338 DISEASES OF THE HEART. 



we find, by physical exploration, that an old person, suffering irom cya- 

 aosis and dropsy, has a dilated heart, that his superficial arteries are 

 tortuous, pulsate visibly, and feel hard to the touch, the case is prob- 

 ably one of endarteritis deformans with secondary degeneration of a 

 heart which was once hypertrophied. If, on the other hand, there bo 

 no such condition of the peripheral arteries, the degeneration is prob- 

 ably the primary disease to which the dilatation is secondary. 



Physical Signs. Inspection never reveals the prominence of the 

 precordial region sometimes seen in excentric hypertrophy. 



When there is much enlargement, the apex of the heart is found, 

 upon palpation, to beat abnormally low down, and too much to the 

 outer side of the chest. Its impulse is often extremely feeble, and 

 may even be quite imperceptible. In other cases, particularly during 

 moments of excitement, it may be unnaturally strong (Skoda) , and 

 may even be equal to that of an excentrically hypertrophied heart, 

 although, indeed, the heaving pulsation is never seen in cases of sim- 

 ple dilatation. 



Percussion shows an extension of the cardiac dulness like that 

 arising in hypertrophy, so that in general an extension of the cardiac 

 dulness with intensification of the impulse is indicative of hypertrophy, 

 while a similar extension with diminution of the force of the impulse 

 signifies dilatation. Dilatation of the left ventricle, which accompanies 

 the first stage of insufficience of the aortic valve, produces the same 

 alterations of the percussion-sound which accompany the subsequent 

 hypertrophy of the ventricle. The same is true of the right ventricle. 

 In dilatation of the right auricle, the sound of percussion is dull under 

 the sternum, and at its right edge, from the second rib to the fifth or 

 sixth rib. Dilatation of the left auricle cannot be demonstrated by 

 percussion, as the auricle lies too far to the rear. Upon auscultation, 

 the normal sounds, which are loud and strong in hypertrophy, in 

 dilatation are found to be unusually feeble, although pure ; since both 

 the auriculo-ventricular valves and the arterial walls are set into very 

 languid vibrations by the feeble action of the heart. In other cases, 

 the sounds are muffled ; perhaps because the papillary muscles, which 

 are atrophied as well as the wall of the heart, produce a less vigorous 

 tension of the valves. Finally, and very frequently, too, we hear 

 murmurs over a dilated heart instead of the normal sounds, from 

 which, however, we are not warranted in concluding that the valves 

 have suffered alteration in their structure. These murmurs depend 

 rather upon the irregularity of the vibrations, into which the ill- 

 stretched valves are thrown by the current of the blood. They are 

 nearly allied to those which we notice in cases of abnormal innervation 

 of the organ, where there is no dilatation of the heart, in febrile disease 



