Infective Endocarditis Flashcards
Definition
Endovascular infection of:
- any part of the heart (native valves, atria or ventricles)
- large intrathoracic vessels (eg in PDA)
- foreign bodies within the heart eg prosthetic valves, PPM
Diagnosis
Duke criteria
Needs with 2 major, 1 major and 3 minor, or 5 minor
Major criterion
- 2 positive blood cultures typical of IE (eg strep viridins, strep Bovis, HACEK (haemophilus) organisms, community staph aureus or enterococcus without obvious source.
Or - microorganism consistent with IE with persistently positive blood cultures (2 samples >12 hours apart or all of 3 or majority of 4 separate cultures, the first and last being at least 1 hour apart)
- evidence of endocarditis involvement: either vegetation (must be independently mobile mass on echo), intracardiac abscess or new dehiscence of a prosthetic valve or new valvular regurgitation
Minor criterion
- serological evidence if active infection with an irganusm consistent with IE or positive blood cultures not reaching major criterion
- vascular embolic phenomena (arterial, septic pulmonary or intracranial emboli, splinter haemorrhages, Conjunctival haemorrhage, janeway lesions
- immunologic phenomena (Roth spots, oslers nodes, GN, positive RF
- fever
- predisposing heart condition or IV drug use
- echo findings suggestive but don’t meet major criterion
ESC classification of Disease activity
- active
- healed (definite prior diagnosis but now sterile)
- peristent
- recurrent (difficult to distinguish from persistent but worse diagnosis)
ESC classification of Certainty of Diagnosis
- Definite (meets dukes criteria)
- Suspected (strongly suspected with evidence of infection but endocarditis involvement not established
- Possible
ESC classification of type of valve involvement
- native valve
- prosthetic valve
- IVDU
ESC culture status
- culture positive
- culture negative (diagnosis made but BC’s negative)
Population type
Neonates Children Elderly Congenital heart disease Nosocomial
ESC classifications of IE
- Disease activity
- active
- healed
- persistent
- recurrent - Certainty of diagnosis
- definite
- suspected
- possible - Culture status
- positive
- negative - Side of heart
- left or right - Site
- native
- prosthetic
- IVDU - Population
Signs
Those due to infection itself:
- fever
- new/change in murmur
- heart failure due to regurgitation
Due to immune complex formation and dissemination
- Roth spots
- oslers nodes (tender so ask or if tender)
- micro haematuria or proteinuria (GN)
Due to vascular embolism
- splinter haemorrhages (check toenails also)
- janeway lesions
- conjunctival haemorrhage (get them to look up and down)
- signs of mycotic aneurysm presence/rupture
Investigations
- Blood cultures (at least 2 sets before abx started)
- TTE
- TOE if TTE negative (especially important if prosthetic valve) or to examine for extent of damage from infection (valve perf or aortic root abscess formation)
- if aortic valve involve needs ECH at least every 2 days as if PR increasing suggests root abscess implying requirement of early surgery
Management
Blood cultures (ideally at least 2 before starting abx)
TTE
TOE if above negative, rap if prosthetic valves or to assess valve perforation/ aortic root abscess
ECG at least alt days if aortic valve involvement. If PR prolonging suggests root abscess implying early surgery
Complications of IE
- Direct tissue destruction
- acute or subacute valve failure
- extravalvular involvement such as aortic root abscess which can cause heart block or septic pericarditis - Septic emboli with lung, brain and splenic abscesses with formation and possible rupture of mycotic aneurysms
- Renal failure (GN due to immune complex formation)
Indications
Debatable but uncontrolled infection, haemodynamic instability due to heart failure or worsening heart block are indications
Some would argue renal failure and prosthetic valve involvement to be indications.
If surgery is required, the sooner it is performed the better the outcome
