4:02 DISEASES OF THE PERICARDIUM. 



3. If the substance of the heart be not degenerated, the dilatation 

 turns into hypertrophy, which is usually total, and is to be set down 

 as a not unfrequent sequel. 



4. The nutritive state of the organ suffers under the perpetual 

 pressure of the pericardial exudation, and the constant infiltration of 

 its substance, resulting in atrophy and fatty degeneration. 



Physical Signs Inspection. If the thoracic wall be yielding, and 

 the effusion large, inspection often reveals a distinct bulging of the 

 cardiac region. Ossification of the costal cartilages tends to prevent 

 this prominence, which, therefore, is to be found principally in children 

 and youthful persons. 



Palpation at the outset of the disease often enables us to feel that 

 the beat of the heart is in its proper position, and frequently, too, that 

 the vigor of the beat is increased. When the exudation is more copi 

 ous, the impulse is usually weaker than normal, unless the heart bo 

 hypertrophied or violently excited. Sometimes the beat is quite im- 

 perceptible. It may frequently be felt while the patient is standing 

 upright, but is lost as soon as he lies down, as the heart then sinks 

 back into the liquid, and is separated from the thoracic wall. The im- 

 pulse often is situated too low down, the diaphragm having become 

 depressed by the accumulation of liquids. Oppolzer's statement, that 

 the shifting of the heart-beat as the patient alters his attitude is a 

 characteristic token of pericardial effusion, is incorrect. According to 

 a number of observations of G-erhardt, the truth of which I can fully 

 vouch for, the apex of the heart of a healthy person generally moves 

 to the left about two centimetres when he lies upon his left side. 

 Sometimes the hand laid upon the chest perceives a distinct sensation 

 of friction, caused by the rubbing together of the rugged surfaces of 

 the pericardium. 



Percussion. If the lung intervene between the pericardium and 

 the thoracic wall, percussion will reveal nothing abnormal even when 

 the exudation is tolerably large (half a pound). At other times an un- 

 natural dulness arises early, which, from the point at which it first be- 

 comes perceptible, and the form which it afterward assumes, is one of 

 the most important signs of the disease. At first, as the liquid rises, 

 and the heart takes the deepest position possible, we find a dulness 

 upon percussion at the root of the aorta and pulmonary vessels. It 

 extends upward to the second rib, or even higher, and passes beyond 

 the right edge of the sternum. When very copious, the exudation 

 bathes the entire organ, and the dulness forms a triangle with the 

 base downward, and with an obtuse apex above. The dulness, which 

 always grows broader as it extends lower, often passes far beyond the 

 left mammillary line and the right border of the sternum. 



