Infective Endocarditis Flashcards
What is infective endocarditis?
It is defined as a condition in which there is inflammation of the endocardium, the inner lining of the heart covering the heart valves, secondary to infection
This inflammation results in the formation of vegetations on the affected heart valves
What are vegetations?
They are deposits of pathogen, platelets, fibrin and other serum molecules
What is the pathophysiological consequence of infective endocarditis?
The formed vegetations have the potential to embolise and cause further complications
Which valve is most commonly affected in infective endocarditis?
Mitral valve
Which valve is most commonly affected in infective endocarditis - who are IVDUs?
Tricuspid valve
What are the eleven risk factors associated with infective endocarditis?
Male Gender
Older Age
Intravenous Drug Users
Poor Oral Hygiene
Recent Piercings
Endocarditis History
Valvular Heart Disease
Prosthetic Heart Valves
Rheumatic Heart Disease
Hypertrophic Cardiomyopathy
Congenital Heart Disease
What three congenital heart defects are associated with infective endocarditis?
Ventricular septal defect
Patent ductus arteriosus
Atrial septal defect
What are the thirteen clinical features of infective endocarditis?
Fever > 38C
Dyspnoea
Fatigue
Night Sweats
Weight Loss
Tachycardia
New Heart Murmur
Splinter Haemorrhages
Bibasal Crepitations
Finger Clubbing
Splenomegaly
Roth’s Spots
Osler’s Nodes
How can we remember the clinical features of infective endocarditis?
FROM JANE
Fever
Roth’s spots
Osler’s nodes
New murmur
Janeway lesions
Anaemia
Nail changes
Emboli
What are Roth’s spots?
They are defined as boat-shaped retinal haemorrahages, which are pale in the centre
What are Osler’s nodes?
They are defined as tender subcutaneous nodules in the fingers and toes
What are Janeaway lesions?
They are defined as painless erythematous macule on the palms and soles
What additional feature is present in IVDUs?
Discitis
What six investigations are used to diagnose infective endocarditis?
Blood Tests
Blood Culture
Urinalysis
ECHO Scan
ECG Scan
Chest X-Ray (CXR)
What four blood test results indicate infective endocarditis?
Decreased Haemoglobin Levels
Increased WCC Levels
Increased CRP Levels
Increased ESR Levels
What additional blood test is used to investigate infective endocarditis? Why?
U&Es
They are conducted to identify the baseline renal function and creatinine clearance
This enables individuals to be started on nephrotoxic antibiotics, such as gentamicin
What is the first line laboratory investigation used to diagnose infective endocarditis?
Blood culture
How do we conduct blood cultures in cases of suspected infective endocarditis?
They should be obtained on three occasions, at least 30 minutes apart, from three separate peripheral sites
What eight organisms commonly colonise infective endocarditis?
Staphylococcus Aureus
Staphylococcus Epidermis
Streptococcus Viridans
Streptococcus Bovis
Coxiella Burnetti
HACEK Organisms
Candida
Aspergillus
What is the most common organism to colonise infective endocarditis?
Staphylococcus Aureus
In which two patient groups does infective endocarditis tend to be caused by staphylococcus aureus?
Intravenous drug users
> 2 months of prosthetic valve surgery
In which patient group does infective endocarditis tend to be caused by staphylococcus epidermis?
Initial 2 months following prosthetic valve surgery
In which two patient groups does infective endocarditis tend to be caused by streptococcus viridian?
Poor dental hygiene
Dental procedures
In which patient group does infective endocarditis tend to be caused by streptococcus bovis?
Colorectal cancer
What are HACEK organisms?
Haemophilus
Actinobacillus
Cardiobacterium
Eikenella
Kingella
What are the five blood culture negative organisms associated with infective organisms?
HACEK organisms
Coxiella burnetti
Chlamydia species
Bartonella species
Legionella