What is Infective Endocarditis?
Infective endocarditis (IE) is defined as an infection of the endocardial surface of the heart, which may include one or more heart valves, the mural endocardium, or a septal defect. Its intracardiac effects include severe valvular insufficiency, which may lead to intractable congestive heart failure and myocardial abscesses. IE also produces a wide variety of systemic signs and symptoms through several mechanisms, including both sterile and infected emboli and various immunological phenomena.
What are the major manifestations of bacterial endocarditis?
· Manifestations of a systemic infection: fever, weight loss, pallor, splenomegaly.
· Manifestations of a vasculitic phenomenon: cardiac failure, changing murmurs, petechia , Roth's spots , Osler nodes , Janway lesions , splinter hemorrhages, stroke, infarction of viscera, mycotic aneurysm.
· Manifestations of immunological reactions: arthralgia, finger clubbing, uraemia.
What are common organisms found in infective endocarditis?
Streptococcus viridans, Staphylococcus aureus, Strep.faecahs, fungi.
What precautions would you take to prevent bacterial endocarditis?
Antibiotic prophylaxis before any dental, gastrointestinal, urological or gynaeco-logical procedure is recommended in rheumatic valvular disease, most congenital heart lesions (except uncomplicated atrial septal defect of secundum type), valvular aortic stenosis, prosthetic heart valve, previously documented infective endocarditis and calcified mitral valve annulus.
What are Prognostic factors?
· Heart failure.
· Non-streptococcal endocarditis, especially Staph. aureus, fungal endocarditis. · Infection of a prosthetic valve.
· Elderly patients.
· Valve ring or myocardial abscess.
A few conditions that can simulate clinical manifestations of infective endocarditis?
· Atrial myxoma.
· Non-bacterial endocarditis.
· Systemic lupus erythematosus (SLE).
· Sickle cell disease.
What are the complications of infective endocarditis?
· Congestive heart failure: may develop acutely or insidiously; it portends a grave prognosis.
· Conduction disturbances caused by abscesses in ventricular septum.
· Valve destruction: acute regurgitation, pulmonary oedema, heart failure.
· Embolism: occurs in 22-50% of cases, leading to infarction in any vascular bed including lungs, coronary arteries, spleen, bowel, and extremities; renal: flank pain and haematuria.
· Local extension of infection: purulent pericarditis, aortic root abscess (may cause sinus Valsalva fistula), myocardial abscess (conduction disturbance).
· Septic emboli to vasa vasorum: may lead to mycotic aneurysms anywhere in vas-cular tree; most worrying in cerebral vessels, resulting in cerebral haemorrhage.
· Distal infection (metastatic): due to septic emboli, e.g. brain abscess, cerebritis.
· Candidal endocarditis: may be manifest by fungal endophthalmitis.
· Glomerulonephritis: the renal lesions of SBE are of two kinds,
(a) a diffuse pro-liferative glomerulonephritis and
(b) focal embolic glomerulonephritis. This is associated with low complement levels and immune complexes.
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