4. Epidemiology
Annual incidence in the UK is 6-7 per 100,000.
It is more common in developing countries.
Without treatment, mortality approaches 100%
and even with treatment there is significant morbidity
and mortality.
5. Pathophysiology
Normally due to two factors:
Microorganisms in the bloodstream
Abnormal cardiac epithelium (facilitating their
adherence / growth)
6. Pathogenesis
Bacteria are delivered to the heart during an
episode of bacteraemia.
E.g. tooth brushing, post-surgery.
The organisms adhere to, and invade, the valve.
Endocardium is very resistant to infection.
Therefore, either there is an abnormality of
the endocardium or the organisms are highly
pathogenic.
7. Pathogenesis
Multiplication of the bacteria.
As the bacteria replicate, they become
tangled within layers of platelets and fibrin.
These protect them from host defences.
Bulky masses called vegetations form.
These destroy the underlying valve.
Due to valvular softening caused by release
of enzymes from activated neutrophils.
10. Clinical features
Skin lesions (lol derm):
Osler’s nodes (painful, red, raised lesions
found on the hands and feet)
Splinter haemorrhages
Janeway lesions (non-tender, haemorrhagic
macular or nodular lesions on the palms or
soles)
Petechiae
14. Treatment
Antibiotic therapy
Based on blood culture
Usually intravenous, usually in combination
4-6 weeks
Surgery (some cases)
Remove and replace infected valve
