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Infective Endocarditis. Supervisor : Dr: Mohammed Al marwala Presented by : Dr : Areej Aljabali. Items of Presentation General definitions Pathology Pathogenesis Pathophysiology Clinical features Diagnosis Treatment Prevention . Definition :
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Infective Endocarditis Supervisor : Dr: Mohammed Al marwala Presented by : Dr :AreejAljabali
Items of Presentation General definitions Pathology Pathogenesis Pathophysiology Clinical features Diagnosis Treatment Prevention
Definition : Infective endocarditis is characterized by colonization or invasion of the heart valves or the mural endocardium by a microbe, leading to the formation of bulky friable vegetations composed of thromb and organisms, often associated with destruction of the underlying cardiac tissues.
Acute • Toxic presentation • Progressive valve destruction & metastatic infection developing in days to weeks • Most commonly caused by S. aureus • Sub acute • Mild toxicity • Presentation over weeks to months • Rarely leads to metastatic infection • Most commonly S. viridans or enterococcus
55-75% of patients with native valve endocarditis (NVE) have underlying valve abnormalities • MVP • Rheumatic • Congenital • I.v. drug abuse • 7-25% of cases involve prosthetic valves • 25-45% of cases predisposing condition can not be identified
Pathology : • NVE infection is largely confined to leaflets • PVE infection commonly extends beyond valve ring into annulus/peri annular tissue • Ring abscesses • Septal abscesses • Fistulae • Prosthetic dehiscence • Invasive infection more common in aortic position and if onset is early
Pathogenesis : Endothelial damage Platelet-fibrin thrombi Microorganism adherence
Nonbacterial Thrombotic Endocarditis • Endothelial injury • Hypercoagulable state • Lesions seen at coaptation points of valves • Atrial surface mitral/tricuspid • Ventricular surface aortic/pulmonic • Modes of endothelial injury • High velocity jet • Flow from high pressure to low pressure chamber • Flow across narrow orifice of high velocity • Bacteria deposited on edges of low pressure or site of jet impaction
:Pathophysiology • Clinical manifestations • Direct • Constitutional symptoms of infection (cytokine) • Indirect • Local destructive effects of infection • Embolization – septic or bland • Hematogenous seeding of infection may present as local infection or persistent fever, metastatic abscesses may be small • Immune response • Immune complex or complement-mediated
Local destructive effects • Valvular distortion/destruction • Chordal rupture • Perforation/fistula formation • Paravalvular abscess • Conduction abnormalities • Purulent pericarditis • Functional valve obstruction
Embolization • Clinically evident 11 – 43% of patients • Pathologically present 45 – 65% • High risk for embolization • Large > 10 mm vegetation • Hypermobile vegetation • Mitral vegetations (esp. anterior leaflet) • Pulmonary (septic) – 65 – 75% of i.v. drug abusers with tricuspid IE
: Clinical Features • Fever, chills, weakness, lethargy, weight loss, flu-like illness (not always present) • Longstanding IE (rarely seen now with earlier diagnosis): splinter haemorrhages, Janeway lesions, Osler nodes, Roth spots • Murmurs are present in 80 - 85% of patients with left sided IE
In IVDU right sided IE usually affect the tricuspid valve & occasionally the pulmonary valve, instead of systemic issues pulmonary embolism is the most important complication which can evolve into: • Pulmonary infarction • Pulmonary abscess • Bilateral pneumothoraces • Pleural effusion • Empyema
The severity of valvular destruction depends on virulence of infecting organism & infection duration • Heart failure can be the initial presentation
: Diagnosis Modified Duke criteria It is based on clinical, microbiological & echo findings providing high sensitivity & specificity (~80%) for diagnosis of IE when applied to patients with native valve IE with +ve BC
Modified Duke Criteria • Major Criteria: Positive blood cultures Typical microorganism for IE from 2 separate blood culures Viridanssreptococci Sreptococcusbovis HACEK group Saph . Auresus Community acquired enerococci , in the absence of primary focus
Persistently positive blood culture , defined as recovery of a microorganism consistent with IE from: Blood culture drawn more than 12 h apart OR All of 3or majority of 4 or more separate blood cultures , with first last drawn at least one h apart Single positive blood culture for Coxiellaburnetiior antiphase I IgG AB titer more than 1: 800
