Acute endocarditis can probably not occur without some inyocarditis, and myocarditis probably does not occur without some endocardial disturbance and perhaps some pericardial irritation. This is especially true in endocarditis which occurs during any acute infection, even in rheumatism. The greater the amount of pericarditis, the more serious is the acute condition. The greater the amount of myocarditis, the more doubtful is the heart strength in the near future. The greater the amount of endocarditis, the greater the doubt of freedom from future permanent valvular lesions.
Endocarditis may be divided into: acute mild (simple) endocarditis, acute malignant (ulcerative, infective) endocarditis, chronic endocarditis and valvular disease.
ACUTE MILD ENDOCARDITIS
This inflammation of the endocardium is generally confined to the region of the valves, and the valves most frequently so inflamed are the mitral and aortic. There may be a slight inflammation or actual ulceration and loss of tissue. Vegetations more or less constantly occur on the inflamed surfaces, with more or less danger of particles becoming loosened and moving free in the blood stream, causing embolic obstruction in different parts of the body. There is also more or less probability of serious adhesions or contractions occurring from the healing of the ulcerated surfaces. The future health and welfare of the valves depend on the fact that the inflammation has healed without contractions or adhesions.
It is often difficult to decide when acute endocarditis has developed; but with the knowledge that the endocardium often becomes inflamed during almost any of the acute infections, the physician should repeatedly examine the heart for murmurs, for m.u.f.fled closure of the valves, or for other evidences of endocarditis or myocarditis during the acute infective process.
It has been shown positively that acute endocarditis is due to micro-organisms, generally streptococci, staphylococci or pneumococci, and, more frequently than once believed, gonococci. The most frequent causes are acute rheumatic fever, diphtheria, pneumonia, cerebrospinal meningitis, scarlet fever, erysipelas, influenza, ch.o.r.ea, gonorrhea, sepsis and typhoid fever. It may also follow a follicular tonsillitis or some infection of the mouth or throat with or without arthritis. Tuberculosis may also occasionally cause an endocarditis. Organisms may be found in a terminal simple endocarditis due to a chronic disease, as tuberculosis or cancer; such inflammations may have been caused by circulating toxins.
It will be noticed by the foregoing cla.s.sification that the terms "mild" and "malignant" endocarditis are used. The purpose is to convey the fact that there may be no etiologic distinction between the two forms, and it is impossible to decide clinically in the beginning of an endocardial inflammation which form is present. In the malignant form the infection is probably more serious or the infective germs are more active, the ulcerations deeper, and the likelihood of emboli and the seriousness of such embolic infarcts more serious and more dangerous. The differences in inflammation in the two cases is really one of degree, and the cla.s.sification is made to coincide with this probable fact. it is, of course, clinically recognized that endocarditis following certain diseases, especially rheumatism, is of the simple or mild type, while that termed ulcerative endocarditis may occur apparently as a primary or general infection, and the causative bacteria, as a rule, are readily discovered in the blood. The Streptococcus viridans is one of the most dangerous of these bacteria.
A SECONDARY AFFECTION
Mild endocarditis is rarely a primary affection, and is almost invariably secondary to one of the diseases named above. Nearly 75 percent of secondary endocarditis occurs as a complication of acute articular rheumatism and ch.o.r.ea, or subsequently. On the other hand, about 40 percent of all patients with acute articular rheumatism develop endocarditis, sometimes perhaps so mild as to be hardly discoverable. This complication is most likely to occur during the second or third week of rheumatic fever. It is not sufficiently recognized that a subacute arthritis, recurring tonsillitis, open and concealed infections in the mouth, and even a condition of the system with acute, changeable and varying joint and muscle pains may all develop a mild endocarditis, even with subsequent valvular lesions. Therefore in all of these conditions the decision can be made only as to how much rest the patient must have or how serious the condition is to be considered by careful examination of the heart in every instance.
