Definition.—Simple acute endocarditis is an inflammation of the endocardium, characterized by the formation of small, beady excrescences on the margin of the valves.
Etiology.—Endocarditis is rarely, if ever, a primary affection, and where there is apparently no antecedent lesion to account for it, there is in all probability an acid or toxin that has not given rise to any marked lesion, yet has existed in latent form.
Rheumatism stands first as a causative factor. Pepper says it is the cause in from 60 to 85 per cent of cases examined.
Pneumonia is also a fruitful source of this affection; so is Bright's disease and the infectious fevers, scarlatina especially; but in measles, diphtheria, and typhoid fever, endocarditis is rare. Chorea and tonsillitis, when of a severe type, have also been found to precede this affection.
Stengler and Wegheim each records gonorrhea as an important factor in producing endocarditis, though this and the septic fevers are more likely to result in the ulcerative or malignant forms. Syphilis may also give rise to endocarditis.
Pathology.—The morbid changes are, first, a reddened and injected appearance of the endothelium, which soon becomes opaque and swollen from congestion of the small blood-vessels. This swelling or thickening of the membrane furnishes a favorable resting-place for deposits of fibrin, and we have small, beady deposits from the size of a pin-point to that of a pea, or even larger. These small, beady excrescences may become detached, and, floating off in the general current, give rise to embolism in distant parts; viz., the brain, kidneys, or spleen; and, as a result of this, we may have hemorrhagic infarction of these organs.
The inflammation is mostly confined to the valves, the mitral being far more frequently involved, the aortic following next.
Osier gives an estimate of the frequency with which, in one hundred and eighty-seven cases, different parts of the heart were affected, as follows: Aortic valves, 53; mitral valves, 77; tri-cuspid valves, 19; the pulmonary valves, 15; and the heart-walls, 33. The left heart is most constantly affected in the adult; the right in fetal endocarditis; the reason, as explained by Anders, is that before birth the right side, and after birth the left side, are the most active, and that this increased activity accounts for the location of the inflammation. The lesion may not be confined to the valves, but include the endothelial lining of the cavities, and also the chordae tendineae.
When resolution takes place, the excrescences are gradually absorbed, though there is apt to remain some thickening of the tissue. As a result of the inflammatory process, there is nearly always more or less myocarditis, and in severer cases the pericardium will share in the general ravages.
Symptoms.—Perhaps in the whole range of heart affections there are few as well-defined subjective symptoms present as in endocarditis. The disease comes on so insidiously that its presence is confirmed before it is recognized, or possibly never is known unless determined by an autopsy.
The symptoms commonly given—pain in the precordial region extending from the left nipple to the back and down the left aim, palpitation, and dyspnea—may occur in pericarditis or myocarditis, or they may be entirely absent. However, if the patient is suffering from rheumatism, and there is an increase in fever, rapid pulse, increase of temperature, pain in the region of the heart, with dyspnea, a careful examination must be at once made for the characteristic bellows murmur. In the more aggravated cases, the patient will lie on the back, or incline to the left side. There will be distention of the veins of the neck, with marked cyanosis.
Physical Signs.—Inspection.—The patient is found lying on his back, or inclined to the left side. In severe forms there will be fullness of the cervical veins, with a general cyanotic appearance. The apex beat may be visibly increased, though usually not perceptible.
Palpation.—The results of inspection are confirmed by palpation. The impulse, if weak, suggests myocarditis as a complication. In some cases a systolic thrill may be recognized.
Percussion.—Percussion gives negative ^results in a large per cent of cases; but if complicated by myocarditis with dilatation, the area of dullness will be increased, especially in the transverse diameter.
Auscultation.—Auscultation gives us the most positive information in the blowing systolic murmur, telling us of mitral insufficiency. There may be aortic murmurs accompanying this, or a double systolic murmur over the tricuspid valves. If the endocarditis arises as a complication of chronic valvular disease, the sounds of the latter are but little, if any, changed, hence are but of little diagnostic value. We are to remember, however, that these adventitious sounds may be heard in other affections of the heart, or they may be so feeble as not to be recognizable at all.
Diagnosis.—This is a disease that is very apt to be overlooked, unless the more pronounced symptoms are present; namely, rapidity and irregularity of the heart-beat, distress in the precordial region, and dyspnea with mitral murmur. It is important, therefore, in all cases of acute rheumatism and the infectious diseases, to make a thorough physical examination of the chest daily. If the murmur is soft and over the base of the heart, it is most likely due to anemia or to functional derangements; but if it be over the apex, and is the mitral cystolic murmur, the diagnosis is quite conclusive.
To distinguish the ulcerative or malignant from the acute is often impossible, though the aggravated symptoms attending the latter enable us to recognize it from myocarditis.
Prognosis.—If no complications exist, endocarditis rarely proves fatal at the time, though it is often the beginning of permanent lesions of the valves. If the primary lesion is grave, the prognosis must be guarded, or if complicated with myocarditis or pericarditis, it will result unfavorably.
Treatment.—The prevention of endocarditis can be accomplished in many cases, if the proper anti-rheumatics are used in the primary disease. If the result of infectious fevers, rest in bed, precaution against taking cold, and the proper antiseptics, will give the minimum cases of endocarditis.
In the management of this affection, great care must be taken to secure rest and quiet. The patient should be placed between blankets, and all company, or anything that would tend to excite the patient, must be forbidden. For the excitation of the heart in the early stage, we use the direct sedative,—aconite for the small, frequent pulse, or veratrum if the pulse be full and strong. For the dyspnea, lobelia is one of our best remedies; ten to twenty drops to water four ounces.
For the pain, if there is muscular soreness, use macrotys one-half dram, to four ounces of water. If the pain is sharp and lancinating, simulating pleurisy, bryonia is the better agent: ten drops, to water four ounces. If there is puffiness of the face, swelling of the joints, with pericardial effusion, apocynum is to be given. When the heart becomes weak, cactus, digitalis, convallaria, or strophanthus may be given. Where there is great oppression or a sense of constriction of the chest, with sharp, stabbing pains, give spigelia.
Alcoholic stimulants, nitroglycerin, and strychnia are to be freely given when the heart flags. Iodide of potassium has long been given for its supposed influence in producing absorption of the vegetative growths, but its beneficial effects have been largely magnified.
The diet should be generous, though easily digested, and a sparing use of fluids should be advised. The convalescent period should be watched very carefully, to prevent taking cold, and also to avoid any and all exercise or excitement that would produce a strain upon the weakened valves. A climate where the temperature is equable and there is plenty of sunshine, and not of too high altitude, will be the most beneficial.
The Eclectic Practice of Medicine, 1907, was written by Rolla L. Thomas, M. S., M. D.