392 DISEASES OF THE HEART. 



normally low. Experience, however, shows that even with toler- 

 ably good compensation, when there is great excitement of the 

 heart with very frequent or irregular pulse, digitalis is of decided 

 benefit ; and hitherto neither quinine, veratrin, delphinium, nor 

 bromide of potassium all of which are recommended for palpita- 

 tion has proved itself to be an efficient substitute for digitalis ; 

 far less has any of them supplanted it. 



But at the same time an immoderate and too protracted use of 

 digitalis may have a directly opposite after-effect, with acceleration 

 and irregularity of the pulse, and even danger of heart-palsy ; hence, 

 when the heart's action is already enfeebled, we must be doubly 

 on guard lest we do harm instead of good. 



3. P. 334. 



John Seitz describes a spontaneous dilatation of the heart, based 

 upon numerous observations in Biermer's clinic. These cases can- 

 not be ascribed either to structural changes in the heart or to any 

 general disorder ; but they arise apparently from protracted over- 

 exertion of the organ. 



4. P. 351. 



The acute ulcerous form of endocarditis, which is much more 

 rare, arises in this wise : A finely-granular disintegration takes 

 place in the infiltrated tissues at an early stage of the process, be- 

 fore there has been time for suppuration to begin ; so that at some 

 point the thickened pericardium is converted into a soft, pulpy mat- 

 ter, which, by the joint action of the motions of the valves and of 

 the friction of the blood-current, is detached and washed away. 

 Thus an erosion the endocardial ulcer is formed. Traces of for- 

 mer endocardial lesions are in most cases to be found in the vicinity 

 of these ulcers ; and the supposition has been advanced that the 

 ulceration is due, not so much to a particular cause in the disease 

 itself, but rather to the seat of the attack, which is upon tissues al- 

 ready predisposed to degeneration in consequence of former inflam- 

 mation (Rudolph Meyer). 



This destructive process may speedily cripple or totally destroy 

 a valve by causing rupture of the chordae tendineae, or by detach- 

 ment of the papillary muscles from their insertion. Sometimes one 

 of the valve-flaps is split or perforated, or even torn loose for a con- 

 siderable distance from its ring of attachment ; for should by 

 chance one of the lamellae of the valvular duplicature be eroded at 

 one circumscribed point only, and if the ulcer should lie on that 

 face of the valve against which the blood-stream rushes when the 