Children are more liable than adults to this complication, especially with rheumatism. Therefore, acute mild endocarditis with future valvular lesions occurs most frequently during childhood and adolescence, and if one attack has occurred, a subsequent infection, especially of rheumatism, is liable to cause another acute endocarditis.
PATHOLOGY
The part of the heart most affected is the part which has the most work to do--the left side of the heart--and of this side the left ventricle and therefore the mitral and aortic valves; the most frequent valve to be inflamed and to stiffer permanent disability is the a mitral valve, the valve which in its inflamed condition is subjected to the greatest amount of pressure and therefore irritation. Not infrequently soft systolic murmurs are heard at the pulmonary and tricuspid valves during acute endocarditis. It is rare, however, that these valves are so affected during childhood or adult life as to be permanently disabled.
Whether a diminished alkalinity of the blood in rheumatism has anything to do with the cause of the frequent complication of endocarditis has not been determined. Whether the administration of alkalies to the point of increasing the alkalinity of the blood is any protection against the complication of endocarditis has also not been positively demonstrated, although clinically such treatment is believed by a large number of pract.i.tioners to be wise.
A chronic endocarditis with permanent lesions of the valves may become an acute inflammation with an infectious provocation.
It has been shown that even in a few hours after endocarditis has started, little vegetations composed of fibrin, with white blood cells, red blood pigment and platelets, may develop. Practically in all instances such vegetations develop, and later become more or less organized into connective tissue. These little vegetations, generally minute, perhaps not exceeding 4 mm. in height, are irregular in contour like a wart. Some of these may have small pedicles, and as such, of course, are more likely to become loosened and fly off into the blood stream. It is of interest to note that these little vegetations are more likely to be on the left side of the heart than the right; on the valves than any other part, and on the mitral valve than on the aortic. The consequence is a more frequent permanent disability of the valves of the left side of the heart, and of these more frequently the mitral. Although these little vegetations and excrescences sooner or later become mostly connective tissue, still fibrin and white blood cells may form thin layers over them, more or less permanent. In this fibrin are frequently found bacteria, even when there has been no recent acute inflammation. The deeper layers of the endocardium during acute inflammation may become infiltrated with young cells, with resultant softening and destruction of the intercellular substance. This softening and some swelling of the lower layers of the endocardium allow the pushing up of these extravasated blood cells which, being covered with fibrin, makes the little vegetations above described; and as just stated, the fibrin may form a more or less permanent cap. If this cap is disintegrated or lost and the cells under it washed away in the blood stream, ulceration takes place, which may be more or less serious, even to the perforation of a valve or actual erosion of one of its cusps, and the parts of the valves most seriously affected are the parts which strike against each other on closure; as previously stated, the parts subjected to the greatest strain and the greatest amount of friction during the inflammation are the parts most seriously affected afterward.
If a perforation has occurred, it may make a permanent leak. If an erosion of the edge of the valve has occurred, it may make permanent insufficient closure. If the valve has become thickened and stiffened during the cicatricial healing, it may not only be incompetent, but may not open perfectly, and a narrowed orifice may be the consequence. During the healing of these granulating ulcers there may be thickening of the part or shrinking of the tissue, and the valve may become shortened by adhesion to the wall, or the cusps of the valve may adhere together so that the valve becomes permanently unable to open properly or to close properly, or to do either.
Not infrequently and probably more frequently than we recognize, recovery without any of the pathologic lesions just described follows mild endocarditis. The occurrence of simple endocarditis is undoubtedly frequent during acute disease, and is unrecognized because there are no lesions of the heart at the time or subsequently; but valvular lesions only too frequently follow the endocarditis which occurs with rheumatism. Occasionally the ulcerations become serious, and ulcerative endocarditis or malignant endocarditis develops on the mild inflammation. In this form the little vegetations are liable to become loosened, fly off into the blood stream, and cause emboli in different parts of the body.
Recently Fraenkel [Footnote: Fraenkel: Beitr. z. path. Anat. u. z.
allg. Path., 1912, iii, 597.] concluded that the microscopic nodules which occur in endocarditis in the myocardium, and which consist of the several varieties of white blood corpuscles first referred to by Aschoff in 1904, are characteristic only of acute rheumatism.
