Endocarditis

Endocarditis is a cardiac disorder that generally goes unnoticed but an accurate diagnosis can be reached by observing clinical signs of organs affected by this circulatory disorder such as nephritis , weakness, fatigue and exercise intolerance, in addition, of course, to the presentation of congestive heart failure.

Summary

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  • 1 Causes
  • 2 Classification
  • 3 Symptoms
  • 4 Clinical Picture
  • 5 Diagnostic Aids
  • 6 Differential Diagnosis
    • 1 Pathologies that resemble endocarditis
  • 7 Treatment and Medications
  • 8 Surgery
  • 9 Surgical Treatment
  • 10 Complications
  • 11 Rofilaxis
  • 12 Prevention
  • 13 Sources
  • 14 External links

Causes

Bacteria can get to the heart through the blood . They can enter the blood from an infection in another part of the body. They can also enter when performing an activity that causes breaks in the skin or mucous membranes, for example, dental work, surgery or intravenous (IV) drug use . Only certain bacteria cause this infection. The most common are:

  • Streptococci
  • Staphylococci
  • Enterococci

The bacteria can then attach to the endocardium. Some heart conditions can increase the chances of infection. These conditions can cause obstruction or accumulation of blood flow. This situation allows bacteria to accumulate .

Endocardial damage can be initiated by previous inflammatory conditions such as rheumatic valvulitis or by trauma due to turbulent flows by high-pressure gradients in narrow orifices, such as in aortic stenosis or ventricular septal defect (IVC). To the endothelial lesion certain organisms specifically adhere according to their selective affinity, (for example S. aureus binds to fibronectin).

The multiplication of organisms and the aggregation of platelets and fibrin originate the vegetation. Location of the infection. The hydrodynamics of the flow that passes through an orifice from a high pressure to a low pressure area favors the deposit of bacteria at the site where the jet injures the endocardial surface. Thus, in mitral regurgitation, bacterial endocarditis compromises the atrial surface of the mitral valve; in aortic regurgitation, the ventricular surface of the aortic valve is affected, as are the tendon cords. Bacteria adherence.

The ability of the micro-organism to adhere to the endothelial surface plays an important role in the pathogenesis of the infection. Streptococcus and staphylococcus are the most common causative germs of bacterial endocarditis, but gram negative bacilli have increased their frequency participation, particularly pseudomonas aeruginosa and Serratia marcescens in drug addicts, and in the complications of prosthetic surgery. valvular.

Species of the genus Salmonella, which give rise to bacteremia in the absence of murmurs or an evident intracardiac focus, have also been linked as a cause of infective endocarditis. Entry way. In 60% of patients with infectious endocarditis of natural valves, the route of entry is unknown; It has been calculated that 15% of them have a dental origin and 5% genitourinary, this infection being three times higher in people with coexisting heart disease.

Classification

Bacterial endocarditis is the most recognized form and is classified as acute or subacute depending on its clinical presentation. Fungal endocarditis is detected almost exclusively in drug addicts or in patients with valve prostheses.

Symptoms

  • Symptoms range from mild to severe, depending on:
  • The bacteria causing the infection
  • The amount of bacteria in the bloodstream
  • The extent of structural heart defects
  • Your body’s ability to fight infection
  • Your overall health

Some of the symptoms that can manifest in the two weeks after the bacteria enter the bloodstream are:

  • Fever
  • Shaking chills
  • Fatigue
  • Weakness
  • Discomfort
  • Unexplained weight loss
  • Lack of appetite
  • Muscle pains
  • Joint pain
  • Cough
  • Shortness of breath

Small red spots on the skin , inside the mouth , and / or under the nails. Bumps on the fingers and toes. The first symptom may be caused by part of the growth of the infected heart coming off. One of the symptoms could be a stroke or a complication in another organ.

Clinical Picture

The clinical manifestations reflect the underlying pathophysiological changes: the infectious process; valvular heart damage; metastatic infection; immune responses by the production of auto antibodies and the development of immune complexes (immune complexes nephritis, arthritis, arthralgia).

