1、Infective Endocarditis Infective endocarditis(IE)is a microbial infection of the endothelial surface of the heart.Acute IE Subacute IEDefinitionThe characteristic lesion-IE The vegetation,is a variably sized amorphous mass of platelets and fibrin in which abundant microorganisms and moderate inflamm
2、atory cells are enmeshed.Acute IE Acute IE arises with marked toxicity progresses over days to several weeks to valvular destruction and metastatic infection.Acute IE is caused typically,although not exclusively,by Staphylococcus aureus(金金黄色葡萄球菌黄色葡萄球菌).Subacute IE Subacute IE evolves over weeks to m
3、onths with only modest toxicity and rarely causes metastatic infection.Subacute IE is more likely to be caused by viridans streptococci(绿色链球菌),enterococci(肠球菌),or gram-negative coccobacilli(球杆菌).Predisposing Conditions in Adult Rheumatic heart disease (25-30%)Congenital heart disease (10-20%)Mitral
4、valve prolapse (10-30%)Degenerative heart disease(30%in elderly)Parenteral(肠胃外的)drug abuse(15-35%)Other (10-15%)None (25-45%)Pathogenesis Development of nonbacterial thrombotic endocarditis(NBTE).Two major mechanisms appear pivotal in the formation of NBTE:endothelial injury and a hypercoagulable st
5、ate.Pathogenesis Development of nonbacterial thrombotic endocarditis(NBTE).Three hemodynamic circumstances may injure the endothelium,initiating NBTE:(1)a high-velocity jet striking endothelium,(2)flow from a high-to a low-pressure chamber,and(3)flow across a narrow orifice at high velocity.Pathogen
6、esis Conversion of NBTE to infective endocarditis.Pathophysiology Local destructive effects of intracardiac infection Embolization of septic fragments of vegetations to distant sites,resulting in infarction or infection Hematogenous seeding of remote sites during continuous bacteremiaPathophysiology
7、 Antibody response-The infecting organism with subsequent tissue injury caused by deposition of preformed immune complexes or antibody-complement interaction with antigens deposited in tissues.Pathophysiology NBTE Conversion of NBTE to IE Embolization Antibody responseSubacute Infective Endocarditia
8、 常在风湿性心内膜炎基础上合并较弱的草绿色链球菌感染。主动脉瓣的常在风湿性心内膜炎基础上合并较弱的草绿色链球菌感染。主动脉瓣的 两两个瓣膜上浅褐色赘生物附着（个瓣膜上浅褐色赘生物附着（），瓣膜结构破坏。），瓣膜结构破坏。Acute Infective Endocarditis 二尖瓣心房面粉红色赘生物形成（二尖瓣心房面粉红色赘生物形成（），部分脱落），部分脱落形成溃疡。形成溃疡。AIE 多由毒力较强的多由毒力较强的化脓菌引起正常心化脓菌引起正常心内膜的炎症。内膜的炎症。1.1.瓣膜坏死，大瓣膜坏死，大量蓝染细菌散落在量蓝染细菌散落在坏死组织中坏死组织中.2.2.中性粒细胞浸中性粒细胞浸润。润。
9、3.3.共同形成赘生共同形成赘生物。物。4.4.赘生物脱落。赘生物脱落。Clinical Features Fever Heart murmurs Enlargement of the spleen Systemic emboli Neurological symptoms Petechiae,Splinter or subungual hemorrhages,Osler nodes OthersClinical Features-Fever The most common symptom and sign in patients with IE.Clinical Features-Heart
10、 murmurs Noted in 80-85%of patents with native valve endocarditis(NVE).The new or changing murmurs are relatively infrequent in subacute NVE and are more prevalent in acute IE and prosthetic valve endocarditis(PVE).Clinical Features Enlarge-of spleen Common in subacute IE of long duration.Clinical F
11、eatures-Systemic emboli Musculoskeletal symptoms-arthralgias(关节痛)and myalgias(肌痛)Renal,Cerebral,ArteryClinical Features-Neurological symptoms Embolic stroke Intracranial hemorrhage Aneurysms(动脉瘤),Cerebritis(大脑炎),Purulent meningitis(化脓性脑膜炎).Clinical Features-Petechiae(淤点)Petechiae(淤点)Splinter or subu
12、ngual(指甲下的)hemorrhages Osler nodesClinical Features-Others Renal insufficiency as a result of immune complex-mediated glomerulonephritis.A.SplinterhemorrhageB.Conjunctival patechiaeC.Osler nodeD.Janeways lesion*Early PVE:often lake of peripheral vascular lesions 右边的感染性心内膜炎患者手指，上面有小块右边的感染性心内膜炎患者手指，上面
13、有小块裂片形出血，出血位于指甲下，呈线性暗红色条纹裂片形出血，出血位于指甲下，呈线性暗红色条纹类似的出血还可见于外伤。类似的出血还可见于外伤。感染性心内膜炎患者左手大拇指的指甲下可见另一感染性心内膜炎患者左手大拇指的指甲下可见另一个小的呈线型的裂片形出血，血培养为金黄色葡萄球菌个小的呈线型的裂片形出血，血培养为金黄色葡萄球菌阳性。阳性。Clinical and Laboratory Data Echocardiography.Establishing the microbial cause Obtaining blood culturesClinical and Laboratory Data
14、-Echocardiography Detect vegetations in patients if mutiplanar TEE and TTE are combined.二维超声二维超声左室长轴左室长轴切面示二切面示二尖瓣附着尖瓣附着之赘生物之赘生物随瓣叶活随瓣叶活动，舒张动，舒张期随瓣叶期随瓣叶开放活动开放活动至左室。至左室。Clinical and Laboratory Data Establishing the microbial cause A microbial cause of IE is established by recovering the infecting age
15、nt from the blood or by identifying it in surgically removed vegetations or embolic material.Clinical and Laboratory Data Obtaining blood cultures Three separate sets of blood cultures,each from a separate venipuncture,obtained over 24 hours.Recommended to evaluate patients with suspected endocardit
