INFECTIVE ENDOCARDITIS.docx

**INFECTIVE ENDOCARDITIS (IE)** **Definition:** IE is direct microbial infection of the heart valves, endothelial lining, blood vessel or congenital anomaly. It is a potentially fatal disease, if not well treated. IE is classified based on the onset of symptoms into acute or sub-acute IE. It can a...

**INFECTIVE ENDOCARDITIS (IE)** **Definition:** IE is direct microbial infection of the heart valves, endothelial lining, blood vessel or congenital anomaly. It is a potentially fatal disease, if not well treated. IE is classified based on the onset of symptoms into acute or sub-acute IE. It can also be described as native or prosthetic valve endocarditis (NVE) or (PVE) depending on the nature of the valve. **The type of causative organism is also a basis for classification e.g., bacterial or fungal endocarditis.** Incidence of IE on the decline due to wider availability of antibiotics. **Risk Factors:** The risk for IE varies, could be low, intermediate or high. Usually affects diseased valve, but structurally normal valves can be affected, particularly in an immune compromised host or virulent organisms. **High risk factors:** Previous IE, Prosthetic valves, congenital heart disease (VSD PDA COA BAV). Heart transplant, intravenous drug abusers (IVDA), Long term indwelling catheters, tunneled neck lines, pace makers. **Low risk factors include** Mitral valve prolapse Degenerative valve disease Rheumatic heart disease. **Pathophysiology:** Almost any organism can cause IE, but the commonly implicated organisms include Streptococcus viridans, strep bovis, staph aureus, and entrerococcus faecalis. **Clinical Features:** Nonspecific symptoms of inflammation, and constitutional symptoms such as, fever, malaise, fatigue, and arthralgia weight loss are common. A murmur is also common. **INVESTIGATIONS:** Full blood count / Erythrocyte sedimentation rate; Normochromic normocytic anaemia, thjrombocytopaenia, leucocytosis elevated ESR and CRP. Urinalysis; Microscopic haematuria proteinuria Chest X - ray; Features of heart failure, pulmonary septic emboli Electrocardiography (ECG); Conduction defect, myocardial infarction Blood Cultures; At least 3 separate sets of BL, from separate puncture sites taken 1 hour apart. **DIAGNOSIS:** The individual clinical features have a low sensitivity and specificity; a combination of features is therefore needed. The diagnosis of IE is based on the Modified Dukes criteria which has both major, and minor criteria. Major criteria consist of echocardiography, and blood culture results. Major echocardiography criteria are A. Oscillating intra cardiac mass on the valves or supporting structures (vegetation) B. Abscess C. New valvular dehiscence D. New valvular regurgitation Major blood culture criteria are A. Positive blood culture with microbes consistent of IE from 2 separate blood cultures; B. Persistently positive blood cultures with microbes consistent with IE from \> than 4 blood cultures more than 12 hours apart; C. All 3 or more of the 4 blood cultures with 1^st^ and last taken at least more than 1 hour apart. **MINOR CRITERIA:** A. One predisposing structural heart disease or IVDA, B. Fever \> 38 C. Vascular phenomena; Major arterial emboli, septic pulmonary infarct, mycotic aneurysm, intracranial haemorrhage, conjuctival haemmorrhage, janeway lesions. D. Immunological phenomena: Glomerulonephritis, Osler's nodes, Roth spots, rheumatoid factor, E. Microbiological evidence: Positive blood culture, but not meeting major criteria. Serological evidence of active infection with organism consistent with IE. **Definite IE:** Two major, or one major + 3 minor, or 5 minor **Probable IE:** One Major + 1 minor or 3 minor criteria **Rejected IE:** Firm alternative diagnosis for manifestation of endocarditis or sustained resolution of MOE with antibiotic therapy for 4 days or less **Treatment:** Multidisciplinary approach with the physician, cardiothoracic surgeon, and bacteriologist. Th e main stay of treatment is a combination of intravenous penicillin and aminoglycocside for 4 to 6 weeks