Endocarditis

The endocarditis infectious is an infection that occurs in the endocardial vegetations. It is almost always fatal if left untreated.

Usually the heart valves are damaged, but the infection can be located in an alteration of a septum (between two chambers of the heart) or in a heart wall.

Infection of an arterial blood vessel is more appropriately termed endarteritis and causes a similar clinical syndrome. The following comments on endocarditis apply to endarteritis.

Causes of endocarditis

It is a disease produced by infectious agents, mainly bacteria.

Three types can be distinguished: primitive valvular endocarditis (of the individual), endocarditis in intravenous drug addicts, and endocarditis of the prosthetic valves.

Primitive valvular endocarditis : Although all bacteria can cause endocarditis, the vast majority are due to streptococci, enterococci, and staphylococci. There is fungal endocarditis, although it is rare. It occurs mainly in patients with intravenous catheters, treatment with corticosteroids, antibiotics or chemotherapy.
There are heart diseases that predispose to the formation of vegetations, where infectious agents will later settle, such as rheumatic heart disease, congenital heart disease and degenerative heart disease. However, in 20-40% of patients with infective endocarditis, no heart disease is detected.

Intravenous endocarditis in drug addicts : the most common infectious agent is staphylococcus. Other bacteria are also involved. Fungi are other infectious agents that produce it.

Endocarditis of the prosthetic valves : the bacteria that most frequently cause endocarditis in these cases are staphylococci and streptococci. Fungi are also involved.

The characteristic lesions of infective endocarditis are vegetations. The disease usually appears as a consequence of the location of the microorganisms on the formed vegetations. These usually form in traumatized portions of the endothelium, in areas of blood turbulence, on scars, or in patients with debilitating diseases, especially tumors.

The clinical manifestations of endocarditis stem from vegetations and an immune reaction to infection.

Endocarditis symptoms

Endocarditis symptoms appear within approximately two weeks of the triggering event.

The onset is usually gradual, with a slight fever , general malaise, if it is a not very virulent germ. If the germ is very virulent, the onset may be acute, with a very high fever, except in some cases such as the elderly, kidney failure, congestive heart failure, or severe weakness. Except when the disease is acute, the fever is usually moderate (less than 39.5 ºC). Arthralgia (joint pain) is common, and arthritis sometimes occurs . Besides fever, the other characteristic symptom of endocarditis is the appearance of a heart murmur.

The frequency of splenomegaly (enlargement of the spleen) and petechiae (red dots, caused by bleeding under the skin) is approximately 30% for each of them, when the disease is prolonged. Petechiae are most often seen on the conjunctiva, buccal mucosa, and upper limbs.

The bleeding “splinter” are linear stripes, dark red, subungual that may appear in endocarditis, but most often occur from trauma.

The Roth spots (bleeding in eye retina) occur in 5% of patients, and also appear in other diseases.

The Osler ‘s nodes are a painful nodules on the fingertips of the hands or feet to a few hours or days, they appear in 10-25% of patients persist, but also occur in other diseases.

The Janeway lesions are small hemorrhages appearing on the soles and palms.

In some cases of long evolution, clubbing appears, which are widening and thickening of the tips of the fingers.

Other frequent symptoms are embolic processes, heart failure, neurological manifestations, kidney diseases, myocardial abscesses, and mycotic aneurysms.

How is it diagnosed?

Endocarditis should be suspected, either in unexplained fever and a heart murmur lasting at least a week, or in intravenous drug users with fever, even if there are no murmurs.

Laboratory data (blood tests) help guide the diagnosis.

However, the definitive diagnosis requires positive blood cultures (blood cultures). Blood cultures are positive in 95% of patients. There are other diseases that can produce the same symptoms as endocarditis. Therefore, if there are no negative blood cultures, another allegation of prolonged fever should be sought. In addition, blood cultures can be negative in endocarditis caused by delicate microorganisms and by many of the fungi.

Although without diagnostic value, transthoracic echocardiography will demonstrate vegetation in 50-80% of cases of endocarditis on native valves (of the individual himself).

Transesophageal echocardiograms are much more sensitive, determining them in 90% of cases.

Treatment of endocarditis

The cure of endocarditis requires the eradication of all microorganisms settled in the vegetations. Therefore, microbicidal drugs must be applied in high enough doses and for a long enough time to achieve sterilization of vegetations.

Regimens containing penicillins, cephalosporins, and vancomycin give better results than when these drugs cannot be used due to resistance of microorganisms or adverse drug reactions. With rare exceptions, the administration of antibiotics should be intravenously to ensure the passage of a sufficient amount into the blood.

The usual antipyretics are used for fever.

When appropriate microbicidal treatment is not available and blood cultures remain positive despite treatment, or there is a relapse after correct treatment, the valve should be replaced by surgical intervention. Valve replacement should ideally be performed several days after completing the most appropriate microbicidal treatment possible. Likewise, there are other complications that require valve replacement.

How can I avoid it?

Although the risk of endocaditis is small and there is no evidence of the efficacy of preventive microbicide treatments, these treatments are recommended for patients with predisposing cardiac lesions who undergo techniques known to promote the passage of microorganisms into the blood. .

These predisposing diseases are valvular and congenital heart disease (except uncomplicated atrial septal defect), intracardiac prostheses, asymmetric septal hypertrophy, and whether there were previous episodes of endocarditis.

The most frequent techniques that favor the passage of microorganisms into the blood are dental or other interventions performed in the mouth, nose and pharynx, interventions on the digestive tract and genitourinary tract, and cardiac surgery. Oral hygiene should be maximum in patients with predisposing heart lesions, especially in those who are going to have prosthetic valves implanted.

Whenever there is a prolonged fever of unknown origin, the possibility of endocarditis should be considered, especially if there is a predisposing factor.