Infective endocarditis
The content of the article:
- Causes and risk factors
- Forms of the disease
- Disease stages
- Symptoms
- Diagnostics
- Treatment
- Possible complications and consequences
- Forecast
- Prevention
Infective endocarditis is an inflammatory process of infectious origin that affects the inner lining of the heart (endocardium), which lines its chambers and valves.
The incidence of infective endocarditis, according to different authors, ranges from 3 to 10 cases per 100,000 population. Women get sick half as often as men.
Infective endocarditis is an infectious polyposis-ulcerative inflammation of the endocardium
Causes and risk factors
For the development of infective endocarditis, a combination of several factors is necessary:
- damage to the endothelium of blood vessels and endocardium;
- transient bacteremia (temporary circulation of pathogenic or opportunistic microorganisms in the bloodstream);
- decreased general immunity;
- violation of hemodynamics and hemostasis.
The cause of transient bacteremia usually lies in a focus of chronic infection in the body or in the performance of invasive (that is, those occurring with damage to the integrity of the skin) medical procedures.
The most common causative agent of the subacute form of infective endocarditis is green streptococcus.
The acute form of the disease can be caused by:
- Staphylococcus aureus;
- Pneumococcus;
- enterococcus;
- Escherichia coli.
Staphylococcus aureus can cause acute infective endocarditis
Infectious endocarditis caused by fungal infection, anaerobic and gram-negative pathogens are very difficult. The cause of fungal endocarditis is long-term antibiotic therapy or a long-standing catheter in the vein.
Microorganisms circulating in the bloodstream penetrate into the cavity of the heart and adhere to the endocardium. This process is called adhesion, the conditions for its course are impaired immunity, as well as congenital or acquired defects of the valve apparatus.
Hemodynamic disturbances caused by heart defects contribute to the occurrence of microtraumas of the endocardium and valves. Through these injuries, infectious agents enter the endocardium. Microbial colonies very quickly destroy the valves, as a result of which they can no longer perform their functions, and the patient develops rapidly progressive heart failure.
Against the background of infective endocarditis, an immune damage to the endothelium (inner layer) of the capillaries of the mucous membranes and skin occurs. This is manifested by symptoms of hemorrhagic capillarotoxicosis or thrombovasculitis.
Forms of the disease
Depending on the cause of infective endocarditis, it happens:
- primary - the infectious process in the endocardium develops against the background of initially unchanged valves;
- secondary - an infection in the endocardium develops against the background of an already existing pathology of the valve apparatus or blood vessels.
By the nature of the course, the following forms of infective endocarditis are distinguished:
- acute - arises as a complication of medical manipulations on blood vessels, heart or acute septic condition, lasts 1.5-2 months;
- subacute - occurs with insufficiently active treatment of the underlying disease or acute form of endocarditis, lasts more than 2 months;
- protracted - characterized by a slow course and the absence of an obvious primary purulent-septic focus.
According to the activity of the inflammatory process, infective endocarditis can be active and inactive (healed).
The inflammatory and destructive process can be limited (only the leaflets of the heart valve are affected) or go beyond the affected valve.
Disease stages
In the clinical course of infective endocarditis, several stages are distinguished:
- Infectious toxic. It is characterized by transient bacteremia and the formation of microbial vegetations (colonies) on the valves of the heart and endocardium.
- Immuno-inflammatory (infectious-allergic). Symptoms of damage to internal organs are characteristic, that is, signs of splenomegaly, nephritis, hepatitis, myocarditis.
- Dystrophic. It develops against the background of progressive heart failure and septic process. It manifests itself as severe irreversible lesions of internal organs, including myocardial necrosis.
Symptoms
The acute form of infective endocarditis is clinically characterized mainly by signs of toxemia and bacteremia. These include:
- severe general weakness;
- increased fatigue;
- decreased appetite;
- loss of body weight;
- dyspnea;
- an increase in body temperature to high values, which is accompanied by tremendous chills;
- profuse sweating with a decrease in body temperature;
- Iron-deficiency anemia;
- earthy skin color;
- petechiae (small punctate hemorrhages) on the mucous membranes and skin;
- pinch symptom (bruising with minor skin injury).
The classic clinical picture of infective endocarditis
Against the background of infective endocarditis, most patients have damage to the heart muscle itself (myocarditis). During auscultation of the heart, functional murmurs are heard, the appearance of which is explained by valve damage and anemia.
