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HEART DISEASE
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See also:HEART DISEASE .—In the See also:early ages of See also:medicine, 'the See also:absence of correct anatomical, physiological and pathological knowledge prevented diseases of the heart from being recognized with any certainty during See also:life, and almost entirely precluded them from becoming the See also:object of medical treatment. But no sooner did See also:Harvey (1628) publish his See also:discovery of the circulation of the See also:blood, and its dependence on the heart as its central See also:organ, than derangements of the circulation began to be recognized as signs of disease of that central organ. (See also under VASCULAR See also:SYSTEM.) Among the earliest to profit by this discovery and to make important contributions to the literature of diseases of the heart and circulation were, R. See also:Lower (1631–1691), R. Vieussens (1641-1716), H. Boerhave (1668–1738) and the See also:great pathologists at the beginning of the 18th See also:century, G. M. Lancisi (16J4–1720), G. B. See also:Morgagni (1682–1771) and J. B. Senac (1693–1770). The See also:works of these writers See also:form very interesting See also:reading, and it is remarkable how careful were the observations made, and how See also:sound the conclusions See also:drawn, by these pioneers of scientific medicine. J. N. Corvisart (1755–1821) was one of the earliest to make See also:practical use of R. T. Auenbrugger's (1722—1809) invention of percussion to determine the See also:size of the heart. R. T. H. Laennec (1781–1826) was the first to make a scientific application of mediate See also:auscultation to the diagnosis of disease ofthe See also:chest, by the invention of the See also:stethoscope. J. Bouillaud (1796–1881) extended its use to the diagnosis of disease of the heart. To See also: It is a serious See also:affection associated with See also:pain over the heart, See also:fever, shortness of breath, rapid See also:pulse and dilatation of the heart. As a result of the inflammation, fluid may accumulate in the pericardial sac, or the walls of the sac may become adherent to the heart and tend to embarrass its See also:action. In favourable cases, however, recovery may take See also:place without any untoward sequelae. Diseases of the heart may be classified in two See also:main See also:groups, (1) Disease of the valves, and (2) Disease of the walls of the heart. 1. Valvular Disease.—Inflammation of the valves of the heart, or endocarditis, is one of the most See also:common complications of rheumatism in children and See also:young adults. More severe types, which are apt to prove fatal from a form of blood poisoning, may result when the valves of the heart are attacked by certain micro-organisms, such as the pneumococcus, which is responsible for pneumonia, the streptococcus and the staphylococcus pyogenes, the gonococcus and the See also:influenza bacillus. As a result of endocarditis, one or more of the valves may be seriously damaged, so that it leaks or becomes incompetent. The valves of the left side of the heart, the aortic and mitral valves, are affected far more commonly than those of the right side. It is indeed comparatively rarely that the latter are attacked. In the See also:process of healing of a damaged See also:valve, scar See also:tissue is formed which has a tendency to See also:contract, so that in some cases the orifice of the valve becomes narrowed, and the resulting stenosis or narrowing gives rise to obstruction of the blood stream. We may thus have incompetence or stenosis of a valve' or both combined. Valvular lesions are detected on auscultation over appropriate areas by the blowing sounds or murmurs to which they give rise, which modify or replace the normal heart sounds. Thus, lesions of the mitral valve give rise to murmurs which are heard at the apex beat of the heart, and lesions of the aortic valves to murmurs which are heard over the aortic See also:area, in the second right inter-costal space. Accurate timing of the murmurs in relation to the heart sounds enables us to See also:judge whether the murmur is due to stenosis or incompetence of the valve affected. If the valvular See also:lesion is severe, it is essential for the proper from excitement and worry, are among the most important See also:maintenance of the circulation that certain changes should take place in the heart to compensate for or neutralize the effects of the regurgitation or obstruction, as the See also:case may be. In affections of the aortic valve, the extra See also:work falls on the left ventricle, which enlarges proportionately and undergoes hypertrophy. In affections of the mitral valve the effect is felt primarily by the left See also:auricle, which is a thin walled structure incapable of under-going the requisite increase in power to resist the backward flow through the mitral orifice in case of leakage, or to overcome the effects of obstruction in case of stenosis. The back pressure is therefore transmitted to the pulmonary circulation, and as the right ventricle is responsible for maintaining the flow of blood through the lungs, the See also:strain and extra work fall on the right ventricle, which in turn enlarges and undergoes hypertrophy. The degree of hypertrophy of the left or right ventricle is thus, up to a certain point, a measure of the extent of the lesion of the aortic or mitral valve