Infective endocarditis and rheumatic heart disease – presentation, investigation and therapy

Question 1

What are the predisposing factors for infective endocarditis (IE)?

Answer 1

📌 Prosthetic heart valves
📌 Congenital heart disease
📌 Previous endocarditis
📌 Intravenous drug use (IVDU)
📌 Poor dental hygiene/dental procedures
📌 Immunosuppression

Question 2

What are the most common causative organisms of infective endocarditis?

Answer 2

💊 Native valve endocarditis:

Streptococcus viridans (oral flora)
Staphylococcus aureus (IVDU, acute IE)
Enterococcus (GI/GU infections)
💊 Prosthetic valve endocarditis:

Early (<60 days post-op): Staph epidermidis
Late (>60 days post-op): Strep viridans, Staph aureus
💊 Culture-negative IE:

HACEK organisms: Haemophilus, Aggregatibacter, Cardiobacterium, Eikenella, Kingella

Question 3

What are the clinical features of infective endocarditis?

Answer 3

🔹 “FROM JANE” mnemonic:

Fever
Roth spots (retinal haemorrhages)
Osler’s nodes (painful nodules on fingers/toes)
Murmur (new or changing)
Janeway lesions (painless on palms/soles)
Anaemia
Nail-bed splinter haemorrhages
Embolic phenomena

Question 4

What are the Modified Duke’s Criteria for infective endocarditis?

Answer 4

✅ Major criteria:
1️⃣ Positive blood cultures (typical IE organisms, persistent bacteremia)
2️⃣ Echocardiographic evidence (vegetation, abscess, prosthetic valve dehiscence)

✅ Minor criteria:
1️⃣ Predisposing condition
2️⃣ Fever >38°C
3️⃣ Vascular phenomena (emboli, Janeway lesions)
4️⃣ Immunological phenomena (Osler’s nodes, Roth spots, GN)
5️⃣ Positive blood cultures (not meeting major criteria)

🔹 Definitive IE: 2 major / 1 major + 3 minor / 5 minor
🔹 Possible IE: 1 major + 1 minor / 3 minor

Question 5

What are the first-line investigations for infective endocarditis?

Answer 5

🩸 Blood cultures (before antibiotics, 3 sets from different sites)
🩻 Echocardiography (TTE first, TOE if high suspicion)
📊 FBC, CRP, ESR (raised inflammatory markers)
🩺 Urinalysis (microscopic haematuria)
📌 ECG (conduction abnormalities if abscess formation)

Question 6

What is the management of infective endocarditis?

Answer 6

💊 Empirical IV antibiotics:

Native valve, non-IVDU: Amoxicillin + Gentamicin
IVDU / MRSA risk: Vancomycin + Gentamicin
Prosthetic valve: Vancomycin + Gentamicin + Rifampicin
🩺 Surgical indications:
🔹 Severe heart failure
🔹 Large vegetation (>10mm) with embolism
🔹 Uncontrolled infection (abscess, persistent fever)

Question 7

What is rheumatic heart disease (RHD)?

Answer 7

🔹 Chronic sequelae of rheumatic fever
🔹 Immune-mediated response to Group A Strep (Streptococcus pyogenes)
🔹 Causes valve damage, mainly mitral stenosis

Question 8

What are the Jones Criteria for diagnosing acute rheumatic fever?

Answer 8

✅ Major criteria (“J❤️NES”)

Joints (migratory polyarthritis)
❤️ Carditis (pancarditis)
Nodules (subcutaneous)
Erythema marginatum
Sydenham’s chorea
✅ Minor criteria:

Fever
↑ ESR/CRP
Arthralgia
Prolonged PR interval
🔹 Diagnosis: 2 major OR 1 major + 2 minor + evidence of recent GAS infection

Question 9

What are the long-term effects of rheumatic heart disease?

Answer 9

🔹 Mitral stenosis (most common)
🔹 Aortic stenosis or regurgitation
🔹 Heart failure
🔹 Atrial fibrillation (due to left atrial enlargement)

Question 10

What investigations are done for rheumatic heart disease?

Answer 10

📌 Throat swab (Group A Strep)
📌 ASO titre (Anti-Streptolysin O antibodies)
📌 Echocardiography (valvular disease)
📌 ECG (prolonged PR, AF)

Question 11

How is rheumatic heart disease managed?

Answer 11

💊 Acute rheumatic fever:

Benzylpenicillin (eradicate GAS)
Aspirin / NSAIDs (reduce inflammation)
Corticosteroids (severe carditis)
💊 Secondary prevention:

Long-term penicillin prophylaxis
Monitor for valve disease (echocardiography)

Question 12

Mnemonic for Infective Endocarditis & RHD

Answer 12

📌 “FROM JANE loves J❤️NES”

FROM JANE → Clinical features of IE
J❤️NES → Major criteria for rheumatic fever