The defeat of the aortic and (or) mitral valve cusps is accompanied by the appearance and progression of signs of their insufficiency, as well as heart failure.
With subacute infective endocarditis, thrombotic overlays break off from the leaflets of the affected heart valves, as a result of which an embolism of the blood vessels of the spleen, kidneys, and brain may occur with the formation of a heart attack (necrosis) of these organs. The examination reveals:
- enlarged liver and spleen (hepatosplenomegaly);
- polyarthritis;
- diffuse (less often focal) glomerulonephritis.
Diagnostics
When collecting anamnesis, special attention should be paid to previous medical interventions and the presence of foci of chronic infection. Confirmation of the diagnosis of infective endocarditis is carried out according to the laboratory and instrumental examination of the patient, including:
- complete blood count (leukocytosis, shift of the leukocyte formula to the left, a significant increase in ESR);
- bacteriological blood culture with determination of sensitivity to antibiotics. This test is repeated several times, and blood sampling is best done at the height of the fever;
- blood chemistry. There are changes in the immune status (the concentration of anti-tissue antibodies increases, the hemolytic activity of complement decreases) and the protein spectrum (the concentration of α-globulins increases, and subsequently γ-globulins);
- EchoCG. Helps to visualize microbial vegetation with a diameter of more than 5 mm on the heart valves;
- magnetic resonance imaging or multislice computed tomography. Allows to assess with a high degree of accuracy the condition of the valves, as well as the whole heart.
To diagnose infective endocarditis, general, biochemical, bacteriological blood tests are performed
Treatment
With infective endocarditis, the patient is hospitalized; shown strict bed rest. An important element of therapy is the organization of proper nutrition. The diet should be balanced in terms of the content of nutrients, vitamins and microelements, and consist of easily digestible foods.
The main treatment is medication. Antibiotics are prescribed taking into account the sensitivity of the microflora, until the results of the antibioticogram are obtained, broad-spectrum antibiotics are used.
Therapy of infective endocarditis of fungal etiology is carried out with amphotericin B for a long course (up to several months). In the complex drug therapy of the disease, other agents with antimicrobial properties (antistaphylococcal globulin, antistaphylococcal plasma, dioxidine) can be used.
Antibiotics are prescribed to treat infective endocarditis
Methods of extracorporeal detoxification are shown (intravascular ultraviolet blood irradiation, plasmapheresis, hemosorption).
In the presence of concomitant diseases (nephritis, polyarthritis or myocarditis), non-steroidal anti-inflammatory drugs are added to the therapy regimen.
When the heart valves are destroyed with the development of their failure after the inflammatory process subsides, surgical intervention is performed to replace the valves.
Possible complications and consequences
The most dangerous complications of infective endocarditis that can lead to death are:
- acute heart failure;
- respiratory distress syndrome;
- embolism in the vessels of the brain or heart;
- septic shock;
- multiple organ failure.
Forecast
The prognosis for infective endocarditis is always serious. Without treatment, the disease ends in death within 1.5-6 months from the onset of the first symptoms. With timely antibiotic therapy, the mortality rate is 30%. In about 15% of patients, infective endocarditis takes on a chronic course, in which periods of remission are followed by periods of exacerbation.
Prevention
Patients at risk for the development of infectious endocarditis (with congenital or acquired heart defects, prosthetic valves, vascular pathology, foci of chronic infection in the body) should be under medical supervision.
To prevent bacteremia during invasive medical procedures, broad-spectrum antibacterial drugs should be prescribed.
Also, to prevent the development of infective endocarditis, it is necessary:
- regularly sanitize foci of chronic infection in the body;
- avoid bacterial and viral infections, and when they appear, carry out timely treatment;
- avoid hypothermia;
- adhere to proper nutrition;
- carry out hardening procedures.
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Elena Minkina Doctor anesthesiologist-resuscitator About the author
Education: graduated from the Tashkent State Medical Institute, specializing in general medicine in 1991. Repeatedly passed refresher courses.
Work experience: anesthesiologist-resuscitator of the city maternity complex, resuscitator of the hemodialysis department.
The information is generalized and provided for informational purposes only. At the first sign of illness, see your doctor. Self-medication is hazardous to health!
