Infective Endocarditis
Hasan Al_Farhan Prof. of cardiology FACC,FICSM Cardiol,DIC.DMPathogenesis
Disruption of the endocardial layer as a complication of abnormal blood flow associated with underlying cardiac defect Bacterium-endothelium interaction with bacterial attachment and invasion of endothelial cellsEpidemiology
Underlying valvular abnormality predisposing to infective endocarditis rheumatic fever a common cause in the past mitral valve prolapse currently represents the most common underlying cardiac abnormalitymitral valve prolapse
risk for infective ednocarditis is 5x-8x mitral regurgitation increases the riskleaflet redundancy with myxomatous degeneration is a frequent findingage <20 , female predominateage >20 , male accounts for 60%age >50 , male accounts for 68%
Causative Agents
1 .Streptococci 2 .Staphylococci 3 .Gram –negative bacilli 4 .Haemophillus 5 .Anaerobes 6 .Other : Rickettsia ,fungiPredisposing Factors Polymicrobial Infective Endocarditis
Infective Endocarditis; clinical features1. Clinical course 2.Clinical feature
Diagnostic (Duke) CriteriaDefinitive infective endocarditis pathologic criteria microorganisms or pathologic lesions: demonstrated by culture or histology in a vegetation, or in a vegetation that has embolized, or in an intracardiac abscess clinical criteria (see below) two major criteria, or one major and three minor criteria, or five minor criteria
Diagnostic (Duke) Criteria
Possible infective endocarditisfindings consistent of IE that fall short of “definite”, but not “rejected”Rejectedfirm alternate Dx for manifestation of IEresolution ofmanifestations of IE, with antibiotic therapy for 4 daysno pathologic evidence of IE at surgery or autopsy, after antibiotic therapy for 4 daysDiagnostic (Duke) Criteria
Major criteria positive blood culture for IE evidence of endocardial involvement Minor criteria predisposition (heart condition or IV drug use) fever of 38 c or higher vascular or immunologic phenomena microbiologic or echocardiographic evidence not meeting major criteriaDuke’s Major Criteria
positive blood culture for IE typical microorganism (strep viridans, strep bovis, HACEK group, staph aureus or enterococci in the absence of a primary focus) for endocarditis from two separate blood cultures persistently positive blood culture from: blood cultures drawn more than 12 hr apart, or all of 3 or more separate blood cultures,taken over more than 1 hr .Duke’s Major Criteria
Evidence of endocardial involvement positive echocardiogram for endocarditis oscillating intracardiac mass on valve or supporting structure, or in the path of regurgitant jets, or on implanted material, in the absence of an alternate anatomic explanation abscess new partial dehiscence of prosthetic valve new valvular regurgitation (increase or change in pre-existing murmur not sufficient)Duke’s Minor Criteria
predisposition (predisposing heart condition or iv drug use) fever of 100.40F or higher vascular phenomena (major arterial emboli, septic pulmonary infarcts, mycotic aneurysm, intracranial hemorrhage, conjunctive hemorrhages, Janeway lesions)Duke’s Minor Criteria
immunologic phenomena (glomerulonephritis, Osler’s nodes, Roth spots, rheumatoid factor)microbiologic evidence (positive blood culture not meeting major criteria or serologic evidence of active infection with organism consistent with IE)echocardiogram (consistent with IE but not meeting major criteria)Risk for Endocarditis
High risk prosthetic cardiac valve prior episodes of endocarditis complex congenital cardiac defect surgically constructed systemic-pulmonary shunts or conduits