16、is.Clinical and Laboratory Data Obtaining blood cultures Each set should include two flasks,one containing an aerobic medium and the other containing anaerobic（厌氧的）medium,into each of which at least 10 ml of blood should be placed.DiagnosisDiagnosis of IE(Modified Duke Critera)Definitive Infective E
17、ndocarditisPathological criteriaMicroorganisms:demonstrated by culture or histology in a vegetation,or in a vegetation that has embolized,or in an intracardiac abscess Diagnosis of IE(Modified Duke Critera)Definitive Infective EndocarditisPathological criteriaPathological lesions:vegetation of intra
18、cardiac abscess present,confirmed by histology showing active endocarditisDiagnosis of IE(Modified Duke Critera)Definitive Infective EndocarditisClinical criteria,using specific definitions listed belowTwo major criteria,orOne major and three minor criteria,orFive minor criteriaDiagnosis of IE(Modif
19、ied Duke Critera)Possible Infective Endocarditis One major criterion and one minor criterion Three minor criteriaDiagnosis of IE(Modified Duke Critera)Rejected1.Firm alternative diagnosis for manifestations of endocarditis,or2.Sustained resolution of manifestations of endocarditis,with antibiotic th
20、erapy for 4 days or less,or 3.No pathological evidence of infective endocarditis at surgery or autopsy,after antibiotic therapy for 4 days or lessDiagnosis of IE(Modified Duke Critera)Criteria for Diagnosis of Infective EndocarditisMajor criteria1.Positive blood culture-Persistently Typical microorg
21、anism for infective endocarditis from two separate blood culture(Viridans streptococci,Streptococcus boris,HACEK group or Staphylococcus aureus or community-acquired enterococci in the absence of a primary focus.)Diagnosis of IE(Modified Duke Critera)Criteria for Diagnosis of Infective EndocarditisM
22、ajor criteria Positive blood culture Persistently positive blood culture:Blood cultures(2)drawn more than 12 hr apart.All of three or a majority of four or more separate blood culture,with first and last drawn at least 1 hr apart.Diagnosis of IE(Modified Duke Critera)Criteria for Diagnosis of Infect
23、ive EndocarditisMajor criteria2.Evidence of endocardial involvement Positive echocardiogram Oscillating intracardiac mass(on valve or supporting structures,or in the path of regurgitant jets,or on implanted material)in the absence of an alternative anatomical explanation.Abscess New partial dehiscen
24、ce of prosthetic valve,or New valvular regurgitationDiagnosis of IE(Modified Duke Critera)Criteria for Diagnosis of Infective EndocarditisMinor criteria Predisposition:predisposing heart condition or intravenous drug use Fever 38.0C Vascular phenomena:major arterial emboli,septic pulmonary infarcts,
25、mycotic aneurysm,intracranial hemorrhage,conjunctival hemorrhages,Janeway lesionsDiagnosis of IE(Modified Duke Critera)Criteria for Diagnosis of Infective EndocarditisMinor criteria Immunological phenomena:glomerulonephritis,Osler nodes,rheumatoid factor Microbiological evidence:positive blood cultu
26、re but not meeting major criterion as noted previously or serologic evidence of active infection with organism consistent with infective endocarditisTreatment Two major objectives must be achieved to treat IE effectively.The infecting microorganism in the vegetation must be eradicated.Also,invasive,
27、destructive intracardiac and focal extracardiac complications of infection must be resolved if morbidity and mortality are to be minimized.Antimicrobial Therapy for Specific Organisms Penicillin-susceptible viridans streptococci or streptococcus bovis.-Aqueous penicillin G,Aqueous penicillin plus Ge
28、ntamicin,or Vancomycin.Relatively penicillin-resistant streptococci.Aqueous penicillin G plus Gentamincin,or Vancomycin（万古霉素）.Antimicrobial Therapy for Specific Organisms Streptococcus pyogenes,Streptococcus pneumoniae,and group B,C,and G streptococci.Penicillin G in a dose of 3 million units IV eve
29、ry 4 hr for 4 weeks is recommended.Antimicrobial Therapy for Specific Organisms Enterococci.Aqueous penicillin plus Gentamicin,Ampicillin plus Gentamicin,or Vancomycin plus Gentamicin.Staphylococci.Nafcillin or oxacillin with optional addition of gentamicin,cefazolin with optional addition of gentam
30、icin,or vancomycin.Cardiac Surgery in Patients with IEIndications Moderate to severe congestive heart failure caused by valve dysfunction Unstable prosthesis,prosthesis orifice obstructed Uncontrolled infection despite optimal antimicrobial therapyCardiac Surgery in Patients with IEIndications SUnavailable effective antimicrobial therapy:caused by fungi,Brucellae,Pseudomonas aeruginosa(aortic or mitral valves)Staphylococcus aureus PVE with an intracardiac complication Relapse of PVE after optimal therapy Fistula to pericardial sacThanks for your attention