Fraenkel found these nodules in the myocardium in a case of ch.o.r.ea, showing the close relationship between it and rheumatism.
While repeated careful examination of the heart during acute infections will generally show signs of endocarditis if it is present, even if there are no subjective symptoms, the disease may be so insidious as not to be noted until a valvular lesion occurs.
Often, however, during the course of the disease, especially in rheumatism, there is a slight increase in fever and there is a discomfort complained of in the region of the heart, frequently accompanied by slight dyspnea. Real pain is seldom present unless the pericardium is affected. If the myocardium is much inflamed at the same time, the heart becomes more rapid and the blood tension lowered, and the apex beat diminished in intensity and perhaps not palpable. If there is pain, with or without pericarditis, it is often referred to the epigastrium, especially in children. The patient is often nervous, restless and sleepless. In simple endocarditis emboli rarely occur. If they do, of course the signs will be in the part in which the infarct occurs. Besides the diminished intensity of the apex beat and its greater diffusion, the valve sounds may be m.u.f.fled, and sooner or later there may be systolic murmurs over the different orifices. Of course systolic murmurs may be due to a disturbed condition of the blood, but if they occur with the above-mentioned symptoms and signs, endocarditis should be diagnosed. If the heart becomes seriously weak and the patient suffers much dyspnea, myocarditis should be known to be present with the endocarditis. If there is a diastolic murmur, there can be no question of serious endocarditis having occurred.
Unexplainable palpation during acute illness liar been thought to be a distinct symptom of endocarditis.
TREATMENT OF ENDOCARDITIS
As mild endocarditis rarely occurs primarily but is almost always secondary to some acute disease, its immediate treatment is only a slight modification of that of the disease which is causing it. A complication which is so frequent should always be expected, and consequently warded off or prevented, if possible. Knowledge of the diseases which are most liable to cause endocarditis makes frequent heart examinations a necessity, to note when it arrives. While an extra heart tire, sleeplessness, and the circulation of unnecessary toxins from a bad condition of the bowels and from improperly selected food all make this complication more liable, its occurrence is, nevertheless, often unpreventable.
The most efficacious preventive pleasures are sleep, rest, the stopping of pain, prevention of exertion, proper food which does not cause flatulence or other indigestion, good, sufficient daily movements of the bowels, the prevention of intestinal distention, and maintenance of a clean, moist surface of the body, produced by such sponging and bathing as the temperature demands.
The disease having developed, the indications for treatment are really few; in fact, the treatment is mostly negative. There is generally but little local pain; the temperature from simple endocarditis alone is not high and the acute symptoms tend to abate.
Local Treatment.--Endocarditis having been diagnosed, especially if there is palpation or pain, an ice bag over the heart is often of considerable value, but not so efficient as in pericarditis. It often tends to quiet the heart, and may be of some value reflexly in slowing the inflammation. If it causes restlessness, however, and does not lessen the pain (which in some instances it may increase), it certainly should be stopped. Children, in whom this complication so frequently occurs, generally do not bear the ice bag well.
Sometimes it may be advisable to subst.i.tute warm applications, and often a great deal of comfort is derived from them, the patient soon going to sleep. One of the greatest values of either cold or hot applications is diminution of the discomfort from the cardiac disturbance, and the stopping of any pain which may be present. If they do not do this, there is no object in using either cold or heat.
The discomfort from blisters over the heart during the acute stage of endocarditis is greater than any good which they can do. In adults a few small blisters may be used intermittently around the borders of the heart, after the acute symptoms are over, to act reflexly on the heart and possibly aid absorption of inflammatory products. Sometimes improvement seems to follow such treatment; it certainly can do no harm.
During convalescence, the skin over the heart may be painted with iodin, repeated often enough to cause stimulation without injuring the skin; it seems at times to be of value. Various iodin or iodid ointments have been used, but they probably have no more value than the administration of small doses of iodid.
