Endocarditis is sometimes associated with pleurisy or pneumonia. It is less frequently associated with these affections than pericarditis. Endocarditis is occasionally developed in connection with the eruptive and continued fevers, and with that morbid condition known as pyaemia, but its occurrence in these connections is rare. It may also be produced by injuries of the chest; but cases of traumatic endocarditis are rare.
The experiments of Richardson, made by injecting into the peritoneal cavity of a dog a solution of lactic acid, containing ten per cent of the acid, seems to show that lactic acid, when absorbed into the blood, will cause endocarditis.
In about twelve hours after the operation, the symptoms and physical signs of endocarditis appeared. Richardson regarded his experiment as proving synthetically that rheumatic endocarditis is produced by a similar agent. In rheumatism the morbid conditions are supposed to be caused by the presence of lactic acid in the blood.
PATHOLOGICAL RESULTS OF ENDOCARDITIS.
Endocarditis may give rise to immediate pathological results which are important, namely: emboli, or plugs, consisting of detached vegetations, or excrescences, which, propelled with the current of blood into the arteries, are at length arrested in their course in trunks too small to permit their future progress, giving rise to arterial obstruction and diminished supply of blood to certain parts. For a further consideration of this subject, see Valvular Lesions.
“The solidified products in cases of endocarditis, namely: fibrin and lymph, are, to a greater or less extent, disintegrated by the blood-currents, and carried into the circulation, either in solution or suspended in the form of minute particles. It is supposed that the comminuted solid deposits, transported to different organs, and becoming arrested in the capillary vessels, may give rise to vascular obstruction and secondary inflammation in these organs. The kidneys and spleen are most likely to be the seat of disease thus induced. These effects are primarily mechanical; but it is highly probable that morbid changes in the blood itself are sometimes induced by the admixture of the liquid products of endocardial inflammation. It can hardly be otherwise if, as is not improbable, purulent matter is occasionally formed on excoriated or ulcerated surfaces, which are in some instances observed after death in cases of endocarditis.” (Flint.)
The formation of large masses of fibrinous coagula in the cavities of the heart belongs to the immediate pathological effects of endocarditis. It is supposed that these antemortem clots are the formations called by the older writers, polypi of the heart.
SYMPTOMS OF ENDOCARDITIS.
The symptoms of endocarditis are less distinctive even than those of pericarditis. Occurring generally in connection with acute rheumatism, its symptomatic indications are merged in those of the latter affection. In a large proportion of cases, there are no symptoms which attract attention to the heart as the seat of any disease. Examination, however, with a view to determine the presence, or otherwise, of phenomena which point to endocarditis, may elicit symptoms which are of importance in the diagnosis. These symptoms consist of pain referable to the heart, symptomatic fever, and excited action of the organ, or palpitation. Symptoms arising from obstruction to the passage of blood through the orifices of the heart, do not belong properly to the symptomatology of endocarditis, but are due either to lesions resulting from endocardial inflammation, or to accidental events, such as the formation of coagula. (Flint.)
Pain is very rarely a prominent symptom, and, as in other serous inflammations, is sometimes altogether absent. Even when it is present it is not easy to refer it to endocarditis, except by taking into account other symptoms, and especially the physical signs. The pain is generally dull and obtuse, rarely sharp or lancinating. A feeling of uneasiness hardly amounting to pain, is sometimes referred to the praecordia. The suffering which patients endure from the pain in the joints is so much more severe, that they will not be likely to mention the uneasiness in the heart unless you question them closely. If the pain in the region of the heart is so severe and acute as to cause complaint, the probabilities are that pleurisy or pericarditis is present, rather than endo-carditis.
The fever is not of any importance, for it is not distinctive of this disease.
Palpitation in endocarditis may arise indirectly from excitation of the muscular structure of the heart. The action of the heart may be irregular, as well as unnaturally excited.
The pulse may not correspond with the action of the heart, for while the latter may be acting with increased force, the pulse may be weak.
If you observe these symptoms occurring during the course of acute rheumatism, you may safely suspect the presence of endocarditis, and you should resort to physical examination without delay.
PHYSICAL SIGNS OF ENDOCARDITIS.
