Condition- Infective endocarditis

Question 1

What is infective endocarditis?

Answer 1

An infection involveing the endocardial surface of the heart including the valves, the chordae tendineae, sites of septal defects or the mural endocardium

Question 2

List 3 common organisms causing infective endocarditis…

Answer 2

• Streptococcus (40%)- mainly a-haemolytic S.viridance and S.bovis
• Staphylococcus (35%)- S. Aureus and S. Epidermis
• Enterococcus (20%)- Usually E.faecalis

NOTE: Staph aureus is now the most common cause of infective endocarditis

Question 3

Vegetations form when organisms deposit on heart valves. What do these vegetations comprise of?

Answer 3

• Platelets
• Fibrin
• Infective organisms colonise the thrombus

Question 4

List some risk factors for developing infective endocarditis

Answer 4

• Abnormal Valves (congenital, calcification, rheumatic heart disease)
• Prosthetic heart valves
• Turbulent blood flow (PDA)
• Recent dental work/ poor dental hygiene
• IV injections

Question 5

Fever + New murmur =

Answer 5

Endocarditis unless proven otherwise

Question 6

List some of the presenting symptoms of infective endocarditis (+mnemonic)

Answer 6

Severe Cardiac Affliction Makes Many Feverish

Skin lesions
Confusion
Arthralgia
Myalgia
Malaise
Fever, sweats, weight loss (FLAWS)

• FLAWS
  
  • Fever + sweats/ chills/ rigors
  • Lethargy
  • Weight Loss
  • Sweats

Question 7

List some of the signs of infective endocarditis on physical examination (+mnemonic)

Answer 7

Numerous Signs Can Point To Valve Sickness
New regurgitant murmur
Splenomegaly
Clubbing
Pyrexia
Tachycardia
Vascular lesions (Osler’s nodes. Janeway lesions, roth spots, splinter haemorrhages)
Signs of arrhythmia

• Petechiae on pharyngeal and conjunctival mucosa
• Glomerulonephritis

FROM JANE C

Fever

Roth Spots

Osler’s nodes

Murmur

Janeway Lesions

Anaemia

Nail – splinter hemorrhages

Emboli

Clubbing

Question 8

Which sign might you see on a retinal examinaion of a patient with infective endocarditis?

Answer 8

ROTH SPOTS

Question 9

What might you see in an FBC of someone with IE

Answer 9

ACD (normocytic anaemia)

Neutrophilia

Question 10

List some appropriate investigations for a patient presenting with infective endocarditis

Answer 10

• BLOODS: WCC, normocytic anaemia, ESR/CRP, U&Es, Blood culture
• IMAGING: Echocardiogram, ECG, CXR
• URINALYSIS: haematuria, proteinuria

Question 11

What might you see on an ECG of a patient with Infective Endocarditis?

Answer 11

Long P-R interval

Question 12

Which system is used to classify the severity of Infective Endocarditis

Answer 12

Duke’s Criteria

Question 13

State how Duke’s criteria is used to classify Infective endocarditis

Answer 13

MAJOR:

• +ve blood culture for IE from 2 seperate blood cultures
• persistent bacteraemia from 2 blood cultures taken >12hrs apart

MINOR:

• Predisposing heart condition/ IVD use
• Pyrexia >38^oC
• Vascular events (emboli, infarcts, aneurysms, haemorrhages, Janeway lesions)
• Immunological phenomenon (glomerulonephritis, osler’s nodes, roth spots, rheumatoid factors)
• Micro evidence: +ve cultures which don’t meet major criteria
• Echo: consistent with IE

Question 14

How many of the Duke’s criteria need to be fulfilled to conclude the diagnosis of IE?

Answer 14

• 2 major
• 1 major and 3 minor
• 5 minor

Question 15

What is the first line therapy for someone with IE and their own native valve?

Answer 15

Beta-lactam (benzylpencillin/amoxicillin) +/- gentamicin

Question 16

What is the first line therapy for someone with IE and a prosthetic valve?

Answer 16

• vancomycin + rifampicin + low-dose gentamicin

Question 17

List some complications of IE

Answer 17

• valve incompetence
• Intracardiac fistulae/ abscesses
• Stroke (ischaemic + haemorrhagic)
• Aneurysm
• Heart failure
• Renal failure
• Glomerulonephritis