Infective Endocarditis

Question 1

Define Infective Endocarditis

Answer 1

Infection involving the endocardial surface of the heart (valves, chordae tendinae, endocardium)

Clinically = fever + new murmur

Question 2

Aetiology of Infective Endocarditis

Answer 2

Native valve + most common = Strep. Viridans

Prosthetic valves = coagulase -ve staph e.g. S. epidermis

IVDU = S. aureus (R-sided more likely)

Others: HACEK, fungi, SLE, malignancy

Question 3

Risk factors for Infective Endocarditis

Answer 3

History of IE
Prosthetic valves
Congenital heart disease
Post-heart transplant 
Mitral valve prolapse
Hypertrophic cardiomyopathy 
IVDU 
Coarctation
Skin breaches, renal failure, immunosuppression, DM

Question 4

Symptoms of Infective Endocarditis

Answer 4

Subacute:
Fever
Night sweats, malaise, fatigue, anorexia/weight loss, myalgia

Acute:
HF: SOB, orthopnoea, PND
Septic emboli: chest pain, arthralgia, stroke symptoms (weakness)
Anaemia

Question 5

Signs of Infective Endocarditis

Answer 5

Anaemia
Clubbing
Splinter haemorrhages
Janeway lesions
Oslers nodes 
Roth's spots off fundoscopy 
New cardiac murmur 
Vasculitis (haematuria, glomerulonephritis, AKI)

Question 6

What is the criteria for Infective Endocarditis

Answer 6

Duke’s modified criteria
2 major OR 1 major 3 minor OR 5 minor

Major
2 +ve cultures
+echo with specific features

Minor 
Predisposition (heart condition, IVDU)
Fever 
Vascular phenomena 
Immunological phenomena
MIcro +ve cultures not meeting major
Echo +ve but not meeting criteria

Question 7

Investigations for Infective Endocarditis

Answer 7

Blood cultures (3x from different sites) - +ve for cause
TTE (echo) - positive for IE, vegetations, oscillating structure, abscess formation, new valvular regurg

FBC - leucocytosis (neutrophilic), normocytic anaemia
Raised ESR/CRP
LFTs - may show evidence of septic emboli
CXR - cardiomegaly, pulmonary oedema

Question 8

Management for Infective Endocarditis

Answer 8

Empirical broad spectrum antibiotics 4-6 weeks

Native valve: amoxicillin ± gentamicin
Penicillin allergic/MRSA/sepsis: vancomycin + rifampicin + gentamicin

Prosthetics: Flucloxacillin + rifampicin + gentamicin

S. aureus: Flucloxacillin

Question 9

When is surgery indicated by Infective Endocarditis

Answer 9

Haemodynamically instable
Abscess
Recurrent emboli 
Prosthetic valves
Fungal endocarditis 
Severe valvular incompetence
Antibiotic resistance

Question 10

Complications of Infective Endocarditis

Answer 10

Congestive HF 
Embolisation
Mitral valve vegetation
Valvular dehiscence, rupture, fistula
Splenic abscess

Question 11

Prognosis for Infective Endocarditis

Answer 11

Mortality 5-50%
50% require surgery
20% in-hospital mortality
15% recurrence in 2 years