SECTION II. 



DISEASES OF THE PERICARDIUM. 



CHAPTEE I. 



PEKICAKDITIS. 



EriOLOGT. With regard to the pathogeny of pericarditis, we may 

 icier to what we have already said concerning its kindred affection, 

 pleuritis. Li many cases, whese the disease is partial, the inflammatory 

 derangement of nutrition is not such as to produce interstitial exuda- 

 tion and effusion into the sac; but a proliferation of the pericardium 

 takes place, so that its normal tissue forms offshoots, and becomes 

 thickened. Thus the so-called tendinous spots, etc. (jSehnenflecJce) 

 originate. In other cases, the cell-growth in the pericardium is accom- 

 panied by a free exudation. This always contains fibrin, but in vari- 

 able quantity, and we are not warranted in attributing this variation 

 to differences in the crasis of the blood ; indeed, accumulation of fibrin 

 hi the blood must be regarded rather as a consecutive and not as a 

 primary alteration of its composition. 



Pericarditis may be caused, although rarely, by injuries, penetrat- 

 ing wounds, blows, concussions, etc. ; to this class of cases we naturally 

 annex those in which inflammation has spread to the pericardium from 

 a neighboring organ. It is extraordinarily rare for this malady to 

 attack previously healthy persons as an independent isolated disease. 

 When it does occur, it is chiefly at times when pneumonia, pleurisy, 

 croup, and other inflammatory complaints are rife, and epidemic influ- 

 ence prevails. In such cases it is customary to assume that cold has 

 been allowed to act upon the organism, although this is generally diffi- 

 cult to prove. 



Pericarditis occurs much more frequently, allied to other acute or 

 chronic diseases. The most important of these is acute articular rheu- 

 matism, particularly when several joints are successively affected 

 According to Bamberger's carefully-collected statistics, about thirty 