Evidence of endocardial involvement Positive echocardiogram for IE • TEE recommended in patients with PV ,rated at least possible IE by clinical crieria ,or complicated IE ( paravalvular abscess ) TTE as first test in other patients
Definition of positive ECHO - Oscillating intracardiac mass, on valve or supporting structures , or in the path or regurgitant jets , or on implanted material , in he absence of an alternative anatomic explanation - Intracardiac abscess - New partial dehiscence of prosthetic valve New valvular regurgitation Increase in or change in preexisting murmur not sufficent
Minor Criteria • Predisposition such as a heart condition or IV drug use • Fever • Vascular phenomena - major arterial emboli, septic pulmonary infarcts, mycotic aneurysm, intracranial haemorrhage, conjunctivalhaemorrhage, & Janeway lesions
immunological phenomena – glomerulonephritis , Osler s nodes , Roth spots , rheumatoid factor • Other microbial evidence - serological tests, or a positive blood culture but does not meet a major criteria ( excluding single positive cultures for coagulase negative staph and organisms that do not cause endocarditis )
Definite IE 2 major criteria OR 1 major + 3 minor OR 5 minor criteria Possible IE 1 major + 1 minor OR 3 minor
Rejected : Firm alternate diagnosis for manifestation of endocarditisOR Resolution of manifestation of endocarditis , with antibiotic therapy for 4 days or less OR No pathologic evidence of IE at surgery or autopsy after antibiotic therapy for 4 days or less Does not meet criteria for possible IE , as above
TREATMENT : Goals of Therapy Eradicate infection Definitively treat sequelae of destructive intra-cardiac and extra-cardiac lesions
: Antibiotics • Benzylpenicillin is the first choice for Streptococcus or Enterococcus penicillin-susceptible strains • Empirical treatment; flucloxacillin& gentamicin are the usual first line • Vancomycin is used in pts with intracardiac prosthetic material or suspected MRSA • For vanc-resistant MRSA: teicoplanin, lipopeptidedaptomycinor oxazilidones (linezolid) is recommended
IV Abx is normally continued for 4-6 weeks, with the aim of sterilising the vegetations
Indications for Cardiac Surgical Intervention in Patients with Endocarditis Surgery required for optimal outcome • Moderate to severe congestive heart failure due to valve dysfunction • Partially dehisced unstable prosthetic valve • Persistent bacteremia despite optimal antimicrobial therapy • Lack of effective microbicidal therapy (e.g., fungal or Brucellaendocarditis) • S. aureus prosthetic valve endocarditis with an intracardiac complication • Relapse of prosthetic valve endocarditis after optimal antimicrobial therapy
Surgery to be strongly considered for improved outcomea • Perivalvular extension of infection • Poorly responsive S. aureusendocarditis involving the aortic or mitral valve • Large (>10-mm diameter) hypermobile vegetations with increased risk of embolism • Persistent unexplained fever (10 days) in culture-negative native valve endocarditis • Poorly responsive or relapsed endocarditis due to highly antibiotic-resistant enterococci or gram-negative bacilli
Complications • Congestive heart failure • Most common complication • Main indication to surgical treatment • ~60% of IE patients • Uncontrolled infection • Persisting infection • Perivalvular extension in infective endocarditis • Systemic embolism • Brain, spleen and lungs • 30% of IE patients • May be the first symptom
Neurologic events • Acute renal failure • Rheumatic problems • Myocarditis
High-Risk Cardiac Lesions for Which Endocarditis Prophylaxis Is Advised before Dental Procedures • Prosthetic heart valves • Prior endocarditis • Unrepaired cyanotic congenital heart disease, including palliative shunts • Completely repaired congenital heart defects during the 6 months after repair • Incompletely repaired congenital heart disease with residual defects adjacent to prosthetic material • Valvulopathy developing after cardiac transplantation
Antibiotic Regimens for Prophylaxis of Endocarditis in Adults with High-Risk Cardiac Lesionsa,b A. Standard oral regimen • 1. Amoxicillin 2.0 g PO 1 h before procedure B. Inability to take oral medication • 1. Ampicillin 2.0 g IV or IM within 1 h before procedure
C. Penicillin allergy • 1. Clarithromycin or azithromycin 500 mg PO 1 h before procedure • 2. Cephalexinc 2.0 g PO 1 h before procedure • 3. Clindamycin 600 mg PO 1 h before procedure D. Penicillin allergy, inability to take oral medication • 1. Cefazolinc or ceftriaxonec 1.0 g IV or IM 30 min before procedure • 2. Clindamycin 600 mg IV or IM 1 h before procedure