Systemic Treatment.--As this complication most frequently occurs during acute rheumatism, the question arises as to the value or harmfulness of salicylates and alkaline drugs. With our recent better understanding of the action on the heart of pure salicylates (either natural or synthetic saliclic acid, which have been shown to act identically, if equally pure), we must believe that in any ordinary dosage they will injure the heart but rarely. While salicylic acid will not prevent endocarditis, it should he continued, if it is of benefit with regard to the arthritis. The indication for its use depends on its effect on the joints. As it acts at times almost as a specific in rheumatism, it would seem that it should be of value in the endocarditis caused by rheumatism. On the other hand, the endocarditis occurs during the second or third week of acute rheumatism, after the blood has been thoroughly saturated with salicylic acid. Therefore it certainly does not tend to prevent rheumatic endocarditis; hence for this complication alone salicylic acid is not indicated.
ALKALIES
Anything which tends to increase the acidity of the tissues and to diminish the alkalinity of the blood, whether from starvation or outer causes, seems to pro-duce endocardial and myocardial irritation, if not actual inflammation. Therefore in a disease like rheumatism, which seems to be made worse by anything which increases the acidity, alkalies are obviously indicated, and it is probable that an increased alkalinity of the blood tends to prevent endocardial irritation, and may soothe an inflammation already present. Until we have some positive knowledge to the contrary, alkalies should be freely administered during endocarditis, especially during rheumatic endocarditis. Pota.s.sium citrate in 2 gm.
(30 grain) closes, in wintergreen water, should be given every three to six hours, depending on how readily the urine is made alkaline.
This may be given with the salicylic acid treatment, and also when the salicylic acid has been stopped. It may be well, if sodium salicylate is being used, to give also sodium bicarbonate, the sodium bicarbonate often preventing irritation of the stomach from the sodium salicylate, the dose being equal parts of the sodium salicylate and the sodium bicarbonate administered in plenty of water. If some other form of salicylic acid is preferred, novaspirin, which is methylene-citryl-salicylic acid and contains 62 percent of salicylic acid, is perhaps the least irritant to the stomach of the salicylic preparations. This drug is decomposed in the intestine into its component parts, salicylic acid and methylene-citric acid. If this drug is combined with sodium bicarbonate, the disintegration into its component parts would be likely to occur in the stomach.
IRON
It is essential for the welfare of the patient, especially after a long illness before the complication of endocarditis could occur, and in rheumatic fever, in which all meat and meat extractives have been kept from the diet, that small doses of iron should be administered daily. Not only the fever process, but also the salicylic acid tends to prevent the healthy normal growth of red corpuscles. and such patients suffering from rheumatism are often seriously anemic after the aente inflammation has ceased. The iron administered may be 5 drops of the tincture of the chlorid, in lemonade or orangeade, twice in twenty-four hours (and it should be remembered that lemon and orange burn to alkalies in the system and do not act as acids); or 0.1 gm. (1 1/2 grains) of reduced iron in capsule twice in twenty-four hours, or a 3 grain tablet of saccharated ferric oxid (Eisenzucker) twice in twenty-four hours.
OPIUM
As so many times repeated, real pain must be stopped, and morphin, either by the mouth or hypodermically, should be used to the point of stopping such pain. If the patient is a young child, codein sulphate or the deodorized tincture of opium may be used in the dose found sufficient, and either one will act satisfactorily. The dose given should be small but repeated sufficiently often to stop the pain. The dose necessary for the given individual will soon be learned, and that dose may be repeated at such intervals as the condition may require. Sometimes the hypnotic selected, if one is needed, will be sufficient to quiet the cardiac aches or pains.
