1044 Pericarditis. 



with the diastole, or then immediately before or after. Thej may 

 be soft or rough, creaking, and always give the impression of 

 friction, or if they are very short and intense they sound as 

 though two liquid or solid bodies were beating against each 

 other. These sounds are often felt with the hand placed on the 

 cardiac region, and may be increased on pressure upon the inter- 

 costal spaces. They are limited to the region of- the heart, 

 audible oh both sides and are influenced by the respiratory move- 

 ments -at most by becoming less intense during inspiration, 

 because then the lung has moved, between heart and thorax. 



In the presence of a fluid exudate, the friction sounds 

 usually disappear entirely if delicate or few pseudo-membranes 

 are fornied separating the rough surfaces of the pericardium; 

 in the presence of only small amounts of fluid the friction sounds 

 may persist. If there are very copious masses of fibrin, some 

 portions of the fibrin covered surfaces touch even in the pres- 

 ence of much fluid and produce friction sounds to the end. 



In traumatic pericarditis gases and fluid are not infre- 

 quently present together, and then splashing, gurgling and sim- 

 ilar sounds are heard in addition to the friction sounds, also the 

 sound of falling drops, etc., etc. 



The heart beat, which is at first increased in intensity, grad- 

 ually beconies weaker and may at times be unnoticeable, but if 

 much exudate is present, wave-like movements may be felt in the 

 cardiac region. With the weakening of the heart beats the 

 intensity of the - heart sounds diminishes and sometimes they 

 disappear entirely. 



An increased cardiac dullness may be ascertained only in 

 the presence of much fluid, of very much fibrinous exudate or 

 of tuberculous new-formations. The increase then gradually 

 occurs upwards, forwards and backwards ; upward it may reach 

 as high as the shoulder line and may, in small animals, reach 

 forward to the second intercostal space, backwards in all animals 

 to the 6th or 7th intercostal spaces (Fig. 181). In the lateral 

 position the upper border moves slightly down, because then the 

 heart lies somewhat further away from the thorax. In rumi- 

 nants an absolute cardiac dullness is at first noticeable, which 

 later enlarges in the manner indicated. Any dullness on the 

 right side is always less marked than on the left side. In some 

 cases of traumatic pericarditis in which the gases of putrefac- 

 tion form or in which gases from the reticulum have reached the 

 pericardial cavity, a tympanitic and even a metallic percussion 

 sound of varying extent may be elicited on the upper border of 

 the dullness. 



The pulse is accelerated from the beginning; at first fairly 

 full and tense, often arhythmical, later it becomes very small, 

 thread-like, owing to compression and possibly to involvement 

 of the heart, and the arhythmia usually increases. 



With the increase of the exudate the veins are constantly 

 filled more strongly, and this is particularly noticeable in the 



