Cardiac failure. 109 



of tlie aortic recoil after closure of the aortic valve, must favor 

 the development of a local coronary sclerosis on account of the 

 possibility of fibrillary injuries to the walls. Given an arterio- 

 sclerosis there is every reason to expect an imperfection of the cor- 

 onary circulation from the narrowin"; of the lumen and the in- 

 creased rigidity of the tubes ; and with the imperfection of circu- 

 lation thus fixed upon the myocardium, its nutrition and ability 

 to further enlarge are necessarily limited. The functional de- 

 mands progressing, fatigue, degeneration and cardiac failure are 

 the necessities of a not distant future.] 



Diminution of cardiac force is spoken of as cardiac failure, 

 cardiac iiisutficioicy. It follows various influences afl'ecting the 

 myocardium or its ganglia, among wdiich as prominent examples 

 mav be mentioned excessive exertion or fatigue, numerous poisons 

 and the analogous substances present in the system in the infectious 

 diseases, diminution in the blood supply to the myocardium, in- 

 flammations and degenerations of the. muscle, excessive fatty de- 

 posits of the heart, and atroi-)hy of the myocardium. All patholog- 

 ical changes which occasion cardiac insufiiciency are followed by 

 disturbances in the movement and distribution of the blood. A 

 fatigued and weakened heart is incapable of normal contraction, 

 expels from its chambers a smaller amount of blood than normally ; 

 in consequence the arteries are not properly filled, the blood press- 

 ure sinks in them and the movement of the current is slowed. The 

 aspirating power of a weak heart is also low and the blood moves 

 less freely from the venous side of the circulation, the veins becom- 

 ing engorged and the pressure raised. The results of these irregu- 

 larities differ somewhat as the left or right heart alone or the 

 whole organ is especially involved ; in one case the lesser circula- 

 tion, in the other the greater being the more disturbed. Many 

 variations, too, are occasioned by the grade of cardiac insufficiency 

 and by the nature of the original causes (cf. ancvmia and hypcr- 

 (DJua). The luyocardium being weak the cardiac cavities do not 

 contract as in normal conditions, contain an excess of blood, and 

 this engorgement gives occasion for dilatation of one or both sides 

 of the organ. 



Left ventricular insufficiency determines imperfect filling of the aorta 

 and its branches, and in consequence deficiency in the amount of arterial' 

 blood going to the brain, skin, glands and elsewhere. The heart, however, 

 remains full and the blood is dammed back into the pulmonary veins, and 

 the right heart experiences marked difficulty in forcing the blood through 

 the lungs. Insufficience of the right heart, on the contrary, causes incqm;^ 



