Synonyms.—Endarteritis Chronic Deformens; Atheroma; Arterial Sclerosis.
Definition.—Arteriosclerosis is an inflammatory and degenerative condition of the arterial system, primarily of the intima, although later degenerative changes may involve the whole structure. Calcarine deposits are quite common.
Etiology.—The predisposing causes of arteriosclerosis are old age and heredity. We may say that it is essentially a disease of old age, the large majority of cases occurring in persons past the age of forty.
When we remember the work of the arteries, however, day and night, awake or asleep, it is not surprising that, in the feeble, the arterial system ages rapidly. Occasionally we find the disease in persons between the ages of twenty-five and thirty. The inheritance bequeathed to the offspring is frequently a feeble circulatory apparatus, and it is not uncommon to find several members of a family suffering from the same disease.
In some cases it may almost be said to be a physiological condition, the result of the constant work of many years.
The causes that figure most frequently in bringing about this condition of the blood-vessels are, first, the toxins generated by certain diseases.
Syphilis may head the list, and following close in its train may be named alcoholism, its twin brother. Rheumatism, gout, and tuberculosis act in the same way, while typhoid fever, scarlet fever, diphtheria, influenza, and the malignant diseases may so impregnate the blood as to be considered important factors in producing the disease.
Overeating and Drinking.—The overfilling of the. blood-vessels, that follows the ingestion of large quantities of fluids and solids, is regarded by many writers as an important factor in producing the disease. Overwork, whereby increased vascular tension results, also contributes to this condition. Athletes, boiler-makers, miners, and all who perform great and prolonged physical exertion, invite this condition.
Renal Disease.—Quite a difference of opinion exists as to the part Bright's disease plays in the etiology of arteriosclerosis. Some believe that, by increasing the blood-pressure, these secondary results follow, and there seems good reason to believe that in some cases Bright's disease is the primary lesion from which the sclerosis can be traced. On the other hand, we find some cases of chronic nephritis which seem to be due to arteriosclerosis.
Pathology.—The tissue-changes of the coats of the vessels may be divided into two kinds—the localized or nodular, and the diffuse—though, in most cases, there is a combination of the two.
The most frequent seat of the election is in the aorta and coronary; the splenic, iliac, femoral, cerebral vessels; the uterine, bronchial, internal spermatic, common carotid, and hypogastric following next in frequency, according to Rokitansky. The vessels of the stomach and mesentery are but seldom affected. When there is impairment of the pulmonary circulation, as in mitral stenosis, the pulmonary vessels may become sclerotic.
Localised or Nodular Arteriosclerosis.—As a result of proliferation. infiltrated areas begin in the middle and outer coats. These nodules vary in size from that of a small shot to that of a large coin. As they increase in size, the intima loses its smoothness and becomes thickened and rough, and appears yellow over the seat of the lesion. As these changes progress, the middle and outer coats are weakened, but compensatory changes occur in the intima, which result in thickening of the intima, already noted.
Later, necrosis may occur within these atheromatous spots, giving rise to atheromatous abscesses. When these rupture upon the intima, an atheromatous ulcer is the result. In place of this, calcification may occur in these plates. Should the intima undergo softening or liquefaction, dilatation is apt to follow, giving rise to aneurism.
While these changes usually occur in the aorta, they may also occur in the smaller vessels.
Diffuse Arteriosclerosis.—In this form the change in the coats of the vessels extends throughout the greater part of the arterial system, and in some cases invades the capillaries and veins—angina sclerosis. Even in the diffuse form, however, there is apt to be nodular areas in the aorta. The intima, though smooth, is much thickened by proliferation of the sub-endothelial tissue, while the muscle fibers in the media and adventitia may almost entirely disappear, being replaced by fatty, necrotic, and hyalin degeneration.
In senile arteriosclerosis calcareous deposits occur, which render the vessels rigid. Where these tissue-changes involve the capillaries, there may be complete obliteration of their lumen in some places, notably the kidneys.
As a result of the narrowed caliber of the vessels, nutrition is defective, and atrophy of the liver, kidney, and spleen may result. The increased work thrown upon the heart, however, generally results in hypertrophy of this organ.
