Infective Endocarditis - Presentation, Investigation & Therapy Flashcards
What is infective endocarditis?
Infection of the endocardium
What is infection of the endocardium called?
Infective endocarditis
What are the 3 layers of the heart?
Epicardium
Myocardium
Endocardium
In what layer are the valve structures?
Endocardium
In what layer are the chordae tendinae?
Endocardium
What is the mortality of infective endocarditis?
High (15-30%)
What is the prevalence of infective endocarditis?
3-10/100000
What is the male to female ratio of infective endocarditis?
Male to female 2:1
Does infective endocarditis affect more males or females?
Males
Is the prognosis of infective endocarditis worse in males or females?
Females
How is the team that treats infective endocarditis pretty unique?
It has its own team
What is the team that treats infective endocarditis called?
IE team
Who is in the IE team?
Cardiologist
Microbiologist
Cardiothoracic surgeon
Neurologist/neurosurgeons
Reference centre
What is the advantage of infective endocarditis having its own team?
Reduces mortality
Who are some typical people who present with infective endocarditis?
Older patients with degenerative heart disease
Healthcare
Intra cardiac devices (ICD)
Valve diseases
Prosthetic valves
Immunocompromised patients
What does ICD stand for?
Intra-cardiac devices
What are some diseases that lead to infective endocarditis?
Native valve infective endocarditis
Mitral valve prolapse
Congenital heart disease
What are examples of congenital conditions that can lead to infective endocarditis?
Ventricular septal defect
Bicuspid aortic valve
Patent ductus arteriosus
What are some risk factors for native valve infective endocarditis?
Mitral valve disease
Rheumatic heart disease
Congeital heart disease
Degenerative heart disease
Asymmetrical septal hypertrophy
Intravenous drug abusers
Alcoholic cirrhosis
Diabetic mellitus
Indwelling medical devices
What is the pathophysiology for infective endocarditis?
1) Normal valve endothelium is resistance to colonisation and infection
2) Mechanical endothelial disruption exposes extracellular matrix protein causing production of tissue factors
3) Deposition of fibrin and platelets causing nonbacterial thrombotic endocarditis
4) This facilitates bacterial adherence and infection
What is normal valve endothelium resistant to?
Colonisation and infection
What does a damaged endothelial valve lead to?
Turbulent blood flow
Electrodes
Catheters
Inflammation (rheumatic carditis)
Degenerative valve disease
As well as damaged endothelial valve, how may a normal valve lead to infective endocarditis?
Inflammation
What are the different ways a normal valve can lead to infective endocarditis?
Damaged endothelium
Inflammation
Bacteraemia
What is the process of a valve becoming inflammed and leading to infective endocarditis?
1) Inflammation of endothelial cell causes expression of integrins
2) Integrins are transmembrane proteins that bind to circulating fibronectin
3) Staph aureus (and other pathogens) carry fibronectin which binds to these surface proteins
4) Aherent organisms trigger active internalisation into valve endothelial cells
What are integrins?
Transmembranous proteins that bind to circulating fibronectin
What is bacteraemia?
Bacteria in the blood
What is bacteria in the blood called?
Bacteraemia
What does bacteraemia occur due to?
Invasive procedures
Extra-cardiac infections
Non-invasive activites
What are some examples of invasive procedures that can lead to bacteraemia?
Dental procedures
GU and GI surgery
Intravascular catheters
What are some examples of non-invasive activities that can lead to bacteraemia?
Chewing
Tooth brushing
What are some examples of organisms that can cause infective endocarditis?
Virdans group streptococci
Staphylococcus aureus
Enterococci
Coagulase negative staphylococci
Fungi
What are the different classifications of infective endocarditis?
Acute (days/week) to subacute (weeks to months)
Nidus (localisation) of infection with/without intra-cardiac material
Mode of acquisition (IVDU, healthcare or community)
Acute infective endocarditis
Recurrent (relapse or reinfection)
How is infective endocarditis not a constant disease?
Syndrome diagnosis determined by presence of multiple findings
Presence or absence of pre-existing cardiac disease
Different causative organisms
Presence or absence of complication
Underlying patient characteristics
What is seen for the diagnosis of infective endocarditis?
High index of suspicion needed given variable presentation
Bacteraemia with audible murmur should raise suspicion
Classic new or worsening cardiac murmur is rare
Atypical presentation in elderly or immunocompromised
Acutely or subacutely
What is the presentation of infective endocarditis like in the elderly and immunocompromised?
Atypical
What are some common symptoms of infective endocarditis?
Fever
Nigh sweats
Malaise
Fatigue
Anorexia
Weight loss
Weakness
Arthralgia
Headache
Shortness of breath
What are some clinical signs of infective endocarditis?
Cardiac murmur
Janeway lesions
Osler nodes
Roth spot
Splinter haemorrhage
What are janeway lesions?
Haemorrhagic, macular, painless plaques with predilection for palms and soles
What are haemorrhagic, macular, painless plaques with predilection for palms and soles called?
Janeway lesions
What are osler nodes?
Small, painful nodular lesion found on pads of fingers or toes
What are small, painful nodular lesion found on pads of fingers or toes?
Osler nodes
What is a splinter haemorrhage?
Tiny blood clots that run vertically under the nails
What are tiny blood clots that run vertically under the nails?
Splinter haemorrhage
What investigations are done for infective endocarditis?
Blood culture
Blood tests
Urinalysis
ECG
Chest X-ray
Echocardiogram
Why is a blood test done for infective endocarditis?
Look for elevated acute inflammatory markers
Why is urinalysis done for infective endocarditis?
Test for blood
Why is a chest X-ray done for infective endocarditis?
Look for pulmonary congestion or abscess
What is the major criteria for the diagnosis to be infective endocarditis?
Blood culture positive (typical microorganism with 2 blood cultures)
Image positive
What is minor criteria for the diagnosis to be infective endocarditis?
Predisposition such as previous heart condition or injection drug use
Fever (temperature > 38)
Vascular phenomena
Immunological phenomena
Microbiological evidence (does not meet major criteria)
What criteria is required for the diagnosis of infective endocarditis to be definite?
2 major
1 major and 3 minor
5 minor
What criteria is required for the diagnosis of infective endocarditis to be possible?
1 major and 1 minor
3 minor
What criteria is required for the diagnosis of infective endocarditis to be rejected?
Resolution of endocarditis syndrome with antibiotic therapy for less than or 4 days
When should IV antibiotics be initiated for infective endocarditis?
3 sets of blood cultures (taken 30 mins apart) are positive
What is the treatment of infective endocarditis?
IV antibiotics
When does the type of antibiotics used for infective endocarditis change?
Depends on the classification of infective endocarditis
What are examples of different classifications of infective endocarditis?
Community acquired infective endocarditis
Early PVE (<12 months post surgery) infective endocarditis
Healthcare associated infective endocarditis
What antibiotics are used for community acquired infective endocarditis?
Ampicillin with flucloxacillin with gentamycin
What antibiotics are used for community acquired infective endocarditis for people allergic to penicillin?
Vancomycin with gentamycin
What antibiotics are used for early PVE and healthcare infective endocarditis?
Vancomycin with gentamycin with rifampin
What are predictors of a poor prognosis?
Older age
Prosthetic valve infective endocarditis
Complications such as heart failure or renal failure
The organism being staphylococcus aureus or fungi
What are comlications and indications for surgery?
Heart failure in infective endocarditis
Uncontrolled infection
Prevention of systemic embolism
What can infective endocarditis be prevented by?
Using prophylaxis when performing procedures where the patient is at risk of getting infective endocarditis
Good dental hygiene
Disinfection of wounds