Increased extent and degree of dullness on percussion, due to tumefaction of the heart, and accumulation of blood within its cavities, is considered by Bouillard and others as a physical sign of endocarditis. Flint, however, doubts whether the cardiac enlargement often, if ever, exceeds the limit of healthy variations. He thinks if the heart is found enlarged, there must have been a previous hypertrophy. He says, “how far the size of the heart undergoes alternations during the progress of endocarditis, I am unable to say from my own observations, but it is evident that percussion cannot afford very important information with reference to this disease, except in a negative point of view, that is, by aiding in the exclusion of other cardiac affections, more especially pericarditis.”
Palpation and inspection will furnish evidence of excited action of the heart. The impulse is seen and felt to be more violent than in health, or out of proportion to the amount of febrile movement which exists. But the signs furnished you by these methods of exploration will be of little value to you except as associated with other evidence of endocardial inflammation.
Auscultation will furnish you with the only positive proof of the existence of endocarditis, and this proof is the development of the endocardial murmur.
This assertion has been substantiated by clinical experience, and you should give particular attention to its study. The murmur is usually soft, having the character of a bellows-sound. It is systolic, for it accompanies the first, or systolic sound of the heart, but you will not find it always at the commencement of the disease. In fact, its existence is considered rare in that stage. I cannot give you any certain data as to the period of inflammation in which this murmur occurs. There are conflicting opinions on this point. The time of its appearance is, however, in the opinion of all authorities, quite variable. The endocardial murmur is not, of itself, absolute proof of existing endocarditis. Previous valvular lesions may be a cause of the murmur. It occurs in consequence of blood-changes, independently of inflammatory or organic disease of the heart.
Under what circumstances then you will ask, is the presence of the murmur a diagnostic symptom of endocarditis? If you find an endocardial murmur in connection with symptoms denoting cardiac inflammation, and if acute rheumatism co-exists; and, further, if you have made previous careful explorations, and failed to discover any murmur, you may then conclude that the murmur you have detected is a sign of endocarditis. If, however, the murmur is discovered on first examination the symptom is of doubtful value.
A murmur developed by endocarditis generally continues not only throughout the duration of the disease, but even afterward. There seem to be some exceptions to this rule, for Flint says he has repeatedly known a mitral murmur to disappear entirely after recovery from rheumatism, when it was very marked during the disease. This could only occur in those rare cases in which the swelling of the valves diminishes, and the vegetations are detached and washed away, leaving the endocardial surface smooth.
I need not inform you of the cause of the murmurs alluded to. It is doubtless due to a roughness of the endo-cardial membrane covering the valves, produced by the lymph, fibrin, and vegetations; although some authors have conjectured that the murmurs were due to a spasmodic action of the papillary muscles, preventing the mitral valve from fulfilling its function – allowing regurgitation to take place.
The heart-sounds may be abnormally modified during endocarditis. Reduplications have been observed. The first sound, and sometimes the second, may be less distinct than in health, or the first sound may be wanting.
DIAGNOSIS.
You will find that the diagnosis of endocarditis does not depend upon symptoms, but almost entirely on evidence developed by auscultation. Those of you who attempt to rely upon symptoms alone will necessarily overlook this important disease, and allow your patients to lose the aid which might be afforded in the prevention of organic disease. Never neglect this in cases of acute rheumatism. Examine your patient every day, and be on the watch for the endocardial murmur, which is the only sure evidence of this disease.
Hale wrote Lectures On Diseases Of The Heart, Materia medica and special therapeutics of the new remedies Volume 1, Materia Medica And Special Therapeutics Of The New Remedies Volume 2, Saw Palmetto: (Sabal Serrulata. Serenoa Serrulata), The Medical, Surgical, and Hygienic Treatment of Diseases of Women, New Remedies: Their Pathogenetic Effects and Therapeutic Application, Ilex Cassine : the aboriginal North American tea, Repertory to the New Remedies with Charles Porter Hart, The Characteristics of the New Remedies, Materia Medica and Special Therapeutics of the New Remedies, The Practice of Medicine, Homoeopathic Materia Medica of the New Remedies: Their Botanical Description etc.