BROMIDS AND CHLORAL
If there is much restlessness and the circulation is good, that is, if myocarditis is probably not present, the bromids may be of great value, especially in children. The dose should be sufficient to quiet the nervous system. The drug may be discontinued after a few days, if the conditions improve. If the bromid, except in large doses, will not cause sleep, a sufficient dose of chloral should be given. Chloral is one of the most satisfactorily acting drugs which we have to produce sleep and to cause cardiac rest. While it should not be given if there is real cardiac weakness, the good which it does is so much greater than the possible bad effect on the heart, that it should not be forgotten for some newer hypnotic. The worst part of this drug is its taste, and the best way to administer it is to have it in solution in water and the dose given on cracked ice with a little lemon juice to be followed by a good drink of water and a piece of orange pulp for the patient to chew. Ordinarily a bad-tasting drug such as chloral is well administered in effervescing water, but effeverscing waters are generally inadvisable when there is any kind of inflammation of the heart, as they are liable to cause distention of the stomach and pressure on the heart. Some physicians prefer chloralamid as a less disagreeable drug and one which acts almost as efficiently as chloral. As the close of this must be larger than the dose of chloral, it is a question of doubt as to which is the better drug to use. Of the newer hypnotics, veronal=sodium (sodium-diethyl-barbiturate) is among the best. It acts quickly, is less depressant and is a safer salt than most of the other newer hypnotics. It is the readily soluble sodium salt of veronal (diethyl-barbituric acid). When combined with any active drug, sodium seems to make it less toxic and less depressant. The dose of this drug is from 0.2 to 0.3 gm. (3 to 5 grains).
PREVENTION
If the patient is weak, the circulation depressed, the blood pressure low, and the heart rapid, the drug advisable to produce rest and sleep is almost always morphin or some other form of opium.
Morphin, with few exceptions, is a cardiac tonic and a cardiac stimulant, unless the dose is much too large. As long as the bowels are daily moved and the food is not given at the time of the full action of the morphin, when digestion might be delayed or interfered with, in most patients the action of this drug during serious illness is entirely for good. The greatest mistake in using morphin for the production of sleep, or for physical and mental rest and comfort when there is not severe pain, is in giving too large a dose. If pain is not severe, or due to inflammatory distention of some undilatable part, to pressure on some nerve, to distention of some tube by a calculus or to some serious injury to the nerves, large doses of morphin are not needed. Small doses will act much more efficiently. It is excessively rare that a hypodermic of one- fourth grain of morphin sulphate is needed, except for the conditions enumerated. It is often a fact that so small a dose as one-eighth grain of morphin or even one-sixth grain will cause sufficient stimulation of a nervous patient, because its primary stimulant effect on the spinal cord is greater than its depressant effect on the brain, to require another dose (one-fourth grain altogether) to give such a patient rest. On the other hand, this patient may many times be quieted by one-tenth grain of morphin sulphate on account of the size of the dose being not sufficient to stimulate the spinal cord. Many a time clinically when one-eighth grain has failed, a dose of one-fourth grain having been apparently necessary, a change to one-tenth grain has proved entirely and perfectly satisfactory.
DIET
As intimated in the preceding paragraph, the diet during endocarditis must be carefully regulated. It must be sufficient, and appropriate for the disease in which the complication occurs, but it must be in such dosage and administered with such frequency as to cause the least possible indigestion. Large amounts of milk are rarely advisable. Too much milk is certainly given, even in rheumatism. While pretty well tolerated by children, it is often badly tolerated as far as digestive symptoms are concerned, by adults. The amount of liquid given should be governed by the amount of urine pa.s.sed and by the amount of perspiration. The patient should not be overloaded with liquid if he does not need it. Enough carbohydrate must be given.
LAXATIVES
If the bowels are known to be in excellent condition and not loaded with fecal matters, brisk catharsis is not needed simply because endocarditis has developed. If the bowels have been neglected, a small dose of calomel, aided by a compound aloin tablet, is necessary and good treatment. Subsequent movements of the bowels should be daily obtained by vegetable laxatives with occasional enemas, as needed. With all inflammation of the heart and the possibility of myocarditis developing or being actually present, it is not advisable to use salines freely or often.