Infective Endocarditis Flashcards
95% of cases of infective endocarditis affect which side of the heart?
Left
Is infective endocarditis common or rare?
Rare
Is acute infective endocarditis more prevalent on normal or abnormal valves?
Equally prevalent
Define infective endocarditis
A disease resulting from infection of a focal area of the endocardium
Where does infective endocarditis affect?
Heart valves
Chordae tendinae
Site of congenital heart defect
What is the pathogenesis of infective endocarditis?
Bacteraemia
Erosion on endocardium
Implantation on endocardium
Vegetations
What are 10 systematic complications of infective endocarditis?
Pyrexia
Weight loss
Malaise
Chronic anaemia
Splenomegaly
Finger clubbing
Haematuria
Osler’s nodes
Janeway lesion
Splinter haemorrhage
What are some local cardiac features of infective endocarditis?
Arrhythmias
Heart murmur
Heart failure
How to diagnose infective endocarditis?
Clinical features examination
Blood cultures
Imaging
What should be included in the general examination of infective endocarditis?
Pale face/pallor
Pyrexia
Arrhythmia
Skin lesions
Sub-conjunctival haemorrhages
Unilateral blindness
What are the major Duke criteria for infective endocarditis?
Blood cultures positive for IE
Typical microorganisms consistent with IE
Evidence of endocardial involvement
Echocardiogram positive
Vegetation
Abscess
New partial dehiscence of prosthetic valve
New valvular regurgitation
What are the minor Duke criteria for infective endocarditis?
Predisposing heart condition
Injection drug use
Fever 38oC
Vascular phenomena eg major arterial emboli
Immunologic phenomena eg Osler’s nodes
Microbiological evidence: positive blood culture
Diagnosis of infective endocarditis is definite if:
2 major Duke criteria
1 major and 3 minor Duke criteria
5 minor Duke criteria
Diagnosis of infective endocarditis is possible if:
1 major and 1 minor Duke criteria
3 minor Duke criteria
How to treat infective endocarditis?
Antimicrobial treatment/antibiotics
Surgery for infected prosthetic heart valve
Management and prevention of complications eg drainage of myocardial abscess
Is antibiotic prophylaxis against infective endocarditis routinely recommended in dentistry?
No
Which risk groups of patients undergoing bacteraemia-producing dental procedures may be offered antibiotic prophylaxis?
High and medium
Indications of patients at high risk of infective endocarditis according to SDCEP:
Previous infective endocarditis
Any form of prosthetic heart valve/prosthetic material used in valve or congenital heart disease repair
Any type of cyanotic congenital heart disease
Indications of patients at moderate risk of infective endocarditis according to SDCEP:
Previous history of rheumatic fever
Valvular heart disease
Unrepaired congenital defects of the heart valves
What should be covered during antibiotic prophylaxis discussion with high risk IE patients?
Explanation of what IE is (infection of the lining of the heart, often involving the heart valves, caused mainly by bacteria which enter the blood from outside the body)
Explanation that due to their heart condition/previous episode of IE, there is a small risk of developing IE following an invasive dental procedure which may increase the chances of bacteria entering the bloodstream
Benefits and risks of antibiotic prophylaxis
Importance of maintaining good oral health to prevent infective endocarditis
Symptoms that may indicate IE and when to seek expert advice
Risks of undergoing invasive procedures such as body piercing or tattooing
What are some risk factors for developing infective endocarditis?
Congenital lesions such as ventricular septal defect, tetralogy of Fallot, coarctation of aorta and patent ductus arteriosus
Vascular abnormalities such as rheumatic involvement of any valve, bicuspid or calcific aortic valve, sub-aortic stenosis, mitral valve prolapse
IV drug abuse
Abortion
Prosthetic valve
Cardiac/urinary catheterisation
Any invasive diagnostic or surgical procedure
Damage secondary to rheumatic fever
Right-sided endocarditis:
- Incidence
- Predisposing factors
- Affected area
- 5% of cases
- IV drug abusers or immunosuppressed
- Tricuspid valve
What is the prevalence and average mortality rate of infective endocarditis?
1-10 per 100,000 people (still increasing)
Twice as common in men than in women
Average mortality rate of 20% (higher in patients >65 y/o; 0.1% of all cardiac deaths)
Where is bacterial endocarditis most common in?
Damaged valves
Elderly patients
What are the common causes of bacterial endocarditis?
Oral and faecal streptococci (35%)
Staphylococci (50.5%)
Which bacteria is the acute form of bacterial endocarditis most commonly caused by?
Staphylococcus aureus (MRSA)
What other bacteria are indicated in 5% of endocarditis? (HACEK)
Haemophilus
Actinobacillus actinomycetemcomitans
Cardiobacterium hominis
Eikenella corrodens
Kingella spp
What fungi could be indicated in 1% of endocarditis?
Candida
Aspergillus
How does pathogenesis affect prognosis of infective endocarditis in terms of mortality?
- Oral streptococci
- Staphylococcus aureus
- Fungal infections
- Complication of abscess formation, congestive heart failure or neurological event
- Right-sided endocarditis in IV drug abusers
- 4-16% mortality
- 25-47% mortality
- > 50% mortality
- Increased mortality if endocarditis is complicated by these events
- 10% mortality
What causes infective endocarditis?
Bacteria entering the blood from outside the body
