318 DISEASES OF THE HEART. 



and dropsy. Often as we see these symptoms in such cases, they are 

 always to be ascribed to the complications, and never to the disease 

 itself, if the hypertrophy be genuine ; that is, if it depend upon multi- 

 plication of the normal muscular fibres of the heart. Bouillaud justly 

 denounces the statements of authors, according to whom a hypertro- 

 phy of the heart gives rise to cyanosis and dropsy. He says : " Can 

 any one, according to sound physiology, suppose that a true and sim- 

 ple hypertrophy of the heart can be capable, by itself, of producing 

 phenomena which indicate embarrassment and weakening of the func- 

 tion of the heart ? " In spite of this clear and vigorous protest, cyano- 

 sis and dropsy are still set down among the symptoms of hypertrophy 

 of the heart. 



Let us first suppose a hypertrophy of both ventricles. The blood 

 must then be propelled into the arteries with unwonted energy upon 

 every stroke of the systole, and if (as is usually the case) the ventri- 

 cles be at the same time dilated, the arteries will become abnormally 

 full. But just as, during the systole, the hypertrophied ventricle com- 

 pletely expels its contents, so during diastole the efflux of the blood 

 to the heart from the veins must be made easier. The veins become 

 more empty, while the arteries fill. Nor can the capillaries ever un- 

 dergo any undue distention, for the outflow from them becomes easy 

 in proportion as the vis a tergo is increased. The effect, then, of a 

 general hypertrophy of the heart is, that the arteries become fuller, 

 the veins less full, and that the circulation is accelerated. 



If the left side alone be hypertrophied, its contents must be more 

 completely expelled than if its walls possessed merely their normal 

 thickness. Hence (and all the more so if dilatation also exist) the 

 aortic system becomes over-filled, while the volume of blood in the 

 pulmonary system must be correspondingly reduced. In spite, how- 

 ever, of the over-filling of the aortic system, it can never become so 

 great as to cause dropsy or cyanosis by over-distention of the capil- 

 laries and veins. This is prevented by the depletion which takes place 

 in the vessels of the pulmonary circulation. The vessels of the lung, 

 being imperfectly filled, offer but little resistance to the entrance into 

 them of blood from the right ventricle, which, although not hyper- 

 trophied, can propel its blood with unusual ease. Thus the engorge- 

 ment of the vena cava subsides, its blood, under the increased pressure 

 from behind, flowing readily into the empty right heart ; and the right 

 ventricle, being well supplied with blood, and its contents readily pass- 

 ing out into the meagrely-filled vessels, soon is propelling quite as 

 much blood as the left ventricle, into which the blood runs, under a 

 reduced pressure, and which discharges its contents into the over-filled 

 aorta with difficulty. Hence the effect of hypertrophy, especially of 



