Infective endocarditis Flashcards
What is infective endocarditis?
Endovascular infection of cardiovascular structures, usually involving the cardiac valves.
Aetiology of infective endocarditis?
Usually the consequence of two factors: the presence of organisms in the bloodstream, and abnormal cardiac endothelium that facilitates their adherence and growth.
Risk factors for infective endocarditis?
Abnormal cardiac endothelium:
- Previous rheumatic heart disease
- Congenital heart disease
- Age related valvular degeneration
- Prosthetic heart valve
Organisms in the bloodstream:
- Intravascular lines
- Septicaemia
- Poor dentition and dental infections
Others:
- Age > 60 years
- Male sex
What is the most causative cause of acute infective endocarditis in all groups?
Staph aureus
What is the most causative cause of subacute infective endocarditis, especially in pre-damaged native valves?
Strep viridans
What organism particularly causes infective endocarditis in patients with prosthetic valves?
Staph epidermis
Acute clinical features of infective endocarditis?
Overwhelming sepsis and failure
Usually due to aggressive organisms e.g. staph aureus
Subacute symptoms of infective endocarditis?
Fever
Malaise
Weight loss
Tiredness
Dyspnoea
Subacute signs of infective endocarditis?
New/changing heart murmur
Finger clubbing
Splinter haemorrhages
Splenomegaly
Roth spots: non-specific red spots seen on the retina
Microscopic haematuria
Investigations for infective endocarditis?
ECG
CXR
Blood culture: at least 3 sets of blood cultures should be taken at different times from various sites.
Serology: consider if blood cultures are negative to look for “atypical” organisms.
What is the first line imaging investigation for infective endocarditis?
Transthoracic echocardiogram
Antibiotic treatment for staph aureus (not MRSA)?
IV flucloxacillin
What is the most sensitive diagnostic test for infective endocarditis?
Transoesophageal echocardiogram
Antibiotic treatment for viridans streptococci?
Benzylpenicillin and gentamicin IV
Antibiotic treatment for staph epidermis?
Vancomycin and gentamicin IV
