ORGANIC DISEASE OF THE HEART. 471 



2. Organic disease -will be sufficiently illustrated by a well- 

 marked case of progressive heart disease from some morbid 

 state of the aortic valves. These valves, from their position 

 and constant movement, are peculiarly subject to disease. 

 They thus become distorted or even destroyed, and rendered 

 unfit to direct the movements of the blood, which is con- 

 sequently obstructed in its exit from the heart in systole, and re- 

 gurgitates from the aorta during diastole. The great power of 

 adaptation to change of circumstances possessed by the circula- 

 tion is generally sufficient to%ompensate for moderate valvular 

 disease, by hypertrophy of the muscular walls of the heart. 

 The serious symptoms set in when compensation fails, i.e. 

 as a rule, when the nutrition of the ventricular wall is in- 

 sufficient to supply the increased possibly ever-increasing 

 demand for muscular force. The order of events is then as 

 follows : systole fails to overcome the intra ventricular pressure ; 

 the chamber is imperfectly emptied, and therefore over- 

 distended in diastole ; the walls are stretched ; and the 

 cavity is dilated. Pain and " oppression " make their appear- 

 ance at this stage, and cause great distress. Henceforth derange- 

 ment proceeds apace. "With the dilatation of the chamber, the 

 mitral valve becomes incompetent or misfitting; blood regur- 

 gitates in systole into the left auricle; the pulmonary circula- 

 tion becomes over-distended ; the obstruction makes itself felt in 

 the right ventricle ; and, after a time, in the right auricle, by 

 forcing the tricuspid. The systemic veins now become con- 

 gested from obstruction a fronte ; the viscera become loaded 

 with venous blood ; their functions are disordered ; and haemor- 

 rhage, dropsy, fluxes of plasma from the bowels and bronchi, 

 and discharges of albumen in the urine occur. These derange- 

 ments, coupled with those of respiration, the cardiac distress, 

 and the effects of anaemia from imperfect arterial supply, finally 

 render life impossible. During this process of backward dilata- 

 tion, the cardiac action is necessarily disordered in all respects, 

 the strength and regularity of the pulse giving way, and its 

 rate being decidedly accelerated. 



3. Haemorrhage. Bleeding produces certain effects on the 

 system, partly referable to loss of blood, and partly to fall of 

 the blood pressure. It is naturally arrested by this fall of 

 pressure, by coagulation of the blood at the seat of disease, and 

 Toy retraction of part of the coats of the vessel. If the haemor- 

 rhage be severe, fainting or syncope occurs, that is, loss of 

 consciousness from failure of the heart and consequent de- 

 ficiency of blood and blood pressure in the brain. Any other 

 cause of cardiac failure will produce the same effect. At the same 

 time, the weight of the body cannot be supported on account of 



