Cardiovascular Infections

Question 1

What are the causes of infective endocarditis?

What valves are most commonly affected?

Answer 1

Staph aureus ** most common **
Strep viridans

The mitral and aortic valves

Question 2

What are the clinical signs of infective endocarditis?

Answer 2

Fever
New murmur
Immunological signs: splinter haemorrhages, Janeway lesions, Oslers nodes, Roth spots
Constitutional symptoms
n.b. may present with systemic embolisation e.g. PE or stroke

Question 3

What are the initial investigations for suspected infective endocarditis?

Answer 3

Use the Duke criteria for diagnosis
3 sets of blood cultures at different times and sites from the peak of fever (reduce risk of false positive from cross-contamination)
Urinalysis
Twice weekly ECG - looking for AV block
Echo looking for vegetations

Question 4

Outline the Duke criteria for a diagnosis of infective endocarditis

Answer 4

2 major/ 1 major and 3 minor/ 5 minor
Major: 2 x positive blood culture for typical organisms or evidence of endocardial involvement on ECHO
Minor: predisposition, fever >38, vascular/immunological signs, positive blood culture (but not major), positive echo (but not major)

Question 5

What are the risk factors for infective endocarditis?

Answer 5

Structural congenital heart disease
Valve replacement
Previous endocarditis
IVDU
Recent/current vascular access
Recent dental work

Question 6

What are the complications of infective endocarditis?

Answer 6

Acute heart failure
Systemic embolisation including stroke
AKI
Conduction defects

Question 7

What are the differences between Janeway lesions and Osler’s nodes?

Answer 7

Janeway: painless papules palms
Oslers: ouch painful, nodules, fingers and toes