MYOCARDITIS. 1 45 



leaden colour, or the muscular tissue is slightly infiltrated, and of the 

 same tint as the surface of the organ ; on the more or less discoloured 

 base are scattered greyish -yellow patches and a few blackish areas or 

 points, the former corresponding to centres of degeneration, the others 

 to haemorrhages. 



On microscopic examination, inflammatory and other degenerative 

 esions are seen. Many of the fibres appear swollen, fusiform in shape, 

 and slightly granular ; their striation is less marked than normal, or 

 may be altogether lost. Of the interstitial lesions, the chief is hyper- 

 aemia and infiltration with leucocytes. At a later stage the affected 

 fibres undergo granular, fatty, or hyaline degeneration, become sepa- 

 rated, more or less filled with fine granulations, or parti}- broken down, 

 while signs of obliterating endarteritis, or periarteritis, and abundant 

 cellular infiltration may be seen. As a rule these lesions are difi"use, 

 and irregularly distributed ; alongside degenerated fibres others are 

 sometimes found which have remained healthy, or appear scarcely 

 changed. 



In purulent myocarditis section of the muscle exposes little ab- 

 scesses disseminated throughout its substance. They are generally 

 metastatic, and due to embolism, as in other viscera. They may also 

 be the direct consequence of infectious inflammation of the cardiac 

 muscle, in which case they are not found in other organs. The tissue 

 surrounding them is markedly hyperaemic, infiltrated, and softened. 

 Superficial abscesses may break into the interior of the heart, or into 

 the pericardium. Cases of complete perforation of the septum be- 

 tween the ventricles, by abscesses developed in its thickness, have 

 been published. 



In a general sense the symptoms of acute myocarditis all point to 

 enfeeblement of the heart. Nevertheless, at first symptoms of irrita- 

 tion almost always occur. There is a period of abnormal irritability ; 

 the heart beats faster and more strongly ; sometimes the contractions 

 are violent, rapid, and tumultuous ; the pulse is accelerated and 

 strong ; the respiration short, and suggestive of dyspnoea. 



The local changes gradually develop, and the vague early symptoms 

 are exchanged for others of a precise character. The heart beats more 

 slowly and feebly, and is often irregular or intermittent. Little by 

 little the first sound diminishes in intensity until it becomes scarcely 

 perceptible. The second sometimes remains normal, sometimes it 

 also diminishes. In certain patients a slight systoHc murmur can be 

 heard, due to weakness of the papillary muscles. Percussion occa- 

 sionally produces pain ; at an advanced stage it is said to reveal 



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