Clinical features :

The classic tetrad of the clinical features of endocarditis is:

Fever (96-100 %) with rigors, sweats, lassitude, arthralgia, myalgia are features of infection. Splenomegaly is present in 60% of the patients and anemia in 100% of patients.

Majority will reveal signs of pre-existing valvar or shunt lesions (85%). The sudden occurrence of an aortic insufficiency or mitral insufficiency arises because of destruction of valve leaflets by the infected vegetations.

Finger clubbing may develop in acyanotic lesions or may already be present in cyanotic heart disease. Hepatomegaly and other signs of heart failure may be present.

Any child with unexpected embolism should be suspected as having endocarditis. The brain, kidneys, liver, spleen and bones are particular sites for emboli.

Many classic signs of endocarditis, which were previously thought to embolic, are now known to represent immunological phenomenon. The mechanism of these features is thought to be antigen-antibody complement complexes being deposited in tissues. These features are:

Diagnosis:

Infective endocarditis should be suspected in any child who presents with fever of unknown origin, heart murmur and splenomegaly.

A positive blood culture confirms the diagnosis . Bacteremia in endocarditis is continuous and not related to temperature spikes hence timing of collection of blood for cultures is not necessary. If six blood cultures are taken within 24 hours, positivity will be 90%. In strongly suspected cases of endocarditis if routine blood culture fails to grow, the microbiology laboratory should be notified to incubate cultures for 2 or more weeks.

Cardiac patients with prolonged fever of undetermined origin and negative blood culture should probably be treated as having infective endocarditis.

The most common hematological abnormality is normochromic, normocytic anemia of chronic disease reflecting chronic inflammatory nature of the process. The leukocytosis is a common but variable finding. ESR and CRP (C reactive protein) are always elevated at presentation. Hematuria results from embolization in renal arteries. Serum globulins are increased and rheumatoid factor is elevated in 20% of patients.

Echocardiography has been successfully utilized to visualize endocardial vegetations larger than 2mm and for the non-invasive hemodynamic evaluation of cardiac lesions.

X-Ray chest reveals findings compatible with the pre-existing heart disease. Cardiomegaly is present if the patient has congestive heart failure. On occasions, evidence for pericardial effusion will be present.