There are several clinical pictures that are associated with different microbial etiologies:

  • Subacute bacterial endocarditis. Symptoms start insidiously, are nonspecific, and can persist for several months. The most frequent complaints are: fever, diaphoresis , myalgia, malaise, arthralgia and weakness. Anorexia is an almost constant data. The most frequent causing germs are Streptococcus viridans (more than 50% of cases) and Enterococcus faecalis .

Physical examination detects splenomegaly and neurological manifestations such as hemiparesis and / or monoplegia in 1/3 of the patients. The cardiac expressions are those of the congenital lesion or background valve. Cardiac murmurs are detected in more than 90% of patients, which may be mild in intensity and erroneously classified as innocent or functional.

  • Acute bacterial endocarditis. The onset is sudden, with a progressive evolution where the fever is high and often remitting from 39.4 to 40.6ºC. Skin manifestations, particularly petechiae, are important. In 50% of cases it develops without underlying heart disease and is associated with pyogenic processes from another location, the use of intravenous drugs or long-term central catheters.

Embolic manifestations are common, particularly in the central nervous system and kidneys. Acute bacterial endocarditis can occur in the absence of heart murmurs, but the sudden onset, a few days after the disease has started, of a new murmur, especially if it is treated one of valve failure is highly suggestive of valve destruction and confirmation of the diagnosis is imperative.

These changes can evolve into congestive heart failure, requiring immediate valve replacement. Right endocarditis: It is associated with the use of intravenous drugs and central catheters and is manifested by septic embolisms. Etiologically it is related to Staphylococcus aureus , gram-negative bacilli (Pseudonoma aeruginosa) and fungi (Candida) .

The latter are characterized by negative blood cultures. Prosthetic valve endocarditis: Depending on the time of its appearance, it is divided into early and late. The early one is associated with the contamination acquired during the surgical process, the most frequently compromised microorganisms being Staphylococcus aureus and gram negative bacilli. The latter is a consequence of bacteremia due to instrumental manipulation or some other underlying infectious process. The most commonly detected germs are gram-negative bacilli, fungi (candida and aspergillos) and diphteroids.

Diagnostic Aids

The blood count usually shows leukocytosis and high sedimentation rate. Urine urinalysis reveals microscopic hematuria and mild proteinuria . Microscopic hematuria suggests renal infarction due to septic embolism.

Computed tomography (CT) scan : Chest x-ray may reveal signs of heart failure. The multiple and small pulmonary infiltrates, orient towards a septic embolism especially in those patients who abuse intravenous drugs. A normal radiograph does not exclude an infective endocarditis. Blood cultures are positive in 2/3 of the patients. The common practice of obtaining four samples for culture before starting antibiotic treatment is correct to confirm bacteremia.

Electrocardiogram (ECG): This is a study that records the heart’s activity by measuring the electrical currents that pass through the heart muscle. It detects vegetations in only 35% of cases but it is very useful to identify the risk of complications (emboli) and as a pre-surgical examination.

Echocardiogram —a test that uses high-frequency sound waves (ultrasound) to examine the size, shape, and movement of the heart

Transesophageal echocardiogram — An ultrasound probe is passed through the mouth into the esophagus to better view the heart valves.

Differential Diagnosis

The differential diagnosis includes septicemia without endocarditis due to Staphylococcus aureus, Neisseria, pneumococci and gram-negative bacilli. Polyarteritis nodosa produces fever, anemia, and kidney disease that may suggest subacute bacterial endocarditis (Table No.1). There is also a symptomatic similarity between cardiac myxoma and infective endocarditis. In both diseases, an accelerated sedimentation rate, anemia and hyperglobulinemia are observed . Negative blood cultures, changing murmurs with position, and the absence of splenomegaly allow the diagnosis to be differentiated. Echocardiography is very useful for clarification.

Pathologies that resemble endocarditis

  • Vascular diseases of collagen
  • Atrial myxoma
  • Rheumatic fever with carditis
  • Non-bacterial thrombotic endocarditis (marántica)

 

Treatment and Medications

Antibiotic therapy is the key to a good final result. For this, it is necessary to know the germ causing the infectious pathology to order the indicated drug. Hence, all patients suspected of infectious endocarditis should have blood culture samples taken. In an emergency, an empirical regimen will be implemented while the results of the samples are known.

