INFECTIVE ENDOCARDITIS
Dr. Muayad AL-QaisyInfective Endocarditis
A microbial infection of the endothelial surface of the heart or valves Usually is near congenital or acquired cardiac defects Designated by the causative organism Also classified as NVE or PVEAcute IE
Infection of previously normal heart valve by a highly virulent organism that produces necrotising, ulcerative, destructive lesions Difficult to cure with Abx & usually require Sx Death can occur within days to weeks despite RxSubcute IE
Organisms are usually of lower virulence Cause insidious infections of deformed (native) valves that are less destructive Can take prolonged course: weeks to months More amenable to treatment with antibioticsClinical Features
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 EmpyemaPNEUMATOCELE
Epidemiology
Incidence <1% Of General PopulationEpidemiology
Population Groups At Greater Risk: Rheumatic Fever History Hemodialysis Previous History Of Endocarditis Patients With Prosthetic Valves IV Drug Users (30% Risk Within 2 Years)Predisposing Conditions
Mitral valve prolapse Aortic valve disease Congenital heart disease Prosthetic valve Intravenous drug use No identifiable cause in 25-47%Epidemiology
More Common In MenMedian Age 50 YearsAcute Cases IncreasingStreptococcal Cases Slightly; Fungal And Gram Negative Cases IncreasingEpidemiology
Incidence Increases With Age, Probably Due To Increased Cardiac Disease And Decreased Immunity Prosthetic Heart Valve Infections Are IncreasingDentistry And Endocarditis
Streptococcus viridans: Usual Etiologic AgentUsually Is Not Acute (Subacute)(That Is Why It Is Referred To As “SBE”)Incubation Period Approximately Two Weeks
Epidemiology
Mitral Valve Prolapse: Only 1/4 Of MVP Patients Have Mitral Insufficiency (Regurgitation Or Murmur) - This Results In The Very Slight Increased Risk For EndocarditisMVP
Mitral valve prolapse accounts for 25-30% of adult cases of native valve endocarditis MVP is now the most common underlying condition among patients who develop infective endocarditis
Aortic Valve Disease
Accounts for 12-30% of IE cases3 Types Of Endocarditis Lesions
Cardiac Lesions Embolic Lesions: Friable Cardiac Lesions That Break Away General LesionsCardiac Lesions
Usually Valvular Most Often Mitral Valve May Cover The Entire Valve Mass Of Platelets, Fibrin And Bacteria Sterile Vegetations May Occur In 50% Of Lupus PatientsEmbolic Lesions
Osler’s Nodes: Are Small, Painful Petechiae In ExtremitiesJaneway Lesions
Pathognomonic of IE Non-tender dermal abscessesSplinter Hemorrhages
Late-appearing symptom in endocarditis These represent damage to capillaries May also appear due to nail traumaGeneral Lesions
Enlarged Spleen Arthritis Clubbing Of Fingers Cardiac Failure Conduction Abnormalities Stroke Renal FailureMortality
Overall Rate About 40% Death Usually Due To Heart Failure Resulting From Valve Dysfunction Highest Death Rate Is In Early Prosthetic Valve EndocarditisClassic Triad - But May Not Always Be Present
1.Fever2.Positive Blood Culture3.Heart MurmurSometimes Insidious Onset“Flu-Like” SymptomsLab Findings
+Culture In 95% Of BE Strep viridans Most Commonly Causes SBE Staph aureus Most Commonly Causes ABE Electrocardiography: Will Determine If Infection Progresses To Myocardium
Lab Findings
Echocardiography - As Important As A Positive Blood Culture Are Results Which Show Vegetations, Abscesses, Etc.Major Diagnostic Criteria
Positive Blood Culture Echocardiogram Findings Of Endocardial Involvement New Valvular RegurgitationMinor Diagnostic Criteria
Predisposing Heart Conditions IV Drug Use Vascular Emboli Osler Nodes Aneurysm Roth Spots Of The Eye Splinter HemorrhagesTreatment
Treat It Early! Culture Use Bactericidal Agents PCN G; Cefatriaxone; PCN G + Gentamicin; Nafcillin; VancomycinAntibiotics
Empirical treatment; flucloxacillin & gentamicin are the usual first line Vancomycin is used in pts with intracardiac prosthetic material or suspected MRSA Benzylpenicillin is the first choice for Streptococcus or Enterococcus penicillin-susceptible strains For vanc-resistant MRSA: teicoplanin, lipopeptide daptomycin or oxazilidones (linezolid) is recommendedTreatment
Use Adequate Dosage Parenteral Route Sufficient Duration: 4-6 Weeks Or LongerSurgery
Antimicrobial therapy can only offer curative treatment in ~50% The other 50% require surgery The surgical goal is valve repair but most require valve replacement Pts with IE + large vegetations, intracardiac abscess (9-14%) or persisting infection (9-11%) almost always require surgeryAntibiotic Prophylaxis
Regimen Designed For Alpha-hemolytic Strep (S. viridans) No Clinical Trials Available To Show This Works! (Actually Prevents BE In Humans) 25-50% Hospital Antibiotic Usage Is For Prophylaxis Effective For Patients With Prosthetic Valves And Previous Endocarditis HistoryAntibiotic Prophylaxis
Complications: Resistant Bacteria, Toxicity, Allergies, Suprainfections, Costs Will Not Prevent All CasesAmerican Heart Association Guidelines
Not Intended To Be A Standard Of CareNot A Substitute For Clinical JudgmentMust Be Considered If You Receive A Medical Opinion That Conflicts With The Guidelines (You Are Responsible For The Outcome Of Your Patient’s Dental Treatment)American Heart Association Guidelines
Can Still Develop Endocarditis Even When Using GuidelinesProphylaxis Myths
Most Cases Of BE Of Oral Origin Are Caused By Dental Procedures AHA Regimens Give Almost Total Protection Against Endocarditis After Dental Procedures