Infective Endocarditis (IE) is a microbial infection of the endocardium (heart’s inner lining), usually affecting heart valves.
Characteristic Lesion: Vegetation → Mass of platelets, fibrin, bacteria, and inflammatory cells.
Mnemonic: "IE = Infection of Endocardium"
TYPES OF
INFECTIVE ENDOCARDITIS
1. Acute
Infective Endocarditis (AIE)
• Rapid & Severe (Few Days).
• Caused by Staphylococcus aureus (High Virulence).
• Common in Healthy Valves (IV Drug Users).
2. Subacute
Bacterial Endocarditis (SBE)
• Slow & Milder (Weeks to Months).
• Caused by Streptococcus viridans (Low Virulence).
• Affects Diseased or Prosthetic Valves.
Mnemonic: "A = Aggressive (Acute), S = Slow (Subacute)"
RISK FACTORS OF
INFECTIVE ENDOCARDITIS
• Valvular Heart Disease (RHD, MVP, Prosthetic Valves).
• Congenital Heart Disease (VSD, PDA).
• IV Drug Abuse (Affects Right Heart – Tricuspid Valve).
• Immunosuppression (HIV, Diabetes, Cancer).
• Prosthetic Heart Valves (After Surgery).
Mnemonic: "V.I.P.I.P." (Valves, IV Drug Use, Prosthetic, Immunosuppression, Prosthetic Surgery)
PATHOGENESIS OF
INFECTIVE ENDOCARDITIS
1. Endocardial
Damage (From Turbulent Blood Flow or Injury).
2. Platelet-Fibrin
Deposition (Forms Sterile Vegetation).
3. Microbial
Entry (Via Blood – Dental, Surgery, IV Drug Use).
4. Infected
Vegetation (Bacteria Grow, Cause Damage & Embolization).
Mnemonic: "D.P.M.V." (Damage → Platelets → Microbes → Vegetation)
SYMPTOMS OF
INFECTIVE ENDOCARDITIS
• Fever (Most Common Symptom – Night Sweats, Chills).
• Weight Loss, Fatigue.
• Heart Murmur (New or Changing).
• Signs of Embolization (Stroke, Limb Ischemia, Lung Abscess).
Mnemonic: "F.W.H.E." (Fever, Weight Loss, Heart Murmur, Embolization)
SPECIFIC SIGNS OF
INFECTIVE ENDOCARDITIS
• Osler’s Nodes → Painful, Red Nodules on
Fingers/Toes (Immune Complexes).
• Janeway Lesions → Non-Painful Red Spots on
Palms/Soles (Embolic).
• Splinter Hemorrhages → Dark Red Streaks in Nail
Beds.
• Roth Spots → Retinal Hemorrhages with White Center.
• Clubbing (Seen in Chronic Cases).
Mnemonic: "O.J.S.R.C." (Osler, Janeway, Splinter, Roth, Clubbing)
DIAGNOSIS OF
INFECTIVE ENDOCARDITIS
- Blood Culture (Gold Standard – 3 to 6 Samples Before Antibiotics).
- Echocardiography (Best Test – Detects Vegetations).
- Duke’s Criteria (For Confirming IE Diagnosis).
- Blood Tests → High ESR, CRP, Anemia.
Mnemonic: "B.E.D." (Blood Culture, Echo, Duke’s Criteria)
DUKE’S CRITERIA
(For Diagnosis of IE)
Major Criteria:
1. Blood
Culture Positive (For Typical IE Organisms).
2. Echo Shows
Vegetation (Or New Valve Regurgitation).
Minor Criteria:
• Fever >38°C.
• Predisposing Heart Condition (RHD, IV Drug Use).
• Vascular Signs (Janeway Lesions, Stroke, Splinter Hemorrhages).
• Immunologic Signs (Osler’s Nodes, Roth Spots).
Mnemonic: "B.E.F.V.I." (Blood, Echo, Fever, Vascular, Immune)
Diagnosis:
• Definite IE = 2 Major OR 1 Major + 3 Minor OR 5 Minor Criteria.
COMPLICATIONS OF
INFECTIVE ENDOCARDITIS
• Heart Failure (Valve Destruction).
• Embolization (Stroke, Organ Infarcts).
• Mycotic Aneurysm (Infected Arterial Wall → Rupture).
• Kidney Damage (Glomerulonephritis).
Mnemonic: "H.E.M.K." (Heart Failure, Embolization, Mycotic Aneurysm, Kidney Failure)
TREATMENT OF
INFECTIVE ENDOCARDITIS
1. MEDICAL
MANAGEMENT
High-Dose IV Antibiotics (4-6 Weeks).
Empirical Therapy (Before Culture Reports):
• Vancomycin + Gentamicin (Covers Most Organisms).
• Modify Based on Blood Culture Reports.
Mnemonic: "A.L.E." (Antibiotics, Long Duration, Echo Follow-Up)
2. SURGICAL
MANAGEMENT (If Indicated)
• Valve Replacement (For Severe Valve Damage or Heart Failure).
• Abscess Drainage (If Present).
Mnemonic: "V.A." (Valve Surgery, Abscess Drainage)
PROPHYLAXIS FOR
INFECTIVE ENDOCARDITIS
Who Needs Prophylaxis?
• Patients with Prosthetic Heart Valves, Congenital Heart Disease,
History of IE.
• Before Dental or Surgical Procedures (Causing Bacteremia).
Antibiotics for Prophylaxis:
• Amoxicillin (Or Clindamycin if Allergic) 1 Hour Before Procedure.
Mnemonic: "P.A.D." (Prosthetic, At-Risk, Dental Procedures)
FINAL REVISION WITH MNEMONICS
- Types of IE = "A = Aggressive (Acute), S = Slow (Subacute)"
- Risk Factors = "V.I.P.I.P." (Valves, IV Drug Use, Prosthetic, Immunosuppression, Prosthetic Surgery)
- Pathogenesis = "D.P.M.V." (Damage → Platelets → Microbes → Vegetation)
- Symptoms = "F.W.H.E." (Fever, Weight Loss, Heart Murmur, Embolization)
- Signs = "O.J.S.R.C." (Osler, Janeway, Splinter, Roth, Clubbing)
- Diagnosis = "B.E.D." (Blood Culture, Echo, Duke’s Criteria)
- Duke’s Criteria = "B.E.F.V.I." (Blood, Echo, Fever, Vascular, Immune)
- Complications = "H.E.M.K." (Heart Failure, Embolization, Mycotic Aneurysm, Kidney Failure)
- Treatment = "A.L.E." (Antibiotics, Long Duration, Echo Follow-Up) & "V.A." (Valve Surgery, Abscess Drainage)
- Prophylaxis = "P.A.D." (Prosthetic, At-Risk, Dental Procedures)
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