Infective endocarditis Flashcards
Clinical features most common for subacute endocarditis (4)
- Slower onset
- Fever, malaise, fatigue, loss of weight
- Clubbing — symptom of chronic suppurative condition
- Murmurs
What are the most common sites of valve damage in subacute endocarditis?
Mitral and aortic valve commonest
Intracardiac factors that can show risk for endocarditis are? (6)
- Chronic RHD
- Congenital cardiac abnormalities
- MV prolapse
- Degenerative calcific stenosis
- Bicuspid AV
- Prosthetic valves + indwelling catheters
What are some of the host factor’s contributory conditions for endocarditis? (4)
- Immunodeficiency
- Neutropaenias (abnormally low levels of neutrophils)
- Malignancy
- Diabetes mellitus
What are the major clinical findings for endocarditis? (3) duke
- Positive blood culture indicating characteristic organism or persistence of unusual org.
- ECG — valve- or implant-related mass or abscess, partial separation of artificial valve
- New valvular regurgitation
Staph aureus is most likely to cause which type of endocarditis?
Acute endocarditis
Clinical features most common for acute endocarditis? (3)
- Rapid onset, fever, rigors, malaise
- Chest pain, dyspnoea, rapid fatigue
- Sudden death
Describe acute endocarditis (virulence, vegetation)
- Highly virulent i.e.staph aureus (ATTACK NORMAL VALVES)
- Vegetations are at the line of valve closure
- Easily dislodgable vegetation
- Fulminating (pt can die withing 6 weeks if not treated)
Origin of infection in endocarditis (7)
- Trivial injuries
- Poor dental hygiene
- Recent surgery or non-surgical invasive procedure
- IV drug use
- Localised suppurative inflammation
- Systemic sepsis
- Long-term haemodialysis
Using the duke criteria, what is the clinical criteria for endocarditis?
- 2 major findings
- 1 major + 3 minor findings
- 5 minor findings
Regurgitation with regards to valvular disease means?
Failure to close sufficiently, allows reversed flow = volume overload
Which population is most at risk for acute endocarditis (3)
- IV drug users
- Pt with intracardiac catheters ( risk for right sided endocarditis)
- Older pts
Complications of infective Endocarditis (6)
- Systemic embolisation
- Septicaemia
- Brain abscesses, splenic or renal infection — septic infarcts - Right sige — pulmonary septic infarcts
- Ring abscess — erodes into underlying myocardium
- Valve cord/rupture
- Immune complex formation — leads to glomerulonephritis
Stenosis with regards to valvular disease means?
Failure to open sufficiently, impedes forward flow = pressure overload
Once diagnosis of infective endocarditis is considered what are the 2 essential investigations? (3)
- Echocardiogrpahy (transthoracic or transoesophageal)
- Blood cultures — 3 in 24 hour period (multiple daily)
Sources of low virulence organisms that could cause subacute endocarditis? (5)
- Teeth
- Gums (Streptococcus viridans variety)
- Urinary tract
- Skin
- Lungs
What are some minor clinical findings for endocarditis? (6)
- Predisposing heart lesion or IV drug use
- Fever
- Vascular lesions — petechiae, splinter haemorrhages
Osler’s nodes, Roth spots, septic infarcts, Janeway lesions - Immunologic phenomena — glomerulonephritis, splinter haemorrhages
Osler’s nodes, Roth spots - Single culture showing uncharacteristic organism
- ECG findings consistent with but not diagnostic of endocarditis — incl. new valvular regurgitation and pericarditis
Most common charactersistics for hosts of subacute endocarditis (3)
- Immunodeficient patients
-
Abnormal valves -> prior damage by non-infective
endocarditis (RHD in 50%), floppy valves, prosthetic
valves - Congenitally abnormal hearts ® VSD, PDA in 20%
Describe subacute endocarditis (4)
- Involves organisms of low virulence organisms i.e. strep viridans
- Can affect people or any age group
- Usually occurs on incompetent MV
- Lasts 6-12 weeks
List the anatomical findings associated with infective endocarditis
- Friable, bulky vegetations
- Fibrin, platelets and organisms
- Destruction of cardiac tissue
- Single or multiple valves affected –
- Mitral and aortic commonest
- Fungal IE results in larger vegetations
Which classification of endocarditis as opposed to the other?
Acute endocarditis is highly destructive with high mortality
