心臟病及保健 Heart Disease And Health http://心臟病.tw www.heartdisease.idv.tw
Andrew Ying-Siu Lee, MD,PhD.
Infective endocarditis is microbial infection of heart valves, mechanical valves, congenital or acquired
cardiac anomaly, arterio-venous shunts or fistulas. It can be acute (duration from days to few weeks) or subacute
(duration from few weeks to few months) in onset. It occurs more frequently in patients with congenital or valvular
heart diseases (ventricular septal defect, aortic stenosis or regurgitation, patent ductus arteriosus, mitral valve
prolapse or regurgitation, mechanical valves), intravenous drug abuse, post cardiac surgery with drains. Common
microbes are streptococcus viridans, staphylococcus, gram(-) cocci, fungi, virus etc. Once infected, vegetation
will develop, which may (1) damage the heart valves causing valvular regurgitation, (2) infect the surrounding
tissues and vessels causing abscess formation, fistulas or heart block, (3) lead to immune-complex formation
affecting kidneys, joints and skin, (4) lead to systemic embolization to major organs or limbs causing ischemia.
Common symptoms of infective endocarditis include : fever, body weight loss, cold sweating, poor appetite,
joint pains, muscle pain, heart valves damage (leading to heart murmur, acute heart failure, myocarditis, septic shock,
heart block, arrhythmias etc), embolization (leading to acute myocardial infarction, pulmonary embolism, limb ischemia,
hematuria, acute abdomen, stroke, paralysis, sudden blindness, meningitis, brain abscess, subarachnoid hemorrhage etc),
petecchiae in oral cavity, cornea and skin, splinter hemorrhage in nails, osler nodes in palm or fingers. Blood culture
is positive. Echocardiography show vegetation, damage of heart valves or chordae tendinae, abscess formation over
myocardium or perivalvular regions, and abnormal heart function.
Treatment is antibiotics. In cases of large vegetation, abscess formation, recurrent embolization, mechanical valve
infection, persistent bacteremia, fistulas, heart failure etc., surgical removal of vegetation or mechanical valve
replacement may be considered.
To prevent infective endocarditis, antibiotic prophylaxis is recommended before any surgical intervention in
patients with congenital or acquired valvular heart diseases, mechanical valves, history of endocarditis etc.