DISEASE OF THE PULMONARY VALVE& 373 



CHAPTER VIII. 



INSUFFICIENCE OP THE SEMILUNAR VALVES AND CONTRACTION OF 

 THE MOUTH OF THE PULMONARY ARTERY. 



As endocarditis scarcely ever attacks the right heart during extra- 

 uterine life, and as atheroma of the pulmonary arteries is rare, it is 

 easy to see that valvular deformities, which are almost always the con- 

 sequence of one or other of these morbid processes, have been met with 

 in the pulmonary artery in but few solitary instances. In these the 

 insufficience depended upon the same causes which occasion valvular 

 disease of the aorta. The few cases of stenosis on record do not 

 always affect the valve ring, some of them arising from annular indu- 

 ration of the conus arteriosus. 



The symptoms of valvular insufficience of the pulmonary artery 

 seem to be mainly those of hypertrophy of the right ventricle, just as 

 the excentric hypertrophy of the left ventricle forms the chief sign of 

 corresponding aortic disease. In the cases which have been observed, 

 the quantity of blood in the lungs was not abnormally small, indeed 

 was abnormally great. Dyspnoea, haemorrhagic infarction, and even 

 consumption of the lungs, followed upon the insufficience. Stricture, 

 at this point, too, seems to be less perfectly neutralized by consecu- 

 tive hypertrophy, so that cyanosis, dropsy, and other tokens of venous 

 engorgement of the greater circulation soon set in in cases of contrac- 

 tion at the root of the pulmonary artery. Diagnosis of valvular dis- 

 ease of this artery is only possible by means of physical examination ; 

 as the functional disturbances, to which the malady gives rise, admit 

 of a too manifold interpretation. In either case, but more especially 

 hi insufficience, we find the signs of enlargement of the right heart, so 

 often described ; and over the region of the pulmonary artery (that is, 

 over the third left costal cartilage) a murmur during systole is audible 

 in stenosis, while in insufficience it is heard during diastole. These 

 murmurs are produced just as those are which occur in the aorta ; 

 they are heard most distinctly over the right ventricle, and over the 

 left upper region of the chest, but are inaudible in the carotids. On 

 account of the extreme rarity of valvular disease at this point, we must 

 employ the utmost caution in diagnosis, and make sure that the mur- 

 mur heard in the region of the pulmonary is actually loudest at that 

 point, and is not conducted from the aorta. 



The treatment can only be symptomatic, and the same rules which 

 <ve have set forth in the foregoing chapter are applicable here in man- 

 agement of the more threatening manifestations. 



