410 DISEASES OF THE PERICARDIUM. 



effect of aggravating the dyspnoea arising from the primary disease. 

 Such an effusion often helps to prevent the patient from lying down 

 without danger of suffocation, and compels him to sit day and night 

 leaning forward upon his chair or bed. Moreover, the pressure exerted 

 by the liquid upon the heart and mouths of the great vessels impedes 

 the systemic circulation, causing the jugular veins to swell up, and 

 aggravating the cyanosis and dropsy. Frequent as is the coexistence 

 of such symptoms with hydrops pericardii, yet the presence of every 

 one of them does not afford sufficient ground for a positive diagnosis 

 of hydropericardium, unless supported by the evidence drawn from 

 physical exploration. All these symptoms may be present without 

 there being any increase in the amount of the pericardial liquid 

 Upon physical examination, the prominence of the region of the heart 

 is observable, although in a less degree than in cases of inflammatory 

 effusion. The depression of the intercostal spaces is not obliterated. 

 The impulse of the heart is very feeble, and is often quite impercep- 

 tible, especially when the patient lies upon his back. When the effu- 

 sion is large, and provided that the lungs are capable of retraction, 

 the cardiac dulness is extended, and has the same shape and exhibits 

 the same modifications, upon change from the upright to the recum- 

 bent attitude, which already have been described as characteristic of 

 pericardial effusion. It happens more frequently in this affection than 

 it does in pericarditis, that the lung is unable to retract, owing either 

 to emphysema or to adhesions of the costal and pulmonary pleurae. 

 In such cases, notwithstanding the existence of a very large effusion, 

 the area of dulness is not extended. Upon auscultation, unless the 

 valves of the heart be diseased, the heart-sounds are pure though 

 feeble. Friction-sounds are never heard. 



TREATMENT. All the measures recommended for the treatment of 

 hydrothorax are equally applicable to that of hydropericardium. The 

 only rational procedure is to treat the primary disease. It rarely is 

 practicable to reduce the liquid in the pericardium by means of diuretics 

 and drastics. 



CHAPTER IV. 



PNEUMOPERICABD1UM. 



AIB sometimes enters the pericardium through a perforating wound 

 of the thorax ; in other cases the pericardial sac suffers perforation by 

 some destructive morbid process, and ah- is admitted into it from some 

 organ which naturally contains air. I have observed one instance of 

 this kind (which has been reported by Dr. Tutd^ my assistant at the 