respectively. When the effects of the valvular lesion are so neutralized by these structural changes in the heart that the circulation is equably maintained, " See also:compensation " is said to be efficient. When the heart gives way under the strain, compensation is said to break down, and See also:dropsy, shortness of breath, cough and cyanosis, are among the distressing symptoms which may set in. The See also:mere existence of a valvular lesion does not See also:call for any See also:special treatment so See also:long as compensation is efficient, and a large number of See also:people with slight valvular lesions are living lives indistinguishable from those of their neighbours. It will, however, .be readily understood that in the case of the more serious lesions certain precautions should be observed in regard to over-exertion, excitement, over-See also:indulgence in See also:tobacco or See also:alcohol, &c., as the See also:balance is more readily upset and any undue strain on the heart may cause a breakdown of compensation. When this occurs treatment is required. A See also:period of See also:rest in See also:bed is often sufficient to enable the heart to recover, and this may be supplemented as required by the See also:administration of See also:mercurial and saline purgatives to relieve the embarrassed circulation, and of suitable cardiac tonics, such as See also:digitalis and strychnin, to reinforce and strengthen the heart's action. 2. affections of the Muscular Wall of the Heart.—Dilatation of the heart. or stretching of the walls of the heart, is an incident, as has already been stated, in pericarditis and in the earlier stages of valvular disease antecedent to hypertrophy. Temporary over-distension or dilatation of the cavities of the heart occurs in violent and protracted exertion, but rapidly subsides and is in no See also:wise harmful to the sound and vigorous heart of the young. It is otherwise if the heart is weak and flabby from a too sedentary life or degenerative changes in its walls or during convalescence from a severe illness, when the same circumstances which will not injure a healthy heart, may give rise to serious dilatation from which recovery may be very protracted. Influenza is a common cause of cardiac dilatation, and is liable to be a source of trouble after the acute illness has subsided, if the patient goes about and resumes his See also:ordinary avocations too soon. Fatty or fibroid degeneration of the heart wall may occur in later life from impaired See also:nutrition of the muscle, due to partial obstruction of the blood-vessels supplying it, when they are the seat of the degenerative changes known as arteriosclerosis or atheroma. The affection known as angina pectoris (q.v.) may be a further consequence of this defective blood-See also:supply. The treatment will vary according to the nature of the case. In serious cases of dilatation, rest in bed, purgatives and cardiac tonics may be required. In commencing degenerative See also:change the Oertel treatment, consisting of graduated exercise up a See also:gentle slope, See also:limitation of fluids and a special See also:diet, may be indicated. In cases of slight dilatation after influenza or See also:recent illness, the Schott treatment by See also:baths and exercises as carried out at See also:Nauheim may he sometimes beneficial. The change of See also:air and See also:scene, the enforced rest, the placid life, together with freedom factors which contribute to success in this class of case. Disorders of See also:Rhythm of the Heart's Action.—Under this heading may be grouped a number of conditions to which the name " functional affections of the heart " has sometimes been applied, inasmuch as the disturbances in question cannot usually be attributed to definite organic disease of the heart. We must, of course, exclude from this See also:category the irregularity in the force and frequency of the pulse, which is commonly associated with incompetence of the mitral valve. The heart is a muscular organ possessing certain properties, rhythmicity, excitability, contractility, conductivity and tonicity, as pointed out by See also:Gaskell, in virtue of which it is able to maintain a See also:regular automatic beat independently of See also:nerve stimulation. It is, however, intimately connected with the See also:brain, blood-vessels and the abdominal and thoracic viscera, by innumerable nerves, through which impulses or messages are being constantly sent to and received from these various portions of See also:tile See also:body. Such messages may give rise to disturbances of rhythm with which we are all See also:familiar. For instance, sudden fright or emotion may cause a momentary See also:arrest of the heart's action, and excitement or See also:apprehension may set up a rapid action of the heart or palpitation. Palpitation, again, is often the result of See also:digestive disorders, the See also:message in this case being received from the See also:stomach, instead of the brain as in emotional disturbances. It may also result from over-indulgence in tobacco and alcohol. Tachycardia is the name applied to a more or less permanent increase in the See also:rate of the heart-beat. It is usually a prominent feature in the affection known as See also:Graves' disease or exophthalmic See also:goitre. It may also result from chronic alcoholism. In the See also:condition known as paroxysmal tachycardia there appears to be no adequate explanation for its onset.