Symptoms.—The disease may come on so insidiously, and the general health be so little disturbed, owing to compensatory change in the heart, that the disease may never be suspected during life, and only revealed on autopsy. At other times, while examining our patient for some other disease, the increased tension of the pulse, the accentuated aortic second sound, will draw our attention to the existing change in the vessels.
A uniform picture of arteriosclerosis can not be given; for the symptoms depend largely upon the vessels involved, and we will have to consider various types depending upon the parts involved, as cardiac, cerebral, renal, and peripheral arteriosclerosis.
Cardiovascular Type.—The symptoms will depend, upon the degree of the arterial tension. The pulse at the wrist, as a result of thickening of the arterial walls, is hard and incompressible, and, if calcification has taken place, can not be felt on palpation. The artery in such cases feels like a rigid cord, or, if nodulated, feels like a bird's neck.
The pulse-rate is usually diminished, and, when compared with the apex-beat, shows a decided retardation, due to want of elasticity of its coats. This slow pulse is known as the "pulsus tardus."
The sphygmograph shows a characteristic tracing in the gradual ascent, the broad top, and equally gradual descent, with the dicrotic notch almost, if not entirely, obliterated. The increased arterial tension, caused by inelasticity of its walls and increased action of the heart to propel the necessary blood supply, causes hypertrophy of the left ventricle, which may be recognized by increased dullness downward and to the left, and by the accentuated ringing second sound.
When the hypertrophy is sufficient to compensate for the resistance due to rigid walls, the health is but little affected, and the disease may be overlooked. When myocardial degenerations take place, the first sound of the heart is very weak, and often a systolic murmur can be heard at the apex. Palpitation often occurs, and if slight exertion is made, dyspnea becomes marked. There is more or less constriction, and if the coronary arteries are involved, angina pectoris is not uncommon.
Cerebral Type.—The first evidence of this form may be headache, more or less intractable, melancholy, dizziness, with ringing in the ears. Attacks of vertigo, especially on slight exertion, are quite frequent. As the disease advances hemiplegia or aphasia may occur. The memory becomes treacherous and the intellectual faculties generally fail.
Renal Type.—The symptoms differ but little from those of atrophy of the kidneys, and result from a diminished blood-supply due to the sclerotic vessels.
Peripheral Type.—In this form the arteries leading to the extremities become so obstructed as to practically cut off the blood-supply, the extremities become cold and lifeless, and gangrene follows.
Diagnosis.—Where the disease is well marked, the diagnosis is usually comparatively easy. The increased arterial tension, thickening of the temporal, radial, bronchial, and femoral arteries, which may be recognized by the hard, cordlike feel; the hypertrophy of the left ventricle, as shown by dullness to the left and downwards; and the accentuation of the second aortic sound,—make a group of symptoms that can hardly be mistaken for those of any other lesion.
Prognosis.—As to completely curing or removing the sclerotic condition, the prognosis is unfavorable, but the patient may be assured of fairly good health and probably years of life. Nature provides against starvation of the tissues by compensatory changes in the heart, which compensation may be maintained for years. Finally, however, degenerations may occur, and the blood supply is not sufficient for the purpose of the body, and tired nature succumbs to the inevitable.
Treatment.—In the treatment of this disease we need the cooperation of the patient, and it is best to explain to him his true condition, that he may the more readily acquiesce in the restrictions placed upon him.
Alcohol and all intoxicating liquors should be absolutely forbidden, as well as the use of tobacco. Dissipation of all kinds must be avoided, and regular habits enjoined. The diet should be nourishing, but easily digested, and fluids should be restricted at meal-times and for one or two hours thereafter.
When possible, the patient will do better if taken to an equable climate, where there is plenty of sunshine, and he can be much out of doors. The altitude must not be too great. A quiet life should be enjoined.
Where syphilis is present, Donovan's solution of arsenic, phytolacca, and echinacea will be found useful, while the iodides will be the favorite remedies with many, especially the iodide of potassium and the iodide of lithium. The lithiates for the kidneys. with an occasional saline for the bowels, will give some relief. Cactus, collinsonia, carduus marianus, strophanthus, and like remedies may be of some benefit when myocardial degeneration? have taken place, though medicines in most cases will but feebly influence the disease.