Endocarditis Flashcards
Define Infective Endocarditis?
Infection of the heart material. Can include endocaridum/valves/septa/chordae tendinae/intra-cardiac devices
What is non-infective Endocarditis and what causes it?
Non-Bacterial Thrombotic Endocarditis
The formation of a sterile Fibrin-platelet vegetation due to some disruption of the valve endothelium.
Turbulent Flow - Electrodes/Catheters - Rheumatic Carditis - Degenerative Disease - Local inflammation (~25% of cases)
How do we classify cases of endocarditis
Acute/Subacute/Chronic pattern
Also which side theyre on, what structure, if a valve is it native or prosthetic, if prosthetic is it early or late? (<1yr or >1yr)
How can Infective endocarditis be acquired?
- Via IVDA
- Community Acquired
- Nosocomial
- Healthcare Related but Non-Nosocomial
How do the IE organisms reach the circulation?
From:
Extra Cardiac Infection - Invasive Procedures - Gingival Disease - Daily livinig (e.g. brushing teeth & defecating)
What are the risk factors for IE?
Male (though women have worse prognosis Elderly Invasive Procedures recently IVDA Prosthetic Valves Any Heart Defect/Disease Diabetes AIDS Burns Immunocompromised
What are the symptoms of IE?
FEVER - MALAISE - FATIGUE
also chills - arthralgia - weight loss - headache
What are the clinical signs of IE?
General:
Pyrexia - CHF - New Murmur - Splenomegaly - Emboli - Anaemia
Vascular: Janeway Lesions (blood seeped into palms/soles) Splinter Haemorrhages Vasculitic Rash (feet, purple/red spots from burst capillaries)
Immunological:
Roth Spots (Retinal Haemorrhage)
Osler’s Nodes (Red raised painful spots of fingers, palms & soles)
Nephritis
When could the clinical signs be absent from IE?
In the elderly, immunocompromised or post antibiotic treatment
What does the mnemonic FROM JANE stand for?
Fever - Roth Spots - Oslers Nodes - Malaise - Janeway Lesions - Anaemia - Nephritis & Nail haemorrhages - Emboli
What details about a patient would give a high suspicion of IE?
Any of:
Unexplained fever - New Murmur - Known IE causin organism detected - New conduction disorder.
Also we suspect anyone with Prosthetic valves - Previous IE - CHD - New conduction Disorder - IVDA - Immunocompromised
What investigations are done on a suspected IE case?
FBC(neutrophilia)/CRP/ESR U + Es Blood Cultures Urinalysis ECG CXR ECHO
What are we lookin for with a FBC, CRP & ESR>
Any markers of infection/inflammation.
E.g. neutrophilia, a high CRP and high ESR
What are we looking for in the Urea + Electrolytes?
Analyse kidney function for nephritis & sepsis
What are we looking for in urinalysis?
Blood
What are we looking for an ECG?
A conduction delay caused by IE forming an abscess over part of the bundle of his or purkinje fibres.
Wide QRS
What shows up on a CXR in IE?
Heart Failure and Pulmonary Abscesses
What kind of ECHO do we use for Infective Endocarditis?
A Trans-Thoracic Echo (TTE) is 1st line
TOE is used if TTE is -ve but your still suspicious OR if TTE is +ve for a better view of abscess/vegetation/complications
What do we do if both TTE & TOE are -ve but were still suspicious of IE?
Repeat them 7-10 days later or earlier if theres a new complication
How many blood cultures do we take for IE?
3 from different sites with 6 hours between them.
Or if they’re in septic shock then just 2 from different sites with 1 hour between them.
Other than not having IE what else could cause -ve blood cultures?
Recent antibiotics
Fastidious Organisms have different diets so wont grow on blood culture (Nutritionally varied Strep - HACEK gram -ve bacilli - Brucella - Fungi)
Nor would Intracellular Bacteria (Coxiella Burnetii - Bartonella - Chlamydia)
What are the common complications of IE?
Heart Failure - Fistula Formation - Leaflet Perforation - Uncontrolled Infection - Abscess Formation - Atrioventricular Heart Block - Embolism - PVE & PV dysfunction
What criteria are needed to have a sure diagnosis of IE?
Either 2 Major, 1M & 3m or 5minor of the Modified Duke Criteria for a firm diagnosis
What are the Major Duke criteria?
- IE causing organisms in 2 seperate blood cultures
- IE organisms found in persistant blood cultures
- +ve blood culture for Coxiella Burnetii
- +ve ECHO
- New Murmur
