DISEASES OF THE HEAET. 239 



DILATATION OF THE HEART. 



This is an enlargement, or stretching, of the cavities of the heart, 

 and may be confined to one or extend to all. Two forms of dilata- 

 tion may be mentioned — simple dilatation^ where there is normal 

 thickness of the walls, and passive, or attenuated, dilatation, where 

 the walls are simply distended or stretched out without any addition 

 of substance. 



Causes. — Any cause producing constant and excessive exertion of 

 the heart may lead to dilatation. Valvular disease is the most fre- 

 quent cause. General anemia predisposes to it by producing relaxa- 

 tion of muscular fiber. Changes in the muscular tissue of the heart 

 walls, serous infiltration from pericarditis^ myocarditis, fatty degen- 

 eration and infiltration, and atrophy of the muscular fibers may all 

 lead to dilatation. 



Symptoms. — The movements of the heart are feeble and prolonged, 

 a disposition to staggering or vertigo, dropsy of the limbs, very pale 

 or very dark-colored membranes, and difficult breathing on the slight- 

 est excitement. 



Treatment. — General tonics, rich food, and rest. 



FATTY DEGENERATION OF THE HEART. 



Fatty degeneration may involve the whole organ, or may be limited 

 to its walls, or even to circumscribed patches. The latter is situated 

 at the exterior, and gives it a mottled appearance. When generally 

 involved it is flabby or flaccid, and in extreme cases collapses when 

 emptied or cut. Upon dissection the interior of the ventricles is 

 observed to be covered with buff-colored spots of a singular zigzag 

 form. This appearance may be noticed beneath the pericardium, and 

 pervading the whole thickness of the ventricular walls, and in ex- 

 treme cases those of the fleshy columns in the interior of the heart. 

 These spots are found to be degenerated muscular fibers and colonies 

 of oil globules. Fatty degeneration is often associated with other 

 morbid conditions of the heart, such as obesity, dilatation, rupture, 

 aneurism, etc. It may be connected with fatty diseases of other 

 organs, such as the liver, kidneys, etc. Wlien it exists alone its pres- 

 ence is seldom suspected previous to death. It may be secondary to 

 hyi^ertrophy of the heart, to myocarditis, or to pericarditis. It may 

 be due to deteriorated conditions of the blood in wasting diseases, 

 excessive hemorrhages, etc., or to poisoning with arsenic and 

 phosphorus. 



Symptoms. — The most prominent symptoms of fatty degeneration 

 are a feeble action of the heart, a remarkably slow pulse, general 

 debility, and attacks of vertigo. It may exist for a long time, but is 

 apt to terminate suddenly in death upon the occurrence of other dis- 

 eases, surgical operations, etc. It may involve a liability to sudden 

 death from rupture of the ventricular walls. 



