Infective Endocarditis  

Aetiology

Categorised according to causative organism. Organisms usually arising from normal flora, which have become liberated into the blood stream.

Streptococcus viridans—S.mutans, S. oralis, S. mitior, S. bovis, S. sanguis, S. anginosus.

Others—Corynebacterium, S. epidermidis, Anaerobic bacteria.

 

Pathology

Vegetations on valve leaflets or chordae tendinea. Congenital defects (patent ductus arteriosus, coarctation or arteriovenous fistula) can also be involved. The size of the vegetations varies from a small nodule to a large friable mass.

 

Predisposing factors:

¨ Mitral and aortic valvular disease

¨ Degenerative, atherosclerotic or syphilitic valve disease

¨ Congenital defects

¨ Prosthetic heart valves

¨ Drug addicts

 

Symptoms of Infective Endocarditis

Signs and symptoms of Infective Endocarditis are very varied. Nearly always a fever and heart murmur are evident. Non-specific symptoms include anorexia, weight loss, malaise, chills, nausea, vomiting and night sweats. Peripheral manifestations include splinter haemorrhages and Osler nodes.

 

Complications

¨ Cerebral and retinal emboli

¨ Bronchopneumonia and pulmonary infarct

¨ Valvular incompetence and myocarditis

¨ Renal infarcts and Glomerulonephritis

¨ Haematuria

¨ Splenomegaly +/ - infarcts

¨ Anaemia

 

Diagnosis of Infective Endocarditis

¨ Blood cultures (three consecutive samples within a 24 hour period BEFORE antibiotics are given

¨ Doplar (evidence of endocarditis only)         

¨ Blood count, ESR

¨ Echocardiographs (vegetations)

                                                                

Dental procedures transient bacteraemia ranges from 18—85% (sensitivity of detection system). Incidence of transient bacteraemia with dental procedures include removal of non-diseased primary teeth, removal of diseased primary and permanent teeth, removal of healthy permanent teeth, and other causes of transient bacteraemia: rocking of teeth, scaling of gums, periodontal operations, use of unwaxed dental floss.          

 

Prevention of Infective Endocarditis

¨ Ask all dental patients for history of heart disease, especially murmurs, valve problems, surgery or endocarditis

¨ Good dental hygiene important. Chlorhexidine gluconate mouthwash before procedures

¨ Prophylactic antibiotics for dental procedures and other operative procedures

¨ Avoidance of line infections—short-term central lines, pacemakers, indwelling catheters.

 

Treatment of Infective Endocarditis

Long course of antibiotic treatment (often 2—4 weeks intravenous treatment, then oral). Valve replacement if necessary acutely or after antibiotic treatment.                        

The physical presence of micro-organisms causing  infection of the endocardial surface of the heart.