380 



PERICARDITIS. 



It appears to be characteristic of the presence of air in the peri- 

 cardial cavity, and its special quality varies with the quantity accumu- 

 lated in the pericardium. Masked by these pericardial sounds the 

 beating of the heart seems dull, badly defined, distant and stifled. 



B. Jugular symptoms. The "jugular" symptoms are secondary, 

 and result from the accumulation of liquid in the pericardial cavity. 

 No intra-pericardial exudate can exist without exerting pressure on the 

 heart, and as the auricles have very thin walls and are more compres- 

 sible than the ventricles, this pressure immediately causes difficult}^ in 

 the return circulation, whence venous stasis, varying in intensity, but 



clearly visible and appre- 

 ciable on account of the 

 distension of the jugulars. 

 The venous stasis is 

 general, for the pulmonary 

 veins are as much com- 

 pressed as the posterior 

 and anterior venae cavse, 

 but it is only apparent in 

 the large superficial veins. 

 This stasis is accompanied 

 by venous pulse, and par- 

 ticularly by peripheral or 

 internal oedema, oedema of 

 the lung, intestine, mesen- 

 tery, etc., of the submaxil- 

 lary space and of the dewlap 

 and entrance to the chest, 

 ffidema of the submaxillary 

 space is specially charac- 

 teristic, for it appears almost 

 first amongst external signs. That of the dewlap follows at a later stage, 

 and extends backwards as far as the umbilicus, rising above this point as 

 high even as the entrance to the chest and the axillary region. 



C. Pulmonary symptoms. The pulmonary symptoms result from 

 difficulty in the return circulation and from the venous stasis. They are 

 due to passive congestion and oedema of the lung or to hydro-thorax. At 

 rest the respiration may appear fairly regular, but at the least movement 

 it is accelerated, and may rise to 40 or even 60 per minute. 



Percussion reveals lessened resonance of the parts, and in the case of 

 hydro-thorax dulness marginated by a horizontal line, as in pleurisy. 



On auscultation the vesicular murmur may sometimes have dimi- 

 nished or even disappeared, while the respiration may be blowing, as in 



Fig. 175. — Appearance of a patient suffering from 

 fully-developed pericarditis. 



