DISEASES OF THE CIECULATORY OEGANS. 



SECTION I. 

 DISEASES OF THE HEART. 



CHAPTER I. 



HYPERTROPHY OF THE HEART. 



ETIOLOGY. The term hypertrophy of the heart io applied exclu- 

 sively to a thickening of the cardiac wall, arising from ah increase in 

 the volume of its muscular tissue. It is of importance to observe a 

 sharp distinction between this true hypertrophy of the heart and other 

 enlargements of the cardiac wall, due to heterologous deposits, which 

 may be called false hypertrophy, since the effect which the one dis- 

 ease has upon the circulation and the symptoms to which it conse- 

 quently gives rise are entirely different from those of the other. If, 

 as not unfrequently happens, the hypertrophied heart undergo de- 

 generation, and if the genuine hypertrophy be converted into a spu- 

 rious one, we find that the effects of the former disorder gradually sub- 

 side, and that, if at length the degeneration preponderate over the 

 Hypertrophy, a group of symptoms arise which are almost directly the 

 reverse of those which formerly existed. We know that the muscle? 

 of the heart, as well as those of the rest of the body, waste away and 

 become atrophied from insufficient supply of nourishment, or in dis 

 eases attended by consumption ; and we also know that a most abun- 

 lant supply of nourishment has but little effect in augmenting the bulk 

 of the muscles. On the other hand, it is a matter of daily remark that 

 the external more visible muscles of the body undergo hypertrophy 

 whenever they are subjected to constantly recurrent and vigorous con- 

 traction. The muscles of the blacksmith's arm, and of the leg of the 

 mountaineer, are thus hypeHrophied, and, as we have told in a previous 