Bradycardia or abnormal slowness of the heart-beat, is the converse of tachycardia. An abncrmally slow pulse is met with in See also:melancholia, cerebral See also:tumour, See also:jaundice and certain toxic conditions, or may follow an attack of influenza. There is, however, a See also:peculiar affection characterized by abnormal slowness of pulse (often ranging as See also:low as 30), and the onset, from See also:time to time, of epileptiform or syncopal attacks. To this the name " See also:Stokes-See also: The treatment of these disorders of rhythm of the heart will vary greatly according to the cause and is often a See also:matter of considerable difficulty. (J. F. H. B.) See also:Surgery of Heart and Pericardium.—As the result of acute or chronic inflammation of the lining membrane of the fibrous sac which surrounds the heart and the neighbouring parts of the large blood-vessels, a dropsical or a purulent collection may form in it, or the sac may be quietly distended by a thin watery fluid. In, either case, but especially in the latter, the heart may be so embarrassed in its work that See also:death seems imminent. The condition is generally due to the cultivation in the pericardium of the germs of rheumatism, influenza or gonorrhoea, or of those of ordinary suppuration. Respiration as well as circulation is embarrassed, and there is a marked fulness and dulness of the front wall of the chest to the left of the See also:breast-See also:bone. In that region also pain and tenderness are complained of. By using the slender, hollow See also:needle of an aspirator great See also:relief may be afforded, but the tapping may have to be repeated from time to time. If the fluid drawn off is found to be purulent, it may be necessary to make a See also:trap-See also:door opening into the chest by cutting across the 4th and 5th ribs, incising and evacuating the pericardium and providing for drainage. In short, an See also:abscess in the pericardium must be treated like an abscess in the pleura. Wounds of the heart are apt to be quickly fatal. If the See also:probability is that the enfeebled action of the heart is due to pressure from blood which is leaking into, and is locked up in the pericardium, the proper treatment will be to open the pericardium, as described above, and, if possible, to See also:close the opening in the auricle, ventricle or large See also:vessel, by sutures. (E. 0.*) .
HEART-See also:BURIAL, the burial of the heart apart from the body. This is a very See also:ancient practice, the special reverence shown towards the heart being doubtless due to its early association with the soul of See also:man, his affections, courage and See also:conscience. In See also:medieval See also:Europe heart-burial was fairly common. Some of the more notable cases are those of See also:Richard I., whose heart, preserved in a See also:casket, was placed in See also:Rouen See also:cathedral; See also: Subsequently the heart was buried at See also:Melrose See also:Abbey. The heart of James, See also:marquess of See also:Montrose, executed by the Scottish See also:Covenanters in 165o, was recovered from his body, which had been buried by the roadside outside See also:Edinburgh, and, enclosed in a See also:steel See also:box, was sent to the See also:duke of Montrose, then in See also:exile. It was lost on its journey, and years afterwards was discovered in a curiosity See also:shop in See also:Flanders. Taken by a member of the Montrose See also:family to See also:India, it was stolen as an See also:amulet by a native See also:chief, was once more regained, and finally lost in See also:France during the Revolution. Of notable 17th-century cases there is that of James II., whose heart was buried in the church of the See also:convent of the Visitation at Chaillot near Paris, and that of See also:Sir See also: (1294-1303), but See also:Benedict XI. withdrew the See also:prohibition. See Pettigrew, See also:Chronicles of the Tombs (1857). Additional information and CommentsThere are no comments yet for this article.
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