  • Staphylococcus aureus:Oxaxylin 12 g / day intravenously or vancomycin 1 g every 12 hours IV for four weeks.
  • Staphylococcus epidermis:Vancomycin 1g IV every 12 hours for four weeks plus rifampin 600 mg / day orally for four weeks.
  • Gram-negative rods:The combination of a beta-lactam (ceftriaxone) plus an aminoglycoside is ideal.
  • Streptococcus viridans:Crystalline penicillin sodium (10 to 20 million units / day) alone or in combination with an aminoglycoside which is used during the first two weeks. In case of penicillin allergy, ceftriaxone 2 g / day or vancomycin 15 mg / kg IV is used, not exceeding 1 g every 12 hours.
  • Enterococci:crystalline penicillin sodium (10 to 20 million units / day or ampicillin 8 g / day) IV or vancomycin 1g every 12 hours plus gentamicin 1mg / kg IV every 8 hours.
  • Fungi:Amphotherericin B, 0.5 mg / kg / day plus valve replacement in all cases.
  • Negative cultures. In approximately 5% of patients with probable endocarditis, no microorganism is isolated in blood cultures. If the clinical and laboratory findings are compatible with the disease, the diagnosis of endocarditis is adopted and a penicillin or vancomycin plus an aminoglycoside is recommended.

Surgery

It is possible that the antibiotics can not kill bacteria. Also, the infection may return. In this case, surgery may be necessary. Surgery may also be necessary if there was damage to the heart or valves due to the infection.

Surgical Treatment

It consists of the removal of the infected valve and insertion of a prosthesis. The indications for surgery are:

  • Valvular destruction with progressive heart failure.
  • Failure of medical treatment to control infection.
  • Endocarditis caused by fungi .
  • Valve ring abscess.
  • Repeat embolism .
  • Unstable prosthesis .
  • Dehiscence of the prosthetic valve.

Complications

  • Blood clots or emboli that travel to the brain, kidneys, lungs, or abdomen
  • Brain abscess
  • Congestive heart failure
  • Glomerulonephritis
  • Jaundice
  • Neurological changes
  • Fast or irregular heartbeat, including atrial fibrillation
  • Severe valve damage
  • Cerebrovascular accident

Rofilaxis

The cardiac disorders most frequently associated with endocarditis and that warrant the use of prophylaxis are:

  • Prosthetic valves.
  • Congenital malformations.
  • Rheumatic valve dysfunction.
  • Hypertrophic cardiomeopathy.
  • Mitral valve prolapse.

The dental and surgical procedures with the highest risk are:

  • Dental procedures that induce bleeding.
  • Tonsillectomy .
  • Rigid bronchoscopy .
  • Esophageal dilation .
  • Cystoscopy .
  • Vaginal hysterectomy .

For dental and upper respiratory procedures where S. viridans is the main pathogen to be covered, amoxacillin 3 g PO is used one hour before the procedure and 1.5 g six hours after. In the case of genitourinary procedures, it should be especially protected against Enterococcus faecalis, so intravenous administration of ampicillin (2g) and gentamicin (1.5 mg / kg) is recommended 30 minutes before the procedure and amoxacillin 1.5 g PO six hours after.

Prevention

The best way to prevent endocarditis is to avoid using illegal IV drugs. Certain heart conditions can increase your risk. Talk to your doctor to find out if you are at increased risk for this condition.

People at high or moderate risk should take antibiotics before and after certain medical and dental procedures. Also: Take an antibiotic just before and after any procedure that could put you at risk. Tell the dentist and other health professionals about your heart condition. Maintain good oral hygiene: Brush your teeth twice daily. Floss your teeth daily. Visit your dentist for a cleaning at least every six months. Consult your dentist if the dentures cause discomfort. Seek medical care immediately for symptoms of an infection.

 

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