DISEASES OF THE CIRCULATORY SYSTEM. 209 



one-half inches, the antero-posterior diameter seven and one-half 

 inches, and its lateral diameter five and one-half inches. 



Before examining the heart as regards dimensions, soak it in 

 water so as to relax it. 



In hypertrophy, the muscular substance looks darker and is 

 more resisting, it being harder and more like fibrous tissue. 



There may be fatty degeneration, in which case the muscle is 

 lighter in color and easily torn. 



The heart often weighs twice as much as normal; it has been 

 found to weigh fourteen pounds (in Eclipse), or more. 



The apex is broader in these cases. 



How is this caused ? 



It may be due to diseases of the valves, altered innervation, 

 adhesions of the pericardium, any interference with the pulmonary 

 circulation, narrowing of the openings, prolonged muscular exer- 

 tion, contractions or diseases of the arteries or capillaries. 



Give the symptoms of cardiac hypertrophy. 



Dyspnoea is often present as the first symptom. 



There are often symptoms of a passive congestion of the lungs, 

 which are apt to take place in these cases and cause the dyspnoea. 



There is an increased impulse to the heart, it usually being 

 more bounding and full. 



What are the physical signs ? 



On palpation, the impulse is more forcible, the pulse is full 

 and slow; on percussion, the area of dulness is found to be in- 

 creased in size; on auscultation, the sounds may present no special 

 change, except the first sound, which may be dull and prolonged. 



Give the indications for treatment. 



Eest, with any of the following drugs, according to indications: 

 digitalis, aconite, veratmm viride, iodide of potassium, camphor, 

 ether, caffeine. 



CARDIAC DILATATION. 



Give the definition. 



Dilatation of the heart is an increase in the size of one or 

 more of the cavities of the heart, with or without thickening of 

 the walls. 



