ADVENTITIOUS GROWTHS OR NEW FORMATIONS. 57'" 



V. Adventitious Grow^ths or New Formations in 

 Connection with the Heart. 



In addition to the structural changes, either of extra deve- 

 lopment of muscular tissue or minute elemental changes, we 

 find that the heart is liable to become the seat of various 

 morbid growths or new formations, which may directly or 

 indirectly terminate fatally. 



The most commonlyoccurringmay be classed as — (1) Growths 

 of parasite or/f/Mi, situated internally or externally; (2) Cancer- 

 ous or malignant growths ; (3) Fibroid tumours, or cardiac 

 polypi ; (4) Vascular tumours. 



Adventitious growths or new formations of any of these 

 several varieties, m the influence which they exercise upon the 

 animal health and in their tendency to produce fatal results, 

 as well as the urgency of the symptoms which accompany 

 their existence during life, depend probably more upon their 

 situation in the cardiac structures than upon their extent or 

 even their intrinsic character. 



Thus it is easy to understand that a comparatively small 

 tumour, or amount of adventitious deposition, situated in 

 either of the cavities of the heart is more likely to be produc- 

 tive of serious or fatal consequences than a more extensive or 

 more malignant growth in connection with the external and 

 free surface of the organ. Even the exact situation of these 

 growths, when occurring either within the cardiac cavities or 

 on the outer surface of the heart, has an important influence 

 in determining symptoms of illness, as also the ultimate results. 

 A very small tumour, if interfering with the valvular sufficiency 

 of any of the cavities, is a more serious matter than a more ex- 

 tensive growth situated apart from these structures ; in hke 

 manner, interference with the great vessels at the base of the 

 heart by the presence of fibroid or other tumours is more 

 likely, by interfering with the free course of the blood to and 

 from the heart, to be productive of functional disturbance and 

 other changes, than would be the case if the same growth 

 existed at the apex. 



The chief parasitic growths found connected with the heart 

 are hydatids, or echinococcus cysts, which, although I have 



