Disease of the aortic valves is very frequently a slow process, analogous to the atheromatons disease of the root of the aorta ; the two conditions being, in fact, very often found together : but it is also the result of endocardial inflammation, especially when associated with mitral disease. Simple Lughening, or thickening of the valves, such as does not prevent tolerably perfect closure, without regurgitation, is not of itself a disease of much moment ; but the bruit heard over these valves during the contraction of the heart is of much importance from its being an early index of the tendency to atheroma: by destroying the elasticity of the aorta, this form of degeneration produces hypertrophy, and when affect ing the arteries of the brain, leads to disturbed circulation within the cranium, and ultimately to apoplexy.
The valvular disease comes to be of real importance when re gurgitation is permitted : a permanent obstacle to the complete ness of the circulation is established by a portion of the blood propelled during each systole returning into the cavity ; and to counteract this defect hypertrophy is soon established : but the constant and excessive distension during the diastole also produces dilatation, and it is in cases of double aortic murmur that the largest hearts are usually found. The effect of the affiux and reflux of the blood upon the character of the pulse in these cases is most striking. Patency of the valve, while very generally dependent on rigidity or irregular form of the flaps interfering with their mutual adaptation, is also known as a result of acci dent when one of the valves is torn, or of ulceration: the absence of systolic murmur might lead to a suspicion that these last were the causes of the diastolic murmur. It very seldoms happens that we know that the heart was free from disease before some unusual strain, and it is dangerous to conclude from the patient's state ment that rupture has taken place on such an occasion ; in very severe disease of the heart, of long standing, the patient is often utterly unconscious of its existence till some such event call his attention to it. Imperfect closure of the aortic valves is not unfrequently caused by dilatation of the vessel, while the valves themselves are free from disease. The same dilatation at a more distant part of the vessel occurs as aneurism of the arch, which is generally attended with hypertrophy, and, to an inexperienced observer, may present many of the phenomena of valvular lesion.
Among the associations of cardiac disease some may be traced to it as their cause, more or less remote ; of these, dropsy is perhaps the most fre quent, both in its generic form as anasarca, and as passive effusion into various cavities. Bronchitis, or rather bronchorrhcea, results from the ob struction to the pulmonic circulation, giving rise to congestion and cedema of the lungs; and, for the same reason, simple bronchitis from exposure is more severe in persons with disease of the heart. limmoptysis occurs in conse quence of more decided congestion or plethora of the pulmonary vessels. Epistaxis is perhaps also excited by cardiac disease. Disordered cerebral circulation produces those affections which we have denominated functional disturbance of the brain, or may lead to epileptic, and especially to apoplectic seizures. Congestion of the liver is often manifested in jaundice ; the same condition of kidney leads to the transient presence of albumen in the urine.
Other associations are rather to be regarded as causes of disease of the heart; such as rheumatism, pleurisy, albuminnria, and that form of malnutri tion which produces atheroma ; in the former, we expect to find inflammatory changes, in the latter, diseases of chronic form ; the one more frequent in early life, the other found at later periods. Similarly all of the forms of car diac disease tend matually to develop each other. Not only does the valvular lesion lead to hypertrophy and dilatation, but these, in their turn, serve to increase the valvular imperfection. Partial adhesions of the pericardium become very often a cause of hypertrophy, while its complete adhesion is more commonly followed by dilatation or atrophy. Permanent albuminuria is asso ciated alike with hypertrophy or dilatation, and with degeneration of the valves; but while it seems to be a direct cause of the hypertropy, its asso ciation with the other forms is rather secondary and concomitant ; it bears, however, some very close relations to the inflammatory lesions, pericarditis especially being frequently found in the course of Bright's disease. Inflam mation of the pleura is liable to spread to the pericardium, but seldom affects the lining membrane or valves of the heart.