DISEASE OF THE MITRAL VALVE. 3(55 



Stricture of the aortic outlet requires measures of quite a difieren 

 aature. Here we have no threatening hyperajmia to allay, or over- 

 action of the heart to moderate. Much more depends upon furthering 

 the nutritive state of the system, and, with it, that of the heart, so 

 that its contractions may have force enough to prevail over the resist- 

 ance at the outlet. Rich animal food, and even the moderate* use 

 of wine, are quite as strongly indicated here as they are contraindi- 

 cated in insufficience. Blood-letting must never be practised. Use 

 of digitalis is to be confined to those cases in which compensation be- 

 gins to become imperfect. It is most effective in the cases in which 

 the action of the heart is so accelerated that the left ventricle appar- 

 ently has not the time to expel its contents through the narrowed 

 opening during the short period of systole. 



CHAPTER VII. 



TNSUFFICIENCE OF THE MITRAL VALVE, AND CONSTRICTION OF THE 

 LEFT AITRICUXO-VENTRICTJLAR ORIFICE. 



ETIOLOGY. The mode of origin of insufficience of the mitral is, in 

 many cases, quite analogous to that of insufficience of the aortic valve ; 

 in other cases, however, it depends upon a morbid state of the papillary 

 muscles and chordae tendineae ; and, indeed, there have been instances 

 in which, although during life the valve was deficient, yet after death 

 no palpable alteration in it could be detected. Stenosis of the auric- 

 ulo-ventricular passage, which is often found to accompany insuffi- 

 cience, arises partially through contraction of the ring of valvular 

 insertion, partially through adhesions of the valve-tips, or chordae 

 tendineae. 



Valvular disorder of the mitral is almost always a consequence of 

 endocarditis, or of myocarditis ; more rarely of atheromatous degen- 

 eration. It is only when valvular disease of the aorta accompanies 

 similar disease of the mitral that the latter depends upon the chronic 

 form of inflammation caused by atheroma. 



ANATOMICAL APPEARANCES. The most common lesion found in 

 mitral insufficience is a marked shortening of the valve-tips, the valve 

 itself being thickened and indurated, often enclosing large, flat plates 

 of calcareous matter. The delicate, tender web on the free edge of 

 the valve has disappeared, the edge forming a thick, clumsy pad, upon 

 which the chordae tendineaB originating from the papillary muscles are in- 

 serted. Of the secondary chordae tendineae, which, springing from the 

 primary set, are inserted into the web of the valve, there is hardly any 

 trace. In other cases, instead of these lesions, or, in addition to them, 



