EXUDATIVE PERICARDITIS DUE TO FOREIGN BODIES. 379 



There is only moderate fever. As soon as the exudation becomes 

 considerable, the symj)toms of pericarditis grow very marked : they may 

 be groui^ed in the following order, according to their importance. 



A. Cardiac symptoms. On palpation of the cardiac zone on the left 

 the impulse of the heart is no longer felt. Percussion, which under 

 normal circumstances reveals only partial dulness, now seems to give 

 pain, and indicates abnormal dulness distributed in a vertical plane. 

 The pulmonary lobes between the pericardium and thoracic walls are 

 thrust upwards. The distended pericardial sac approaches the parietal 

 layer of the pleura and may adhere to it, hence the dulness. This dul- 

 ness extends as far back as the xiphoid appendix of the sternum, and can 

 be detected on both sides, marginated above by a convex line. 



In rare cases the dulness is absent, being partially replaced by tym- 

 panitic resonance, due to the presence of gases in the distended j)eri- 

 cardial cavity, which gases originate in the digestive reservoirs or result 

 from j)utrid fermentation of the ^pericardial exudate. 



Simple or double pleurisy, or even pneumonia of the cardiac lobes 

 resulting from infection by contiguity, may complicate cases of rapid 

 pericarditis. The dulness then appears modified, as do the signs ob- 

 served on auscultation. 



Auscultation furnishes valuable indications. From the outset it re- 

 veals acceleration of the heart. At a later stage, but only for a short 

 time, it permits of the detection of the pericardial rubbing sound which 

 precedes serous exudation, and which may persist for several days when 

 large quantities of false membrane are produced. 



If exudate is present in considerable quantities a liquid sound is 

 heard at each heart beat. The heart appears to be beating in water, but 

 the liquid note varies considerably. It has been termed the " claclaque " 

 sound (Lecouturier, 1846), in allusion to the sound j)roduced by the 

 meeting of water ripples; " clapotement " sound (Boizy, 1858), with 

 reference to the sound produced under the influence of a light breeze 

 on the borders of a stream ; " glouglou " sound (Eoy, 1875), suggested 

 by the noise of liquid escaping from an inverted bottle into a resonant 

 vessel, etc. It is important, however, to remember that cases occur 

 (principally when the pericardium is greatly distended and entirely filled 

 with liquid) where, with the animal at rest, these sounds are difficult to 

 detect. To render them noticeable the patient must be walked for a few 

 yards. 



Yernant, again, has described a sound as of dripping water, of quite 

 special character ; he compared it to that resulting from the fall of drops 

 of liquid on to a marble table or into a half-filled vessel. So far as can 

 be ascertained this sound of dripping water greatly resembles that heard 

 in pneumo-thorax, but it is less resonant and less prolonged. 



