274 CIRCULATOr.Y APPAllATUS. 



of the heart In the course of acute febrile diseases, the exanthe- 

 mata, typhus (cf. § 112, note), &c. 



13. As a fatty disintegration of the superficial, subpericardial 

 layer of the cardiac muscle, in consequence of the nutritive dis- 

 turbance caused by inflammation of the adjoining pericardium 

 (see Pericarditis). 



y. In the form of numerous foci not exceeding a pin's head 

 in size, disseminated tln-ough the innermost, subendocardial layer 

 of the muscular substance of such hearts as have been subjected 

 to a high degree of dilatation (valvular insufficiency). In such 

 cases, the whitish dots and stri^ due to this • affection may be 

 detected even through the endocardium, particularly upon the 

 musculi papillares and columnas carneae near the apex. 



8. As a single focus of fatty softening (even as large as a 

 hazel-nut) usually situated in the substance of the wall of the 

 left ventricle near its apex. The atony and friability of the 

 degenerated parenchyma usually cause rupture of the heart, 

 differing from rupture due to other causes by the very gradual 

 manner in which the muscular substance gives way layer after 

 layer. Atheromatous degeneration of the coronary arteries with 

 plugging of one of their larger branches by a thrombus may be 

 regarded in every instance as the cause of this dangerous lesion. 



§ 239. AjypendLx, Fatty degeneration of the muscular sub- 

 stance of the heart must not be confounded with that excessive 

 infiltration of the subpericardial connective tissue with fatty 

 matter which is commonly called " fatty heart." The latter is 

 associated with general obesity, and may give rise to very serious 

 troubles, even to death itself. For the masses of fat overgrow 

 the heart from the sulcus circularis and transversus to such an 

 extent as to conceal the entire surface of each ventricle with the 

 exception of a small patch; it is hardly conceivable that the 

 movements of the heart should not be hindered by so great a 

 burden ; then again, the infiltration forces its way into the inter- 

 stitial connective tissue of the myocardium itself. The latter 

 phenomenon indeed is always confined to a limited patch ; the 

 pressure is enough however to cause wasting of the corresponding 

 portion of the heart's wall ; and it tends thereby directly to 

 impair the functional powers of the organ. 



