Infective Endocarditis Flashcards
What is infective endocarditis?
- it is a infectious inflammation of the endocardium that affects the heart valves
- it is as a result of bacteria lodging on the heart valves from dental procedures, surgery, primary infections, and non-sterile injections
What bacteria causes the acute disease?
Staphylococcus aureus and this causes rapid valve destruction
What bacteria causes sub-acute disease?
Streptococci viridans and this is as a result. Of prosthetic valves, previously damaged valves and heart defects
How long does it take for staphylococcus to kill you?
6 weeks if left untreated
What is the etiology of IE?
- Staphylococcus aureus (most common with 45-65%)
- Streptococci viridans (mostly 30% and on already damaged valves)
- most from dental procedures - Gram (-) HACEK group
- Enterococci
- Candida aspergillus (immune-compromised patients and IV drug users)
- Staphylococcus epidermis (multiple drug resistance)
Which groups of people are usually affected by staph aureus?
- previously healthy valves
- IV drug users
- people with prsothetic valves
What does the HÁČEK group stand for?
H- Haemophillus A-Aggregatebacter C-Cardiobacterium E-Eikenella K-Kingella
What are the predisposing factors that lead to the increased chance of IE?
- Damaged heart valves
- Prosthetic heart valves
- Congenital heart defects
- Diabetic children
- Previous IE
- Children on corticosteroids
- Rheumatic Heart Disease
Which valves are most affected by IE?
First are mitral valves, second being aortic valves then tricuspid and last being pulmonic valves
Which valve is affected most by IV drug users?
Tricuspid valve
What are the constitutional symptoms of IE?
- Fever and chills in 90% of people
- Tachycardia
- Myalgia, arthralgia
- General malaise
- Night sweats, weight loss
What are the extra-cardiac manifestations of IE?
- Janeway lesions
- Roth spots in the eye
- Osler Nodes
- Petechiae
- Clubbing
- Splenomegaly
What are the cardiac manifestations for IE.
- Murmurs
Mitral valve regurgitation - holosystolic murmur radiating to the left axilla
Tricuspid valve regurgitation - holosystolic murmur occurring in IV drug users, HIV positive
Aortic regurgitation- early-diastolic murmur - Dyspnea
What are the special investigations we do in these patients?
- 3 blood cultures in 3 hours
- FBC
- ESR and CRP
- Urinalysis
- U&E
- Echocardiogram (Transthoracic echocardiogram)
What is the Duke criteria?
It is the modified criteria that is used to diagnose infective endocarditis
What makes a definitive diagnosis?
-2 major criteria or 1 major with 3 minor criteria
What makes a possible IE diagnosis?
1 major and 1 minor OR 3 minor criteria
What are the major criteria?
- > 2 positive blood cultures with pathogens
- New valvular manifestations
- Positive findings on echocardiography
What are the minor criteria for IE?
- Immunological phenomenon
- Vascular phenomenon-petechiae, purpura
- Pre-disposing factors
- Fever> 38 degrees
- Positive blood culture inflammatory markers
What is the management of IE?
We give antibiotics for a maximum of 6 days
For streptococci viridans- penicillin and gentamicin/amikacin
For staphylococcus aureus we give cloxacillin or gentamicin/amikacin
If severe you can surgically replace valves
What are some of the preventative measures we can implement?
- antibiotic cover during procedures
- change IV lines regularly
- remove in dwelling catheters regularly
What clinical signs do we look for Infective Endocarditis?
- Ossler nodes
- Janeway lesions
- Digital clubbing
- Splinter Haemorrhages
