so that 

 the epicardium at last forms a dense indurated capsule around the 

 neart. The parietal surface is usually less thickened, and here, too, if 

 the effusion be fully absorbed, it may be firmlv joined to the visceral 



